Jiang J, Nasuda S, Dong F, Scherrer C W, Woo S S, Wing R A, Gill B S, Ward D C
Department of Horticulture, University of Wisconsin, Madison 53706, USA.
Proc Natl Acad Sci U S A. 1996 Nov 26;93(24):14210-3. doi: 10.1073/pnas.93.24.14210.
Repetitive DNA sequences have been demonstrated to play an important role for centromere function of eukaryotic chromosomes, including those from fission yeast, Drosophila melanogaster, and humans. Here we report on the isolation of a repetitive DNA element located in the centromeric regions of cereal chromosomes. A 745-bp repetitive DNA clone pSau3A9, was isolated from sorghum (Sorghum bicolor). This DNA element is located in the centromeric regions of all sorghum chromosomes, as demonstrated by fluorescence in situ hybridization. Repetitive DNA sequences homologous to pSau3A9 also are present in the centromeric regions of chromosomes from other cereal species, including rice, maize, wheat, barley, rye, and oats. Probe pSau3A9 also hybridized to the centromeric region of B chromosomes from rye and maize. The repetitive nature and its conservation in distantly related plant species indicate that the pSau3A9 family may be associated with centromere function of cereal chromosomes. The absence of DNA sequences homologous to pSau3A9 in dicot species suggests a faster divergence of centromererelated sequences compared with the telomere-related sequences in plants.
重复DNA序列已被证明在真核生物染色体的着丝粒功能中发挥重要作用，包括来自裂殖酵母、黑腹果蝇和人类的染色体。在此，我们报告了一种位于谷类染色体着丝粒区域的重复DNA元件的分离情况。从高粱（双色高粱）中分离出一个745碱基对的重复DNA克隆pSau3A9。通过荧光原位杂交证明，该DNA元件位于所有高粱染色体的着丝粒区域。与pSau3A9同源的重复DNA序列也存在于其他谷类物种染色体的着丝粒区域，包括水稻、玉米、小麦、大麦、黑麦和燕麦。探针pSau3A9也与黑麦和玉米B染色体的着丝粒区域杂交。其重复性质及其在远缘植物物种中的保守性表明，pSau3A9家族可能与谷类染色体的着丝粒功能相关。双子叶植物物种中不存在与pSau3A9同源的DNA序列，这表明与植物端粒相关序列相比，着丝粒相关序列的分化更快。
