Institute of Animal Breeding and Husbandry, Christian-Albrechts-University of Kiel, 24098, Kiel, Germany.
IT Solutions for Animal Production (Vit), 27283, Verden, Germany.
Sci Rep. 2020 Oct 12;10(1):17032. doi: 10.1038/s41598-020-73807-5.
Polledness in cattle is an autosomal dominant trait. Previous studies have revealed allelic heterogeneity at the polled locus and four different variants were identified, all in intergenic regions. In this study, we report a case of polled bull (FV-Polled1) born to horned parents, indicating a de novo origin of this polled condition. Using 50K genotyping and whole genome sequencing data, we identified on chromosome 2 an 11-bp deletion (AC_000159.1:g.52364063_52364073del; Del11) in the second exon of ZEB2 gene as the causal mutation for this de novo polled condition. We predicted that the deletion would shorten the protein product of ZEB2 by almost 91%. Moreover, we showed that all animals carrying Del11 mutation displayed symptoms similar to Mowat-Wilson syndrome (MWS) in humans, which is also associated with genetic variations in ZEB2. The symptoms in cattle include delayed maturity, small body stature and abnormal shape of skull. This is the first report of a de novo dominant mutation affecting only ZEB2 and associated with a genetic absence of horns. Therefore our results demonstrate undoubtedly that ZEB2 plays an important role in the process of horn ontogenesis as well as in the regulation of overall development and growth of animals.
牛的无角性状是一种常染色体显性性状。先前的研究表明，在无角基因座存在等位基因异质性，已鉴定出四个不同的变体，均位于基因间区域。本研究报道了一例无角公牛（FV-Polled1）的诞生，其父母均为有角，表明该无角性状为新生突变。使用 50K 基因分型和全基因组测序数据，我们在第 2 号染色体上鉴定出 ZEB2 基因第二外显子中的 11 个碱基缺失（AC_000159.1:g.52364063_52364073del; Del11）是导致该新生无角性状的致病突变。我们预测该缺失将使 ZEB2 的蛋白产物缩短近 91%。此外，我们表明所有携带 Del11 突变的动物都表现出类似于人类 Mowat-Wilson 综合征（MWS）的症状，这也与 ZEB2 的遗传变异有关。牛的症状包括成熟延迟、体型小和颅骨形状异常。这是首例报道的仅影响 ZEB2 的新生显性突变，并与角的遗传缺失有关。因此，我们的研究结果无疑表明，ZEB2 在角发生过程以及动物整体发育和生长的调控中起着重要作用。
