15种蔷薇属matK基因的密码子偏好性分析

Codon preference analysis of matK genes in 15 genera of Rose

基于15种蔷薇属叶绿体全基因组图谱,筛选其matK基因并对其密码子偏好性进行分析。结果表明:(1)GC1、GC_(2)、GC_(3)的平均值分别为39.09、31.75、27.98,密码子第1位的GC含量最高,第3位的GC含量最低,具有显著差异性;有效密码子数与第3位密码子的GC含量显著相关;(2)GC_(3)与GC_(12)的相关性不显著,且密码子的偏好性受自然选择的影响;(3)matK基因的有效密码子数低于预期值,位于标准曲线的下方,说明matK基因密码子的偏好性受到了选择的影响;(4)共计29个密码子的同义密码子相对使用度(RSCU)大于1,其中,有27个密码子均以A/U结尾,仅有2个密码子以G结尾,说明matK基因的密码子偏好以A或者U结尾。RSCU较高的3个密码子为UGA(3.00)、UCU(2.08)、ACU(1.98)。

The mat K genes in the chloroplast genomes of 15 genera of Rose were analyzed for codon preference.The results showed that the mean GC1,GC_(2) and GC_(3)contents were 39.09,31.75 and 27.98,respectively,and GC 1 content was significantly different from that of GC_(3).The effective codon number(ENC)was significantly correlated with the GC_(3) content.In contrast,the correlation between the content of GC_(3)and GC_(12) was insignificant,and the codon preference was affected by natural selection.The ENC of the mat K genes were lower than predicted values and located under the standard curve,indicating that the codon preferences of mat K gene were affected by natural selection.The relative synonymous codon usage(RSCU)of 29 codons were greater than 1,among which 27 codons ended with A/U and 2 codons ended with G,indicating the preferences of codon ending with A or U.The 3 codons with the highest RSCU values were UGA(3.00),UCU(2.08)and ACU(1.98).