哺乳动物凋亡相关基因p53同源序列在玉米(Zea mays L.)中的检出及其染色体原位杂交定位(英文)

p53基因普遍存在于动物组织中，是一个高度保守的肿瘤抑制基因，对细胞的生长、增殖和分化等多种发育程序进行调控。p53基因也是一个重要的细胞凋亡相关基因,决定着多种动物细胞的凋亡。有报导：用人P53抗体和p53基因的cDNA探针在玉米（ZeamaysL．）中检出了P53的同源蛋白及相应的mRNA，并初步确定其在功能上与动物中的P53蛋白非常相似。本实验首先用人p53基因的cDNA为探针，经SouthernBlotting初步确定其同源序列的存在（Fig．1），然后进一步用生物素标记的原位杂交（DAB－ISH）和荧光原位杂交（FISH）对这些同源序列进行了染色体定位。DAB－ISH（Plate1）和FISH（Plate2）得到了一致的结果，在5S（第5染色体短臂）次末端、IL（第1染色体长臂）近末端、8L中部、3L中部近着丝粒以及9L近中部均镜检到p53基因探针的杂交信号，信号与着丝粒的百分距离分别为70．0±3．2、89．1±1．3、50．5±1.1、37．0±0．3和66．7±2．0（Tab．1，Fig．2）。利用异源探针是寻找植物凋亡相关基因的一种重要手段，也是目前国外的研究热点之一。本研究首次从DNA水平上证明了p53基因在玉米中的存在。为寻找和研究植物细胞凋亡基因提供了重要线索。

Detection of the Sequences Homologous to p53 in Maize and Their Chromosome Localizationsvia Hybridization in situ

The highly conserved tumor suppressor gene p53 in animals has been shown toplay a central role in regulating multiple developmental processes including growth,proliferation and differentiation. It is also one of the important genes related to apoptotic celldeath. In the present paper, the DNA sequences in maize (Zea mayS L.), which arehomologous to p53 in human, as well as the chromosomal locations of them, were detected forthe first time using Southern Blotting and chromosome hybridization in situ. For detection,DAB and fluorescence staining techniques were used. Both of them gave the identical results,indicating that the signals of the test probe corresponding to p53 were localized on the shortarm of the fifth chromosome (5S) and on the long arms of the first, the eighth, the third and theninth chromosomes (IL, 8L, 3L and 9L) simultaneously. All these results provided a valuableinsight into searching for genes associated with apoptotic cell death in plants.