Analysis of Reproductive Isolation Between Sibling SpeciesAnopheles albitarsissensu stricto andAnopheles deaneorum, Two Malaria Vectors Belonging to the Albitarsis Complex (Diptera: Culicidae)

Abstract

Complexes of sibling species are common among mosquitoes, and their existence within vector species can have important epidemiological consequences. Anopheles albitarsis sensu stricto and Anopheles deaneorum Rosa-Freitas are two putative vectors of malaria parasites belonging to the Albitarsis species complex (Diptera: Culicidae). Using an induced mating technique, we studied the reproductive isolation between these two closely related species and their reciprocal hybrids. Evidence for hybrid male sterility consistent with Haldane's rule was found. The results indicate that male hybrids show very low insemination rates, probably due to abnormalities in their reproductive organs. In addition, the data show that hybrid males carrying an X chromosome derived from An. deaneorum perform significantly worse than hybrid males carrying an An. albitarsis s.s. X chromosome.

Hybrid sterility in crosses between two Brazilian sibling species of the Anopheles albitarsis complex

“…Concerning the postzygotic isolation mechanisms, the hybrid sterility seems to be one of the first outcomes observed in anophelines [16,29,[42][43][44][45][46]. Crosses between An.…”

“…Adults were used in the subsequent crosses. Intra and interspecific mating experiments were performed and the hybrid offspring were used in backcrosses according to Lima et al [16]. The parameters evaluated for each crossing experiment were: the number of inseminated females, the total number of eggs, hatching eggs, larvae, pupae and adults, and also the male and female ratio.…”

“…marajoara (Richard C. Wilkerson, personal communication). In the second study, Lima et al [16] observed that hybrid males from crosses between An. albitarsis s.s. and An.…”

“…occurring as a species complex was described by Kreutzer et al [10]. Since then, several approaches were applied to investigate and characterize the species members: cytogenetics, alloenzymes, morphological and feeding behavioral analysis, hybridization experiments, RAPD-PCR and RFLP and DNA sequencing of mitochondrial and nuclear markers [6,[10][11][12][13][14][15][16][17][18][19][20].…”

“…In addition, laboratory crossing experiments are likely to reveal the exchange of genes potentially involved in vectorial capacity or insecticide resistance, being therefore important for vector control programs [16,[26][27][28]. In the Albi tarsis species complex only two hybridization studies between siblings have been published so far [16,29].…”