Aberrant histone H4 acetylation in dead somatic cell-cloned calves

Abstract

In somatic cell-cloned animals, inefficient epigenetic reprogramming can result in an inappropriate gene expression and histone H4 acetylation is one of the key epigenetic modifications regulating gene expression. In this study, we investigated the levels of histone H4 acetylation of 11 development-related genes and expression levels of 19 genes in lungs of three normal control calves and nine aberrant somatic cell-cloned calves. The results showed that nine studied genes had decreased acetylation levels in aberrant clones ( p < 0.05) and two genes had no significant variations ( p > 0.05). Whereas 13 genes had significantly decreased expression ( p < 0.05) in aberrant clones, five genes showed no significant differences between controls and clones ( p > 0.05), and only one gene had higher expression level in clones ( p < 0.05). Furthermore, FGFR, GHR, HGFR and IGF1 genes showed lowered levels of both histone H4 acetylation and expression in aberrant clones than in controls, and the level of histone H4 acetylation was even more lowered in aberrant clones than those in controls. It was suggested that the lower levels of histone H4 acetylation in aberrant clones caused by the previous memory of cell differentiation might not support enough chromatin reprogramming, thus affecting appropriate gene expressions, and growth and development of the cloned calves. To our knowledge, this is the first study on how histone H4 acetylation affects gene expression in organs of somatic cell-cloned calves.