 Είμαστε αρκετές που είμαστε αρκετές. Ευχαριστώ για όλοι και ευχαριστώ για έναν άλλο σημερινό της Σεμίναρς Σεμίναρς. Είμαστε όλοι όλοι within the Worldwide Neuroinitiative. Είμαι ο Γιώργος Καφέτζης. Είμαι ο Μάστος Γραδίου από το Μασόλειο's Lab Σε 2012 είχα σημερινότητα από το Μασόλειο της Σεμίναρς Σεμίναρς, πριν να σημερινότητα από το Μασόλειο της Γραδίου, σε 2015, όπου έχει been located ever since, τώρα στις σημερινότητας από το Μασόλειο της Σεμίναρς Σεμίναρς. Η σημερινότητα της σημερινότητας θα είναι ένα σημερινό σημερινότητα σύστημα, αλλά στην Σεμίναρς της Σεμίναρς they additionally investigate the evolution both of simple light detection and of eye loss. Θα μπορούσα να πω και να δημιουργήσω τις πρόσφυγες they exploit in their holistic approach, αλλά η σημερινότητα της Σεμίναρς στις σημερινότητας σύστημα. Φυσικά, σήμερα έχουμε την ευκαιρία να ακούσουμε their latest and I'm so excited in findings in her talk entitled The Evolution and Development of Visual Complexity, insights from stomatopod, visual anatomy, physiology, behavior and molecules. So, without any further ado from my side, please all welcome Professor Porter. Σας ευχαριστώ για την ευκαιρία σας. Ευχαριστώ. Ευχαριστώ, καλή ημέρα, καλή ημέρα, καλή ημέρα, καλή ημέρα, depending on where everyone is at the moment. Αυτό είναι πολύ ευκαιρικό να μπορούσα να μιλήσω σε έναν πρόσφυγο κράτος για την ευκαιρία μου και κάποια από τα δουλειά που έχω κάνει πιο recently. Αυτό θα δούμε. Πρώτα ήθελα να ξεκινήσω με κάποιες ευχαριστώ. Δεν θα δούμε την ευκαιρία που θα σας δείτε. Θα θα μπορούσα να μην υπάρξει ένα κομμάτι για αυτοπρόσφυγο και συμβουλίες να δούμε. Αλλά εσύ, η μαντιστραμία, το stomatopod, θα σας πω για τον ευχαριστώ και τον Τόμ και τον Ροί. Το τραιμβουλί της stomatopod-αυτοπρόσφυγησης, όπου εγώ ένιωσα πρώτα ευτοπρόσφυγησης, ευχαριστώ τον Τόμ και όλα τα πράγματα που γνωρίζω για το stomatopod. Ευχαριστώ also to Mike and Kate, τα οποίοι είμαστε όλοι στην Τόμκρονα's λεπτά. Θα δούμε και συμβουλίες των stomatopods και να συμβουλίσουμε σήμερα. Θα ήθελα να ξεκινήσω με ένα σημερινό για τη δημιουργία, για να σας πω για τη δημιουργία. Είναι έναν τρόπο μεγάλο σειρά της τάξης εκεί, αφού όχι τάξης μεταξύ with two of the people που έχω συγχωρήσει με Τόμ και Mike Fogg, πρέπει να δείξουν τα τάξης, αν δεν έχετε δει. Θα έδωσαν τον ευχαριστώ για ό,τι θα σας πω. Τόμ και Τόμ και της δημιουργίας της τάξης, δημιουργίες των σημερινών grotins, δημιουργίες των ευρώνωνanse anadomins, διάστηρες δεκκοκλάτεςomb, δημιουργίες των ευρώνωνανών, δεκκοκλάτες των ευρώνων, δημιουργίες των ευρώνων. Είναι ένα δημιουργείο της μεταστινής, π embodied by the amazing newly attached to a chroma 4 to get to the form of visual pigments and those visual pigments are responsible for light detection in all animal visual systems as well as light detection and other contexts as well. But in mantis shrimp or stomata pods you know the color signaling that Mike talked about. It's these visual pigments, these opposite proteins that are responsible for detecting those different wavelengths of color and then initiating this out of your cascade sending the signal down to the neural και προσπαθούν αυτοκρότημα για προοδοχές αυτοκρότημα. Λοιπόν, υπάρχει ένα βινόραο στον κομμάτι. Για να πω για το λευκό μου, το Πορταβιζιν λαμ, εμείς να δούμε δάστιο να μην χρησιμοποιήσουμε μέσα σε χορές αυτοκρότημα, βέβαια μετά τα τέτοια κοριαστά της Πορταβιζινς, η οποία είναι η σημερινή μου. Αλλά εμείς έχουμε been working on things like worms with Mike, που πήρας σε αυτό το συμβαίνατο. We work on a number now of terrestrial arthropod systems as well, and every once in a while a vertebrate sneaks in there. There's a student in the lab now, a PhD student studying seabird vision. So diversity of different animal systems all trying to understand sort of how the molecules of vision fit into a greater understanding of how the visual system works and what an animal is perceiving, how they're using that information. And in thinking about this talk, thinking about my work and how to present it, I realized that there's sort of this theme as well in a lot of the work that we're doing in the lab. And that's getting at this idea that in many animal visual systems now it's been documented that there is a mismatch between what we know about photoreceptor diversity and what we are learning about expressed ops and diversity. And some examples of that. So here are just two examples of that for more recent literature on the left from Dragonflies from paper 2015. That's a phylogeny of ops and diversity across a number of species broken down by the, what type of visual pigment those options form, whether they're UV sensitive short wavelength sensitive sort of the blue parts of the spectrum or long wavelength sensitive and the green parts of the spectrum. And you see a range of just of ops and thought to be involved in vision, you know, anywhere from 11 up to 29 copies expressed in these eyes. That's a lot of options for what we understand about how Arthur pods. Anatomy visual anatomy, the diversity of photoreceptors and some of these systems. But also happens in vertebrate so recent paper as well and the fish in the silver spine Ethan, they found 40 options in the genome, which is a crazy number of options for vertebrate. And if you know showed that at least 14 of those are expressed. So, across a large number of animal systems now. Thanks a lot to the as tools, the genetic tools for investigating option expression have have have gotten easier to use and we learn more we can get more information. We see this really big mismatch in the number of options express and what we understand currently anyway about the types of photoreceptors in these animal visual systems. One options are doing some things that we don't understand yet and visual systems, but also maybe there's some hidden diversity and photoreceptors that we haven't uncovered yet based, you know, using the physiological and anatomical studies that these have been characterized in the past. So, what I'm going to tell you about today are my studies trying to reconcile this mismatch in crustaceans. Mostly about my work in stomatopolis also called mantis shrimp, you'll hear me go back and forth with that between the scientific name and the common name. But also I'm going to tell you a little bit about sort of my new crustacean obsession, which is copepods copepods I think are fantastic another fantastic group for studying the evolution of visual system diversity. But just tell you a little bit about that and hopefully convince you that everyone should love copepods as much as I do and should consider them for their studies. Before I get into the details, I just want to thank all the people in my lab who, in addition to the people I've already thanked, the people in my lab a lot of the recent work is due to their spectacular research and their questions. They're just, they're interested in passion for science. So thanks to all of them. I'm in particular, I'm going to show you some of Tatar and Marissa's dissertation work towards the end of the talk. Okay, so to start off, I want to take a broad stroke overall view. As I said, I work mostly in crustaceans and when I say crustaceans, I mean the pan crustaceans minus the insects taxonomy has changed a little bit. But I want to take a broad stroke view both of the sort of diversity on the anatomical side, the morphological side and the diversity on the molecular side, and then use that as a place to start drilling down deeper to try to figure out these mismatches that we're seeing. So on the morphological side of this phylogeny is one that was published a number of years ago now, and it just shows across crustacean lineages, the variation in the design of the compound eyes. And I'm not going to go into the details of that other than to say that the differences that you see here are mostly due to the optical structures that are focusing light onto the underlying photoreceptors. But this simple sort of broad stroke view misses a lot of the complexity and the variation in the visual systems and the way that those are put together. And you can see that just in the sort of small selection of crustacean eyes I have there on the right. And as an example of some of the hidden diversity when you take a broad stroke view that you find when you start to drill down deeper into some of these lineages. I'm going to talk a little bit about the copepods. So copepods are typically one of the crustacean lineages that are thought to have a simple eye. A simple eye has been referred to in the literature as a maplior eye or a tripartite eye, because it has three receptor cups here is a cross section of it sort of frontal cross section here is a lateral cross section. It's got paired sets of Oceli or putter receptor cups that are dorsal, a single one that is ventral that are sort of all merged together into a structure. But if you look at the eye morphology across different species of copepods and this is just one order copepods. An example of some of the morphological diversity and eye structures of that simple eye. The structures are colored the same. So the paired Oceli dorsal Oceli are in sort of salmon color, the unpaired and sort of this dark red. There are lenses and blue. You get a sense of the modifications to the simple structure. Some species have greatly enlarged the dorsal set of receptor cups. Some have greatly enlarged down here the ventral set single pigment cup. Some have pulled apart those three cups into separate eyes. Some have added lenses or multiple lenses. There's sort of a dizzying array of eyes based on just the simple design and copepods that I think is really interesting evolutionarily and needs some further work. And we're starting to dig into how the molecular components compare with this as well. But they're a fabulous system for studying the evolution of visual system diversity. And that's just as an example of, you know, all of this diversity. And I think diversity in the anatomy of visual systems and the underlying photoreceptors that we, there's still a lot that we don't understand. On the molecular side, which is where most of my work has been, we are also wanted to start with a broad stroke brush and just look and see across crustaceans again here across orders. What types of options are different groups of crustaceans expressing individual systems. And to do this we took published data transcriptome data and just searched through for expressed options and for each species identified the non visual and visual visual options as we understand them based on evolutionary placement to get a sense of what lineages are expressing what options. This is just like overall crustaceans have in you look just here in this part that's the visual options. They seem to be expressing long wavelength options of a plate of long wavelength options. They have three clades of what we we typically think of as middle wavelength or blue sensitive options, noting that the barnacles sort of have their own plate. A clade of purple here indicates short wavelength probably ultraviolet options. So again this is a broad start view but when you begin to drill down most of the species that we're looking at at least many of them, you look at the numbers of options expressed in each of these groups there are many more than we predict based on the little bit that we know about the photoreceptor array and their eyes. So, so what's going on here and I think the work that I'm going to show you is attempting to drill down from sort of both sides both morphology and molecular, adding in some physiology as well to try to figure out where that mismatch is and use those mismatches to identify some hidden visual system diversity that that we have in the characterized. Okay, so with that is the broad stroke foundation overview of some of this work. Let's get into the main part of the talk which is the evolution development of visual complexity and I like to start off with this picture by Roy Caldwell, because it really, I think clearly demonstrates the differences between larval and adult eyes in this group. So here you have these giant eyes of an adult lysiosquiloid species, which lives in a sand borough so it's just poking out of its hole. And in between that you have an entire larval individual with its tiny eyes. So they're big differences just in size, but the eyes are different in a lot of other ways as well. The mattepards I think are an interesting system for looking at the development of visual systems for a lot of reasons. One we can get this to go. There we go. We can collect clutches of eggs, we can watch those eyes develop so you can catch different stages of eye development. We can watch those out into early stage larvae, which we then can study using various molecular but they're also interesting developmentally, because the larvae up until recently were typically thought to have a visual system like any other crustacean larvae, which is of a type called a transparent aposition eye, where the optics are sort of stretched out and the pigmented receptors are condensed to a small an area as possible without any diversity in those photoreceptors. So we tend to call them simple eyes. As we put that all together into the life history of a stomatopod, we have these complex adult eyes. I'm going to tell you about in a minute where I spent a lot of time trying to understand how the molecules fit into what we know about the visual system. We can catch the development of that visual system into this simple larvae that has a simpler eye than the adult anyway. We have this transition between this simple eye and this adult eye, which is another feature of stomatopods that makes the visual system interesting. The larval eyes are physiologically and morphologically distinct from the adults. So here's a close up of a pair of larval eyes. This particular larva is in the process of transitioning from a pelagic larval form, something that lives up in the water column. It's metamorphosing into a juvenile and transitioning to the benthos. So adults live on the bottom of the ocean. What you see happening here is that they don't transition directly from the larval eye to the adult eye. They just build an entirely new adult eye right next to that larval eye as they're making that transition. So you see here this blob in pale yellow is the larval eye and on top of that it is building a completely separate and different adult retina. So it makes this really interesting system because we have very distinct eyes, the larvae and the adult are in very different habitats and ecologies. And not only do they build new retinas, here is a schematic that Kate Feather put together along with that adult retina. It's also building new neural processing centers, at least through the lamina and medulla here in orange whereas the larval is here in sort of pale yellow. So there's some questions here about how much of this neural circuitry is recreated for that adult retina, when and where does it get wired into the existing circuitry. Those are questions we don't know yet but it is part of this complexity. It's a piece of the puzzle that we're hopefully one day we'll understand. So that sets the stage in terms of the lifecycle and the visual system between larval and adult mantra shrimp. So I wanted to start off with the complex adult eye because that is where most of what we understand about mantra shrimp visual systems comes from studies of adult visual systems. So if you've never seen a mantra shrimp up close, this is what one looks like in an even closer view of its eye. They are crustaceans so they have compound eyes which means they have individual units, but they're very different from other crustaceans and other arthropods in that you can see here from these dark patches which are pseudo-pupils. The pseudo-pupils are the parts of the eye that are looking directly at the observer. So you can see that there are three parts in this eye looking directly at you, which means that they have trinocular vision, they have depth perception with one eye. And the reason is because they have this specialized set of omitidia that run around the equator of the eye that we call the mid-bands. And then the most complex eye forms, there are six rows of omitidia in that mid-bands. So what do the underlying photoreceptors look like, if this is the sort of most complex eye in terms of external morphology. Now understand that, first let me tell you what a typical crustacean eye looks like. And then we'll get to the adult. So a typical crustacean eye, it's compound, it has those facets. Each one of those facets represents a single optical unit, we call an omitidium. If you take a cross-section of one of those, there are some optical structures on top, light coming in from the top, their cornea, a crystalline cone, and then there's light onto receptor cells underneath. And crustaceans typically have eight receptor cells. A single cell that sits on top, we call it R8, typically sensitive to violet or ultraviolet light. And then the remaining seven cells work together to form what we call a main rad dome, a photoreceptor, where those seven cells form a tube and project microvilli into that tube. So that's where the visual pigments are found. So light travels down through these photoreceptor cells, and that's where you get the light detection. So if we go back to stomatopods, and we look both anatomically and physiologically at the receptors underlying that sort of overall eye design that I talked about with the mid-band rows. So now we're looking at this cross-section, here are the six mid-band rows, light is coming in from this direction. We have this omatidium here represents the dorsal part of the eye, the dorsal hemisphere. This represents the ventral part of the eye, the ventral hemisphere. Each of those photoreceptors is colored based on the measured spectral sensitivity. And there are 16, at least 16 different types of spectrally different photoreceptor. I think Justin Marshall is arguing for a few more these days. I want to break down how we get to some of these differences. I also want to point out, I've been using these terms a little bit already, but I'm going to be saying ultraviolet sensitive to refer to sensitivity or absorbance on this part of the visible spectrum. Middle wavelength sensitivity sort of in the blue range 450, 500 nanometers and long wavelength sensitivity sort of anything above 500 nanometers. All right, so if we break down that diversity, stomatopods have in those R8 cells, in the most complex size, six different types of ultraviolet photoreceptors. Interestingly, from Mike Bach's work, those photoreceptors are due to two types, that's six different spectral sensitivities or photoreceptors are due to sort of absorbance of two types of photoreceptor, that you R8 photoreceptor cells and four different ultraviolet filters found in the crystalline cones. So, two photoreceptors, four filters put together in different ways, equals six types of photoreceptors. The main raddoms, those are 127 cells in the thinnest spheres of the eye are thought to be used for spatial and motion vision and based on this, they have a single spectral sensitivity in the blue range of the spectrum. In rows five and six, those main receptors, there are two receptor types. They have the same spectral sensitivity but differ in anatomy, so the microvilli oriented differently in those two sets of receptors in rows five and six. And then in rows one through four of the mid band, those seven cells that I talked about have been subdivided into two sets of photoreceptors, each with a unique spectral sensitivity. And together those eight receptors are what are used for color vision in mantis shrimp. And I should point out that the spectral tuning of those photoreceptors is also due to some filtering. So in the most complex visual systems there are also four colored filters that sit between photoreceptors. So that's a lot of pieces to put together. And that's just for the most complex visual system in sematopods. But we know if we look across species that there are variations in all of these components. So here's just three species. You can see variations in the size and shape of the eye. There are also variations externally in the number of mid band rows, which says immediately that there's variations in the complexity of the photoreceptors underlying those visual systems. So one of the things that I want to do to try to set the stage for the more phylogical anatomical complexity is to put this all together in an evolutionary sense. So taking a phylogeny from some of my earlier work. There's seven families represented here by the sort of single letter codes. I'm going to put together all that information. So first of all, just the number of mid band rows varies across species. In this particular set, anywhere from two to six mid band rows, those seem to be the most common types found in sematopod visual systems. Underlying that, we have the number of photoreceptor types that I just walked you through, anywhere from one to 16. But contributing to that, we already know that there's differences in the number of visible filters between those photoreceptors that play a role in those photoreceptor types. So there's variation there. There's also variation in the number of filters on the UV part of the spectrum from Mike's work. So to me, when you put this all together, first of all, looking at just the variation in the number of ultraviolet visible light filters, it suggests to me that maybe we need to go back and revisit our estimate of photoreceptor types. There's some variation there, I think, that we haven't put together yet. But for the most part, all of these pieces make sense based on what we know about the physiology of visual systems in Manterstrom. So this is where I wanted to start plugging in the molecular data to see how that fits in. And over some number of years now I've been collecting transcriptome data from a number of species to try to get at this. When you plug in the number of expressed visual options, it stops making sense again. So we have in many cases, many more options than predicted based on what we understand again about that photoreceptor diversity. Sometimes twice as much here for some of the species expressing 30 some options. So they are varying in in sort of unpredictable ways. So which means that there's something that we don't understand yet. Given these numbers are squishy, right, so they're, they're estimates they're from transcriptome data, the assembly process is difficult. But I think they are hinting at, at things that, you know, that we don't understand about this mismatch between photoreceptor and offset diversity. But you might say, wait, Megan, there are some species that look like they match up pretty closely. But if you pull that apart and look at the number of options expressed in each spectral class, whether that's ultraviolet middle wavelength or long wavelength sensitive there's still a mismatch between number of options expressed. And, and the number of photoreceptors that have that we think is there based on the information we have so far. So what's the next step. That really is to go into one of these species. We chose neogonodactylis ersterdi, and to figure out where all of these options are expressed in the eye to give us the next piece of information about this mismatch. Thank you. This species neogonodactylis ersterdi, we think has at least 16 types of photoreceptors. It's got 33 expressed options. And the next piece of information I'm going to show you is, is in situ hybridization data for the expression patterns of each one of those options across this retinal schematic. We started off with the ultraviolet sensitive options. There are three of those. And this is, again, from some of my box work. And the expression of these options, there were three, two of these, those options lined up really well with my work from measuring photoreceptor absorbences. They fit that pattern, but we still have this one that's expressed that doesn't, we weren't able to find it expressed in the eye. So it's unknown what it is doing, whether it's expressed someplace else, maybe in a neural processing center. So there's a mystery there that we're not quite sure what that particular option is doing. We jump next to the expression patterns and the long way of my sensor options. There were plenty of these in neogonodactylis ersterdi. I know this is a big figure. The clades, the ops and transcripts are numbered and colored by clade now rather than anything related to spectral sensitivity. Here you see the actual insitu data and the schematic is colored to show, give you sort of a reference point, something hopefully you're a little familiar with to where that expression is. The takeaway from this really is that most of these opsons are expressed in what we have been characterized as long wavelength sensitive photoreceptive cells. That is good. That includes things down here like the main receptors of the hemispheres or in the mid band receptor cells that have been physiologically characterized as long wavelength sensitive. The thing here is just that there are so many of these opsons that most of these photoreceptor cells are expressing many copies of them. There may be some co-expression going on and that's sort of the next step in understanding this mismatch. We also uncovered a transcript that doesn't seem to have a visual function, at least based on this expression pattern. So this is a transcript that is expressed in all eight of the receptor cells that are responsible for color vision and mentorship. The idea here is that it can't have a visual function because each of those receptor cells have a distinct spectral sensitivity. So what this opson is doing, whether it's turned into a protein, we don't know and we're actually working on that now trying to do some protein localization studies to try to give us a clue as to what's going on. And then finally, if we look at the 10 opsons that are middle wavelength sensitive, again, same setup, each opson is numbered, colored by evolutionary clade with the in situ data here and then the schematic showing you what that labeling pattern looks like. Some of these opsons are expressed in middle wavelength photoreceptors, which is good with what was expected. But some of them, the remaining actually are all expressed in what's had been previously characterized as long wavelength sensitive photoreceptors. So all of the long wavelength sensitive photoreceptors express at least one middle wavelength sensitive opson. So there's something going on there in this Tamanapot visual system. Again, we need to do some protein localization studies to try to figure out what's going on. We were particularly interested in, there are three opson transcripts that have a very distinct expression pattern, just in the very dorsal part of the eye, which is intriguing, particularly given some recent work by Ricky Patel, behavioral work showing that Can use celestial cues to navigate. So we think we have identified using this molecular approach, some receptors in the dorsal part of the eye that hadn't yet been characterized and to sort of squint at that in-situ data. You can maybe convince yourself that the receptors in that part of the eye change direction and sort of point up. So this is a particular part of the eye we're focusing on now that we've identified using molecular expression, something unusual is going on here, perhaps related to navigation. And so we're working more on a whole group of people is thinking about that now and trying to characterize that part of the eye. So just to sort of summarize all of that work and where we think we are. This graph, so we have dorsal hemisphere photoreceptors, the photoreceptors of the mid band rose one through four, five and six and then the ventral hemisphere receptors. And then the bars on the y-axis here just the number of opson transcripts colored by clade, as you saw in the previous figures. So just to give you a broad stroke idea of the pattern, some of the patterns are seen. So if you look just at the receptors used for color vision. They seem to express one maybe two transcripts, plus this transcript that is expressed in all of them. So they all have sort of a unique transcript plus this common opson, but they, they express many fewer transcripts than the rest of the receptors in the hemispheres, which have previously been characterized as long wavelength sensitive, they all express, you know, six or more opson transcripts of multiple spectral classes, at least as determined by their evolutionary placement. And in particular, we're really interested in this sort of very dorsal part of the eye that's expressing multiple middle wavelength sensitive options, and maybe related to navigation. Okay, so we've learned a lot about from from coming in and adding the molecular perspective to what was known about the way the stomatopod visual system works in the adults. What about in the simple larvae lie that clearly there's still a lot to be done there but at some point I thought okay maybe maybe we should take a step back. So let's look at a simpler system, let's try to understand what's going on in the larvae, so we can understand how we get developmentally from this simple eye to this really complex system. There's been a little bit of work done in the amount of these simple larval eyes from a paper from Kate Feller and Tom Cronin, however, I'm characterizing the peak absorbance of different photoreceptors and different species. Most of them seem to have photoreceptors that that have peak absorbance in the blue part of the spectrum. But if you look at some of these, the, there's a huge range in the data points right and those measured values of peak absorbance with some outliers you know are really long wavelength, some that are down really short wavelength. So this suggests that these eyes are not as simple as maybe we assumed that they were. And so again, we went in first pass in my lab is generally molecular so we went and started to look at stomatopod larval visual systems, these molecular tools and this is some of satara palakonda's work, her dissertation work. So she started looking at the expression of options across development and various species of mantis shrimp. So what you see here are the different developmental stages she looked at in a way a school at homicide. There are a couple of different embryonic stages, an early larval stage that he here is that transition between larval and adults so that's a double retina stage, and then the adult. And then below that is the number of ops and transcripts broken down again by spectral class ultraviolet middle wavelength long wavelength sensitive. So there are some interesting patterns to notice here. First of all, you know, as the eyes develop, they start to express more options that's maybe not too surprising. The time point of school at Thomasini is a larvae is expressing 13 options total, including to ultraviolet. And that again is certainly more than we would have predicted based on what we understood about the anatomy of the eye prior to the study. Not too surprising, as it's building that adult eye and that transitional stage you get a jump that is expressing almost all of the adult complement of options. And then we get to the adults, it has about double the number of options of middle wavelength and long wavelength as the larval phase. Because of this, this seemed to be where the interesting transition was in number of options expressed. Sitara went and looked at another species, gonodactylaceous falcatus, and found the same thing so early larval stage transitional stage adult, the early larval stage expresses more options than we would have predicted. And it's about half ish of what what we find expressed in the adult. So some interesting things about this is noticed that for the ultraviolet sense of options that stays constant. And those are the same options in both larval and adult. And in general what happens, even though that these eyes are separate, the, all of the options that the adults use are just expressing the same set as in the larval form and just adding to that. So just expressing more. So even though the eyes are separate, it's still using all those same larval options in to build that retina and build that visual system. But again, what I was hoping would be a much simpler visual system, in terms of be out at least from the opposite perspective, or diverse than we had predicted. So they're suggesting something is going on. There's, there's sort of a cryptic photoreceptor diversity in the larval eyes that we haven't really characterized yet. So we're going to take a little bit closer look at just sort of pieces of some of these larval transcripts this is again some of Satara's work. Here's a piece of a phylogeny of larval opsum transcripts. So, these are oyster dye opsum transcripts from that adult study I just showed you. So these are some of the several ones and then to the side we've got red yellow or green dots, which indicate whether which stage that option was found expressed in. The interesting thing here is that basically all of the stages express all of these options. And we know from oyster dye, at least we think we know that those options are expressed in the mid band row. So that's particularly intriguing to be finding options expressed in the larval form with that doesn't have that mid band. Or are found in that specialized set of receptors. So, I think, looking at the expression patterns of some of these options and larvae may give us a clue as to how evolutionarily, developmentally, some adipods were able to get to this complex visual of the similar C in the adults. The interesting thing in ultraviolet transcripts. So here in oyster dye. I showed you this a little bit ago. We find all of those opsum transcripts and basically every larval that we've looked at, including that UV3 transcript that we, that doesn't seem to be expressed in the adult eye. So maybe that's a larval specific trans opsum making a visual pigment just for larvae. But we found all three of those options in the larvae of neogonodactylists as well. So maybe that will help us unravel what's going on with that transcript. So we found the molecules. A week or so ago, has been studying this from anatomical and physiological perspective. So she has done a bunch of TEM work to show that. So this is a TEM of a receptor right at that R8, our one through seven boundary, if I color that. So you can see it clearly. She found the presence of these R8 cells that are the ultraviolet photoreceptor cells in larvae from six species across three super families. So we think that that predominantly stomatopod larvae are going to have UV sensitivity. So we did some really tricky physiology using ERG recordings, I looked at the grams and some chromatic adaptations. I'm not really going to describe the details of those because we're getting short on time, but she did this in a couple of species. And just to show you, you know, she found physiological differences in the larvae between species. And got a dactylus falcatus, she found a peak in the blue at 460. But using chromatic adaptations with different colored lights, she was able to show they also have a peak in the UV at 340, a spectral sensitivity peak. The sensitivity peak and long wavelengths at 581 nanometers. So this matches with what we're seeing with ops and expression. They have sensitivity in UV blue and long wavelengths. It doesn't necessarily match up to the numbers of transcripts we're seeing yet. But at least we know that physiologically they've got a diversity of photoreceptors. In a different species, Poyoskilla Tomassini, she found that the dominant peak was in the long wavelengths, actually. This matches up with some anatomical studies that Kate Feller has previously published. But again, using chromatic adaptations showed that there's a peak in the blue at 464, and a sensitivity peak in the UV as well. So if you put it all together, she's done this in larvae from three different species now. They all have at least three spectral sensitivity peaks. I think the interesting thing here is that, you know, the peaks in the blue are pretty consistent. We've seen variation both in where the spectral placement of the peak and the long wavelengths are as well as in the UV side. So, you know, the stomata pod larvae have visual systems designed for different visual tasks. We just don't understand what those are yet. All right, so to wrap up to get back to this idea that many visual systems have this mismatch. What have we learned from these studies of the evolution and development of visual systems and stomata pods? Larvae express fewer options than adults, but more than predicted. So we still have this mismatch, suggesting we need to go in and look for this photoreceptor diversity and understand what's going on. Larvae express options found in the mid-bend receptors in the adults, so structures they don't have, which may give us a clue as to the evolution of those complex structures. They certainly have UV vision, which, you know, we have shown molecularly, anatomically and physiologically. And that by adding the molecular piece to our overall understanding of vision in Mentoshramp, we've come up with cells, photoreceptor cells with different functions that have different patterns of Austin expression. Some visual options have non-visual functions. We think that that needs some further investigation. We've been able to uncover some of this hidden photoreceptor diversity by looking at those patterns of expression. So with that, hopefully, well, first I have to thank all of my funders for a lot of that work. And again, all of my collaborators, hopefully I've inspired you to think about, you know, putting all of these pieces together for understanding visual systems. And maybe piqued your curiosity about copepods a little bit and stomatopods a whole lot. And with that, I'd be happy to take any questions. Thank you very much, Megan, for this very interesting presentation personally. And I hope it's not just a personal view, but like the bigger part of the audience also agrees with me. I find it astonishing, like how complex, even at the opposite level, their vision might be. I already posted the Zoom room link in the YouTube chat. And the first question that I personally have is the following. So you mentioned that the larvae also have UV sensitivity, right? And we know, like, from other animals that how they use UV differs from animal to animal. Like, for example, for mice, you use UV to find predators in the sky. For zebrafish, you use UV to catch your prey. Do you know if the larvae and the adults would use UV for similar goals, or if that would differ completely? Well, there's a lot of speculation, particularly for larvae. One of the hypotheses is that it is to help them catch prey to sort of improve contrast in the aquatic realm. But Marissa actually has tried some behavioral feeding trials to try to test that. And it's a difficult thing. It's a difficult thing to get at, particularly for tiny things that are hard to find to begin with. It could be related to circadian rhythms. There were some ideas that maybe it's related to movement up and down in the water column. But probably, in particular, in adults, I think it's being used in a completely different behavioral context, probably for a lot of Mike's work. And Amanda Frapen's work shows that it's probably being used in aggressive interactions. Right. Yeah, in the behaviors. So I think it's interesting, they're using these are the same sets of options in very different behavioral contexts. It's interesting to see how the, from the ops and work, how the photoreceptors, those different ops and are expressed across the eye, if that will give us a clue about how they're using them. Right. Thank you very much. So the first question appearing in the chat is from Thomas Cronin. Megan, are there no larva specific options that you have found? There's maybe one, there's one possible one, I think, in a gonadactylaceous falcatus. But the majority of the options that we're finding to larvalize are entirely, all that entire set is used in the adult eye and then they just add some more on top of them. Yeah, his emphasis was also like if you, because he highlights the no larva specific codes. So the next one is from Simon Laughlin. How fast do raptomers turn over? That is a great question. I have no idea. I would love for somebody to study that. We can get you some larvae if you'd like to look at that adults as well. I have no idea. Simon, if you want you can already join us in the Zoom room and actually like his question kind of takes smoothly to one of mine. So isn't there even indirect evidence of potentially different kinetics in photoreceptors, like from transcriptomics or something, because like we know about ops is quite a lot like confusingly a lot, but what about the rest of the molecular machinery in these cells. So from some of the earlier work that I did with ops is expressed in adults. Some of the sort of studies of selection in these suggest that sites under selection are not related to spectral tuning. So in the chromophore binding pocket, but more related to G protein binding. So my sort of hand wavy hypothesis based on that is that yeah I think some of these transcripts and the number of transcripts that we say may indeed be involved in fine tuning kinetics of the photoreceptors. But I think I'm a long way off from from being able to really get at that and test that in any real way. So so yeah I think there's a there's there's a large potential that that is something that is going on. I'm pretty far away from being able to test it. And Thomas Kron adds as a remark to your answer most likely that it's the situation that we are describing is very different from dragon flies. For instance, so yeah like another question I have is like because you mentioned that they create a new retina for the adult. And this is only for the retina it's not like for the lamina modular. Or is it like altogether is really created. So when they when they make that new new adult retina they, it also appears that they make a new lamina and a new modular to go with that I don't how much farther down the neural circuitry. I don't know that that's become the black box about how much more is is of that new circuitry is needed to process the complex set of photoreceptors and the adult eye. So it needs entirely new processing centers to be able to handle that information. I think there's a question of how much is is built new for that that new adult retina and when and where does that get wired in to the existing neural pathways. We don't know yet. And I guess no one has actually tried like to see if these retinas have the potential to regenerate like after injury, as we see another. So I think similar to other crustaceans in stomata pod adults anyway if you if they lose an eye they grow back in antenna. So they're not capable of regenerating the eye. Okay, very interesting. So at this point Megan if you want you can stop screen sharing, even though the eyes are magnificent. Just so we appear on people's screens, bigger and I will post the zoom room link again. And I would like to thank our audience for being here with us I would like to thank you Megan for this amazing talk. And I will be stopping the live broadcast after my next question so if anyone wants to keep track or participate in the brief conversation we will have. Please make sure you follow the zoom room link that I just posted. So one last question I have is like, you mentioned these seven families right. So, do we know what might be the ancestral kind of form and how similar that is to a larval like do we have the relationship between phylogeny and togeny and and so on. So, I mean, there's a little bit of back and forth on the, the phylogenetic arrangement of families and in stomata pods. The basal lineage anyway, I think most of us agree on now is, it's simpler than the most complex form but it is not. I don't think we have had the opportunity to study the larvae in that particular group of species. You know, based on the reconstructions that we've done, you know, I think that the ancestral place adult stomata pod I was probably pretty complex it's probably had six mid bedrooms it probably had some subset of those filters. And then the diversity that we see in the group is either building on that or losses of components of that. We don't have enough information about the larvae across that text on the university. So, I think we need to fill in that piece to be able to like link those two pieces together. We need more humans. Yes. Yes, we did more people in this effort. Yeah. You know, we can get you to spend on larvae if you'd like to study them. Before I stop the live broadcast just so you know, like because you cannot see the messages. Simon laughing said that Megan I regret that I have to leave very interesting talk so much to think about thank you. And with that comment from Simon I will be terminating the broadcast. So thank you once again Megan for this fantastic talk. You guys are officially offline. So