Changes in the embryonic protein profile and hatching as a response to thermal stress in the Eri silkworm, Samia cynthia ricini

Abstract

The biological architecture determining the post-embryonic development and traits is well programmed during the process of morphogenetic movements and organogenesis in the embryo. However, changes in the environmental temperature for a few hours, which is uncommon, affecting the embryo development, protein expression, and hatching of larvae in the Eri silkworm ( Samia cynthia ricini ) remain enigmatic. Hence, for the first time, the eggs of new Eri silkworm breed C2 were exposed to heat shock (HS) temperature of 35°C, 40°C, and 45°C for 2 hours not only to measure heat sensitivity but also to uncover differential expression of proteins in a different age of the embryo. Interestingly, the quantum of protein not only increased but also a differential expression of 70, 60, 45, 36, and 30 kDa proteins was obvious due to induction of HS. The induction of HS has shown a significant impact on embryonic development wherein 45°C is found to be lethal as none of the eggs hatched. On other hand, an improvement in the hatching was observed in the eggs HS at 40°C, which could be due to the expression of HS proteins (HSPs). Taken together, we suggest that hatching of the embryo is one of the key traits to determine tolerance potential of the silkworm strains/breeds to heat stress by expressing HSPs. Therefore, this strategy shall be followed for development of a new Eri silkworm breed with better acquired tolerance to high temperature suitable