Expression of primary cilia-related genes in developing mouse gonads.

Mechanisms governing differentiation of the bipotential gonad into the testes or ovaries are complex and still vague. The primary cilium is an organelle involved in cell signaling, which controls the development of many organs, but the role of primary cilium in the sex determination and sexual differentiation of gonads is com-pletely unknown. Here we studied the expression of genes involved in primary cilium formation and function-ing in fetal mouse gonads, before, during and after sexual differentiation. We studied the expression of 175 primary cilia-related genes using microarray technique. 144 of these genes were ubiquitously expressed in all studied cell types with no significant differences in expression level. Such a high level of expression of primary cilia-related genes in developing mouse gonads suggests that the primary cilia and/or primary cilia-related genes are important for the development of both somatic and germline component of the gonads. Only 31 genes showed a difference in expression between different cell types, which suggests that they have different functions in the somatic and germ cells. These results justify further studies on the role of primary cilia and the primary cilia-related genes in gonad development.