Alberti Andrea C, Confalonieri Viviana A, Zandomeni Ruben O, Vilardi Juan C
Laboratorio de Genética, Departamento de Ecología Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, (C1428EHA), Buenos Aires, Argentin.
Genetica. 2008 Jan;132(1):1-8. doi: 10.1007/s10709-007-9143-8. Epub 2007 Feb 22.
Anastrepha fraterculus is an important pest of commercial fruits in South America. The variability observed for morphological and behavioural traits as well as genetic markers suggests that A. fraterculus represents a complex of synmorphic species rather than a single biological species. We studied the correlation between geographical distribution and genetic variation in natural populations from Argentina and south Brazil. Fragments of the mitochondrial gene COII were sequenced in 28 individuals. The matrix of aligned sequences was phylogenetically analysed by parsimony, yielding a cladogram of haplotypes. Based on Templeton's nested method, no clade showed any geographic pattern for the gene COII, indicating lack of significant association between haplotypic variability and geographic distribution. The analysis of nucleotide substitution distances by Neighbour-Joining algorithm showed that geographically distant populations exhibit low genetic distances. The corresponding trees clustered the populations without showing any geographic pattern. This result suggests that the populations studied are not reproductively isolated.
南美按实蝇是南美洲商业水果的一种重要害虫。在形态和行为特征以及遗传标记方面观察到的变异性表明，南美按实蝇代表了一个同形物种复合体，而非单一的生物物种。我们研究了来自阿根廷和巴西南部的自然种群中地理分布与遗传变异之间的相关性。对28个个体的线粒体基因COII片段进行了测序。通过简约法对排列好的序列矩阵进行系统发育分析，得到了单倍型分支图。基于Templeton的嵌套方法，没有一个分支显示出COII基因的任何地理模式，这表明单倍型变异性与地理分布之间缺乏显著关联。通过邻接法对核苷酸替代距离进行分析表明，地理上相距遥远的种群表现出较低的遗传距离。相应的树将种群聚类，未显示出任何地理模式。这一结果表明，所研究的种群没有生殖隔离。
