Carbone Ignazio, Anderson James B, Kohn Linda M
Department of Botany, University of Toronto, Erindale College, Mississauga, Ontario, L5L 1C6, Canada.
Evolution. 1999 Feb;53(1):11-21. doi: 10.1111/j.1558-5646.1999.tb05329.x.
Clonal lineages in the filamentous ascomycete (fungi) Sclerotinia sclerotiorum were determined by analysis of genealogies of four loci: the intergenic spacer of the nuclear ribosomal repeat (IGS; approximately 4 kb), the translation elongation factor (EF-1α; approximately 300 bp), an anonymous region (44.11; approximately 700 bp), and the calmodulin gene (CAL; approximately 400 bp). Three of the four loci are physically unlinked. The combined analysis of the four loci provided the best estimate of phylogeny, which is consistent with a pattern of some recombination among clonal lineages against a background of predominant clonality. Comparison of gene genealogies with a phylogeny inferred from DNA fingerprints and a combined phylogeny of the entire dataset identified convergent or parallel changes in fingerprints. Analysis of the entire data matrix allowed us to resolve patterns of descent among clonal lineages that could not be inferred from fingerprints alone and to discern recent episodes of divergence that were not detected in gene genealogies. Prerequisites for applying this approach to other systems are a haploid context for inferring multiple gene genealogies (such as the mitochondrial genome) that indicate limited recombination and another data matrix that identifies recently evolved genotypes.
通过对四个基因座谱系的分析,确定了丝状子囊菌(真菌)核盘菌的克隆谱系:核糖体重复序列的基因间隔区(IGS;约4kb)、翻译延伸因子(EF-1α;约300bp)、一个无名区域(44.11;约700bp)和钙调蛋白基因(CAL;约400bp)。四个基因座中的三个在物理上没有连锁。对这四个基因座的综合分析提供了系统发育的最佳估计,这与在主要克隆性背景下克隆谱系之间存在一些重组的模式一致。将基因谱系与从DNA指纹推断的系统发育以及整个数据集的综合系统发育进行比较,确定了指纹中的趋同或平行变化。对整个数据矩阵的分析使我们能够解析仅从指纹无法推断的克隆谱系之间的遗传模式,并识别基因谱系中未检测到的近期分化事件。将这种方法应用于其他系统的前提条件是,用于推断表明有限重组的多个基因谱系(如线粒体基因组)的单倍体背景,以及识别最近进化的基因型的另一个数据矩阵。