Meeting Abstract

P2.172  Monday, Jan. 5  Effects of molting and salinity stress on the expression of HIF, molting, and immune response genes in juvenile Cancer magister MILLER, WA*; TERWILLIGER, NB; University of Oregon, Charleston; Universtiy of Oregon, Charleston wmiller2@uoregon.edu

Hypoxia inducible factor, HIF, is known to regulate gene expression in response to hypoxia in vertebrates and invertebrates, but its role in multi-stress regulation is not fully understood. HIF involvement in normoxia has been shown under specific stress conditions in mammals and fish. Molting and salinity stress in Cancer magister require extensive morphological and metabolic changes. We hypothesize that in juvenile Dungeness crabs, which undergo multiple molt cycles in estuarine habitats of varying salinities, HIF participates in the molecular response to molting and salinity stress. This study investigated the mRNA expression of HIF alpha in juvenile C. magister when stressed under normoxic conditions. Based on recent microarray evidence showing stress-specific changes in gene expression of cryptocyanin 2, arthrodial membrane 6, and anti-lipopolysaccharide (anti-LPS) in C. magister (Phillips, 2007), we also monitored their mRNA levels. One cohort of 1st instar juveniles was maintained across the entire molt cycle. Beginning at ecdysis and daily until 2nd instar, crabs were sampled for total RNA. A second cohort of juvenile C. magister was exposed to 50% seawater for 3, 8, and 24 hours, and then sampled for total RNA. After reverse transcription, cDNAs of HIF alpha, molting and immune defense genes were analyzed by real-time quantitative PCR. HIF alpha, cryptocyanin 2, arthrodial membrane 6, and anti-LPS all showed changes in mRNA expression during the molt cycle and gene-specific changes in expression in response to salinity stress. Supported by MDIBL NIA (NBT).