Genetic Map of Sympatric Introgression in Hybridizing Colias Butterflies

杂交 Colias 蝴蝶同域基因渗入的遗传图谱

• 批准号: 0216005
• 负责人: Adam Porter
• 金额: --
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0216005&HistoricalAwards=false
• 关键词: Genetic; Map; Sympatric; Introgression; Hybridizing

The sulfur butterflies, Colias eurytheme and C. philodice, common in fields and along roadsides across most of North America, are remarkable because they hybridize extensively. Up to 10% of the butterflies are hybrids, an interbreeding rate that is sufficient to blend them into a single species. Yet, they have remained distinct. Many other species pairs show similar patterns of hybridization, including Darwin's Finches and numerous plant species. These cases challenge our traditional definition of species, which do not normally interbreed.One untested hypothesis, first proposed in 1957, is that hybridizing species do in fact share part of their genome, and that selection acts to keep the remaining parts of the genomes distinct. To test this, new methods will be used to map the chromosomes of these butterflies in great detail. This genetic map will then be used for a fine-scale analysis of the rates that genes are able to spread between species. If superficially distinct, hybridizing species do share major portions of their genomes in common, then it will cause biologists to restructure their thinking about what species are. It would suggest that species identities can exist as a mosaic of genomically complex, stable polymorphisms, maintained in an otherwise dynamic, fluid genome. If this alternative explanation is not upheld, the study will provide strong support of the traditional view of species.

硫磺蝴蝶，Colias euryheme和C.Philodice，在北美大部分地区的田野和路边很常见，因为它们广泛杂交而引人注目。高达10%的蝴蝶是杂交蝴蝶，这一杂交比率足以将它们混合成一个物种。然而，它们仍然是截然不同的。许多其他物种对表现出类似的杂交模式，包括达尔文雀和许多植物物种。这些案例挑战了我们对物种的传统定义，这些物种通常不会进行杂交。1957年首次提出的一个未经检验的假说是，杂交物种实际上分享了它们的部分基因组，而选择的作用是保持基因组的其余部分保持不同。为了验证这一点，将使用新的方法非常详细地绘制这些蝴蝶的染色体图。然后，这张遗传图谱将被用于对基因在物种之间传播的速度进行精细分析。如果表面上不同的杂交物种确实分享了它们基因组的大部分共同之处，那么这将促使生物学家重新思考什么是物种。这将表明，物种身份可以作为基因组复杂、稳定的多态的马赛克存在，保持在另外一个动态、流动的基因组中。如果这一替代解释不被支持，这项研究将为传统的物种观点提供强有力的支持。