title: Chromosomal Locations of 5S and 45S rDNA in Gossypium Genus and Its Phylogenetic Implications Revealed by FISH.
abstract: We investigated the locations of 5S and 45S rDNA in Gossypium diploid A, B, D, E, F, G genomes and tetraploid genome (AD) using multi-probe fluorescent in situ hybridization (FISH) for evolution analysis in Gossypium genus. The rDNA numbers and sizes, and synteny relationships between 5S and 45S were revealed using 5S and 45S as double-probe for all species, and the rDNA-bearing chromosomes were identified for A, D and AD genomes with one more probe that is single-chromosome-specific BAC clone from G. hirsutum (A1D1). Two to four 45S and one 5S loci were found in diploid-species except two 5S loci in G. incanum (E4), the same as that in tetraploid species. The 45S on the 7th and 9th chromosomes and the 5S on the 9th chromosomes seemed to be conserved in A, D and AD genomes. In the species of B, E, F and G genomes, the rDNA numbers, sizes, and synteny relationships were first reported in this paper. The rDNA pattern agrees with previously reported phylogenetic history with some disagreements. Combined with the whole-genome sequencing data from G. raimondii (D5) and the conserved cotton karyotype, it is suggested that the expansion, decrease and transposition of rDNA other than chromosome rearrangements might occur during the Gossypium evolution.
authors.affiliation: Institute of Tropical Bioscience and Biotechnology of Chinese Academy of Tropical Agricultural Sciences/Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture (China), Haikou, Hainan, P. R. China.
authors.forename: Yimei
authors.initials: Y
authors.lastname: Gan
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.forename: Qin
authors.initials: Q
authors.lastname: Qin
authors.forename: Chunying
authors.initials: C
authors.lastname: Wang
authors.forename: Shaohui
authors.initials: S
authors.lastname: Li
authors.forename: Xiangdi
authors.initials: X
authors.lastname: Zhang
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Wang
authors.forename: Kunbo
authors.initials: K
authors.lastname: Wang
mesh_terms: D032461:Chromosomes, Plant; D017124:Conserved Sequence; D004275:DNA, Ribosomal; D019143:Evolution, Molecular; D056426:Genetic Loci; D003368:Gossypium / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D010802:Phylogeny; D011003:Ploidies; D012335:RNA, Ribosomal / Q000235:genetics*; D012341:RNA, Ribosomal, 5S / Q000235:genetics*
chemical_list: D004275:DNA, Ribosomal; D012335:RNA, Ribosomal; D012341:RNA, Ribosomal, 5S; C088179:RNA, ribosomal, 45S