Analysis of codon usage patterns and influencing factors in rice tungro bacilliform virus.

Rice tungro bacilliform virus (RTBV) belongs to genus Tungrovirus within the family Caulimoviridae harbors circular double-stranded DNA (dsDNA). Rice tungro disease (RTD) caused by RTBV, responsible for severe rice yield losses in South and Southeast Asia. Here, we performed a systematic evolutionary and codon usage bias (CUB) analysis of RTBV genome sequences. We analysed different bioinformatics techniques to calculate the nucleotide compositions, the relative synonymous codon usage (RSCU), and other indices. The results indicated slightly or low codon usage bias in RTBV isolates. Mutation and natural selection pressures have equally contributed to this low codon usage bias. Additionally, multiple factors such as host, geographical distribution also affect codon usage patterns in RTBV genomes. RSCU analysis revealed that RTBV shows mutation bias and prefers A and U ended codons to code amino acids. Codon usage patterns of RTBV were also found to be influenced by its host. This indicates that RTBV have evolved codon usage patterns that are specific to its host. The findings from this study are expected to increase our understanding of factors leading to viral evolution and fitness with respect to hosts and the environment.

The Cloning and Functional Characterization of Peach CONSTANS and FLOWERING LOCUS T Homologous Genes PpCO and PpFT.

Flowering is an essential stage of plant growth and development. The successful transition to flowering not only ensures the completion of plant life cycles, it also serves as the basis for the production of economically important seeds and fruits. CONSTANS (CO) and FLOWERING LOCUS T (FT) are two genes playing critical roles in flowering time control in Arabidopsis. Through homology-based cloning and rapid-amplifications of cDNA ends (RACE), we obtained full-lengths cDNA sequences of Prunus persica CO (PpCO) and Prunus persica FT (PpFT) from peach (Prunus persica (L.) Batsch) and investigated their functions in flowering time regulation. PpCO and PpFT showed high homologies to Arabidopsis CO and FT at DNA, mRNA and protein levels. We showed that PpCO and PpFT were nucleus-localized and both showed transcriptional activation activities in yeast cells, consistent with their potential roles as transcription activators. Moreover, we established that the over-expression of PpCO could restore the late flowering phenotype of the Arabidopsis co-2 mutant, and the late flowering defect of the Arabidopsis ft-1 mutant can be rescued by the over-expression of PpFT, suggesting functional conservations of CO and FT genes in peach and Arabidopsis. Our results suggest that PpCO and PpFT are homologous genes of CO and FT in peach and they may function in regulating plant flowering time.

parasitic worm infections in a flat commune of Quang Ninh province

442 stool samples in 2 groups of population of Lien Vi commune, Yen Hung district, Quang Ninh provine were examined by Kato method. The infection rate of Ascaris, Trichuris, hookworm were 83.7%, 70.3%, 16.7%, respectively. The infection rate of Opisthorchis viverrini was 5.6%. 607 stool samples from primary and basical schools in the commune were examined. The results showed that the infection rate of Ascaris, Trichuris, Hookworm were 99%, 89%, 7.3%, respectively. The mix infection rate was 70%. It was found that most of the local people were using not standardized latrines. They have a habit of using untreated stool as fertilizer or habit of eating raw fish and their low awareness about disease prevention