Non-genetic sex determination occurs when the sex of an organism can be altered during a sensitive period of development due to external factors such as temperature, humidity, or social interactions. Cluster of Crepidula snails. Location-dependent sex determination in Bonellia and Crepidula As mentioned in Chapter 3, the sex of the echiuroid worm Bonellia depends on where a larva settles.
In this species, high incubation temperature during egg development reverses genotypic males ZZ into phenotypic females; so females can be ZZ or ZW, but males are always ZZ.
The consequences of TSD on fitness, or reproductive success, are largely unknown. Temperature levels and periods of sex determination during incubation of eggs of Chelydra serpentina. Help Community portal Recent changes Upload file. A study found that hot temperatures altered the expression of the sex chromosomes in Australia's bearded dragon lizards.
Inhibition of reductase, the enzyme that converts testosterone into non-aromatizable dihydrotestosterone DHTalso sex-reverses hatchlings from a male-biased temperature [ 23 ].
Most turtles are subject to temperature-dependent sex determination. Global Change Biology. Alex Quinn, a Ph. In most species, gender is determined during fertilization.
Temperature-dependent sex determination in three reptile species: the American alligator Alligator mississippiensis , the red-eared slider turtle Trachemys scripta elegans , and the alligator snapping turtle Macroclemys temminckii. In most species, gender is determined during fertilization. Sex-determining mechanisms in reptiles are broadly divided into two main categories: genotypic sex determination GSD and temperature-dependent sex determination TSD.