Project description:The study was designed to investigate the impacts of hatchery spawning and rearing on steelhead trout (Oncorhynchus mykiss) versus the wild fish on a molecular level. Additionally, epigenetic differences between feeding practices that allow slow growth and fast growth hatchery trout were investigated. The sperm and RBC DNA both had a large number of DMRs when comparing the hatchery versus wild steelhead trout populations. Interestingly, the DMRs were cell type specific with negligible overlap. Slow growth compared to fast growth steelhead also had a larger number of DMRs in the RBC samples. Observations demonstrate a major epigenetic programming difference between the hatchery and wild fish populations, but negligible genetic differences. Therefore, hatchery conditions and growth rate can alter the epigenetic developmental programming of the steelhead trout, which may correlate to the phenotypic variations observed.
Project description:Migration is essential for the reproduction and survival of many animals, yet little is understood about its underlying molecular mechanisms. We used the salmonid Oncorhynchus mykiss to gain mechanistic insight into smoltification, which is a morphological, physiological, and behavioral transition undertaken by some juveniles that culminates in a seaward migration. This species is experimentally tractable and, unlike common model species, displays intra- and inter-population variation in migration propensity. Migratory individuals can produce non-migratory progeny and vice versa, indicating a high degree of phenotypic plasticity. One potential way that phenotypic plasticity might be linked to variation in migration-related life history tactics is through epigenetic regulation of gene expression. To explore this, we quantitatively measured genome-scale DNA methylation in fin tissue using reduced representation bisulfite sequencing of F2 siblings produced from a cross between steelhead (migratory) and rainbow trout (non-migratory) lines. We identified 57 differentially methylated regions (DMRs) between smolt and resident O. mykiss juveniles. DMRs were of high magnitude, ranging from 20-62% differential methylation between life history types, and over half of the gene-associated DMRs were in transcriptional regulatory regions. Many of the DMRs encode proteins with activity relevant to migration-related transitions (e.g. circadian rhythm pathway, nervous system development, protein kinase activity). This study provides the first evidence of a relationship between epigenetic variation and life history divergence associated with a migration-related transition in any species. Comparing global DNA methyldation profiles (via RRBS) of resident and smolt O. mykiss siblings using caudal fin tissue.
Project description:Comparison of gene expression of exposed versus non-exposed Oncorhynchus mykiss hepatocytes to four model chemicals and a synthetic mixture. Hepatocytes were exposed for 24 hours to a single chemical and a synthetic mixture of 10 nM 17 alpha-ethinylestradiol (EE2), 0.75 nM 2,3,7,8-tetrachloro-di-benzodioxin (TCDD), 100 μM paraquat and 0.75 μM 4-nitroquinoline-1-oxide (NQO). Four biological replicates for both exposed and non-exposed Oncorhynchus mykiss hepatocytes with corresponding dye flips.
Project description:These files represent single cell RNA-Seq data generated on a 10x Chromium genomics platform from Oncorhynchus mykiss B cells isolated from blood.
2021-05-10 | GSE158102 | GEO
Project description:Whole-genome resequencing to evaluate life history variation in anadromous migration of Oncorhynchus mykiss