Effect of high fat diet versus low fat diet on histone distribution in sperm of male mice

Several studies have described phenotypic changes in offspring of mice exposed to environmental factors including diet, but the effect of diet on sperm chromatin remains unclear. We used a high fat diet (HFD) induced obesity mouse model, and examined chromatin of paternal spermatozoa. We performed chromatin immunoprecipitation followed by high throughput sequencing using specific H3 antibodies or specific H3K4me1antibodies. Overall design: Genome-wide maps of H3 and H3K4me1 in spermatozoa of high fat diet and low fat diet male C57BL/6J mice. C57BL/6J males were fed for 10 to 12 weeks a high-fat diet (HFD)( with 60 kcal% fat) or a low-fat diet (LFD)(with 10 kcal% fat). Male mice show increased body weight, elevated blood glucose and impaired glucose tolerance without developing overt diabetes. Spermatozoa (live motile sperm) were isolated from the cauda epididymis. Spermatozoa from five animals were pooled for each experimental group and their biologic replica (HFD4 n=5, LFD5 n=5, HFD7 n=5, LFD8 n=5). Chromatin immunoprecitation (ChIP) assay was performed using anti- H3 antibody or anti- H3K4me1 antibody. ChIP DNA libraries were made using the Illumina ChIP-seq library preparation kit and subjected to Solexa sequencing (Illumina). Reads were aligned to mouse genome build mm9 as reference genome