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Relationships between the transcriptome and physiological indicators of reproduction in female rainbow trout over an annual cycle
Author(s) -
Hook Sharon E.,
Nagler James J.,
Cavileer Tim,
Verducci Joseph,
Liu Yushi,
Hayton William,
Schultz Irvin R.
Publication year - 2011
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.407
Subject(s) - biology , medicine , endocrinology , transcriptome , luteinizing hormone , ovary , hypothalamic–pituitary–gonadal axis , gene expression , microarray , ovarian follicle , hormone , gene , genetics
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. Environ. Toxicol. Chem. 2011;30:309–318. © 2010 SETAC