author(s)
Bela Keshan, Satinath Paul, Thounaojam Bembem, Kh. Sanathoibi Devi

abstract
The present study reports the survival and expression patterns of heat shock protein 90 (hsp90) in silkworm Bombyx mori. The ubiquitous expression of hsp90 mRNA was observed within all examined tissues such as fat body, ovary, wing disc and dorsal abdominal epidermis during larval stage, and fat body and ovary during pupal stage. Under heat stress, depending on its severity, hsp 90 expression was found to vary among different tissues. At mild and mild-to-severe heat stressed condition (39 ºC and 42 ºC), its expression was found to be significantly up-regu­lated in all examined tissues except pupal ovary. At severe-to-lethal heat stressed condition (45 ºC), no significant up-regulation in hsp90 transcript level was observed in tissues except dorsal abdominal epidermis. The up-regulation of hsp90 was found to be associated with the ability of the animal to survive at the particular heat shock temperature. The spinning larvae were found to be more heat resistant than pupae.