Melo Maria C, Salazar Camilo, Jiggins Chris D, Linares Mauricio
Instituto de Genética, Universidad de los Andes, Carrera 1E No 18-10, P.O.Box 4976, Santafé de Bogotá D.C., Colombia.
Evolution. 2009 Jun;63(6):1660-5. doi: 10.1111/j.1558-5646.2009.00633.x.
Homoploid speciation generates species without a change in chromosome number via introgressive hybridization and has been considered rare in animals. Heliconius butterflies exhibit bright aposematic color patterns that also act as cues in assortative mating. Heliconius heurippa has a color pattern that can be recreated by introgression of the H. melpomene red band into an H. cydno genetic background. Wild H. heurippa males show assortative mating based on color pattern and we here investigate the origin of this preference by studying first-generation backcross hybrids between H. melpomene and H. cydno that resemble H. heurippa. These hybrids show assortative mating preferences, showing a strong preference for their own color pattern over that of either parental species. This is consistent with a genetic basis to wing pattern preference and implies, first, that assortative mating preferences would facilitate the initial establishment of a homozygous hybrid color pattern by increasing the likelihood that early generation hybrids mate among themselves. Second, once established such a lineage would inherit assortative mating preferences that would lead to partial reproductive isolation from parental lineages.
同倍体物种形成通过渐渗杂交产生染色体数目不变的物种，在动物中被认为较为罕见。光明女神闪蝶呈现出鲜艳的警戒色图案，这些图案在选型交配中也起着线索作用。赫氏闪蝶具有一种色彩图案，通过将美神闪蝶的红色带渐渗到电蛱蝶的遗传背景中可以重现。野生赫氏闪蝶雄性基于色彩图案表现出选型交配，我们在此通过研究美神闪蝶和电蛱蝶之间类似于赫氏闪蝶的第一代回交杂种来探究这种偏好的起源。这些杂种表现出选型交配偏好，相较于任一亲本物种的色彩图案，它们对自身的色彩图案表现出强烈的偏好。这与翅膀图案偏好的遗传基础相一致，并且首先意味着选型交配偏好会通过增加早期杂种之间相互交配的可能性来促进纯合杂种色彩图案的初步建立。其次，一旦建立起这样一个谱系，它将继承选型交配偏好，这将导致与亲本谱系的部分生殖隔离。
