Pereira R M, Mesquita P, Batista M, Baptista M C, Barbas J P, Pimenta J, Santos I C, Marques M R, Vasques M I, Silva Pereira M, Santos Silva F, Oliveira Sousa M C, Fontes C M G, Horta A E M, Prates J A M, Marques C C
L-INIA, Quinta da Fonte Boa, 2005-048 Vale de Santarém, Portugal.
Anim Reprod Sci. 2009 Aug;114(1-3):157-66. doi: 10.1016/j.anireprosci.2008.10.003. Epub 2008 Oct 11.
Transgenic knockout of the gene encoding the prion-like protein Doppel leads to male infertility in mice. The precise role of Doppel in male fertility is still unclear, but sperm from Doppel-deficient mice appear to be unable to undergo the normal acrosome reaction necessary to penetrate the zona pellucida of the oocyte. The objective of this study was to characterize Doppel (Prnd) gene polymorphisms in eight Portuguese sheep breeds and to determine a possible relationship between these polymorphisms and ram fertility. Ovine genomic DNA of 364 animals of different breeds (Bordaleira entre Douro e Minho, Churra Badana, Churra Galega Mirandesa, Churra Mondegueira, Merino da Beira Baixa, Merino Branco, Saloia and Serra da Estrela) were analysed by multiple restriction fragment-single-strand conformation polymorphism (MRF-SSCP). This analysis revealed a synonymous substitution G-->A in codon 26 of Prnd gene. Churra Galega Mirandesa and Saloia breeds were more polymorphic (P=0.005 and P=0.04, respectively) than the overall population, while Serra da Estrela and Merino Branco animals were less polymorphic (P=0.007 and P=0.04). No polymorphism was found in Churra Mondegueira breed. Semen from 11 rams of Churra Galega Mirandesa breed (7 homozygous wildtype GG and 4 heterozygous GA) routinely used in the Portuguese Animal Germoplasm Bank was collected and frozen for fertility tests. A classification function was estimated, using data from post-swim-up semen motility and concentration and Day 6 embryo production rate, allowing the identification of the Doppel homozygous GG genotype with 86.7% of accuracy. This preliminary study detected the presence of only one polymorphism in codon 26 of Prnd gene in the Portuguese sheep breeds. In the polymorphic Churra Galega Mirandesa breed, GG genotype could be characterized through a model using three fertility traits, suggesting a relationship with male reproduction. Any future research should investigate not only AA genotype and its influence on ram fertility but also the possible consequences of the European Community selection program to eradicate Scrapie on the Prnd genotypes and indirectly on sheep breed's viability and preservation.
朊病毒样蛋白多普蛋白（Doppel）编码基因的转基因敲除导致小鼠雄性不育。多普蛋白在雄性生育中的具体作用仍不清楚，但来自缺乏多普蛋白的小鼠的精子似乎无法进行穿透卵母细胞透明带所需的正常顶体反应。本研究的目的是表征八个葡萄牙绵羊品种中多普蛋白（Prnd）基因的多态性，并确定这些多态性与公羊生育力之间的可能关系。通过多重限制性片段-单链构象多态性（MRF-SSCP）分析了364只不同品种动物（杜罗河与米尼奥之间的博尔代莱拉、巴达纳丘拉、米兰德萨加利西亚丘拉、蒙德盖拉丘拉、贝拉巴伊亚美利奴、白美利奴、萨洛亚和埃斯特雷拉山脉）的绵羊基因组DNA。该分析揭示了Prnd基因第26密码子中的同义替换G→A。米兰德萨加利西亚丘拉和萨洛亚品种比总体群体具有更高的多态性（分别为P = 0.005和P = 0.04），而埃斯特雷拉山脉和白美利奴动物的多态性较低（P = 0.007和P = 0.04）。在蒙德盖拉丘拉品种中未发现多态性。收集了葡萄牙动物种质库中常规使用的11只米兰德萨加利西亚丘拉品种公羊（7只纯合野生型GG和4只杂合GA）的精液并冷冻用于生育力测试。利用上游后精液活力和浓度以及第6天胚胎生产率的数据估计了一个分类函数，能够以86.7%的准确率识别多普蛋白纯合GG基因型。这项初步研究在葡萄牙绵羊品种的Prnd基因第26密码子中仅检测到一种多态性。在多态性的米兰德萨加利西亚丘拉品种中，GG基因型可以通过一个使用三个生育性状的模型来表征，这表明与雄性繁殖有关。未来的任何研究不仅应该调查AA基因型及其对公羊生育力的影响，还应该调查欧盟根除羊瘙痒病的选择计划对Prnd基因型以及间接对绵羊品种生存能力和保存的可能后果。
