Cloning and Characterization of the Caspase Family Member BmDronc from Bombyx mori (Lepidoptera: Bombycidae) Embryo Cells

Abstract

Caspases are a family of cysteinyl aspartate proteinases known for their essential roles in the regulation of apoptosis. To date, «=20 caspases have been identified, although few have been cloned and characterized in Bombyx mori (L.). Two caspase-9 variants from the B. mori embryo cell line (BmE), designated BniDroncL and BmDroncS, were cloned. BniDroncL has three classic domains: a caspase recruitment domain and large and small subunits, and is a homologue oí Drosophila Drone, human caspase-9, Aedes Drone, and fish ciispase-9, whereas BmDroncS lacks the large subunit. Instantaneous expression of ßjnDroricL caused typical apoptosis in Sf-9 cells. Moreover, BmDroiK gene expression increased markedly during the silkworm metamoiphosis at the larva-pupa and pupa-moth stages, which suggested that BmDronc plays a crucial role during B. mori metamorphosis.

Research progress on the immune mechanism of the silkworm Bombyx mori

“…Based on the available genomic data, 52 apoptosis‐related candidate genes have been identified in silkworms (Courtiade et al, ), including five caspases (Zhang et al, ). Furthermore, BmIce‐2, Bmp53 (Yi et al, ) and BmDronc (Zhang et al, ) can enhance the apoptotic rate of cells. In BmN cells, BmIAP and BmBuffy are involved in inhibiting apoptosis (Pan et al, ) and mitochondrial cytochrome C plays a minor role in regulating Drosophila cell apoptosis (Zhang et al, ).…”

Role of BmDredd during Apoptosis of Silk Gland in Silkworm, Bombyx mori

“…So far, several studies have elucidated that some homologous genes in silkworms also function similarly as in mammals. Bm Ice-2, Bm p53 [20] and Bm Dronc [21] have been reported to enhance the rate of apoptosis in Bm N cells, while Bm IAP [22] and Bm Buffy [23] function in inhibition of apoptosis. Bombyx mori death related ced-3/Nedd2-like protein ( Bm Dredd) has relatively high homology with the mammalian initiator caspases which include an N-terminal death effector domain (DED) or caspase recruitment domain (CARD) and a C-terminal CASc domain.…”