Centre of Excellence for Genetics and Genomics of Silkmoths, Laboratory of Molecular Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.
PLoS One. 2012;7(8):e43716. doi: 10.1371/journal.pone.0043716. Epub 2012 Aug 28.
The 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 FINDINGS: We 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 F(ST) = 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.
印度金黄土星鳞翅目蚕蛾（Antheraea assama），俗称木甲蚕蛾，是一种半驯化的产丝昆虫，仅限于印度东北部地区狭窄的栖息地范围内。由于普遍存在的社会政治问题，印度东北部地区的木甲蚕栖息地无法进入，这阻碍了对这种稀有蚕蛾的系统地理学研究。最近，我们虽然在一定程度上成功地从其自然栖息地收集了木甲蚕茧样本。在之前为 A. assama 开发的 87 个微卫星标记中，我们使用了 13 个信息标记对来自六个种群的 97 个个体进行了基因型分析，并分析了它们的种群结构和遗传变异。
方法/主要发现：我们观察到其中一个种群（WWS-1，来自梅加拉亚邦西加罗山区的一个种群）具有非常显著的遗传多样性。进一步分析有和没有 WWS-1 种群的结果表明，由于 WWS-1 种群贡献的高遗传多样性，导致了显著的遗传分化（全球 F(ST) = 0.301）。对其余五个种群（不包括 WWS-1）的分析表明，所有使用的基因座的等位基因数量明显减少。结构分析表明只存在两个聚类：一个由 WWS-1 种群形成，另一个包括其余五个种群，推断这五个种群之间和内部没有显著的遗传多样性，并表明这五个种群可能来自单一的种群。在研究的六个种群中，没有明显的近期种群瓶颈模式。
结论/意义：栖息在 WWS-1 地区的 A. assama 表现出非常高的遗传多样性，与研究的五个种群在遗传上存在差异。应该继续努力从该地区以及其他木甲蚕栖息地识别和研究这些种群。所产生的信息将非常有助于保护印度东北部日益减少的木甲蚕文化。
