Comparative analysis of codon usage bias in chloroplast genomes of ten medicinal species of Rutaceae.

Rutaceae family comprises economically important plants due to their extensive applications in spices, food, oil, medicine, etc. The Rutaceae plants is able to better utilization through biotechnology. Modern biotechnological approaches primarily rely on the heterologous expression of functional proteins in different vectors. However, several proteins are difficult to express outside their native environment. The expression potential of functional genes in heterologous systems can be maximized by replacing the rare synonymous codons in the vector with preferred optimal codons of functional genes. Codon usage bias plays a critical role in biogenetic engineering-based research and development. In the current study, 727 coding sequences (CDSs) obtained from the chloroplast genomes of ten Rutaceae plant family members were analyzed for codon usage bias. The nucleotide composition analysis of codons showed that these codons were rich in A/T(U) bases and preferred A/T(U) endings. Analyses of neutrality plots, effective number of codons (ENC) plots, and correlations between ENC and codon adaptation index (CAI) were conducted, which revealed that natural selection is a major driving force for the Rutaceae plant family's codon usage bias, followed by base mutation. In the ENC vs. CAI plot, codon usage bias in the Rutaceae family had a negligible relationship with gene expression level. For each sample, we screened 12 codons as preferred and high-frequency codons simultaneously, of which GCU encoding Ala, UUA encoding Leu, and AGA encoding Arg were the most preferred codons. Taken together, our study unraveled the synonymous codon usage pattern in the Rutaceae family, providing valuable information for the genetic engineering of Rutaceae plant species in the future.

[Discussion on the regular of acupoint selection of acupuncture and moxibustion for lumbar disc herniation during recent 10 years].

By taking "lumbar disc herniation", Chinese medicine", "acupuncture and moxibustion" as key words Chinese articles about acupuncture for lumbar disc herniation in recent 10 years were searched in three major Chinese databases of Wan fang database, VIP database and CNKI. Totally 546 relative articles were retrieved. After the elimination of invalid articles, 173 were included as valid articles with 49 main acupoints. The hierarchical clustering statistical method was used to analyze the possible rules among the former 20 acupoints. It turned out that there were 10 most common used acupoints on Bladder Meridian [Geshu (BL 17), Xiaochangshu (BL 27), Shenshu (BL 23), Dachangshu (BL 25), Pangguangshu (BL 28), Guanyuanshu (BL 26), Weizbong (BL 40), Zhibian (BL 54), Chengshan (BL 57), Kunlun (BL 60)], 2 on Gallbladder Meridian [Huantiao (GB 30), Yanglingquan (GB 34)], 2 on Governor Vessel [Yaoyangguan (GV 3), Shuigou (GV 26)], 2 on Stomach Meridian [Zusanli (ST 36), Juliao (ST 3)], 2 on Spleen Meridian [Sanyinjiao (SP 6), Xuehai (SP 10)], and the rest were extra points (Huatuo Jiaji) and Ashi points, so a conclusion could be drawn that the most common used acupoints were Bladder Meridian acupoints and supplemented by Gallbladder Meridian, Governor Vessel, Stomach Meridian, Spleen Meridian, extra points and Ashi points. The selected acupoints were most located on the lumbosacral region, leg and fewer located on the face, back and local part.