Profiles of Gonadal Gene Expression in the Developing Bovine Embryo

Abstract

Our current understanding of the molecular basis of sex determination and gonadal development in humans is mostly an extrapolation of knowledge gained from studies in the mouse. However, the timing of gene expression in the mouse is unusual among mammals, and it is therefore important that data from other models are also available to help elucidate this pivotal process in human development. Here we describe the sequence of molecular and morphological events marking testis differentiation in bovine embryos. The genital ridges first appeared at CRL 12 (day 32). SRY expression began at CRL 18 (day 37) and peaked at CRL 20 (day 39), leading to a cascade of regulatory, signaling, and steroidogenic gene expression at later stages, detected by quantitative real-time RT-PCR and immunohistochemistry. Testis cords were distinguishable at CRL 27 (day 42). We conclude that the timing of gene expression observed in developing human embryos is much more similar to bovine development than it is to the mouse. Therefore, Bos taurus may represent a useful model in which to study gene expression during sex determination, relevant to human development.

Expression of miRNAs in ovine fetal gonads: potential role in gonadal differentiation

“…Based on the correlations observed between miRNA expression and their predicted targets, we postulate that miRNAs are important regulators of gene expression and function during fetal gonadal development. Similar to what has been proposed for the cow [47], the sheep is a useful model to study gonadal development and differentiation in mammals. For example, estrogen signalling appears to play a role in human, cow, and sheep fetal ovarian development [38,39,43,48].…”

Molecular Mechanisms of Sexual Development

“…As reported above, while the beginning of SRY expression is a critical parameter, its duration does not seem to be meaningful as several mammals show a persistent SRY expression beyond testis development. This expression profile was reported in goats [Pannetier et al, 2006], pigs [Parma et al, 1999], sheep [Payen et al, 1996], humans [Hanley et al, 2000], rabbits [Díaz-Hernández et al, 2008], and cattle [Ross et al, 2009]. The function of such persistent expression in these species is still unknown; though, a recent study performed in goats suggests its possible influence on male fertility and testicular maintenance [MontazerTorbati et al, 2010].…”

Methods for the Study of Gonadal Development

“…qRT-PCR is commonly used to study gene expression during gonadogenesis (Abramyan et al 2009;Barrionuevo et al 2006;Barske and Capel 2010;Beverdam and Koopman 2006;Bogani et al 2009;Bouma et al 2005Bouma et al , 2007Bradford et al 2009;Britt et al 2002;Chang et al 2008;Chassot et al 2008;Chen et al 2012;Childs et al 2011;Combes et al 2011;Cupp et al 2003;DeFalco et al 2014;Hiramatsu et al 2009;Houmard et al 2009;Koubova et al 2006;Li et al 2012;Liu et al 2015;Maatouk et al 2008;Manuylov et al 2007;Molyneaux et al 2003;Moniot et al 2009;Munger et al 2013;Nef et al 2003Nef et al , 2005Nicol and Yao 2015;Parma et al 2006;Rolland et al 2011;Ross et al 2009;Smith et al 2008aSmith et al , b, 2009Tang et al 2008;Tevosian et al 2002;Wilhelm et al 2005). In the majority of studies of gonad development, primers labeled with SYBR Green fluorochrome are used although TaqMan probes have also been applied Liu et al 2015;Smith et al 2008a, b).…”

“…There is a plethora of gonadal development studies in which immunolabeling was used, usually IHC or IF (Abramyan et al 2009;Bagheri-Fam et al 2008;Barrionuevo et al 2006Barrionuevo et al , 2009Bendel-Stenzel et al 2000;Best et al 2008;Beverdam and Koopman 2006;Bogani et al 2009;Bradford et al 2009;Britt et al 2002;Chang et al 2008;Chassot et al 2008;Chen et al 2012;Childs et al 2011;DeFalco et al 2015;DiNapoli and Capel 2007;Dumond et al 2011;Dupont et al 2000;Fleming et al 2012;Fr€ ojdman et al 1992;Hanley et al 2000;Hiramatsu et al 2009;Hummitzsch et al 2013;Jameson et al 2012;Karl and Capel 1998;Nef et al 2005;Li et al 2012;Li and Kim 2004;Liu et al 2009Liu et al , 2015Maatouk et al 2008;MacLean et al 2009;Matzuk et al 1995;Molyneaux et al 2003;Moniot et al 2009;Morais da Silva et al 1996;Mork et al 2014;Nicol and Yao 2015;Ohe et al 2002;Oshima et al 2005;Ross et al 2009;…”