Comparative study of susceptibilities of two cell lines to Bombyx mori nucleopolyhedrovirus (BmNPV)
S. O. Qureshi
Department of Zoology, Adarsha Sc., J. B. Arts & Birla Commerce College, Dhamangaon Rly. District Amravati (MS) (India) email drsoqureshi@gmail.com, Phone +91 7620055822
ABSTRACT
Insect cell lines have emerged as a prime candidate for study of baculovirus replication and production of recombinant viruses leading to foreign gene expression. Study of variations in cell line susceptibilities to nucleopolyhedroviruses may shed light on in vitro replication of these viruses. The present study compares susceptibilities of two cell lines viz. DZNU-Bm-1 and NIAS-MaBr-92 to Bombyx mori nucleopolyhedrovirus (BmNPV). The cell lines were grown at 25 ± 1oC in MGM-448 medium supplemented with 10% FBS. At early stages of infection, hypertrophy of nuclei, cell aggregation and adherence of cells to the bottom of the culture flask were observed in DZNU-Bm-1. NIASMaBr- 92 cells showed hypertrophy of nuclei and loss of motility. The criterion of BmNPV infection was presence of polyhedral inclusion bodies (PIBs) in a cell. In DZNU-Bm-1, mature OBs were seen in the nuclei of infected cells by 66 h.p.i. while in NIAS-MaBr-92 mature OBs could be seen only after 120 h.p.i. At passage I of BmNPV, the infection rate was higher in DZNU-Bm-1 cells (92.50%) than that in NIAS-MaBr-92 cells (64.33%). DZNU-Bm-1 cells exhibited an average yield of 23 OBs/cell while NIAS-MaBr-92 cells showed an average of 10 OBs/cell. Thus, DZNU-Bm-1 cell line exhibits better figures of percentage infection and yield of OBs/cell. The results indicate that DZNU-Bm-1 cell line can be used to produce recombinant BmNPV and foreign gene expression through BmNPV/B. mori system.