de Koning D J, Rattink A P, Harlizius B, van Arendonk J A, Brascamp E W, Groenen M A
Animal Breeding and Genetics Group, Wageningen Institute of Animal Sciences, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
Proc Natl Acad Sci U S A. 2000 Jul 5;97(14):7947-50. doi: 10.1073/pnas.140216397.
The role of imprinting in body composition was investigated in an experimental cross between Chinese Meishan pigs and commercial Dutch pigs. A whole-genome scan revealed significant evidence for five quantitative trait loci (QTL) affecting body composition, of which four were imprinted. Imprinting was tested with a statistical model that separated the expression of paternally and maternally inherited alleles. For back fat thickness, a paternally expressed QTL was found on Sus scrofa chromosome 2 (SSC2), and a Mendelian-expressed QTL was found on SSC7. In the same region of SSC7, a maternally expressed QTL affecting muscle depth was found. Chromosome 6 harbored a maternally expressed QTL on the short arm and a paternally expressed QTL on the long arm, both affecting intramuscular fat content. The individual QTL explained from 2% up to 10% of the phenotypic variance. The known homologies to human and mouse did not reveal positional candidate genes. This study demonstrates that testing for imprinting should become a standard procedure to unravel the genetic control of multifactorial traits.
通过中国梅山猪与荷兰商用猪的杂交实验，研究了印记在身体组成中的作用。全基因组扫描发现了五个影响身体组成的数量性状基因座（QTL）的显著证据，其中四个是印记基因座。使用一个统计模型对印记进行了测试，该模型区分了父本和母本遗传等位基因的表达。对于背膘厚度，在猪2号染色体（SSC2）上发现了一个父本表达的QTL，在SSC7上发现了一个孟德尔表达的QTL。在SSC7的同一区域，发现了一个影响肌肉深度的母本表达的QTL。6号染色体在短臂上有一个母本表达的QTL，在长臂上有一个父本表达的QTL，两者都影响肌内脂肪含量。单个QTL解释了2%至10%的表型变异。与人类和小鼠的已知同源性未揭示位置候选基因。这项研究表明，检测印记应成为揭示多因素性状遗传控制的标准程序。
