Abstract:
Strong selection on complex traits can lead to skewed trait means and reduced trait variability in populations. An example of this phenomenon can be evidenced in allele frequency changes and skewed trait distributions driven by persistent human-directed selective pressures in domesticated species. Dog domestication is linked to several genomic variants; however, the functional impacts of these variants may not always be straightforward when found in non-coding regions of the genome. Four polymorphic transposable elements (TE) found within non-coding sites along a 5 Mb region on canine CFA6 have evolved due to directional selection associated with heightened human-directed hyper-sociability in domesticated dogs. We found that the polymorphic TE in intron 17 of the canine GTF2I gene, which was previously reported to be negatively correlated with canid human-directed hyper-sociability, is associated with altered chromatin looping and hence distinct cis-regulatory landscapes. We reported supporting evidence of an E2F1-DNA binding peak concordant with the altered loop and higher expression of GTF2I exon 18, indicative of alternative splicing. Globally, we discovered differences in pathways regulating the extra-cellular matrix with respect to TE copy number. Overall, we reported evidence suggesting an intriguing molecular convergence between the emergence of hypersocial behaviors in dogs and the same genes that, when hemizygous, produce human Williams Beuren Syndrome characterized by cranio-facial defects and heightened social behaviors. Our results additionally emphasize the often-overlooked potential role of chromatin architecture in social evolution.
摘要:
对复杂性状的强烈选择会导致性状均值偏斜和种群性状变异性降低。这种现象的一个例子可以在驯化物种中持续的人为选择压力驱动的等位基因频率变化和扭曲的性状分布中得到证明。狗的驯化与几种基因组变异有关;然而,当在基因组的非编码区中发现时,这些变体的功能影响可能并不总是简单的.在犬CFA6上5Mb区域的非编码位点中发现的四个多态性转座元件(TE)已经进化,这是由于定向选择与驯养犬中人类指导的超社交能力增强相关。我们发现犬GTF2I基因内含子17中的多态性TE,先前报道与犬科动物人类主导的超社交能力呈负相关,与改变的染色质循环有关,因此与不同的顺式调节景观有关。我们报道了E2F1-DNA结合峰与改变的环和GTF2I外显子18的更高表达一致的支持证据,表明选择性剪接。全球范围内,我们发现调节细胞外基质的途径在TE拷贝数方面存在差异.总的来说,我们报道的证据表明,狗的超社会行为的出现和相同的基因之间有一个有趣的分子趋同,当半合子时,产生以颅面缺陷和社交行为增强为特征的人类威廉姆斯·贝伦综合症。我们的结果还强调了染色质结构在社会进化中经常被忽视的潜在作用。