title: Molecular cloning and characterization of hatching enzyme-like gene in the silkworm, Bombyx mori.
abstract: Hatching is the important process for the life of the metazoan, in which hatching enzyme (HE) plays a key role. In this paper, we cloned the full-length sequence of hatching enzyme-like cDNA from bluish-silkworm-eggs of Bombyx mori (BmHEL) by the method of in silico cloning, SMART cDNA synthesis and RACE-PCR technique. The BmHEL is 974 bp in length, and contains an ORF of 885 bp, encoding 294 amino acids residues. The deduced amino acid sequence of BmHEL has 30.3-47.1% identities to that of HE identified in the other species. Two similar signature sequences of HE gene family harbor in the BmHEL. The BmHEL gene structure is 6-exon-5-intron, and a promoter region with high scores has been predicted, which harbors some basal elements and some embryo-development related transcription factor binding sites. In the silkworm eggs at different developmental stages during incubation, the BmHEL transcripts can be detected and keep at a low level during the early stages, increase dramatically since 7th day of incubation, and reach to the maximum on 9th day. Change of BmHEL transcripts is in accordance with the process of embryo development and hatching, indicated that it plays an important role in these processes. Moreover, BmHEL transcript can be detected in the midgut and testis at larval stage, suggested that BmHEL may have other biological functions. To the best of our knowledge, this is the first report on HE gene in the Lepidoptera insects and will be helpful to provide a molecular basis for understanding the complicated mechanism underlying silkworm hatching.
authors.affiliation: College of Biotechnology and Environmental Engineering, Jiangsu University of Science and Technology, Zhenjiang, People's Republic China.
authors.forename: Fu-hao
authors.initials: FH
authors.lastname: Lu
authors.forename: Shun-ming
authors.initials: SM
authors.lastname: Tang
authors.forename: Xing-jia
authors.initials: XJ
authors.lastname: Shen
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.forename: Qiao-ling
authors.initials: QL
authors.lastname: Zhao
authors.forename: Guo-zheng
authors.initials: GZ
authors.lastname: Zhang
authors.forename: Xi-jie
authors.initials: XJ
authors.lastname: Guo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000196:embryology* / Q000201:enzymology*; D003001:Cloning, Molecular; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D040461:Gene Components; D020869:Gene Expression Profiling; D008666:Metalloendopeptidases / Q000235:genetics*; D008675:Metamorphosis, Biological / Q000235:genetics*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D008666:Metalloendopeptidases; C024344:envelysin