Primary investigation on GISH-NOR in cotton
Primary investigation on GISH-NOR in cotton
复制标题
棉花GISH-NOR的初步研究
DOI：
10.1360/982004-582
复制
发表时间：
2005-03-01
影响因子：
--
通讯作者：
Wang, YH
中科院分区：
文献类型：
--
作者：
Liu, SH;Wang, KB;Wang, YH
棉花基因组原位杂交（GISH）检测到6个核仁组织区（NOR）位点。 NOR 是 45S rDNA 的特征，但可以通过从棉属物种中提取的基因组 DNA (gDNA) 作为探针来生成。对同一个草本或陆地棉有丝分裂细胞进行两次FISH，发现45S rDNA和gDNA产生的NORs的数量、位置和大小基本相似甚至相同。因此，以 gDNA 作为探针的 NOR 被永久定义为 GISH-NOR。来自陆地棉和雷蒙德菌有丝分裂图像的 GISH-NOR 均为终末类型。来自 G herbaceum (var. africanum) 的 4 个和 2 个 GISH-NOR 分别是末端型和着丝粒型。对陆地棉中的 6 个 GISH-NOR 进行了染色体定位，其中 2 个位于 A 亚基因组，4 个位于 D 亚基因组。以自身的gDNA为探针的雷蒙德氏小麦有丝分裂图像中也存在GISH-NOR。从以自身的gDNA为探针的草本植物有丝分裂图像中，无法观察到GISH-NOR，但可以看出杂交信号的非完全恢复。这些非完全恢复的杂交信号在大多数染色体的长臂末端检测到，特别是存在于草本植物gDNA探测自身GISH图像中的一对染色体的近半长臂中，这可能是由区域内的低拷贝基因诱导的，而不是亚基因组间片段易位。当分别使用来自 D 和 A 基因组物种的 gDNA 作为探针和块时，主要观察到陆地棉有丝分裂图像中的 GISH-NOR，但当设计来自两个二倍体祖基因组的反向探针和块 gDNA 时，则不会观察到。对于这种特殊现象可能有两种推测：rDNA协同进化；基因组D中rDNA的含量高于基因组A。
Six loci of nucleolar organizer region (NOR) were detected in genomic in situ hybridization (GISH) of cotton (Gossypium). NOR was the characteristic of 45S rDNA but could be generated by genomic DNA (gDNA) extracted from Gossypium species as probe. With twice FISH to the same mitotic cell of G herbaceum or G hirsutum, number, position and size for NORs generated from 45S rDNA and gDNA were identified largely similar or even the same. The NORs with gDNA as probe were therefore permanently defined as GISH-NORs. GISH-NORs from G hirsutum and C. raimondii mitotic images were all terminal types. Four and two GISH-NORs from G herbaceum (var. africanum) were terminal and centromere types, respectively. Six GISH-NORs in G hirsutum were chromosome mapped with two in A- and four in D-subgenomes. There were also GISH-NORs in mitotic image of G raimondii with its own gDNA as probe. From mitotic image of G herbaceum with its own gDNA as probe, GISH-NOR could not be observed but non-whole-recovery of hybridized signals was distinguished. These non-whole-recovery of hybridized signals were detected on long arm terminals of most chromosomes and especially existed in nearly half long arm of a pair of chromosomes in G herbaceum gDNA probed itself GISH image, which may be possibly induced by low copy genes within the regions rather than inter-subgenomic segment translocations. GISH-NORs in G hirsutum mitotic images were dominantly observed when gDNAs from D and A genome species were used as probes and block, respectively, but not when the reverse probe and block gDNA from the two diploid progenitor genomes were designed. There may be two speculations to this special phenomenon: rDNA concerted evolution; content of rDNA in genome D more than genome A.