Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden.
Fungal Genet Biol. 2010 Oct;47(10):869-78. doi: 10.1016/j.fgb.2010.06.008. Epub 2010 Jul 1.
In this study, we investigated the genealogies of genes important for sexual identity, i.e. mating-type (mat) and pheromone-receptor (pre) genes, among heterothallic and peudohomothallic taxa of Neurospora. The resulting genealogies were compared with the species phylogeny derived from non-coding sequences. We found conflicting topologies between the reproductive genealogies and the species phylogeny, and these conflicts were supported by both node support analyses and likelihood tests on the relative fit of datasets to alternative phylogenetic hypotheses. We argue that reproductive genes are more permeable to gene flow, i.e. are more often introgressed between species of Neurospora, than other parts of the genome. Certain conflicts between the species phylogeny and both mat genealogies were observed, suggesting that the two mating-type idiomorphs were selectively introgressed into a species from a single ancestral source. Taken together, the results presented here highlight complex evolutionary trajectories of reproductive genes in the fungal kingdom, which may be of importance for reproductive behavior in natural populations.
在这项研究中，我们调查了性身份重要的基因（即交配型[mat]和信息素受体[pre]基因）在有性生殖和假同配生殖的Neurospora 分类群中的系统发育。将得到的系统发育与非编码序列得出的物种系统发育进行比较。我们发现生殖系统发育与物种系统发育之间存在冲突的拓扑结构，这些冲突得到了节点支持分析和对数据集相对于替代系统发育假设的相对拟合度的似然检验的支持。我们认为，生殖基因比基因组的其他部分更容易受到基因流的影响，即更容易在Neurospora 的物种之间发生基因渗入。在物种系统发育和两个交配型系统发育之间观察到某些冲突，这表明两个交配型等位基因从单一祖先来源被选择性地渗入到一个物种中。总的来说，这里提出的结果突出了真菌界生殖基因的复杂进化轨迹，这对于自然种群中的生殖行为可能很重要。
