Luchetta P, Crétin C, Gadal P
Laboratoire de Physiologie Végétale Moléculaire, Université Paris-Sud, Orsay, France.
Mol Gen Genet. 1991 Sep;228(3):473-81. doi: 10.1007/BF00260642.
We previously described the isolation and the nucleotide sequence of a nuclear gene from sorghum (NMDHI; 4.6 kb) encoding the NADP-malate dehydrogenase. Further analysis led us to identify a second homologous gene (NMDH II; 4.8 kb) located within the same 12.3 kb genomic clone (lambda LM17); these two genes are tandemly organized, in direct orientation. This second gene was entirely sequenced and comparison with the first gene showed that the positions on the 14 exons and 13 introns are conserved in both genes. The analysis of the genomic organization and copy number in the Sorghum vulgare genome revealed that there are no additional homologues and there is only one copy each of NMDH I and NMDH II. The isolation of two different cDNA clones in a previous work suggested that both genes were probably expressed. Analysis of specific mRNA accumulation during the greening process using synthetic oligonucleotide probes showed that the NMDH I gene is induced in the presence of light while the NMDH II gene seems to be constitutively expressed at low level.
我们之前描述了从高粱中分离出的一个编码NADP-苹果酸脱氢酶的核基因（NMDHI；4.6 kb）及其核苷酸序列。进一步分析使我们鉴定出位于同一个12.3 kb基因组克隆（λLM17）内的第二个同源基因（NMDH II；4.8 kb）；这两个基因呈串联排列，方向相同。对第二个基因进行了全序列测定，并与第一个基因比较，结果表明两个基因中14个外显子和13个内含子的位置是保守的。对高粱基因组中的基因组组织和拷贝数分析表明，不存在其他同源物，NMDH I和NMDH II各只有一个拷贝。在之前的工作中分离出两个不同的cDNA克隆，这表明这两个基因可能都有表达。使用合成寡核苷酸探针分析绿化过程中特定mRNA的积累情况，结果表明NMDH I基因在有光的情况下被诱导，而NMDH II基因似乎以低水平组成型表达。
