The genomic underpinnings of apoptosis in the silkworm, Bombyx mori.
BACKGROUND
Apoptosis is regulated in an orderly fashion by a series of genes, and has a crucial role in important physiological processes such as growth development, immunological response and so on. Recently, substantial studies have been undertaken on apoptosis in model animals including humans, fruit flies, and the nematode. However, the lack of genomic data for silkworms limits their usefulness in apoptosis studies, despite the advantages of silkworm as a representative of Lepidoptera and an effective model system. Herein we have identified apoptosis-related genes in the silkworm Bombyx mori and compared them to those from insects, mammals, and nematodes.


RESULTS
From the newly assembled genome databases, a genome-wide analysis of apoptosis-related genes in Bombyx mori was performed using both nucleotide and protein Blast searches. Fifty-two apoptosis-related candidate genes were identified, including five caspase family members, two tumor necrosis factor (TNF) superfamily members, one Bcl-2 family member, four baculovirus IAP (inhibitor of apoptosis) repeat (BIR) domain family members and 1 RHG (Reaper, Hid, Grim, and Sickle; Drosophila cell death activators) family member. Moreover, we identified a new caspase family member, BmCaspase-New, two splice variants of BmDronc, and Bm3585, a mammalian TNF superfamily member homolog. Twenty-three of these apoptosis-related genes were cloned and sequenced using cDNA templates isolated from BmE-SWU1 cells. Sequence analyses revealed that these genes could have key roles in apoptosis.


CONCLUSIONS
Bombyx mori possesses potential apoptosis-related genes. We hypothesized that the classic intrinsic and extrinsic apoptotic pathways potentially are active in Bombyx mori. These results lay the foundation for further apoptosis-related study in Bombyx mori.
The Key Sericultural Laboratory of Agricultural Ministry, Institute of Sericulture and Systems Biology, Southwest University, Chongqing 400715, China.
Jin-Ye
JY
Zhang
Min-Hui
MH
Pan
Zhi-Ya
ZY
Sun
Shu-Jing
SJ
Huang
Zi-Shu
ZS
Yu
Di
D
Liu
Dan-Hong
DH
Zhao
Cheng
C
Lu
D017398:Alternative Splicing / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D012831:Bombyx / Q000166:cytology* / Q000235:genetics* / Q000254:growth & development; D002460:Cell Line; D030541:Databases, Genetic; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect / Q000235:genetics; D049750:Genome, Insect / Q000235:genetics*; D023281:Genomics; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D019476:Insect Proteins