论文部分内容阅读
利用Mi-Seq高通量测序法,分析长江上游特有鱼类裸体异鳔鳅鮀(Xenophysogobio nudicorpa)的基因组微卫星序列,观察其微卫星的组成及其特征。结果显示:在所测得的2到5碱基微卫星重复单元中,两碱基重复所占比例最多(83.15%),其中又以AC/TG类型为主。AAT和ATC是三碱基重复单元出现频率最多的,比例分别为56.01%和13.46%,高于其他六种类型的总和。四碱基重复单元占所有微卫星序列比例的2.73%,AAAG、AAAT和AGAT三种类型出现的次数最多。五碱基重复单元中,只发现3种重复序列,并且重复次数仅在1~2次内。使用引物设计软件Primer Premier Version 5.0设计引物,选择合成50对,通过聚丙烯酰胺凝胶电泳检测,筛选出具有多态性的微卫星引物共23对。实验还对裸体异鳔鳅基因组微卫星各碱基重复单元的长度进行了分析,结果表明裸体异鳔鳅微卫星主要集中在12~20 bp的范围内,占比91.53%。分析认为,在趋同选择的压力下,重复序列有向较短序列进化的趋势。
The microsatellite sequence of Xenophysogobio nudicorpa from the endemic fish in the upper reaches of the Yangtze River was analyzed by Mi-Seq high-throughput sequencing and the microsatellite composition and its characteristics were observed. The results showed that in the measured 2 to 5-base microsatellite repeat units, two base repeats accounted for the largest proportion (83.15%), of which the AC / TG type was the major one. AAT and ATC are the most frequent occurrence of three base repeat units, the ratio was 56.01% and 13.46%, higher than the sum of the other six types. Four-base repeat units account for 2.73% of all microsatellite sequences, and AAAG, AAAT and AGAT occur most frequently. Five base repeat units, only three kinds of repeats were found, and the number of repeats was only within 1 ~ 2 times. Primer Premier Version 5.0 was used to design primers. 50 pairs of primers were selected and 23 microsatellite primers with polymorphism were screened by polyacrylamide gel electrophoresis. The experiment also analyzed the length of each base repeat unit in the genome DNA of the naked loach (Misgurnus datu). The results showed that the microsatellites of the loach were mainly located in the range of 12-20 bp, accounting for 91.53%. The analysis shows that under the pressure of convergence selection, the repetitive sequences tend to evolve to shorter sequences.