Indeed, dihydrotestosterone, a non-aromatizable androgen, can feminize snapping turtle embryos [ Rhen and Lang, ; Rhen, unpublished data]. Sex Dev. Arch Anat Microsc Morphol Exp.
First, there is no guarantee that the primary sex-determining genes in reptiles will be orthologous to sex-determining genes in mammals. Although Harry et al. Evolution and Development.
The consequences of TSD on fitness, or reproductive success, are largely unknown. Second, can we reconstruct the specific molecular genetic sex determination in reptiles n in Terrebonne responsible for the evolution of different sex-determining mechanisms? For example, in many turtle species, eggs from cooler nests hatch as all males, and eggs from warmer nests hatch as all females.
Pieau, Claude. Also, experiments conducted at the pivotal temperature, where temperature is equivocal in its influence, have demonstrated an underlying genetic predisposition to be one sex or the other. Differentially expressed bands were cut out of the gel, extracted, and re-amplified as per the manufacturer's instructions RNAimage Kit.
The next step occurs when the bipotential primordium commits to develop as a testis or an ovary, a process commonly referred to as sex determination.
Adrenal-kidney-gonad complex measurements may not predict gonad-specific changes in gene expression patterns during temperature-dependent sex determination in the red-eared slider turtle Trachemys scripta elegans J Exp Zool Part A. Thus, the distinction between GSD and TSD in reptiles is not as dramatic as some have argued [for a more detailed discussion of this subject see Sarre et al.
Review: fetal programming of polycystic ovary syndrome by androgen excess: evidence from experimental, clinical, and genetic association studies. A study found that hot temperatures altered the expression of the sex chromosomes in Australia's bearded dragon lizards. The Drosophila sex determination signal: How do flies count to two?
In any event, estrogen signaling is clearly necessary and sufficient for ovary development and is a key downstream component of the TSD pathway [ Lance, ; Ramsey and Crews, ].