Isolation of a type 2 metallothionein-like gene preferentially expressed in the tapetum in Zea mays
Isolation of a type 2 metallothionein-like gene preferentially expressed in the tapetum in Zea mays
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DOI：
10.1016/s0378-1119(00)00266-3
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发表时间：
2000-08-22
期刊：
影响因子：
3.5
通讯作者：
Combes, D
中科院分区：
文献类型：
--
作者：
Charbonnel-Campaa, L;Lauga, B;Combes, D
从减数分裂时期的花药中获得的cDNA文库与3周龄幼苗的cDNA进行了差异筛选，获得了一个玉米的cDNA，MZM3-4。对不同发育阶段的玉米不同组织和雄性生殖器官的RNA进行Northern杂交分析，结果表明，从花粉母细胞期到单核小孢子期，花药中只有一个转录本表达。与花药切片的原位杂交只在绒毡层产生明显的信号。MZM3-4基因全长743个核苷酸，有一个开放阅读框，编码75个氨基酸的蛋白质。与不同数据库的序列比较表明，MZM3-4在核苷酸和氨基酸水平上都与2型植物金属硫蛋白有很高的相似性。引物延伸分析表明，MZM3-4基因5‘端缺失13个碱基对。Southern杂交分析表明，MZM3-4基因可能以一个或两个拷贝的形式存在于玉米自交系基因组中。这是首次在玉米中分离到一种类金属硫蛋白。此外，该类金属硫蛋白基因在参与小孢子发生的雄性生殖器官中高表达。(C)2000 Elsevier Science B.V.保留所有权利。
A Zea mays cDNA, MZm3-4, was isolated by differential screening of a cDNA library obtained from meiotic stage anthers against a cDNA of 3-week-old seedlings. Northern blot analysis of RNA from different maize tissues and from male reproductive organs at various developmental stages demonstrated expression of a single transcript in anthers, from the pollen mother cell stage through the uninucleated microspore stage. In situ hybridization to anther sections resulted in a distinct signal only in the tapetum. The MZm3-4 cDNA is 743 nucleotides in length and has an open reading frame encoding a protein of 75 amino acids. Sequence comparisons with various databases revealed that MZm3-4 exhibits high similarities with type 2 plant metallothioneins at both the nucleotide and the amino-acid level. Primer extension analysis indicated that MZm3-4 cDNA is deleted of 13 bp at the 5' end. Southern blot analysis showed that the MZm3-4 gene may be present in one or two copies in a Z. mays inbred line genome. This is the first report of the isolation of a type 2 metallothionein-like protein in maize. Moreover, the expression of this type 2 metallothionein-like gene is high in the male reproductive organs engaged in microsporogenesis. (C) 2000 Elsevier Science B.V. All rights reserved.