Genetic Diversity and Population Structure of Indian Golden Silkmoth (Antheraea assama)

Abstract

BackgroundThe Indian golden saturniid silkmoth (Antheraea assama), popularly known as muga silkmoth, is a semi-domesticated silk producing insect confined to a narrow habitat range of the northeastern region of India. Owing to the prevailing socio-political problems, the muga silkworm habitats in the northeastern region have not been accessible hampering the phylogeography studies of this rare silkmoth. Recently, we have been successful in our attempt to collect muga cocoon samples, although to a limited extent, from their natural habitats. Out of 87 microsatellite markers developed previously for A. assama, 13 informative markers were employed to genotype 97 individuals from six populations and analyzed their population structure and genetic variation.Methodology/Principal FindingsWe observed highly significant genetic diversity in one of the populations (WWS-1, a population derived from West Garo Hills region of Meghalaya state). Further analysis with and without WWS-1 population revealed that dramatic genetic differentiation (global FST = 0.301) was due to high genetic diversity contributed by WWS-1 population. Analysis of the remaining five populations (excluding WWS-1) showed a marked reduction in the number of alleles at all the employed loci. Structure analysis showed the presence of only two clusters: one formed by WWS-1 population and the other included the remaining five populations, inferring that there is no significant genetic diversity within and between these five populations, and suggesting that these five populations are probably derived from a single population. Patterns of recent population bottlenecks were not evident in any of the six populations studied.Conclusions/Significance A. assama inhabiting the WWS-1 region revealed very high genetic diversity, and was genetically divergent from the five populations studied. The efforts should be continued to identify and study such populations from this region as well as other muga silkworm habitats. The information generated will be very useful in conservation of dwindling muga culture in Northeast India.

Genetic Variation within Native Populations of Endemic Silkmoth Antheraea assamensis (Helfer) from Northeast India Indicates Need for In Situ Conservation

“…Our results coincide with other reports based on single marker systems [9], [10], [11] which provide snapshots of allele frequencies in different populations of A. assamensis . Further research is necessary to understand the role of transposable elements and other genomic mechanism(s) that can influence genetic variability within populations of A. assamensis.…”

“…Moderate genetic distance estimates (Table S5) and its concurrence with geographic distance among populations observed in this study may be attributed to low migration and mixing of the genotypes on a limited geographical scale. The observation that genetic differentiation increased with increasing geographic distance further supports the contention that the wild moths do not migrate far [11], [29], [30]. Analysis with STRUCTURE using ISSR data indicated a putative population structure where wild populations and cultivated populations from Upper Assam and Lower Assam formed discrete clusters (Figure 2B).…”

APMicroDB: A microsatellite database of Acyrthosiphon pisum

“…SSRs offers several advantages such as their distribution, specificity, and reproducibility, therefore, they were extensively employed in population genetics [8], [9], genetic diversity [10], [11], [12], [13] and evolution [14], [15]. Based on the origin, SSRs has been classified into two types: 1) genomic SSRs (that derived from genome), and 2) EST-SSRs (that comes from expressed sequence tags) [10], [14].…”

Morphological and genetic variations of Sophora davidii populations originating from different altitudes in the mountains of southwestern China

“…Moreover, many researchers thought that the altitudinal pattern, habitat fragmentation, location and population size have a highly significant impact on genetic diversity within populations (Arunkumar et al, 2012;Feng et al, 2006;Parvin et al, 2014). In the present study, genetic diversity parameters such as n a , n e , PPB, h and I indicated that the higher genetic diversity exists in populations between 1500 and 1950 m asl, whereas the lower genetic diversity exists below 1280 m asl.…”