title: Relationships between the transcriptome and physiological indicators of reproduction in female rainbow trout over an annual cycle.
abstract: Normal transcriptomic patterns along the brain-pituitary-gonad-liver (BPGL) axis should be better characterized if endocrine-disrupting compound-induced changes in gene expression are to be understood. Female rainbow trout were studied over a complete year-long reproductive cycle. Tissue samples from pituitary, ovary, and liver were collected for microarray analysis using the 16K Genomic Research on Atlantic Salmon Project (GRASP) microarray and for quantitative polymerase chain reaction measures of estrogen receptor (ER) isoform messenger RNA (mRNA) levels. Plasma was collected to determine levels of circulating estradiol-17β (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). As an a priori hypothesis, changes in gene expression were correlated to either circulating levels of E2, FSH, and LH, or ER mRNAs quantified by quantitative polymerase chain reaction. In the liver, most transcriptomic patterns correlated to levels of either E2, LH, or ERs. Fewer ovarian transcripts could be correlated to levels of E2, ERα, or FSH. No significant associations were obvious in the pituitary. As a post hoc hypothesis, changes in transcript abundance were compared with microarray features with known roles in gonadal maturation. Many altered transcripts in the ovary correlated to transcript levels of estradiol 17-beta-dehydrogenase 8 or 17 B HSD12, or to glycoprotein alpha chain 1 or 2. In the pituitary, genes involved with the growth axis (e.g., growth hormone, insulin-related growth factor binding protein) correlated with the most transcripts. These results suggest that transcriptional networks along the BPGL axis may be regulated by factors other than circulating steroid hormones.
authors.affiliation: Battelle PNNL-MSL, Sequim, Washington, USA. Sharon.Hook@csiro.au
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Hook
authors.forename: James J
authors.initials: JJ
authors.lastname: Nagler
authors.forename: Tim
authors.initials: T
authors.lastname: Cavileer
authors.forename: Joseph
authors.initials: J
authors.lastname: Verducci
authors.forename: Yushi
authors.initials: Y
authors.lastname: Liu
authors.forename: William
authors.initials: W
authors.lastname: Hayton
authors.forename: Irvin R
authors.initials: IR
authors.lastname: Schultz
mesh_terms: D000818:Animals; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D008099:Liver / Q000378:metabolism; D007986:Luteinizing Hormone / Q000097:blood; D020411:Oligonucleotide Array Sequence Analysis; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000502:physiology*; D010053:Ovary / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012098:Reproduction
chemical_list: D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone