CHROMOSOME ASSIGNMENT OF 4 PHOTOSYNTHESIS-RELATED GENES AND THEIR VARIABILITY IN WHEAT SPECIES
CHROMOSOME ASSIGNMENT OF 4 PHOTOSYNTHESIS-RELATED GENES AND THEIR VARIABILITY IN WHEAT SPECIES
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DOI：
10.1007/bf00223649
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发表时间：
1994-06-01
影响因子：
5.4
通讯作者：
SASAKUMA, T
中科院分区：
文献类型：
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作者：
OGIHARA, Y;SHIMIZU, H;SASAKUMA, T
利用slot-blot技术分析了PhyA、Ppc、RbcS和Lhcb 1 *1等4个光合作用相关基因在小麦基因组中的拷贝数，并利用Southern杂交技术将这些基因定位到普通小麦染色体臂上。PhyA基因的拷贝数估计为每个单倍体基因组一个位点，该基因被分配到染色体4AL，4 BS和4DS。Ppc基因表现为低拷贝的小多基因，位于同源异型群3染色体的短臂和同源异型群7染色体的长臂上。RbcS是一个多基因家族，在普通小麦基因组中约有100个拷贝，位于第2组染色体的短臂和第5组染色体的长臂上。lhcb 1 *1在普通小麦中也是一个多基因家族，约有50个拷贝。由于DNA条带的多样性，只有有限数量的限制性片段（约15%）用于确定该家族成员在第1组染色体长臂上的位置。四个基因杂交带的变异性在多倍体中较小，而在多基因家系中较大。以燕麦PhyA基因、玉米Ppc基因、小麦RbcS基因和小麦Lhcb 1 *1基因为探针，对多倍体小麦及其可能的祖先进行了RFLP分析。普通小麦的RFLP图谱与T. dicoccum（Emmer wheat），T. urartu（A genome），Ae. speltoides（S基因组）和Ae. squarossa（D基因组）。小麦复合体中基因的多样化似乎主要发生在二倍体水平。根据RFLP图谱，B和S基因组可分为两大类。每个基因组的片段数与所有四个基因的倍性水平的增加成比例地减少，这表明某些机制可能起作用以限制多倍体基因组中的基因数，从而使其保持在最小值。然而，位于2BS上的RbcS基因更保守（双倍剂量），表明上述机制对单个基因的作用并不相同。
Copy numbers of four photosynthesis-related genes, PhyA, Ppc, RbcS and Lhcb1*1,in wheat genomes were estimated by slot-blot analysis, and these genes were assigned to the chromosome arms of common wheat by Southern hybridization of DNA from an aneuploid series of the cultivar Chinese Spring. The copy number of PhyA was estimated to be one locus per haploid genome, and this gene was assigned to chromosomes 4AL, 4BS and 4DS. The Ppc gene showed a low copy number of small multigenes, and was located on the short arm of homoeologous group 3 chromosomes and the long arm of chromosomes of homoeologous group 7. RbcS consisted of a multigene family, with approximately 100 copies in the common wheat genome, and was located on the short arm of group 2 chromosomes and the long arm of group 5 chromosomes. Lhcb1*1 also consisted of a multigene family with about 50 copies in common wheat. Only a limited number of restriction fragments (approximately 15%) were used to determine the locations of members of this family on the long arm of group 1 chromosomes owing to the multiplicity of DNA bands. The variability of hybridized bands with the four genes was less in polyploids, but was more in the case of multigene families. RFLP analysis of polyploid wheats and their presumed ancestors was carried out with probes of the oat PhyA gene, the maize Ppc gene, the wheat RbcS gene and the wheat Lhcb1*1 gene. The RFLP patterns of common wheat most closely resembled those of T. dicoccum (Emmer wheat), T. urartu (A genome), Ae. speltoides (S genome) and Ae. squarossa (D genome). Diversification of genes in the wheat complex appear to have occurred mainly at the diploid level. Based on RFLP patterns, B and S genomes were clustered into two major groups. The fragment numbers per genome were reduced in proportion to the increase of ploidy level for all four genes, suggesting that some mechanism(s) might operate to restrict, and so keep to a minimum, the gene numbers in the polyploid genomes. However, the RbcS genes, located on 2BS, were more conserved (double dosage), indicating that the above mechanism(s) does not operate equally on individual genes.