Tsuzuki S, Iwami M, Sakurai S
Division of Life Science, Graduate School of Natural Science and Technology, Kakumamachi, 920-1192, Kanazawa, Japan.
Insect Biochem Mol Biol. 2001 Mar 15;31(4-5):321-31. doi: 10.1016/s0965-1748(00)00124-7.
The anterior silk gland of the silkworm, Bombyx mori, undergoes programmed cell death (PCD) during pupal metamorphosis and PCD is triggered by 20-hydroxyecdysone (20E) in vitro. In order to identify the genes responsible for the PCD, we subtracted cDNAs prepared from the anterior silk glands incubated in the presence or absence of 20E in vitro. After a series of screenings by dot blot hybridization, DNA sequencing and reverse transcription polymerase chain reaction (RT-PCR), we obtained seven novel genes that were activated by 20E in vitro. Nucleotide sequence analysis indicated that two cDNAs (EN78 and EC08) did not have any obvious region to encode proteins, while five genes, designated EC74, EN86, EN03, EN10 and EN16, encoded proteins that are similar to inorganic phosphate cotransporter, TIA-1-like protein, chitinase-related protein, translation-initiation-factor subunit and annexin, respectively. Expression profiles of the genes after 20E stimulation indicated that four genes could be classified as early genes, while two are delayed early genes. The genes identified may provide insight into the PCD induced by a steroid hormone.
家蚕的前部丝腺在蛹变态期间经历程序性细胞死亡（PCD），并且在体外PCD由20-羟基蜕皮激素（20E）触发。为了鉴定负责PCD的基因，我们对在体外存在或不存在20E的情况下培养的前部丝腺制备的cDNA进行了消减。经过斑点印迹杂交、DNA测序和逆转录聚合酶链反应（RT-PCR）的一系列筛选，我们获得了七个在体外被20E激活的新基因。核苷酸序列分析表明，两个cDNA（EN78和EC08）没有任何明显的编码蛋白质的区域，而五个基因，分别命名为EC74、EN86、EN03、EN10和EN16，编码的蛋白质分别类似于无机磷酸盐共转运体、TIA-1样蛋白、几丁质酶相关蛋白、翻译起始因子亚基和膜联蛋白。20E刺激后这些基因的表达谱表明，四个基因可归类为早期基因，而两个是延迟早期基因。鉴定出的这些基因可能为类固醇激素诱导的PCD提供深入了解。
