Evaluating the localization and DNA binding complexity of histones in mature sperm.

The paternal genome in many animal taxa is efficiently packaged into the sperm nucleus by switching from a histone (nucleosome)-based chromatin configuration to one using predominantly protamines. Nonetheless, various studies have shown that some nucleosomes, often containing modified histones are retained in mature sperm and bind DNA with distinct sequence compositions. Considering the significance of histone modifications in epigenetic phenomena and the fact that sperm histones and their bound DNA must be carried into the oocyte, this chapter describes methods aimed at examining and analysing the histone composition of sperm chromatin. The focus is on both microscopic visualisation and evaluation of sequence composition of histones and histone-bound DNA in human and mouse spermatozoa. However, similar methods may be applicable to the sperm of other mammalian and even non-mammalian classes.