The genus Liriodendron belongs to the family Magnoliaceae, which resides within the magnoliids, an early diverging lineage of the Mesangiospermae. However, the phylogenetic relationship of magnoliids with eudicots and monocots has not been conclusively resolved and thus remains to be determined1–6. Liriodendron is a relict lineage from the Tertiary with two distinct species—one East Asian (L. chinense (Hemsley) Sargent) and one eastern North American (L. tulipifera Linn)—identified as a vicariad species pair. However, the genetic divergence and evolutionary trajectories of these species remain to be elucidated at the whole-genome level7. Here, we report the first de novo genome assembly of a plant in the Magnoliaceae, L. chinense. Phylogenetic analyses suggest that magnoliids are sister to the clade consisting of eudicots and monocots, with rapid diversification occurring in the common ancestor of these three lineages. Analyses of population genetic structure indicate that L. chinense has diverged into two lineages—the eastern and western groups—in China. While L. tulipifera in North America is genetically positioned between the two L. chinense groups, it is closer to the eastern group. This result is consistent with phenotypic observations that suggest that the eastern and western groups of China may have diverged long ago, possibly before the intercontinental differentiation between L. chinense and L. tulipifera. Genetic diversity analyses show that L. chinense has tenfold higher genetic diversity than L. tulipifera, suggesting that the complicated regions comprising east–west-orientated mountains and the Yangtze river basin (especially near 30° N latitude) in East Asia offered more successful refugia than the south–north-orientated mountain valleys in eastern North America during the Quaternary glacial period.
9 June 2021 in Genomics, Proteomics & Bioinformatics
The vagina contains at least a billion microbial cells, dominated by lactobacilli. Here we perform metagenomic shotgun sequencing on cervical and fecal samples from a cohort of 516 Chinese women of reproductive age, as well as cervical, fecal, and salivary samples from a second cohort of 632 women. Factors such as pregnancy history, delivery history, cesarean section, and breast feeding were all more important than menstrual cycle in shaping the microbiome, and such information would be necessary before trying to interpret differences between vagino-cervical microbiome data. Greater proportion of Bifidobacterium breve was seen with older age at sexual debut. The relative abundance of lactobacilli especially Lactobacillus crispatus was negatively associated with pregnancy history. Potential markers for lack of menstrual regularity, heavy flow, dysmenorrhea, and contraceptives were also identified. Lactobacilli were rare during breastfeeding or post-menopause. Other features such as mood fluctuations and facial speckles could potentially be predicted from the vagino-cervical microbiome. Gut and salivary microbiomes, plasma vitamins, metals, amino acids, and hormones showed associations with the vagino-cervical microbiome. Our results offer an unprecedented glimpse into the microbiota of the female reproductive tract and call for international collaborations to better understand its long-term health impact other than in the settings of infection or pre-term birth.
In the Supplementary Information file originally published with this Letter, the authors mistakenly omitted Supplementary Table 14; this has now been amended.
The gut microbiome has been the center of attention for human commensal microbiome studies. The vaginal microbiome is also densely populated with bacteria, viruses and fungi, and the presence of microorganisms beyond the cervix is increasingly reported in non-infectious conditions 1–3 . Due to the over 90% of human sequences in female reproductive tract samples 3,4 , metagenomic information has been very limited. 16S rRNA gene amplicon sequencing studies have identified community types in the vaginal microbiota, and observed its dynamic changes due to menstrual cycles and sexual behaviors in small cohorts 5,6 . Here we perform metagenomic shotgun sequencing on cervical samples from 516 women of reproductive age (more than 10-fold of the Human Microbiome Project (HMP) 4 ), and dissect major factors, especially pregnancy and delivery histories and contraception methods on the microbiome composition. Features of other body sites, such as mood fluctuations and facial speckles could potentially be deduced from the vagino-cervical microbiome. Our results offer an unprecedented glimpse into the microbiota in the female reproductive tract and imply disease susceptibilities that may be relieved by behavioural changes.
The vaginal microbiome is essential for women's health, yet its genomic diversity and interaction with the host remain incompletely characterized. Here we present the Global Vaginal Metagenome-assembled Genomes catalog, an extensive repository of vaginal microbial genomes generated by integrating 10,665 in-house Chinese metagenomes, with 2,967 publicly available metagenomes and 1,433 bacterial isolates. The catalog comprises 65,055 genomes from 890 prokaryotes, 11 eukaryotes and 6,590 viral taxonomic units, many not represented in public reference databases. We investigate virus-bacteria interactions, revealing conserved phages-host associations. We then identify substantial intraspecies genomic and functional variations displaying population-specific patterns. A metagenome-genome-wide association study identifies seven host genetic loci associated with vaginal species at study-wide significance and replicated in at least one independent cohort, notably connecting the gene OPRK1 with the potential pathogen Ureaplasma urealyticum. In summary, our research provides a comprehensive reference for future studies on genotype-phenotype interplay within the human vaginal microbiome.