We found that TSD is far less widespread that currently thought. However, there is evidence that during climactic extremes, changes in the sex determining mechanism itself to GSD are selected for, particularly in the highly-mutable turtles. Science — View Article Google Scholar 3.
Warner, Daniel, and Richard Shine.
National Center for Biotechnology InformationU. In researchers established the existence of genotypic sex determination among turtlesa result that weakened support for TSD in reptiles and in vertebrates. Wrote the paper: FP.
Berlin: Springer-Verlag, View Article Google Scholar 5. While sex hormones have been observed to be influenced by temperature, thus potentially altering sexual phenotypes, specific genes in the gonadal differentiation pathway display temperature influenced expression.
Env Biol Fish — In some species, low temperatures produce mainly females, and high temperatures produce mostly males. J Fish Biol —
Devlin RH, Nagahama Y Sex determination and sex differentiation in fish: an overview of genetic, physiological, and environmental influences. However, pattern 3 of fish is not equivalent to pattern II of reptiles female-biased sex ratios at low and high temperatures and male-biased sex ratios at intermediate temperatures but it could be considered an inverse of it.
Briefly, applied here this model states that when a critical time is reached during development, a sexually undifferentiated gonad will develop as an ovary or as a testis depending on whether it has attained a certain size above or below a threshold, respectively Fig. Environmental Sex Determination - Developmental Biology.
After Crain and more