Enhanced histone acetylation in somatic cells induced by a histone deacetylase inhibitor improved inter-generic cloned leopard cat blastocysts

Abstract

The objective was to determine whether alterations of histone acetylation status in donor cells affected inter-generic SCNT (igSCNT)-cloned embryo development. Leopard cat cells were treated with trichostatin A (TSA; a histone deacetylase inhibitor) for 48 h, and then donor cells were transferred into enucleated oocytes from domestic cats. Compared to non-treated cells, the acetylated histone 3 at lysine 9 (AcH3K9) and histone 4 at lysine 5 (AcH4K5) in the TSA group increased for up to 48 h (P < 0.05). The AcH3K9 signal ratios of igSCNT group was higher than control group 3 h after activation (P < 0.05). Treatment with TSA significantly increased total cell number of blastocysts (109.1 +/- 6.9 vs. 71.8 +/- 2.9, mean +/- SEM), with no significant effects on rates of cleavage or blastocyst development (71.1 +/- 2.8 vs. 67.6 +/- 2.9 and 12.2 +/- 2.6 vs. 11.0 +/- 2.6, respectively). When igSCNT cloned embryos were transferred into a domestic cat oviduct and recovered after 8 d, blastocyst development rates and total cell numbers were greater in the TSA-igSCNT group (20.7 +/- 3.0% and 2847.6 +/- 37.2) than in the control igSCNT group (5.7 +/- 2.2% and 652.1 +/- 17.6, P < 0.05). Average total cell numbers of blastocysts were approximately 4.4-fold higher in the TSA-igSCNT group (2847.6 +/- 37.2, n = 10) than in the control group (652.1 17.6, n = 8; P < 0.05), but were similar to 2.9-fold lower than in vivo cat blastocysts produced by intrauterine insemination (8203.8 +/- 29.6, n = 5; P < 0.001). Enhanced histone acetylation levels of donor cells improved in vivo developmental competence and quality of inter-generic cloned embryos; however, fewer cells in blastocysts derived from igSCNT than blastocysts produced by insemination may reduce development potential following intergeneric cloning (none of the cloned embryos were maintained to term). (C) 2010 Elsevier Inc. All rights reserved.