Johnsson Martin, Jonsson Kenneth B, Andersson Leif, Jensen Per, Wright Dominic
AVIAN Behavioural Genomics and Physiology group, IFM Biology, Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.
Department of Surgical Sciences, Orthopaedics, Akademiska Sjukhuset, Uppsala University, Uppsala, Sweden.
PLoS Genet. 2015 May 29;11(5):e1005250. doi: 10.1371/journal.pgen.1005250. eCollection 2015 May.
Birds have a unique bone physiology, due to the demands placed on them through egg production. In particular their medullary bone serves as a source of calcium for eggshell production during lay and undergoes continuous and rapid remodelling. We take advantage of the fact that bone traits have diverged massively during chicken domestication to map the genetic basis of bone metabolism in the chicken. We performed a quantitative trait locus (QTL) and expression QTL (eQTL) mapping study in an advanced intercross based on Red Junglefowl (the wild progenitor of the modern domestic chicken) and White Leghorn chickens. We measured femoral bone traits in 456 chickens by peripheral computerised tomography and femoral gene expression in a subset of 125 females from the cross with microarrays. This resulted in 25 loci for female bone traits, 26 loci for male bone traits and 6318 local eQTL loci. We then overlapped bone and gene expression loci, before checking for an association between gene expression and trait values to identify candidate quantitative trait genes for bone traits. A handful of our candidates have been previously associated with bone traits in mice, but our results also implicate unexpected and largely unknown genes in bone metabolism. In summary, by utilising the unique bone metabolism of an avian species, we have identified a number of candidate genes affecting bone allocation and metabolism. These findings can have ramifications not only for the understanding of bone metabolism genetics in general, but could also be used as a potential model for osteoporosis as well as revealing new aspects of vertebrate bone regulation or features that distinguish avian and mammalian bone.
由于产卵对鸟类提出的要求，它们具有独特的骨骼生理机能。特别是它们的髓质骨在产卵期间作为蛋壳形成的钙源，并经历持续且快速的重塑过程。我们利用鸡在驯化过程中骨骼特征发生巨大分化这一事实，来绘制鸡骨骼代谢的遗传基础图谱。我们在一个基于原鸡（现代家鸡的野生祖先）和白来航鸡的高级杂交群体中进行了数量性状位点（QTL）和表达数量性状位点（eQTL）定位研究。我们通过外周计算机断层扫描测量了456只鸡的股骨骨骼特征，并使用微阵列技术测量了该杂交群体中125只雌性鸡的股骨基因表达。这产生了25个雌性骨骼性状位点、26个雄性骨骼性状位点和6318个局部eQTL位点。然后我们将骨骼和基因表达位点进行重叠，在检查基因表达与性状值之间的关联之前，以确定骨骼性状的候选数量性状基因。我们的一些候选基因之前已被证明与小鼠的骨骼性状有关，但我们的研究结果也表明在骨骼代谢中存在意想不到且大多未知的基因。总之，通过利用鸟类独特的骨骼代谢，我们已经鉴定出了一些影响骨骼分配和代谢的候选基因。这些发现不仅对理解一般的骨骼代谢遗传学有影响，还可以作为骨质疏松症的潜在模型，同时揭示脊椎动物骨骼调节的新方面或区分鸟类和哺乳动物骨骼的特征。
