Phylogenetic interpretation and chromosomal polymorphism among nine strains of human malaria vectors of the Anopheles leucosphyrus group.

Abstract

Cytogenetic observations conducted on 9 strains belonging to the leucosphyrus group (Colless 1956) and their hybrids have revealed the evolutionary facts of the process of divergence among them. Previous paper (Kanda et al 1981b) reported some results of hybridization among them. Three strains- Bangkok (BKK), Kanchanaburi (KCH), and Chantaburi (CTB)-from Thailand can be designated as a subspecies Anopheles balabaceesis dirus, with a small degree of divergence between the latter two strains. Two strains IMR and Kampong Sungai Ular (KSU) from Peninsular Malaysia can similarly be classified as a subspecies Anopheles balabacensis balabacensis B, while the strain Kota Belud (KTD) from Sabah with different genetic characters can be designated as a subspecies Anopheles balabacensis A. These 3 subspecies are included in the balabacensis complex. The two strains from Sarawak (SWK and SWN) were confirmed as a separate species designated as Anopheles leucosphyrus sensu stricto (Kanda et al 1981a) but with homosequential chromosome banding patterns of the leucosphyrus group (Reid 1968). A strain from Taiwan (TSG) is more closely related to CTB than KCH. There may exist some other closely related geographical populations. However, the designation of TSG as a valid species Anopheles takasagoensis distinct from balabacensis can not be confirmed due to insufficient data. Interstrain floating rearrangements of banding patterns were observed in the XR arm of KCH, IMR and CTB strain as well as in the hybrids. Additional descriptions of 2 chromosomal polymorphisms within the species group are given.