Sunday, July 30, 2017

How Temperature Can Influence Sex Changes in Bearded Dragons

Who would have thought that embryonic bearded dragons can switch their sex when the ambient temperature gets hot. These lizards have sex influencing chromosomes where if an egg is incubated at 32 degrees Celsius or below and has two Z chromosomes, then it will develop into a male. If an egg has a Z and a W chromosome, then it will develop into a female. Although, if the temperature rises above 32 degrees Celsius, then the egg with the chromosome ZZ with overturn and become a female with the chromosomes of ZW. DNA was collected from the brain and reproductive organs of the lizards by Clare Holleley, an ecologist from the Commonwealth Scientific and Industrial Research Organization in Canberra. There were three types of lizards, which includes of normal females, normal males, and females who's sex was switched from male.  Studies from the RNA indicated that two genes, JARID2 and JMJD3 had a high activity rate from the sex-reversed female lizards. Deveson, a biologist at the Garvan Institute, noticed something peculiar about the RNA translation. In the sex- reversed female lizards, the RNA section that would naturally be removed during translation, ultimately stayed and carried specific codes that would stop the translation of RNA from JARID2 and JMJD3.

1 comment:

  1. My family has owned bearded dragons for years and this is something I never knew! It is also interesting to learn that similar to birds and other nonhuman species they have ZZ and ZW sex chromosomes rather than X and Y. On top of transforming sexes the heat can actually determine the sex before the egg has hatched which is really neat.