Analysis of Sexually Dimorphic Expression of Genes at Early Gonadogenesis of Pejerrey <i>Odontesthes bonariensis</i> Using a Heterologous Microarray

Abstract

The process of morphological development of a differentiated gonad from an undifferentiated primordium is a very important step of gonadogenesis. Studies on sexually dimorphic gene expression are important to increase our understanding of this process and to investigate how environmental factors such as temperature can regulate gonadal development. The aim of this study was to identify putative genes involved in sex differentiation in pejerrey (Odontesthes bonariensis) reared at male- and female-producing temperatures (MPT and FPT, respectively) using a microarray heterologous from the medaka (Oryzias latipes), a closely phylogenetic species. Genes related to numerous processes presented higher expression at MPT, including those involved in muscular contraction, metabolic pathways, developmental processes, and reproduction. Genes induced by FPT were classified under the gene ontology terms of response to stimulus, transport and proteolysis. From genes selected for validation, at MPT ndrg3 expression was observed in the somatic cells, whereas pen-2 was detected in germ cells in the caudal portion of the gonads, where no apoptotic signals were observed. Finally, hsp90 was highly expressed in somatic cells of the gonads at the FPT. The results suggest that the interplay of pro-apoptotic and anti-apoptotic genes is important during the masculinization process and for the prevention of sterility following exposure to warm temperatures.

Sex Modifies Genetic Effects on Residual Variance in Urinary Calcium Excretion in Rat (Rattus norvegicus)

“…Various X-chromosomal peculiarities, including pseudoautosomal recombination and mutation (Lien et al 2000;Lercher and Hurst 2002;Filatov and Gerrard 2003;Ross et al 2005), variable X-chromosomal deactivation (Heard and Disteche 2006;Leeb and Wutz 2010) including among lineages (Patrat et al 2009) might explain such effects (Charlesworth et al 1987;Evans et al 2007). Some molecular chaperones including hsp70, hsp90, and Piwi-interacting RNA canalize variability in morphological and over environmental and genetic axes (Gibert et al 2007;Fernandino et al 2011;Gangaraju et al 2011). Work in mice suggests that environmental buffers of gene expression are sex specific (Fraser and Schadt 2010).…”

The Reversible Sex of Gonochoristic Fish: Insights and Consequences

“…This suggests that temperature-induced masculinization requires the male-differentiating pathway to be turned on and only after that, the ovarian-differentiating pathway is suppressed. In the TSD pejerrey, a heterologous microarray study revealed that in the masculinization at male-promoting temperature (MPT) there is an interplay of pro-apoptotic and anti-apoptotic genes [Fernandino et al, 2011]. In the sea bass, high temperatures (HT) also promote males, and microarray analysis showed elevated dmrt1 expressions in sex-differentiating HT fish together with increases in cholesterol transporting genes and stress response genes as well as upregulation of epigenetic regulatory genes, while low temperature fish showed high cyp19a1a levels [Diaz and Piferrer, 2015].…”

Thermal and Endocrine Regulation of Gonadal Apoptosis during Sex Differentiation in Pejerrey <b><i>Odontesthes</i></b> <b><i>bonariensis</i></b>

“…Another species that has attracted attention from an environmental perspective is the pejerrey Odontesthes bonariensis because sex determination in this species is strongly labile to water temperature early in life [Strüss-mann et al, 1996a[Strüss-mann et al, , 1997. In this unique and well-studied model for research on temperature-dependent sex determination (TSD), several genes and hormones are expressed in a temperature-(and consequently sex-) specific manner during gonadal differentiation [Fernandino et al, 2008a[Fernandino et al, , b, 2011Hattori et al, 2009].…”

“…Another factor apparently involved in masculinization of the undifferentiated pejerrey gonads is apoptosis [Strüssmann et al, 2008;Hattori et al, 2009;Fernandino et al, 2011]. Similarly, in the zebrafish, which is an 'undifferentiated gonochorist' (i.e.…”