RESUMO
Complete mitochondrial genomes were newly sequenced for eight species of the treehopper subfamily Centrotinae (Hemiptera: Membracidae), four of which represent genera for which mitogenomes were not previously available. The new mitogenomes are generally similar in overall structure, gene order, base composition, and nucleotide content to those of previously sequenced species of the subfamily. Phylogenetic analyses were conducted using both maximum likelihood and Bayesian inference methods based on three separate nucleotide sequence datasets in which RNA gene sequences and/or third codon positions were either included or excluded from the concatenated protein-coding gene alignments. The results are consistent with previous phylogenies based on morphology and partial nuclear genome data, except for the lack of support for the monophyly of Leptocentrini. These results show that mitogenome sequences are informative of both ancient and recent divergence patterns within Centrotinae.
Assuntos
Genoma Mitocondrial , Hemípteros , Animais , Filogenia , Hemípteros/genética , Teorema de Bayes , Sequência de BasesRESUMO
Homosexual contact is one of the main transmission routes of HIV-1 epidemic in Hebei, China. Several subtypes of HIV are prevalent simultaneously in the population, which always lead to the emergency of unique recombinant forms (URFs). In this study, we reported two new URFs from two HIV-1 positive subjects infected through homosexual contact route in Hebei, China. Phylogenetic and recombinant analyses based on the near full-length genome of the two URFs both revealed the two URFs are the second generation of recombinant strains originated from CRF01_AE and CRF07_BC. The CRF01_AE segments of two URFs located in cluster 4 of CRF01_AE strains in the phylogenetic tree. The emergence of the novel CRF01_AE/CRF07_BC recombinant forms with complicated genomic structures indicated the importance of the continuous monitoring of the HIV-1 epidemic and new URFs among the men who have sex with men populations.
Assuntos
Infecções por HIV , HIV-1 , Minorias Sexuais e de Gênero , China/epidemiologia , Genoma Viral , Genótipo , Infecções por HIV/epidemiologia , HIV-1/genética , Homossexualidade Masculina , Humanos , Masculino , Filogenia , Recombinação Genética , Análise de Sequência de DNARESUMO
Although phytosterols in tobacco leaves have specific effects on tobacco quality, there is little research on the distribution of free and conjugated phytosterols in various tobacco leaves. In this paper, we explored the content and composition of phytosterols in representative cured tobacco leaves by gas chromatography of TMS-ether derivatives. We found that phytosterol contents in tobacco leaves ranged from 1.0 to 2.5 mg/g of dried leaf tissue, depending on different types of tobacco leaves. The majority of phytosterols (75-85%) were conjugated as ester and glycosides, with only about 15-25% existing in the free form. Furthermore, the genetic variability gives rise to the significant differences among different tobacco types with phytosterol levels: the contents of phytosterols in tobacco leaves decreased in the order of flue-cured tobacco, Oriental tobacco, Burley tobacco, cigar tobacco, and Maryland tobacco. At the same time, the tobacco curing process leads to a difference in phytosterol existing-form distribution in some variation laws.
