Silk Biotechnology Programme: Prime Features, Major Outcomes

Salient Features

  • The DBT has established a Centre of Excellence in Genetics and Genomics of Silkworm at CDFD, Hyderabad. Transgenic lines of silkworm resistant to baculovirus (BmNPV) have been generated through RNAi technology. The transgenic lines are being transferred to sericulture centres for controlled trials after necessary clearance from RCGM. Analysis of immune transcriptome of bacteria-challenged wild silkmoth, Antheraea mylitta led to the identification of a number of potential immune-related genes.
  • Eleven potential silkworm (Bombyx mori) lines tolerant to BmNPV varying from 27 per cent to 67 per cent have been developed through DNA-marker assisted breeding jointly at Seribiotech Research Laboratory (SBRL), Bangalore and Andhra Pradesh State Sericulture Research and Development Institute (APSSR&DI), Hindupur. The selected lines are at BC-5 F-9 generation and are being further taken up for field trials.
  • A programme on comparative genetic analysis of sex chromosomes and sex determining genes in silkmoths has been continued at CDFD, Hyderabad. Two novel genes predicted to be involved in the silkworm sex determination, were identified using various biochemical and molecular procedures. Their validation is in progress. W-derived gene Bmz1 has been analysed for its involvement in sex determination.
  • Full-length cDNA of vitellogenin receptors from B. mori and Samia ricini and lipophorin receptor from S. ricini have been determined. Functional characterisation of the receptors for their possible role in fecundity using RNAi and binding assays is under progress.
  • Work has been continued under a Consortium Project on Mulberry Genomics (CPMG) involving four institutions – CSR&TI, Mysore, CSGRC, Hosur, UAS, Bangalore and UDSC, New Delhi. A total of 188 genomic and genic SSR markers have been developed in Morus alba, which can be utilised in assessing molecular diversity as well as in QTL mapping towards crop improvement through marker assisted selection at UAS, Bangalore. Transcriptome analysis has been carried out to identify SSRs, SNPs and novel drought responsive genes using mulberry leaf tissues exposed to different levels of drought stress jointly at UAS, Bangalore and UDSC, New Delhi. Over 10,000 ESTs have been identified and annotated. Ten drought tolerance genes have been cloned from mulberry and are being functionally validated in Arabidopsis. Work has been recently initiated to identify QTLs conferring resistance to root rot disease and trait introgression in mulberry at CSR&TI, Mysore.
  • Application of sericin (a silk protein) on alkali modified polyester using a crosslinking agent has been developed at IIT, New Delhi. Improved smoothness, moisture retention and wicking was observed which made the fabric more suitable for medical and sport garments.
  • Silk based supermacroporous cryogel matrices have been synthesised successfully for exploring their potential in cell-material interactions at IIT, Kanpur. Composite silk based biomaterials were synthesised which can be applied for soft and hard tissue engineering applications. The synthesised materials were thoroughly characterised by scanning electron microscopy, micro-computer tomography, TF-IR, mechanical properties, in vitro and in vivo biocompatibility. Nano-silk sericin based hydrogels prepared from silk industry waste have been found to have application in sanitary napkins and baby diapers at RV College of Engineering, Bangalore. The scaffold of nano-fibroin were prepared as an ideal biopolymer for enzyme immobilisation. The dressing membrane made up of fibroin has been found to heal wound much faster.

Major Outcome of DBT Support in Sericulture

  • Successful in bringing together leading molecular biology institutions with those involved in sericulture research.
  • Initiated molecular biology studies on non-mulberry sericulture such as muga, eri and tropical tasar since no other research group in the world is working on these silkworm species.
  • DBT’s support has brought India to the forefront of seri-biotechnology research in the world.
  • It has also ensured that the fruits of biotechnology reach the weaker section of the society in the rural areas.
  • Quality publications have been published in very good national and international scientific journals.