Gender - bending alligators use

It’s a boy! Or is it? We live in an era of blurred gender lines, but for many reptiles this has always been a hot topic. In crocodilian as well as several turtle species, cranking up the thermostat a few degrees during a critical developmental window, called the thermo-sensitive period, will turn a whole clutch of eggs into males. Hormones also contribute to sex determination in these species, and exposure to female hormones – estrogens – can feminize alligators developing at a male-producing temperature. But while there is more than a decade of research on estrogenmediated sex reversal, the mechanisms behind this phenomenon remain largely elusive. Knowing that estrogens can communicate with cells using either of two receptors (ESR1 or ESR2), a team of scientists based in South Carolina, at the lab of Louis Guillette Jr, wanted to know which of these two receptors is responsible for changing baby boy alligators into baby girls.