However, once an individual becomes female, it will not revert to being male Coe Each V. In some species the W chromosome is distinctively larger than the other microchromosomes King and King ; Matsubara et al.
Statistical analyses and graphs were carried out with the aid of StatGraphics v. Muramatsu, S. Skip navigation. Download: PPT. Tamura, K. Neth J Zool — While TSD has been observed in many reptile and fish species, the genetic differences between sexes and molecular mechanisms of TSD have not been determined.
Downstream sexual differentiation processes in alligators follows a fairly similar pattern often shared among vertebrates. Download PDF. Ambient temperature can broadly influence multiple targets at once and most likely several elements temperature-dependent sex determination is observed instance in Brownsville involved in the TSD mechanism one way or the other, including the potential factors investigated previously.
This mechanism hypothesized to be shared among TSD reptiles, including in the alligator as well. Can J Zool — Further, the Atlantic silversides Menidia menidia and M. One possible explanation that TSD is common in amniotes is phylogenetic inertia — TSD is the ancestral condition in this clade and is simply maintained in extant lineages because it is currently adaptively neutral or nearly so.
Among varanids, sex chromosomes have been reported for only eight species Table 1. Therefore, they viewed the karyotype of the salvator clade as ancestral for varanids. Version 3.