To better understand the endocrine mechanisms that underlie sexually dimorphic growth (females grow faster) in yellow perch (Perca flavescens), real-time quantitative polymerase chain reaction (qPCR) was used to measure pituitary, liver, and ovary mRNA levels of genes related to growth and reproduction-sex in this species. Adult perch were collected from Lake Erie and body mass, age, gonadosomatic index (I G), hepatosomatic index (I H), and gene expression for growth hormone (GH), prolactin, somatolactin, insulin-like growth factor Ib (IGF-Ib), estrogen receptor α (esr1), estrogen receptor βa (esr2a), and aromatase (cyp19a1a) were measured. Females had higher body mass, I H, and liver esr1 mRNA level than males, while males had higher liver IGF-Ib, liver esr2a, and liver cyp19a1a mRNA levels. In both sexes, season had a significant effect on GH and liver IGF-Ib mRNAs with higher levels occurring in spring, which also corresponded with higher liver cyp19a1a mRNA levels. For females, I G, liver esr1, and ovary cyp19a1a mRNA levels were higher in autumn than the spring, and ovary cyp19a1a mRNA levels showed a significant negative correlation with pituitary GH and liver IGF-Ib mRNA levels. The most significant (p∈≤∈0.001) relationships across the parameters measured were positive correlations between liver IGF-Ib and esr2a mRNA levels and liver IGF-Ib and cyp19a1a mRNA levels. This study shows significant effects of season and sex on adult yellow perch endocrine physiology.
|Number of pages||13|
|State||Published - Apr 2009|
Bibliographical noteFunding Information:
Special thanks go to J. Swartz of Swartz Fisheries and his crew for being so helpful in the attainment of samples. D. Klarer and the staff at Old Woman Creek NERR/SNP, Huron OH, USA, provided lodging and laboratory facilities. B. O’Hara, University of Kentucky, helped in the implementation of the qPCR assays. This work was funded by NOAA National Estuarine Research Reserve Graduate Student Fellowship #NA16OR2400 to S.G. Lynn. This study was also funded, in part, by grants from the National Research Initiative Competitive Grants Program/USDA award no. 2002-35206-11629 and 2004-05124 and the support of the US Geological Survey and Kentucky Water Resources Research Institute Grant Agreement No. 01HQGR0133 to B.S. Shepherd and ARS/USDA CRIS #3655-31000-020-00D. The views contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the US Government. Mention of trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the USDA and does not imply its approval to the exclusion of other products that may be suitable. This manuscript is submitted for publication with the understanding that the US Government is authorized to reproduce and distribute reprints for governmental purposes.
- Yellow perch
ASJC Scopus subject areas
- Aquatic Science