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In insects infections trigger hemocyte-mediated immune reactions including degranulation by exocytosis; however, involvement of mediator enzymes in degranulation process is unknown in insects. We report here that in silkworm Bombyx mori, infection by endoparasitoid Exorista bombycis and microsporidian Nosema bombycis activated granulation in granulocytes and promoted degranulation of accumulated structured granules. During degranulation the mediator lysosomal enzyme β-hexosaminidase showed increased activity and expression of β-hexosaminidase gene was enhanced. The events were confirmed in vitro after incubation of uninfected hemocytes with E. bombycis larval tissue protein. On infection, cytotoxicity marker enzyme lactate dehydrogenase (LDH) was released from the hemocytes illustrating cell toxicity. Strong positive correlation (R

The vitellogenin receptor (VgR) plays a critical role in egg development by mediating endocytosis of the major yolk protein precursor vitellogenin (Vg). Therefore, identifying the VgR of beneficial insects and its characterization could lead to the development of novel egg production strategies to enhance their commercial values. Here, we present the cloning, expression, and functional characterization of the VgR from an economically important eri silkworm, Samia ricini. The complete mRNA sequence was 6002 bp with an ORF of 5484 bp, encoding a protein of 1827 amino acids. Sequence analyses revealed that the SrVgR contained all of the conservative structural motifs characteristics of LDLR family members. The SrVgR was specifically expressed in the ovary, and the mRNA level increased steadily in pupal stages, reached its peak on day 9, and then declined to a bare minimum in adults. RNA interference (RNAi) clearly reduced the VgR transcript levels, disrupted the ovarian development resulting in malformed ovarioles and abnormal development of eggs. Taken together, these data provide conclusive evidence for the essential roles of VgR in insect reproduction.

Intragenomic variability is known to be present in multi-copy gene sequences of several plant species and causes severe problems on molecular phylogenetic analysis. Initial investigation revealed extensive presence of intragenomic variability in nrITS of Camellia. Detailed investigation using 20–30 sequences from each leaf sample of seven species of Camellia revealed considerable sequence variability in terms of Kimura pair-wise distance, nucleotide diversity and Tamura's D parameters. Fluorescence in situ hybridization (FISH) revealed the dispersion of rDNA loci into multiple chromosomes and a small percentage of species in Camellia were allotetraploids. The distribution of rDNA loci into nonhomologous chromosomes along with long generation period and incidence of the interspecific hybridization are considered the major reasons for the failure of complete homogenization of the nrITS repeats by concerted evolution in Camellia. Nevertheless, in the majority diploid species or in the dominant sequence types of the allotetraploids, nrITS sequence variability was not high enough to obliterate the phylogenetic signals. Thus, utilization of nrITS in the phylogeny of Camellia is still possible, if adequate care is taken.

The purity of DNA is one of the major factors affecting the success of Genomic studies. Nucleic acid isolation from polyphenol rich plants fail to produce good quality DNA or RNA as polyphenols adhere and interfere with DNA during isolation. An improvised, simple and inexpensive protocol has been developed for extracting genomic DNA from Mulberry (Morus spp.). The purity of the DNA as revealed by the ratios of absorbance at 260/280 nm (A 260/280) and 260/230 nm (A 260/230) was closer to 2.0. Genomic DNA analyzed for analytical applications like restriction digestion and PCR amplification with molecular markers viz., Inter Simple Sequence Repeats (ISSR), Random Amplified Polymorphic DNA (RAPD) and Simple Sequence Repeat (SSR) primers further confirmed the purity of the DNA. A modified method of silver staining was employed for the resolution of SSR amplified products. Physiologically mature leaf was found more suitable for getting quality DNA in mulberry.