Gradual development of a genome-wide H3-K9 trimethylation pattern in paternally derived pig pronucleus.
The cytoplasm of a mature oocyte contains many protein complexes that are programmed to restructure incoming sperm chromatins on fertilization. Of the complicated biochemical events that these functional machineries control, the most impressive and important is epigenetic reprogramming. Despite its importance in epigenetic resetting, or "de-differentiation," of gamete genomes back to an incipient status, the mechanisms of epigenetic reprogramming do not seem to be conserved among mammals. Here, we report that, unlike in the mouse, the pig sperm-derived pronucleus is markedly trimethylated at lysine 9 of histone H3 (H3-m(3)K9), which might be associated with preservation of paternally derived cytosine methylation in pig zygotes. The male H3-m(3)K9 pattern is gradually established during pronucleus development, and this process occurs independently of DNA replication. Considering these unique epigenetic features, the pig zygote is, we believe, suited to serve as another model of epigenetic reprogramming that is antithetical to the well-characterized mouse model.
Jeong
Young Sun
YS
Center for Development and Differentiation, KRIBB, Yuseong-gu, Daejon, South Korea.
Yeo
Seungeun
S
Park
Jung Sun
JS
Lee
Kyung-Kwang
KK
Kang
Yong-Kook
YK
D000818:Animals; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism*; D002843:Chromatin / Q000235:genetics; D003596:Cytosine / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004261:DNA Replication; D005220:Fathers; D005260:Female; D016678:Genome / Q000235:genetics*; D006657:Histones / Q000378:metabolism*; D008297:Male; D008745:Methylation; D051379:Mice; D013094:Spermatozoa / Q000378:metabolism; D013552:Swine
D002843:Chromatin; D006657:Histones; D003596:Cytosine; D004247:DNA