Project description:Rainbow smelt (Osmerus mordax) are freeze-resistant fish that accumulate glycerol and produce an antifreeze protein during winter. Quantitative reverse transcription-PCR (qPCR) and subtractive hybridization studies have revealed a few genes in smelt liver to be differentially regulated in winter in comparison with the fall when water temperatures are warmer. In order to further define the suite of processes that are regulated seasonally, we undertook a large-scale analysis of gene expression by hybridization of smelt cDNA to the salmonid 16K cGRASP cDNA microarray. These microarray experiments were conducted as a focused sieving exercise, which identified informative genes for further study in the microarray samples and over a seasonal sampling series using quantitative reverse-transcription PCR. Total RNA was obtained from livers of 3 male fish sampled on October 20th and aliquots were pooled to contain equimolar concentrations of each RNA preparation. Total RNA was prepared from 3 male fish on January 3rd and processed in the same manner. Fluorescently labeled cDNA preparations were made using the fall (October) and winter (January) pools and mixed before hybridization to the microarray. The cDNAs were hybridized to three separate microarrays in order to generate technical replicates. Differential expression was assessed in order to select genes for further study.

2010-05-15 | E-GEOD-17961 | biostudies-arrayexpress

Osmerus mordax

Project description:Osmerus mordax overview

| PRJNA124037 | ENA

Identification and expression analysis of differentially expressed genes in a hepatocyte model of cold-induced glycerol production in rainbow smelt (Osmerus mordax)

Project description:The rainbow smelt (Osmerus mordax, Mitchill, 1814) is an anadromous teleost that overwinters in the estuaries and inshore waters along the North American Atlantic coastline. In the winter months, smelt avoid freezing in subzero temperatures by the production of antifreeze proteins and high levels of glycerol. Glycerol production (glyceroneogenesis) occurs in the liver via a branch point in glycolysis and gluconeogenesis and is directly activated by low temperature. In these studies, hepatocytes were isolated from the liver of individual warm fish and incubated at either a warm (8ºC; non-glycerol accumulating) or cold (0.4ºC; glycerol accumulating) temperature over a 72 h time course. Functional genomic techniques were used to identify and validate hepatic transcripts that were differentially expressed between the warm and cold cells. Reciprocal suppression subtractive hybridization (SSH) cDNA libraries enriched for cold-responsive liver transcripts were constructed at the 72 h incubation time. Microarray analyses using the consortium for Genomic Research on All Salmonids Project (cGRASP) 16K (salmonid) cDNA array were performed at the 24, 48 and 72 h incubation times. For quantitative reverse transcription – polymerase chain reaction (QPCR) studies, we focused specifically on the non-colligative [type II antifreeze protein (AFPII)] and colligative (glycerol accumulation) freeze prevention strategies. AFPII (SSH identified) and 21 transcripts (SSH and/or microarray identified or selected by the authors based on a conceptual link to glycerol production) involved in the metabolism of glycolytic (glycogen, glucose) and gluconeogenic (amino acids) sources of glycerol and of lipids with a glycerol backbone (triglyceride, phosphoplipid) were analyzed using QPCR.

2010-08-11 | GSE23516 | GEO

fOsmEpe

Project description:Osmerus eperlanus (European smelt)

| PRJEB64080 | ENA

Osmerus mordax

Project description:Identification and expression analysis of differentially expressed genes in a hepatocyte model of cold-induced glycerol production in rainbow smelt (Osmerus mordax)

| PRJNA131067 | ENA

fOsmEpe2

Project description:Osmerus eperlanus (European smelt) genome assembly, fOsmEpe2

| PRJEB70540 | ENA