Frankl-Vilches Carolina, Gahr Manfred
Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, 82319, Seewiesen, Germany.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2018 Jan;204(1):113-126. doi: 10.1007/s00359-017-1236-y. Epub 2017 Dec 6.
Singing of songbirds is sensitive to testosterone and its androgenic and estrogenic metabolites in a species-specific way. The hormonal effects on song pattern are likely mediated by androgen receptors (AR) and estrogen receptor alpha (ERα), ligand activated transcription factors that are expressed in neurons of various areas of the songbirds' vocal control circuit. The distribution of AR in this circuit is rather similar between species while that of ERα is species variant and concerns a key vocal control area, the HVC (proper name). We discuss the regulation of the expression of the cognate AR and ERα and putative splice variants. In particular, we suggest that transcription factor binding sites in the promoter of these receptors differ between bird species. Further, we suggest that AR- and ERα-dependent gene regulation in vocal areas differs between species due to species-specific DNA binding sites of putative target genes that are required for the transcriptional activity of the receptors. We suggest that species differences in the distribution of AR and ERα in vocal areas and in the genomic sensitivity to these receptors contribute to species-specific hormonal regulation of the song.
鸣禽的鸣叫对睾酮及其雄激素和雌激素代谢产物具有物种特异性的敏感性。激素对鸣叫模式的影响可能是由雄激素受体（AR）和雌激素受体α（ERα）介导的，它们是配体激活的转录因子，在鸣禽发声控制回路各个区域的神经元中表达。AR在该回路中的分布在不同物种间相当相似，而ERα的分布则因物种而异，且涉及一个关键的发声控制区域——HVC（专有名称）。我们讨论了同源AR和ERα以及假定剪接变体的表达调控。特别地，我们认为这些受体启动子中的转录因子结合位点在鸟类物种间存在差异。此外，我们认为由于受体转录活性所需的假定靶基因的物种特异性DNA结合位点，发声区域中依赖AR和ERα的基因调控在不同物种间也存在差异。我们认为AR和ERα在发声区域的分布差异以及基因组对这些受体的敏感性差异，促成了鸣叫的物种特异性激素调节。
