Expression profile of cathepsin B in the fat body of Bombyx mori during metamorphosis.
Proteolytic enzymes are involved in insect molting and metamorphosis, and play a vital role in the programmed cell death of obsolete organs. Here we show the expression profile of cathepsin B in the fat body of the silkworm Bombyx mori during development. We also compare the expression profiles of B. mori cathepsins B (BmCatB) and D (BmCatD) during normal development and after RNA interference (RNAi)-mediated inhibition. BmCatB is induced by 20-OH-ecdysone, and is expressed in the fat body of B. mori during molting and the larval-pupal and pupal-adult transformations, where its expression leads to programmed cell death. In particular, BmCatB is highly expressed in the fat body of B. mori during the larval-pupal transformation, and BmCatB RNAi treatment resulted in an arrest of the larval-pupal transformation. RNAi-mediated BmCatB knockdown sustained the expression of BmCatD during the larval-pupal transformation. On the other hand, when BmCatD was inhibited via RNAi, the expression of BmCatB was upregulated. Based on these results, we conclude that BmCatB is involved in the programmed cell death of the fat body during B. mori metamorphosis, and that BmCatB and BmCatD contribute to B. mori metamorphosis.
Lee
Kwang Sik
KS
College of Natural Resources and Life Science, Dong-A University, Busan 604-714, Republic of Korea.
Kim
Bo Yeon
BY
Choo
Young Moo
YM
Yoon
Hyung Joo
HJ
Kang
Pil Don
PD
Woo
Soo Dong
SD
Sohn
Hung Dae
HD
Roh
Jong Yul
JY
Gui
Zhong Zheng
ZZ
Je
Yeon Ho
YH
Jin
Byung Rae
BR
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D012831:Bombyx / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D002401:Cathepsin B / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D002402:Cathepsin D / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D004441:Ecdysterone / Q000494:pharmacology; D005216:Fat Body / Q000187:drug effects / Q000378:metabolism*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D055785:Gene Knockdown Techniques; D008675:Metamorphosis, Biological / Q000235:genetics*; D034622:RNA Interference
D004441:Ecdysterone; D002401:Cathepsin B; D002402:Cathepsin D