Meeting Abstract

P2-86   -   Light Adaptation of Closely Related Photosymbiotic Cockles (Subfamily Fraginae)- A Comparative Transcriptomic Study Li, R*; Zarate, D; Avila-Magaña, V; Li, J; University of Colorado Boulder, Department of Ecology & Evolutionary Biology, Boulder, Colorado; University of Colorado Boulder, Department of Ecology & Evolutionary Biology, Boulder, Colorado; University of Colorado Boulder, Department of Ecology & Evolutionary Biology, Boulder, Colorado; University of Colorado Boulder, Department of Ecology & Evolutionary Biology, Boulder, Colorado ruiqi.li@colorado.edu

Photosymbiosis is a mutualistic relationship between a host organism and photosynthetic microbes. It has independently evolved in diverse marine lineages. However, molecular mechanisms behind such symbioses remain less understood, especially in mollusks. This study aims to investigate the expression of photosymbiotic related genes in mollusks using a group of diverse but less studied marine cockles (Subfamily Fraginae), which establishes photosymbioses with algal lineages from the family Symbiodiniaceae. They adapted a wide range of lifestyles in diverse habitats, ranging from shallow reef sediment to deeper sandy bottoms. In this study, we used three photosymbiotic species including highly adapted species Fragum fragum, F. whitleyi from shallower waters (~1m), and F. sueziense from deeper lagoon bottoms (~5m). We kept each species under three different light intensities (normal, reduced, and dark), and obtained a total of 176 transcriptomes from both mantle (symbiont containing) and foot (no symbionts) tissues of the three bivalves through RNAseq. We accessed regulations of genes related to nitrogen metabolism, glucose metabolism, and reactive oxygen species in the three light intensities. We also compared the gene expression patterns from those three pathways of the species that differently relies on photosymbiosis.