For instance, both genes, especially
HoxA13, were expressed in the undifferentiated gonad during the thermosensitive period at a female promoting
temperature, and downregulated in the differentiated gonad. By contrast, expression of both
genes was low in gonads incubated at a male promoting temperature and did not change significantly
in the differentiated gonad. Furthermore, we found high expression levels of HoxA13 in the paramesonephric
duct at the male promoting temperature but not at the female promoting temperature, suggesting
a role for this Hox gene in the partial regression of the Müllerian duct in males.