Wednesday 4/26 1:45 Introductory Remarks - Dr. Andrew Taylor Session I Chaired by Dr. Amy Moran The effect of temperature and pH on respiration and photosynthesis rates in Gracilaria 2:05 salicornia, an invasive red alga Megan Onumura and Celia Smith Despite the relative wealth of studies examining how global climate change will affect corals and other calcifying organisms, there is a lack of information on how global climate change will affect macroalgae. Macroalgae make up an important part of the coral reef ecosystem, providing food and oxygen for reef inhabitants. Understanding how their ecology may change over the next century will be useful knowledge for conservation management. This study focuses on how the interactive factors of temperature and pH affect the respiration and photosynthesis rates of Gracilaria salicornia, an invasive alga in Hawai’i originally from the western Pacific Ocean. Using an outdoor, flow-through seawater system with natural sunlight, we exposed G. salicornia thalli to different temperatures and pH values using a full-factorial design. At the end of a three-day exposure to treatment conditions, respiration was measured using oxygen evolution methods and photosynthesis was measured using Jr. PAM to obtain rapid light curves. Each response variable was analyzed independently using multiple regression models. The models suggest that nighttime temperature and the square of nighttime temperature had significant effects on respiration rates (p<0.03 and p<0.04, respectively). Our analysis indicates that pH had a slight but significant effect on ETRmax (p<0.05). These analyses indicate an increase in respiration and photosynthesis rates under climate change conditions, though further research will be needed to determine how these metabolic increases affect the growth and distribution of the organism. 2:10 Behavioral adhesion and its sensory basis in Astyanax mexicanus Johnathan Choi and Masato Yoshizawa Some of the evolved behaviors, which show significant advantages in survival and/or mating in a particular environment, present striking similarity to human psychiatric behaviors. This reminds us that ‘adaptive’ or ‘maladaptive’ can be context dependent, and such behavior may serve as a model for behavioral adaptation as well as a platform to discover new treatments for human psychiatric disorders. The Mexican blind cavefish, Astyanax mexicanus, show an intense behavioral adhesion to water vibrations between 30 to 40Hz, called vibration attraction behavior (VAB). In the dark environment, VAB showed strong advantage in prey capture. On the other hand, this behavioral adhesion is thought as a proxy of the adhesion to a particular stimulus seen in autistic patients. VAB is regulated by the mechanosensory lateral line system (LLS) that is composed of hair-cells, and those at the eye orbit were especially shown as the major sensory receptor for VAB. However, it is unknown if this LLS at the eye orbit regulates behavioral adhesion at 30-40 Hz. Here we tested the reduction of their VAB tuning by ablation of the LLS units at eye-orbit. We measured VAB against the vibration frequencies at 0, 10, 20, 30, 40 50, 80 and 100 Hz in both before and after ablation. Right after each set of VAB assay (before or after ablation), we imaged the LLS units with a vital dye, DASPEI, to monitor the ablated LLS units. We are currently analyzing data and will discuss the results. 2:15 Expression of selected autism genes in Astyanax mexicanus Nicolas Cetraro, Masato Yoshizawa, Lillian Tuttle, Alexander Settle, Courtney Passow Psychiatric diseases such as autism spectrum disease (ASD) is common but difficult to treat due to its multigenic nature. The presence of several psychiatric disease-like behaviors in Mexican cavefish (Astyanax Mexicanus), many of which are multigenic, led us to test the potential for cavefish as a new model for psychiatric disease. A genome survey revealed that 51 genes from the 55 human genes associated with ASD were present as homologs in cavefish descended from the Pachon cave population. Forty one of these homologs were significantly up- or down-regulated at 72 hours post-fertilization in cavefish, relative to their surface-dwelling conspecifics. Some of these genes include shank3a, shank3b, grin2ab, adnp, pogza, suv420h1, kmt5b, scn2a and ptena. qPCR performed on total brain RNA from 1 month, 2 month, 4 month and 1 year old showed a general expression trend: lower expression in the earlier stage but no difference in the young adults between cave and surface fish. This change in expression suggests that these genes may alter the proper developmental process in the nervous system as suggested in humans. We will soon investigate further details of gene expressions by RNAseq method and look at the expression of more ASD genes based on their ranking from the Simons Foundation Autism Research Initiative. 2:20 Extra-ocular opsin Expression of Astyanax mexicanus cave and surface morphs Noah Simon, Masato Yoshizawa, Megan Porter Opsins are proteins classically known for forming the key light-sensing molecules responsible for the function of binocular and pineal eyes. Recent studies, however, showed opsin expression in deep-brain of fish, suggesting light-sensing function in these tissues. Interestingly, changes in light conditions induced activity shifts in the blind Astyanax cavefish -- calmer in the dark and more active in the light -- suggesting extraocular opsin activity. In zebrafish 42 opsin genes in have been identified and are expressed in many tissues including: brain, eye, gut, heart, liver, muscle, pineal, skin and testis. Functional roles for some extraocular photoreceptors have been demonstrated in zebrafish deep-brain (phototaxis in darkened environment) and the pineal gland of cavefish larvae (shadow response). Here, we aimed to determine the opsin profile of A. mexicanus and explore the expression differences between cave and surface morphs in different tissues: telencephalon, tectum, pineal, basal brain, eye, and skin. A bioinformatics survey of the A. mexicanus genome revealed 29 orthologs of the 42 zebrafish opsins, representing 16 opsin classes thus, majority of teleost opsin classes are covered in the current genebuild. Tissue samples from the retina, pineal, telencephalon, tectum, cerebellum, and deep-brain were dissected from adult surface and cave fish. Using qPCR, we detected high expression levels of multiple opsins in the cavefish pineal, implicating the pineal as a key tissue in cavefish light-dependent activity. We plan to perform CRISPR/Cas9 and/or pinealectomy to test the involvement of opsin genes and pineal for the light-dependent activity observed in cavefish. Do giant Antarctic sea spiders enhance gas exchange by changing their cuticle 2:25 morphology across ontogeny? Ming Wei Aaron Toh and Amy Moran Antarctic sea spiders (class Pycnogonida) have been used to test the oxygen hypothesis of polar gigantism, which states that the low metabolic oxygen demand of Antarctic ectotherms allows them to achieve larger body sizes. The mechanics of oxygen diffusion in pycnogonids are governed by the pore area and thickness of their cuticles, with larger spiders generally having thicker cuticles to support their body mass, and consequently higher porosity to facilitate oxygen transfer. In this study, we quantify the changes to a sea spider’s pore area and cuticular thickness that occur across ontogeny. We examined the cuticle porosity, thickness and mass of 32 Antarctic pycnogonids from four species in two families, ranging in body weight from 0.032g to 2.33g. Our data show that the porousness of the cuticle increases with mass in the genus Colossendeis, but this trend was not seen in Ammothea. We also observed that these two genera had different pore morphology. Our findings suggest that family-level differences in cuticle structure and development may play a role in oxygen diffusion, metabolism and body size in Antarctic pycnogonids. 2:30-2:45 BREAK Session II Chaired by Dr. Dr. Masato Yoshizawa Differential gene expression across tissues, sex, and life stages in the sea urchin 2:45 Tripneustes gratilla. Aki Laruson and Floyd Allan Reed Tripneustes gratilla is a biologically and economically important shallow water sea urchin. With a broad species distribution across multiple ocean climates, the functional genomics of this animal are of interest to the naturalist and aquaculturist alike. The localization and timing of differentially expressed genes can highlight unique functional roles. To this purpose, gene expression profiles of an adult female and male T. gratilla were quantified for three distinct tissues: gonadal, neural, and epidermal. An expression profile was similarly generated for approximately 1,000 plutei larvae. Transcript abundance estimates reveal unique gene expression profile differences between tissues, sexes, and life stages. Furthermore, distinct gene splicing is found to underlie some key profile differences. Alterations of sex determination pathway in males with limited Y chromosome gene 3:00 contribution. Egle Ortega, Mayumi Fernandez, Quinci Salvador, Monika A. Ward Y chromosome is present only in males and encodes genes important for male fertility. Previously, we demonstrated only two Y-encoded genes are required to make a male mouse able to reproduce with assisted reproduction technologies (ART): testis determinant Sry and spermatogonial proliferation factor Eif2s3y. Subsequently, we have shown that the function of these two genes can be replaced by transgenic