Ji L H, Langridge P
Department of Plant Science, Waite Institute, University of Adelaide, Glen Osmond, Australia.
Mol Gen Genet. 1994 Apr;243(1):17-23. doi: 10.1007/BF00283871.
Meiosis occupies only a very short period of the life cycle of higher plants but it is a crucial process ensuring the correct passage and maintenance of genetic information from parent to offspring. A clone (designated pAWJL3) has been isolated from a cDNA library generated from RNA prepared from young wheat florets at early meiosis. The clone was identified through cross-hybridisation to a cDNA clone from maize that, in turn, had been isolated by hybridisation to a Lilium meiosis-specific cDNA clone. The genes encoding the sequence represented in the wheat cDNA clone have been assigned to chromosomes in wheat. The clone, pAWJL3, represents a small family of genes with about 20 members located on the short arms of group 3 and 5 chromosomes. The chromosomal regions harbour genes known to control chromosomal pairing in wheat. DNA prepared from a deletion mutation affecting one of the major genes controlling pairing, Ph2 located on the short arm of 3DS, lacks the 3DS-specific members of the pAWJL3 family bands. The genes are shown to be expressed only after leptotene and predominantly at zygotene and pachytene of meiosis I. The deduced amino acid sequence encoded by the cDNA clone shows two domains, one with three leucine-rich, 24-amino acid repeats and the other with four leucine heptad repeats that resemble those found in basic leucine zipper proteins.
减数分裂在高等植物的生命周期中仅占很短的一段时间，但它是一个关键过程，可确保遗传信息从亲代到子代的正确传递和维持。从减数分裂早期的小麦幼小花序制备的RNA所构建的cDNA文库中分离出一个克隆（命名为pAWJL3）。该克隆是通过与玉米的一个cDNA克隆进行交叉杂交鉴定出来的，而这个玉米cDNA克隆又是通过与一个百合减数分裂特异性cDNA克隆杂交分离得到的。小麦cDNA克隆中所代表的序列的编码基因已被定位到小麦的染色体上。克隆pAWJL3代表了一个小基因家族，约有20个成员，位于3组和5组染色体的短臂上。这些染色体区域含有已知控制小麦染色体配对的基因。从一个缺失突变体制备的DNA，该突变体影响控制配对的一个主要基因Ph2（位于3DS短臂上），缺少pAWJL3家族带中3DS特异性成员。这些基因显示仅在细线期之后表达，并且主要在减数分裂I的偶线期和粗线期表达。cDNA克隆推导的氨基酸序列显示有两个结构域，一个有三个富含亮氨酸的24个氨基酸的重复序列，另一个有四个亮氨酸七肽重复序列，类似于在碱性亮氨酸拉链蛋白中发现的那些序列。
