An Efficient Protocol for Silkmoth Dna Extraction Suitable for Genomic Fingerprinting and Genetic Diversity Analysis

In the present study, fresh Silkmoths were used for DNA extraction. The wings, legs and antennae of moths were cut with sterile scissors, crushed under liquid nitrogen to fine powdered content which yielded high resolution DNA bands using modified phenol chloroform extraction method. The genomic DNA from twelve different silkmoth genotypes was further checked for its suitability in DNA fingerprinting and diversity analysis using eight Randomly Amplified Polymorphic DNA (RAPD) primers. RAPD profile obtained from the genomic DNA with twelve silkworm genotypes revealed high degree of polymorphism. The Silkmoth strains were analyzed using 8 random primers which gave 104 alleles of which 88 were polymorphic generating 79.86 % Polymorphism. Cluster analysis based on Nei’s dis-similarity coefficients resulted in the formation of three main clusters on the dendrogram. Cluster-I included three genotypes viz., SK-6, SK-31 and SK-28 with SK-6 and SK-31 under sub-cluster while as CSR4, SH6, CSR18, CSR19 and NB4D2 grouped together in cluster-II with CSR4 and SH6 in sub-cluster. CSR2 and DUN22 were grouped together in Cluster-III of the dendrogram. However, SK-1 and DUN6 formed separate clusters. Dis-similarity coefficients ranged from 0.0054 to 0.3579 with an average dis-similarity coefficient of 0.18165, indicating considerable genetic diversity within bivoltine silkworm groups. Of the pair wise combinations, DUN6 and SKUAR-1, showed the lowest similarity (0.0054) thus highest genetic distance among the genotypes. Isolated genomic DNA from Silkmoths was found suitable for DNA finger printing studies and identifying diverse genotypes for taking up directional breeding programs to push up bivoltine silk production.