How to study HOX gene expression and function in mammalian oocytes and early embryos.

Mammalian oocytes and early embryos have unique characteristics and can only be obtained in small amounts. As a consequence, the techniques to be used to characterize gene expression and function have to be adapted. It is also important to keep in mind that differences exist between mammalian species. Here we describe a set of techniques useful to analyze gene expression in oocytes and early bovine embryos, including techniques to quantify maternal and embryonic transcripts by RT-qPCR, to evaluate the translation potential of maternal transcripts, to knock down HOX transcripts by injection of siRNA, and to localize HOX proteins by whole-mount immunofluorescence.