Studying meiosis-specific cohesins in mouse embryonic oocytes.

Distinct meiotic cohesin complexes play fundamental roles in various meiosis-specific chromosomal events in spatiotemporally different manners during mammalian meiotic prophase. Immunostaining is one of the essential methods to study meiotic cohesin dynamics. For the study of cohesins in the meiotic prophase of oocytes, ovaries should be taken from the embryos during a very limited period before birth. Here we focus on some technical tips concerning the preparation of oocyte chromosome spreads for immunostaining. Further, we describe a method for chromosome fluorescence in situ hybridization (FISH) against immunostained oocytes.