Figure 3

Hormonal and viral regulation of BmCatD mRNA expression. (A) Expression profiles of BmCatD mRNA in fat body of the fifth larval instar with hormonal and viral treatments. B. mori larvae on day 1 of the fifth instar were treated with 20E (b), JHA (c), BmNPV (d) or JHA+BmNPV (e), respectively. Total RNA from fat body was extracted at 1-day intervals post-treatment and analyzed by Northern blots. The control was the untreated larvae (a). BmNPV p35 (f) gene serves as a marker of viral infection. (B) Relative mRNA levels of BmCatD regulated by treatment. The levels of BmCatD mRNA are means of three assays, which are calculated relative to that of the expression recorded for the control (shown as 100%). Bars represent the means ± SE. Significance of the differences versus a control value is given by ** (P < 0.01) and * (P < 0.05). (C) Internucleosomal DNA fragmentation in the fat body of the fifth larval instar with hormonal and viral treatments. DNA from the fat body cells of all treated larvae was extracted at 1-day intervals post-treatment (as described in A), respectively. DNA fragmentation was assessed by 1.0% agarose gel electrophoresis.