Reproductive isolation between Anopheles sinensis and Anopheles pullus in Korea.
Anopheles sinensis and An. pullus, the 2 predominant anopheline mosquito species in Korea, are major malaria vectors. Their morphological similarity makes them difficult to distinguish, and their taxonomic relationship remains unclear. Kanda and Oguma produced fertile F1 An. sinensis X An. pullus hybrids, suggesting a conspecific relationship. However, our recent internal transcribed spacer 2 DNA sequence comparison of these taxa revealed 32.9% divergence, suggesting that An. sinensis and An. pullus may be distinct species. In the present study, we reassessed the relationship of An. sinensis and An. pullus in hybridization experiments. Laboratory-raised isofemale lines of An. sinensis form B and An. pullus form A and B were reciprocally crossed. The 3 isofemale lines were established from fully engorged females caught from the wild and morphologically identified as An. sinensis or An. pullus. The isofemale lines represented 3 distinct metaphase karyotypes: An. sinensis form B (X, Y2) and An. pullus form A (X1, Y1) and form B (X2, Y2). The F1 hybrid larvae showed low viability and completely asynaptic salivary gland polytene chromosomes. The subset of F1 hybrids that developed to adults showed sex-ratio distortion; ovarian follicles developed abnormally in females, and males suffered atrophy of accessory glands and testes. These results strongly suggest that the Korean morphological species An. sinensis and An. pullus are biological species, separated by complete postzygotic reproductive isolation.
Kim
Se-Joo
SJ
Department of Biological Sciences, Inha University, Incheon 402-751, South Korea.
Choochote
Wej
W
Jitpakdi
Atchariya
A
Junkum
Anuluck
A
Ahn
Dong-A
DA
Baek
Jin-A
JA
Park
Mi-Hyun
MH
Kim
Min-Seok
MS
Chung
Ki-Wha
KW
Min G
Gi-Sik
GS
D000818:Animals; D000852:Anopheles / Q000145:classification* / Q000235:genetics / Q000502:physiology; D002875:Chromosomes / Q000235:genetics; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D006824:Hybridization, Genetic / Q000235:genetics; D007621:Karyotyping; D007723:Korea; D008297:Male; D012098:Reproduction; D013045:Species Specificity
D005819:Genetic Markers