CHARACTERIZATION OF A NEW FAMILY OF TOBACCO HIGHLY REPETITIVE DNA, GRS, SPECIFIC FOR THE NICOTIANA-TOMENTOSIFORMIS GENOMIC COMPONENT
CHARACTERIZATION OF A NEW FAMILY OF TOBACCO HIGHLY REPETITIVE DNA, GRS, SPECIFIC FOR THE NICOTIANA-TOMENTOSIFORMIS GENOMIC COMPONENT
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DOI：
10.1007/bf00713050
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发表时间：
1995-06-01
影响因子：
2.6
通讯作者：
BEZDEK, M
中科院分区：
文献类型：
--
作者：
GAZDOVA, B;SIROKY, J;BEZDEK, M
从烟草（Nicotiana tabacum L.）基因组DNA并进行表征。GRS的克隆、测序单体单元（180-182 bp）表现出具有稳定曲率的分子的特性。GRS家族占总基因组DNA的约0.15%（每个单倍体基因组10（4）个拷贝），并且可能源自双二倍体烟草的T基因组的两个可能的祖先--绒毛烟草（Nicotiana tomentosiformis）或耳托烟草（Nicotiana otophora）。烟草。HRS 60（Koukalova et al.1989）和GRS家族之间的序列同源性估计为57%。用原位杂交技术将GRS定位在有丝分裂染色体上。杂交信号在五对染色体上获得的较长的染色体臂的插入位点。大多数GRS序列似乎以串联阵列的形式组织，少数被发现以短簇的形式分散在基因组中，散布着其他类型的DNA重复序列，包括25 S rDNA序列。还发现了几个同时含有GRS和HRS 60的基因座，这些杂合位点可能表明双二倍体N.烟草。发现GRS序列，如HRS 60（Fajkus等，1992），指定核小体的位置。核小体核心的位置已被映射相对于一个保守的Mbol网站在GRS序列和寡ATT道是一个主要的中心的DNA曲率。
Members of a new family of highly repetitive DNA sequences called GRS were isolated from Nicotiana tabacum L. genomic DNA and characterized. Cloned, sequenced monomeric units (180-182 bp) of GRS exhibit properties characteristic of molecules that possess a stable curvature. The GRS family represents about 0.15% of total genomic DNA (10(4) copies per haploid genome) and could be derived from either Nicotiana tomentosiformis or Nicotiana otophora, two possible ancestors of the T genome of the amphidiploid N. tabacum. Sequence homology between the HRS60 (Koukalova et al. 1989) and the GRS family has been estimated to be 57%. In situ hybridization was used to localize GRS on mitotic chromosomes. Hybridization signals were obtained on five pairs of chromosomes at intercalary sites of the longer chromosome arms. The majority of GRS sequences appeared to be organized in tandem arrays and a minority were found to be dispersed through the genome in short clusters, interspersed with other types of DNA repeats, including 25S rDNA sequences. Several loci containing both GRS and HRS60 were also found. Such hybrid loci may indicate intergenomic transfer of the DNA in the amphidiploid N. tabacum. GRS sequences, like HRS60 (Fajkus et al. 1992), were found to specify the location of nucleosomes. The position of the nucleosome core has been mapped with respect to a conserved Mbol site in the GRS sequence and an oligo ATT tract is a major centre of the DNA curvature.