Kotarska Katarzyna, Lenartowicz Małgorzata, Przybyło Małgorzata, Gołas Aniela, Styrna Józefa
Department of Genetics and Evolution, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Krakow, Poland.
Reprod Fertil Dev. 2013;25(6):900-6. doi: 10.1071/RD12086.
Cumuli oophori surrounding ovulated oocytes of B10.BR(Y(del)) females (sired by males with the Y-chromosome long-arm deletion) are more resistant to hyaluronidase digestion than cumuli oophori around eggs of genetically identical females but sired by males with the intact Y chromosome (B10.BR). This has been interpreted as a result of differences in paternal genome imprinting, which females of both groups inherit from their fathers. The following study shows that it is not hyaluronan, but rather excessive protein concentration, that makes the cumulus extracellular matrix of B10.BR(Y(del)) oocytes more resistant to enzymatic treatment. It was revealed, additionally, that cumulus cells around ovulating oocytes of B10.BR(Y(del)) females display higher surface accumulation of prostaglandin EP2 subtype receptors and higher expression of the Ptgs2 gene (encoding a rate-limiting enzyme of prostaglandin E₂ synthesis) in relation to the cells of control B10.BR females. The expression levels of the prostaglandin-dependent Tnfaip6 and Ccl2 genes were also altered in B10.BR(Y(del)) cumulus cells in a manner indicating increased prostaglandin signalling. The study provides further evidence for the divergence in reproductive phenotypes between B10.BR and B10.BR(Y(del)) female mice. It supports the hypothesis that genes of the Y-chromosome long arm may be involved in establishment of epigenetic marks in X-bearing spermatozoa.
B10.BR(Y(del))雌性小鼠（由Y染色体长臂缺失的雄性小鼠所生）排卵卵母细胞周围的卵丘，比基因相同但由Y染色体完整的雄性小鼠（B10.BR）所生雌性小鼠卵子周围的卵丘，对透明质酸酶消化更具抗性。这被解释为两组雌性小鼠从其父亲那里继承的父本基因组印记存在差异的结果。以下研究表明，使B10.BR(Y(del))卵母细胞的卵丘细胞外基质对酶处理更具抗性的，不是透明质酸，而是过高的蛋白质浓度。此外还发现，与对照B10.BR雌性小鼠的细胞相比，B10.BR(Y(del))雌性小鼠排卵卵母细胞周围的卵丘细胞显示出更高的前列腺素EP2亚型受体表面积累以及Ptgs2基因（编码前列腺素E₂合成的限速酶）更高的表达。前列腺素依赖性的Tnfaip6和Ccl2基因的表达水平在B10.BR(Y(del))卵丘细胞中也发生了改变，表明前列腺素信号传导增强。该研究为B10.BR和B10.BR(Y(del))雌性小鼠生殖表型的差异提供了进一步的证据。它支持了Y染色体长臂基因可能参与携带X染色体精子中表观遗传标记建立的假说。
