Forschungsinstitut für die Biologie landwirtschaftlicher Nutztiere (FBN), Forschungsbereich Genetik und Biometrie, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
J Anim Sci. 2010 Feb;88(2):523-32. doi: 10.2527/jas.2009-2026. Epub 2009 Oct 23.
Imprinted genes are involved in many aspects of development in mammals, plants, and perhaps birds and may play a role in growth and carcass composition of slaughter animals. In the presence of genomic imprinting the expression and, consequently, the effect on the phenotype of maternal and paternal alleles are different. For genetic evaluation genomic imprinting can be accounted for by incorporating 2 additive genetic effects per animal; the first corresponds to a paternal and the second to a maternal expression pattern of imprinted genes. This model holds whatever the mode of imprinting may be: paternal or maternal, full or partial, or any combination thereof. A set of slaughter data from 65,233 German Simmental fattening bulls was analyzed with respect to the relative importance of the genetic imprinting variance. Besides slaughter weight, net daily BW gain, and killing out percentage, there were 22 other traits describing the carcass composition. The latter traits were evaluated by automatic video-imaging devices and were composed of weights of valuable cuts as well as fat and meatiness grade. The number of ancestors in the pedigree was 356,880. Genomic imprinting significantly contributed to the genetic variance of 10 traits, with estimated proportions between 8 and 25% of the total additive genetic variance. For 6 of these traits, the maternal contribution to the imprinting variance was larger than the paternal, whereas for all other traits the reverse was true. Fat grade only showed a paternal contribution to the imprinting variance. Estimates of animal model heritabilities of automatic video-imaging-recorded carcass traits ranged between 20 and 30%.
印迹基因参与哺乳动物、植物，甚至鸟类的许多发育方面，并且可能在屠宰动物的生长和胴体组成中发挥作用。在存在基因组印迹的情况下，母本和父本等位基因的表达及其对表型的影响是不同的。对于遗传评估，可以通过每个动物包含 2 个加性遗传效应来考虑基因组印迹：第一个对应于父本，第二个对应于印迹基因的母本表达模式。无论印迹模式如何：父本或母本、完全或部分，或者它们的任何组合，这种模型都适用。分析了 65233 头德国西门塔尔育肥公牛的一组屠宰数据，以确定遗传印迹方差的相对重要性。除了屠宰体重、净日增重和屠宰率外，还有 22 个其他描述胴体组成的性状。这些性状由自动视频成像设备评估，由有价值的切块重量以及脂肪和肉感等级组成。系谱中的祖先数量为 356880 个。基因组印迹对 10 个性状的遗传方差有显著贡献，估计比例在总加性遗传方差的 8%至 25%之间。对于其中 6 个性状，母本对印迹方差的贡献大于父本，而对于所有其他性状，情况则相反。脂肪等级仅表现出父本对印迹方差的贡献。自动视频成像记录的胴体性状的动物模型遗传力估计值在 20%至 30%之间。
