利用位于45S rDNA内转录间隔区(ITS)的3对SSR引物, 对山茶属(Camellia L.)的40个物种进行PCR扩增, 检测3个SSR位点的多态性, 研究物种倍性与多态性之间的关系。实验结果显示, 37个种(占92.5%)的ITS片段存在个体内长度多态性, 在这些种类的个体内至少有2–6类ITS拷贝, 表明山茶属植物的ITS片段存在广泛的非一致性进化; ITS序列上存在易于滑动的SSR位点, 并且其基因组中有较多位于不同染色体上的rDNA位点, 这很可能是山茶属植物ITS片段存在广泛多态性的原因。然而, 研究中没有发现多倍体种类ITS片段的多态性显著高于二倍体种类。山茶属植物ITS片段的多态性提示该属植物的rDNA可能存在更为复杂的进化模式, 在利用ITS片段解决该属植物的系统分类问题时应更为谨慎。
In this study, we used 3 pairs of simple sequence repeat (SSR) markers from the 45S rDNA internal transcribed spacer (ITS) for PCR amplification in 40 species of Camellia to detect polymorphism in Camellia and the relationship between ploidy and polymorphism of species. In total, 37 species (92.5%) exhibited length polymorphism within individuals. At least 2–6 types of the ITS copies were found in individuals of these species, which indicates that non-concerted evolution is common in the ITS fragments in Camellia. Extensive non-concerted evolution may have resulted from SSR loci, which slip easily in the ITS region, and multiple rDNA loci that are located on different chromosomes. However, we did not find a significant difference in polymorphism between polyploidy and diploid. The polymorphism of the ITS region in Camellia species shows that there may be a more complex model of evolution in the rDNA of the genus, so the ITS sequences should be used with caution in solving the systematics problems of the genus.
马长乐, 周浙昆 (2006). ITS假基因对栋属系统学研究的影响及其对分子系统学研究的启示. 云南植物研究 28, 127-132.
闵天禄 (2000). 世界山茶属的研究. 昆明: 云南科技出版社.
唐绍清, 施苏华, 钟杨, 王燕 (2004). 基于ITS 序列探讨山茶属金花茶组的系统发育关系. 广西植物 24, 488-492.
杨俊波, 李洪涛, 杨世雄, 李德铢, 杨莹燕 (2006). 四个DNA 片段在山茶属分子系统学研究中的应用. 云南植物研究 28, 108-114.
张宏达, 任善湘 (1998). 中国植物志, 第49卷第3分册. 北京: 科学出版社.
Alvarez I, Wendel JF (2003). Ribosomal ITS sequences and plant phylogenetic inference. Mol Phylogenet Evol 29, 417-434.
Arnheim N, Krystal M, Schmickel R,Wilson G, Ryder O, Zimmer E (1980). Molecular evidence for genetic exchanges among ribosomal genes on nonhomologous chromosomes in man and apes. Proc Natl Acad Sci USA 77, 7323-7327.
Bailey CD, Carr TG, Harris SA, Hughes CE (2003). Characterization of angiosperm nrDNA polymorphism, paralogy, and pseudogenes. Mol Phylogenet Evol 29, 435-455.
Baldwin BG, Sanderson MJ, Porter JM, Wojciechowski MF, Campbell CS, Donoghue MJ (1995). The ITS region of nuclear ribosomal DNA: A valuable source of evidence on angiosperm phylogeny. Ann Mo Bot Gard 82, 247-277.
Brown DD, Wensink PC, Jordan E (1972). Comparison of ribosomal DNAs of Xenopus-laevis and Xenopus-mulleri - evolution of tandem genes. J Mol Biol 63, 57-73.
Copenhaver GP, Pikaard CS (1996). Two-dimensional RFLP analyses reveal megabase-sized clusters of rRNA gene variants in Arabidopsis thaliana, suggesting local spreading of variants as the mode for gene homogenization during concerted evolution. Plant J 9, 273-282.
Dover GA (1982). Molecular drive: A cohesive mode of species evolution. Nature 299, 111-117.
Doyle JJ, Doyle JL (1987). A rapid DNA isolation procedure for small quantities of fresh leaf material. Phytochem Bull 19, 11–15.
Eickbush TH, Eickbush DG (2007). Finely orchestrated movements: Evolution of the ribosomal RNA genes. Genetics 175, 477-485.
Ganley ARD and Kobayashi T (2007). Highly efficient concerted evolution in the ribosomal DNA repeats: Total rDNA repeat variation revealed by whole-genome shotgun sequence data. Genome Res 17, 184-191.
Gu ZJ, Xiao H (2003). Physical mapping of the 18S-26S rDNA by fluorescent in situ hybridization (FISH) in Camellia reticulate polyploidy complex (Theaceae). Plant Sci 164, 279-285.
Hillis DM, Moritz C, Porter CA, Baker RJ (1991). Evidence for biased gene conversion in concerted evolution of ribosomal DNA. Science 251, 308-310.
Keller I, Chintauan-Marquier IC, Veltsos P, Nichols RA (2006). Ribosomal DNA in the Grasshopper Podisma pedestris: Escape From Concerted Evolution. Genetics 174, 863-874.
Koch MA, Dobes C, Mitchell-Olds T (2003). Multiple hybrid formation in natural populations: Concerted evolution of the internal transcribed spacer of nuclear ribosomal DNA (ITS) in north American Arabis divaricarpa (Brassicaceae), Mol Biol Evol 20, 338-350.
Kondo K (1977a). Chromosome numbers in the Camellia. Biotropica 9, 86-94.
Kondo K (1977b). Cytological studies in cultivated species of Camellia I. Diploid species and their hybrids. Jap J Breed 27, 28-38.
Kondo K (1978). Cytological studies in cultivated species of Camellia III. Tetralloid species and hybrids between diploid species and hexaploid species. Jap J Breed 28, 197-204.
Kovarik A, Pires JC, Leitch AR, Lim KY, Sherwood AM, Matyasek R, Rocca J, Soltis DE, Soltis PS (2005). Rapid concerted evolution of nuclear ribosomal DNA in two tragopogon allopolyploids of recent and recurrent origin. Genetics 169, 931-944.
Long EO, Dawid IB (1980). Repeated genes in eukaryotes. Annu rev biochem 49, 727-764.
Ohta T, Dover G (1984). The cohesive population genetics of molecular drive. Genetics 108, 501-521.
Parkin EJ, Butlin RK (2004). Within- and between-individual sequence variation among ITS1 copies in the meadow grasshopper Chorthippus parallelus indicates frequent intrachromosomal gene conversion. Mol Biol Evol 21, 1595-1601.
Parks R (1990). Cross-compatibility studies in the genus Camellia. International Camellia J 10, 37-54.
Pedersen C, Linde-Laursen I (1994). Chromosomal location of four minor rDNA loci and marker microsatellite sequence in barley. Chromosome Res 2, 65-71.
Polanco C, Gonzalez AI, de la Fuente A, Dover GA (1998). Multigene family of ribosomal DNA in Drosophila melanogaster reveals contrasting patterns of homogenization for IGS and ITS spacer regions: A possible mechanism to resolve this paradox. Genetics 149, 243-256.
Schlotterer C, Tautz D (1992). Slippage synthesis of simple sequence DNA. Nucleic Acids Res 20, 211-215.
Schlotterer C, Tautz D (1994). Chromosomal homogeneity of Drosophila ribosomal DNA arrays suggests intrachromosomal exchanges drive concerted evolution. Curr Biol 4, 777-783.
Strand M, Prolla TA, Liskay RM and Petes TD (1993). Destabilization of tracts of simple repetitive DNA in yeast by mutations affection DNA mismatch repair. Nature 365, 274-276.
Vijayan K, Tsou CH (2008). Technical report on the molecular phylogeny of Camellia with nrITS: the need for high quality DNA and PCR amplification with Pfu-DNA polymerase. Bot Stud 49, 177-188.
Wendel JF, Schnabel A, Seelanan T (1995). Bidirectional interlocus concerted evolution following allopolyploid speciation in cotton (Gossypium). Proc Natl Acad Sci 92, 280-284.
Xiao LQ, Moller M, Zhu H (2010). High nrDNA ITS polymorphism in the ancient extant seed plant Cycas: Incomplete concerted evolution and the origin of pseudogenes. Mol Phylogenet Evol 55, 168-177.
Xu J, Huang LD, Xu Y, Zhang WJ (2009). Identification of hybrids of golden camellia using SSR molecular markers. J Fudan Univ (Natural Science) 48, 668-673+679.
Zhang DM, Sang T (1999). Physical mapping of ribosomal RNA genes in peonies(Paeonia, Paeoniaceae) by fluorescent in situ hybridization: implications for phylogeny and concerted evolution. Am J Bot 86, 735-740.
Zheng XY, Cai DY, Yao LH, Teng YW (2008). Non-concerted ITS evolution, early origin and phylogenetic utility of ITS pseudogenes in Pyrus. Mol Phylogenet Evol 48, 892-903.
Zimmer EA, Martin SL, Beverley SM, Kan YW, Wilson AC (1980). Rapid duplication and loss of genes coding for the alpha chains of hemoglobin. Proc Natl Acad Sci 77, 2158-2162.
首页