Gene expression in female tawny-flanked prinias (Prinia subflava) during egg laying.

Tawny-flanked prinia is a widespread species of open, mesic habitats across sub-saharan Africa. In large parts of their range, they are hosts to the brood parasitic cuckoo finch (Anomalospiza imberbis). Cuckoo finches lay their eggs in the nests of tawny-flanked prinias (among other host species) and have evolved egg mimicry to prevent their eggs being detected by the host parent. In response to this mimicry, prinias are under selection to evolve a huge diversity of egg phenotypes in order to make the task of discriminating their own from foreign eggs easier. An incomplete range of this diversity is in turn mimicked by cuckoo finches, and in this way a coevolutionary arms race ensues. This project is part of an effort to understand the genetic basis of this incredible diversity. It combines genomic and transcriptomic data from tawny-flanked prinias laying a variety of egg phenotypes and will use a genome-wide association approach to highlight genomic loci correlated with egg phenotype diversity in nature. In so doing, it will shed light on the genetic underpinnings of signature-forgery arms races.

褐胁鹪莺（Tawny-flanked prinia）是撒哈拉以南非洲地区开阔中生境中广泛分布的物种。在其分布范围的大部分区域，它们均为巢寄生杜鹃雀（Anomalospiza imberbis）的宿主。杜鹃雀会将卵产于褐胁鹪莺（及其他宿主物种）的巢中，并演化出卵拟态（egg mimicry）以避免其卵被宿主亲鸟识别。为应对这种拟态，褐胁鹪莺受到自然选择压力，演化出了极为丰富的卵表型多样性，以便更轻松地区分自身卵与外来卵。而杜鹃雀又会对这种多样性中的不完全部分进行拟态，由此便引发了一场协同进化军备竞赛（coevolutionary arms race）。本项目旨在解析这种惊人多样性的遗传基础，属于相关研究工作的一部分。本研究整合了产有多种卵表型的褐胁鹪莺的基因组与转录组数据，并将采用全基因组关联分析（genome-wide association）方法，筛选出与自然界中卵表型多样性相关的基因组位点（genomic loci）。通过上述研究，本项目将阐明“签名伪造军备竞赛”（signature-forgery arms race）的遗传基础。