Genome wide differential H3K4me2 and H3K27me3 profile of spermatozoa from high and sub-fertility buffalo bulls

Sperm carries information to the presumptive embryo upon fertilization in terms of epigenetic codes and transcripts along with the haploid genome. The epigenetic code includes DNA methylation and Histone modifications. During spermatogenesis the chromatin of sperm undergoes wide level of modifications and histone proteins are replaced by Protamine proteins. But some modified Histone forms still remain and they carry epigenetic codes essential for fertility and embryo development. Through this work we are trying to see the difference between H3K4me2 and H3K27me3 kind of histone modifications in spermatozoa of high and low fertility buffalo bulls. Agilent two-color ChIP-on-Chip, 4X180K Microarray designed by Genotypic Technology Private Limited. (AMADID-040096). To see the differential H3K4me2 and H3K27me3 pattern between high and low fertile buffalo bull spermatozoa, the cryopreserved semen samples from the identified bulls were procured. The chromatin was isolated from all the samples, sheared with micrococcal nuclease treatment (NEB, Cat no. MO247S), immunoprecipitated and hybdidized on array to get information for all the probes printed on the array. The data was analyzed and the differentially enriched genes between the two group were identified for both kinds of histone modifications.