Campos-Soto Ricardo, Panzera Francisco, Pita Sebastian, Lages Carol, Solari Aldo, Botto-Mahan Carezza
Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile.
Sección Genética Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay.
Infect Genet Evol. 2016 Nov;45:205-212. doi: 10.1016/j.meegid.2016.09.001. Epub 2016 Sep 4.
Hematophagous insects of the subfamily Triatominae include several species with a large variety of shapes, behavior and distribution. They have great epidemiological importance since most of them transmit the flagellated protozoan Trypanosoma cruzi, the etiologic agent of Chagas disease. In this subfamily several cases of species hybridization have been reported under experimental and natural conditions. Mepraia is a genus of Triatominae endemic in Chile, responsible for transmitting T. cruzi in the sylvatic cycle. This genus includes three species, M. gajardoi, M. spinolai and M. parapatrica; however, the differentiation of M. parapatrica as a separate species remains controversial considering the possible occurrence of introgression/hybridization processes in some populations of this putative species. Mepraia species show conspicuous wing polymorphism, and it has been proposed that the genes related to wings are linked to the Y chromosome, thus wingless males could not engender winged progeny. In order to determine the degree of reproductive isolation and to assess the wing phenotype in the offspring, we performed experimental crosses between the two most divergent Mepraia species (M. gajardoi and M. spinolai) together with chromosome analyses of hybrid progenies. Although fertile F hybrids were obtained in only one direction of crossing, we verified the existence of different isolation mechanisms between parental species, including hybrid breakdown. The occurrence of winged males in the offspring of wingless parental males suggests that the wing character is not linked to the Y chromosome.
锥猎蝽亚科的吸血昆虫包括几种形态、行为和分布差异很大的物种。它们具有重要的流行病学意义，因为其中大多数会传播有鞭毛的原生动物克氏锥虫，即恰加斯病的病原体。在这个亚科中，已经报道了在实验和自然条件下的几起物种杂交案例。梅普拉亚属是智利特有的锥猎蝽属，在野生动物传播循环中负责传播克氏锥虫。该属包括三个物种，即加氏梅普拉亚、斯氏梅普拉亚和邻域梅普拉亚；然而，考虑到这个假定物种的一些种群可能发生基因渗入/杂交过程，邻域梅普拉亚作为一个独立物种的分化仍存在争议。梅普拉亚属的物种表现出明显的翅多态性，有人提出与翅相关的基因与Y染色体连锁，因此无翅雄性无法产生有翅后代。为了确定生殖隔离程度并评估后代的翅表型，我们对两个差异最大的梅普拉亚物种（加氏梅普拉亚和斯氏梅普拉亚）进行了杂交实验，并对杂交后代进行了染色体分析。尽管仅在一个杂交方向上获得了可育的F代杂种，但我们证实了亲本物种之间存在不同的隔离机制，包括杂种衰败。无翅亲本雄性的后代中出现有翅雄性，这表明翅的特征并不与Y染色体连锁。
