Effect of Spermidine Supplementation on Testicular And Ovarian Development in Sex-limited and Non-sex-limited Bivoltine Silk Worm Breeds of Bombyx mori L

Silk worm Bombyx mori L is a holometabolous, lepidopteran model for investigating the effect of various molecules. The sex-limited character of cocoon color is useful for the separation of male and female pupae during commercial seed production. Fecundity is the major limitation of cocoon colour sex-limited breeds. Spermidine is a polyamine, present in all living cells involved in the growth and reproduction of many organisms. The effect of spermidine on testicular and ovarian development in the selected bivoltine sex-limited breed; APS27SL and non-sex-limited hybrid; APS45 x APS12 is studied in the present work. Results showed that foliar feeding of spermidine significantly increased pupal growth, testicular and ovarian growth, number of ovarioles and ovules in the sex-limited breed. Moreover, increased expression of Bm-tektin was observed in the testes of spermidine fed groups. Thus, the study suggests that foliar feeding of spermidine can be used to overcome the limitation of reproductive potential in sex-limited breeds.