Detection of Heterozygosity and Allelic Frequency of Indian and Southeast Asian Types of Oecophylla smaragdina (Fabricius) (Hymenoptera, Formicidae) in Bangladesh using Microsatellite Markers

The two types of Asian weaver ant species, Oecophylla smaragdina, Indian types and Southeast (SE) Asian types can co-occur in the same habitat. Previous study on mtDNA based phylogenesis of O. smaragdina in Bangladesh has revealed the presence of the mixture of both Indian and SE Asian type of O. smaragdina. However, the nuclear DNA based study showed some inconsistency leading the chance of hybridization as colonies encountered from two localities contained O. smaragdina workers from more than one type as identified via longwave length rhodopsin (LWRh) and mitochondrial COI and Cytb gene analysis. The purpose of present study was to detect hybridization status and to find out the identical allele for Indian and SE Asian type of O. smaragdina from different colonies.

A total of seven O. smaragdina colonies had been collected from Bangladesh during 2013 to December 2016. Microsatellite analysis were performed for Gene mapping and heterozygosity study with 11 microsatellite loci through electropherogrum study generated by peak scanner software.

Among 11 microsatellite loci, two loci, MS 8.24 and MS 6.45 provided the identical allele position for Indian and SE Asian types while no allelic position were identified with nine microsatellite loci. The results inferred that weaver ant of both Indian and SE Asian type engage in bidirectional interspecific gene flow. The strong possibility of hybridization between these two types is inferred, which indicates that barriers to hybridization do not exist or can be completely overcome. This is unexpected, given that they are non sister species and broadly sympatric in nature. These findings also indicate the possible occurrence of hybrid-hybrid crosses in some localities of weaver ant, a phenomenon rarely observed in ants.