DNA sequencing leads to genomics progress in China

Tracking and Mapping the Use of CRISPR-Cas Systems for Research in China

Scientists have floated the idea of a "Sputnik 2.0" technological race between the People's Republic of China (PRC) and the United States of America in CRISPR-based genome editing research. This quantitative analysis of articles published between 2010 and 2020 shows that research centers based in the PRC have succeeded in making CRISPR-based genome editing a standard tool. A corpus of 18,863 academic documents containing the acronym CRISPR in their abstract shows that although PRC-based research institutions were slower to start publishing on CRISPR, they have now outpaced the publication rate of institutions located in the European Union (EU). While U.S.-based institutions have kept their leading position in basic research, PRC-based research has become momentous in agriculture-related fields. This corpus hence illustrates how deeply the international landscape of life sciences research has shifted since the Human Genome Project, mostly to the PRC's advantage.

Recent Trends in Research on the Genetic Diversity of Plants: Implications for Conservation

Genetic diversity and its distribution, both within and between populations, may be determined by micro-evolutionary processes, such as the demographic history of populations, natural selection, and gene flow. In plants, indices of genetic diversity (e.g., k, h and π) and structure (e.g., FST) are typically inferred from sequences of chloroplast markers. Given the recent advances and popularization of molecular techniques for research in population genetics, phylogenetics, phylogeography, and ecology, we adopted a scientometric approach to compile evidence on the recent trends in the use of cpDNA sequences as markers for the analysis of genetic diversity in botanical studies, over the years. We also used phylogenetic modeling to assess the relative contribution of relatedness or ecological and reproductive characters to the genetic diversity of plants. We postulated that genetic diversity could be defined not only by microevolutionary factors and life history traits, but also by relatedness, so that species more closely related phylogenetically would have similar genetic diversities. We found a clear tendency for an increase in the number of studies over time, confirming the hypothesis that the advances in the area of molecular genetics have supported the accumulation of data on the genetic diversity of plants. However, we found that the vast majority of these data have been produced by Chinese authors, and refer specifically to populations of Chinese plants. Most of the data on genetic diversity have been obtained for species in the International Union for Conservation of Nature (IUCN) category NE (Not Evaluated), which indicates a relative lack of attention on threatened species. In general, we observed very high FST values in the groups analyzed and, as we focused primarily on species that have not been evaluated by the IUCN, the number of plant species that are threatened with extinction may be much greater than that indicated by the listing of this organization. We also found that the number of haplotypes (k) was influenced by the type of geographic distribution of the plant, while haplotype diversity (h) was affected by the type of flower, and the fixation index (FST), by the type of habitat. The plant species most closely-related phylogenetically have similar levels of genetic diversity. Overall, then, it will important to consider phylogenetic dependence in future studies that evaluate the effects of life-history traits on plant genetic diversity.

HDAM: a resource of human disease associated mutations from next generation sequencing studies

Background

Next generation sequencing (NGS) technologies have greatly facilitated the rapid and economical detection of pathogenic mutations in human disorders. However, mutation descriptions are hard to be compared and integrated due to various reference sequences and annotation tools adopted in different articles as well as the nomenclature of diseases/traits.

Description

The Human Disease Associated Mutation (HDAM) database is dedicated to collect, standardize and re-annotate mutations for human diseases discovered by NGS studies. In the current release, HDAM contains 1,114 mutations, located in 669 genes and associated with 125 human diseases through literature mining. All mutation records have uniform and unequivocal descriptions of sequence changes according to the Human Genome Sequence Variation Society (HGVS) nomenclature recommendations. Each entry displays comprehensive information, including mutation location in genome (hg18/hg19), gene functional annotation, protein domain annotation, susceptible diseases, the first literature report of the mutation and etc. Moreover, new mutation-disease relationships predicted by Bayesian network are also presented under each mutation.

Conclusion

HDAM contains hundreds rigorously curated human mutations from NGS studies and was created to provide a comprehensive view of these mutations that confer susceptibility to the common disorders. HDAM can be freely accessed at http://www.megabionet.org/HDAM.

Exploring the pathogenetic association between schizophrenia and type 2 diabetes mellitus diseases based on pathway analysis

BACKGROUND

Schizophrenia (SCZ) and type 2 diabetes mellitus (T2D) are both complex diseases. Accumulated studies indicate that schizophrenia patients are prone to present the type 2 diabetes symptoms, but the potential mechanisms behind their association remain unknown. Here we explored the pathogenetic association between SCZ and T2D based on pathway analysis and protein-protein interaction.

RESULTS

With sets of prioritized susceptibility genes for SCZ and T2D, we identified significant pathways (with adjusted p-value < 0.05) specific for SCZ or T2D and for both diseases based on pathway enrichment analysis. We also constructed a network to explore the crosstalk among those significant pathways. Our results revealed that some pathways are shared by both SCZ and T2D diseases through a number of susceptibility genes. With 382 unique susceptibility proteins for SCZ and T2D, we further built a protein-protein interaction network by extracting their nearest interacting neighbours. Among 2,104 retrieved proteins, 364 of them were found simultaneously interacted with susceptibility proteins of both SCZ and T2D, and proposed as new candidate risk factors for both diseases. Literature mining supported the potential association of partial new candidate proteins with both SCZ and T2D. Moreover, some proteins were hub proteins with high connectivity and interacted with multiple proteins involved in both diseases, implying their pleiotropic effects for the pathogenic association. Some of these hub proteins are the components of our identified enriched pathways, including calcium signaling, g-secretase mediated ErbB4 signaling, adipocytokine signaling, insulin signaling, AKT signaling and type II diabetes mellitus pathways. Through the integration of multiple lines of information, we proposed that those signaling pathways, which contain susceptibility genes for both diseases, could be the key pathways to bridge SCZ and T2D. AKT could be one of the important shared components and may play a pivotal role to link both of the pathogenetic processes.

CONCLUSIONS

Our study is the first network and pathway-based systematic analysis for SCZ and T2D, and provides the general pathway-based view of pathogenetic association between two diseases. Moreover, we identified a set of candidate genes potentially contributing to the linkage between these two diseases. This research offers new insights into the potential mechanisms underlying the co-occurrence of SCZ and T2D, and thus, could facilitate the inference of novel hypotheses for the co-morbidity of the two diseases. Some etiological factors that exert pleiotropic effects shared by the significant pathways of two diseases may have important implications for the diseases and could be therapeutic intervention targets.