雷蒙德氏棉和亚洲棉SSR重复序列类型和丰度差异比较

 利用生物信息学相关方法对NCBI数据库中39277条亚洲棉（Gossypium arboretum L.）及63588条雷蒙德氏棉（Gossypium raimondii L.）的EST序列共计64.08 Mb（约相当于基因组的6.02％）分别进行拼接，比较分析了两棉种简单重复序列的重复类型及丰度差异。结果表明：拼接后的一致性序列中，亚洲棉比雷蒙德氏棉存在较高比例的单条序列簇；亚洲棉一至六碱基6种重复类型的SSR间隔距离分别比雷蒙德氏棉的大；亚洲棉中二到六碱基等5种重复类型的比例高于雷蒙德氏棉，但单碱基重复类型比例低于雷蒙德氏棉；两棉种的单碱基、四碱基和六碱基重复类型的优势重复基序和丰度也不同。因此，认为利用四、五、六碱基三种重复类型设计的SSR引物可以有效地鉴定亚洲棉和雷蒙德氏棉的基因组差异。对四倍体棉种的A、D亚组供体棉种中SSR的差异分析，为SSR标记开发、棉种起源和进化的深入研究提供更多有用的信息。

Comparison of SSR Types and Abundance Differences between G. raimondii and G. arboreum

The 39277 G.arboreum and 63588 G.raimondii ESTs from NCBI databases which were in a total sizes of 64.08 Mb(approximately 6.02% of total cotton genome)were respectively assembled by bioinformatical methods,and the differences of Simple Sequence Repeat(SSR)types and abundance between these two species were analyzed.The main results were shown as follow:The singleton ratios of G.arboretum were higher than those of G.raimondii in the assembled tentative consensus sequences;The interval distances of six SSR types which were from mononucleotide to hexa-nucleotide repeats in G.arboreum were farther than those of the six SSR types in G.raimondii,respectively;The percentages of the five repeat types which were from di-to hexa-nucleotides were higher in G.arboreum than that of the five repeat types in G.raimondii.However,the percentages of mononucleotide repeat type were lower in G.arboreum.Moreover,the advanced SSR motifs and abundance of mono-,tetra-,and hexa-nucleotides repeat types were also different between two species.Therefore,it is suggested that the primers designed according to the tetra-or more nucleotides repeat types can effectively identify the genome differences between G.arboreum and G.raimondii.The differential analysis of SSR types and abundance in the donor species for A and D sub-genome of the tetraploid species provides more useful information for SSR marker design and profound research of the origin and evolution of Gossypium species.