CSIRO Livestock Industries, St. Lucia, Queensland, Australia.
BMC Genomics. 2010 Jun 11;11:370. doi: 10.1186/1471-2164-11-370.
Two types of horns are evident in cattle - fixed horns attached to the skull and a variation called scurs, which refers to small loosely attached horns. Cattle lacking horns are referred to as polled. Although both the Poll and Scurs loci have been mapped to BTA1 and 19 respectively, the underlying genetic basis of these phenotypes is unknown, and so far, no candidate genes regulating these developmental processes have been described. This study is the first reported attempt at transcript profiling to identify genes and pathways contributing to horn and scurs development in Brahman cattle, relative to polled counterparts.
Expression patterns in polled, horned and scurs tissues were obtained using the Agilent 44 k bovine array. The most notable feature when comparing transcriptional profiles of developing horn tissues against polled was the down regulation of genes coding for elements of the cadherin junction as well as those involved in epidermal development. We hypothesize this as a key event involved in keratinocyte migration and subsequent horn development. In the polled-scurs comparison, the most prevalent differentially expressed transcripts code for genes involved in extracellular matrix remodelling, which were up regulated in scurs tissues relative to polled.
For this first time we describe networks of genes involved in horn and scurs development. Interestingly, we did not observe differential expression in any of the genes present on the fine mapped region of BTA1 known to contain the Poll locus.
牛有两种角——固定在头骨上的角和一种称为叉角的变体，指的是小而松散附着的角。没有角的牛被称为无角牛。虽然 Poll 和 Scurs 基因座都分别被映射到 BTA1 和 19 上，但这些表型的潜在遗传基础尚不清楚，到目前为止，还没有描述调节这些发育过程的候选基因。本研究首次尝试进行转录谱分析，以鉴定与无角牛相比，调控婆罗门牛角和叉角发育的基因和途径。
使用安捷伦 44 k 牛基因芯片获得了无角、有角和叉角组织中的表达模式。在比较发育中的角组织与无角的转录谱时，最显著的特征是编码细胞黏附素连接的基因以及参与表皮发育的基因下调。我们假设这是角蛋白细胞迁移和随后角发育的关键事件。在无角-叉角比较中，最常见的差异表达转录本编码参与细胞外基质重塑的基因，这些基因在叉角组织中相对于无角组织上调。
这是首次描述参与角和叉角发育的基因网络。有趣的是，我们在 BTA1 上已知包含 Poll 基因座的精细映射区域中不存在差异表达的基因。
