【作者】 孙俊； 房经贵； 孙其宝； 章镇；

【Author】 SUN Jun~(1,2),FANG Jing-gui~1,SUN Qi-bao~3,and ZHANG Zhen~(1*) (1 Horticulture Department,Nanjing Agricultural University,Nanjing 210095,China;2 Horticulture Department,Anhui Agricultural University,Hefei 230036,China;3 Horticulture Research Institute,Anhui Academy of Agriculture Science,Hefei 230031,China)

【机构】 南京农业大学园艺学院； 安徽农业大学园艺学院； 安徽省农科院园艺研究所；

【摘要】 根据Ty1-copia类逆转座子逆转录酶(reverse transcriptase RT)区域序列特征,研究了苹果基因组中逆转座子家族构成、特性及其进化关系。根据逆转座子RT保守序列设计引物,利用PCR从苹果嘎拉中克隆了20条RT片段,这些片段存在高度的异质性;结合已报道的37条苹果Ty1-copia类逆转座子RT片段,构建了系统发育树,发现家族1-6中具有转座活性的逆转座子的可能性较大;序列分析表明Ty1-copia类逆转座子是苹果基因组内序列重组的热点。利用RT序列为探针进行Southern杂交,苹果基因组内Ty1-copia类逆转座子拷贝数高、分布广泛,这使得基于Ty1-copia类逆转座子的分子标记能够成为研究苹果基因组进化及其与芽变关系的有力工具。更多还原

【Abstract】 Apple(Malus Mill.),prone to bud mutation,is a kind of woody perennial plant that propagates vegetatively.As the largest transposable element in the plant genome,retrotransposons are deemed to be involved in apple genetic instability and genome evolution.In the present study,twenty conserved domains of reverse transcriptase(RT) genes of Ty1-copia-like LTR retrotransposons were amplified from the cultivar Gala.Sequence analysis of clones demonstrated that these fragments were highly heterogeneous(divergence ranged from 11.5 to 98.8%).These 20 clones and previously reported 37 are combined for analyzing the genetic relationship,characteristics and evolution of Ty1-copia-like retrotransposon group in apple genome. The 57 fragments were used to construct phylogenetic tree.Groups 1-6 with closely related members inserted throughout the genome may contain transposable retrotransposons.Sequence analysis indicated that Ty1-copia-like retrotransposons were prone to recombination in apple genome.Southern blot hybridization using RT as a probe showed that Ty1-copia-like retrotransposons were integrated throughout the apple genome with high copy number,which made the retrotransposon possible an effective molecular marker to detect apple genome evolution events and to reveal its relationship with bud mutation.更多还原