ChIPr: accurate prediction of cohesin-mediated 3D genome organization from 2D chromatin features.

The three-dimensional genome organization influences diverse nuclear processes. Here we present Chromatin Interaction Predictor (ChIPr), a suite of regression models based on deep neural networks, random forest, and gradient boosting to predict cohesin-mediated chromatin interaction strength between any two loci in the genome. The predictions of ChIPr correlate well with ChIA-PET data in four cell lines. The standard ChIPr model requires three experimental inputs: ChIP-Seq signals for RAD21, H3K27ac, and H3K27me3 but works well with just RAD21 signal. Integrative analysis reveals novel insights into the role of CTCF motif, its orientation, and CTCF binding on cohesin-mediated chromatin interactions.

Computational modeling and analysis of the morphogenetic domain signaling networks regulating C. elegans embryogenesis.

Caenorhabditis elegans, often referred to as the 'roundworm', provides a powerful model for studying cell autonomous and cell-cell interactions through the direct observation of embryonic development in vivo. By leveraging the precisely mapped cell lineage at single cell resolution, we are able to study at a systems level how early embryonic cells communicate across morphogenetic domains for the coordinated processes of gene expressions and collective cellular behaviors that regulate tissue morphogenesis. In this study, we developed a computational framework for the exploration of the morphogenetic domain cell signaling networks that may regulate C. elegans gastrulation and embryonic organogenesis. We demonstrated its utility by producing the following results, i) established a virtual reference model of developing C. elegans embryos through the spatiotemporal alignment of individual embryo cell nuclear imaging samples; ii) integrated the single cell spatiotemporal gene expression profile with the established virtual embryo model by data pooling; iii) trained a Machine Learning model (Random Forest Regression), which predicts accurately the spatial positions of the cells given their gene expression profiles for a given developmental time (e.g. total cell number of the embryo); iv) enabled virtual 4-dimensional tomographic graphical modeling of single cell data; v) inferred the biology signaling pathways that act in each of morphogenetic domains by meta-data analysis. It is intriguing that the morphogenetic domain cell signaling network seems to involve some crosstalk of multiple biology signaling pathways during the formation of tissue boundary pattern. Lastly, we developed the Software tool 'Embryo aligner version 1.0' and provided it as an Open Source program to the research community for virtual embryo modeling, and phenotype perturbation analyses (https://github.com/csniuben/embryo_aligner/wiki and https://bioinfo89.github.io/C.elegansEmbryonicOrganogenesisweb/).

Prevalence of BRCA1/BRCA2 pathogenic variation in Chinese Han population.

BACKGROUND: Pathogenic variation in BRCA1 and BRCA2 (BRCA) is one of the most frequent genetic predispositions for hereditary breast cancer. The identification of the variant carriers plays an important role in prevention and treatment of cancer. Despite a population size of 1.4 billion and a quarter million annual new breast cancer cases, knowledge regarding the prevalence of BRCA variation in the Chinese population remains elusive. METHODS: In this study, we used BRCA-targeted sequencing and bioinformatics approaches to screen for BRCA variants in 11 386 Chinese Han individuals, including 9331 females and 2055 males. RESULTS: We identified 1209 BRCA variants, 34 of which were pathogenic, including 11 in BRCA1 and 23 in BRCA2. These variants were distributed among 43 individuals (37 females and 6 males), with 13 carrying BRCA1 and 30 carrying BRCA2 variants. Based on these data, we determined a prevalence of 0.38%, or 1 carrier of a BRCA pathogenic variant out of every 265 Chinese Han individuals, and 5.1 million carriers among the Chinese Han population of 1.3 billion. CONCLUSION: Our study provides basic knowledge about the prevalence of BRCA pathogenic variation in the Chinese Han population. This information should be valuable for BRCA-related cancer prevention and treatment in the population.

Highly diversified core promoters in the human genome and their effects on gene expression and disease predisposition.

BACKGROUND: Core promoter controls transcription initiation. However, little is known for core promoter diversity in the human genome and its relationship with diseases. We hypothesized that as a functional important component in the genome, the core promoter in the human genome could be under evolutionary selection, as reflected by its highly diversification in order to adjust gene expression for better adaptation to the different environment. RESULTS: Applying the "Exome-based Variant Detection in Core-promoters" method, we analyzed human core-promoter diversity by using the 2682 exome data sets of 25 worldwide human populations sequenced by the 1000 Genome Project. Collectively, we identified 31,996 variants in the core promoter region (- 100 to + 100) of 12,509 human genes ( https://dbhcpd.fhs.um.edu.mo ). Analyzing the rich variation data identified highly ethnic-specific patterns of core promoter variation between different ethnic populations, the genes with highly variable core promoters, the motifs affected by the variants, and their involved functional pathways. eQTL test revealed that 12% of core promoter variants can significantly alter gene expression level. Comparison with GWAS data we located 163 variants as the GWAS identified traits associated with multiple diseases, half of these variants can alter gene expression. CONCLUSION: Data from our study reals the highly diversified nature of core promoter in the human genome, and highlights that core promoter variation could play important roles not only in gene expression regulation but also in disease predisposition.

Variants of DNA mismatch repair genes derived from 33,998 Chinese individuals with and without cancer reveal their highly ethnic-specific nature.

PURPOSE: DNA mismatch repair (MMR) genes play important roles in maintaining genome stability. Mutations in MMR genes disrupt their mismatch repair function, cause genome instability and lead to increased risk of cancer in the mutation carriers as represented by Lynch Syndrome. Studies have identified a large number of MMR variants, mostly in the Caucasian population, whereas data from non-Caucasian populations remain poorly illustrated. With the population size of 1.4 billion, knowledge of MMR variants in the Chinese population can be valuable in understanding the roles of ethnic MMR variation and cancer and to further guide clinical applications in MMR-related cancer prevention and treatment in the Chinese population. In this study, we systematically analysed the MMR variants from the Chinese population. EXPERIMENTAL DESIGN: We performed a comprehensive MMR data mining and collected all the MMR variation data reported from 33,998 Chinese individuals consisting of 23,938 cancer and 10,060 non-cancer cases between January 1997 to May 2019. For the collected data, we performed standardisation following Human Genome Variation Society nomenclature and reannotated the MMR variant data following American College of Medical Genetics and Genomics guidelines and comparing with non-Chinese MMR data on various aspects. RESULTS: We identified a total of 540 MMR variants in the Chinese population, including 194 in MLH1, 181 in MSH2, 59 in MSH6, 53 in PMS2 single-base/indel changes and 53 large deletions/duplications in MLH1, MSH2, MSH6 and PMS2, respectively. We determined that the pathogenic/likely pathogenic carrier rate in the Chinese population was 1.6%. Comparative analysis in variant spectrum, variant types, clinical classification and founder mutations showed substantial differences of MMR variation between Chinese and non-Chinese populations and the fact that over 90% of the variants were only present in the Chinese ethnicity reveals the highly ethnic-specific nature of the Chinese MMR variation . We also developed an open-access database, dbMMR-Chinese, to host all data (https://dbMMR-chinese.fhs.um.edu.mo). The rich MMR data from a large non-Caucasian population should be valuable to study MMR variation and its relationship with cancer and provide a valuable reference resource for MMR-related cancer prevention and treatment. CONCLUSION: Our study provides the largest MMR data set from a single non-Caucasian population and reveals that MMR variation in the humans can be highly ethnic-specific.

Germline variation in BRCA1/2 is highly ethnic-specific: Evidence from over 30,000 Chinese hereditary breast and ovarian cancer patients.

BRCA1 and BRCA2 play essential roles in maintaining the genome stability. Pathogenic germline mutations in these two genes disrupt their function, lead to genome instability and increase the risk of developing breast and ovarian cancers. BRCA mutations have been extensively screened in Caucasian populations, and the resulting information are used globally as the standard reference in clinical diagnosis, treatment and prevention of BRCA-related cancers. Recent studies suggest that BRCA mutations can be ethnic-specific, raising the question whether a Caucasian-based BRCA mutation information can be used as a universal standard worldwide, or whether an ethnicity-based BRCA mutation information system need to be developed for the corresponding ethnic populations. In this study, we used Chinese population as a model to test ethnicity-specific BRCA mutations considering that China has one of the latest numbers of breast cancer patients therefore BRCA mutation carriers. Through comprehensive data mining, standardization and annotation, we collected 1,088 distinct BRCA variants derived from over 30,000 Chinese individuals, one of the largest BRCA data set from a non-Caucasian population covering nearly all known BRCA variants in the Chinese population (https://dbBRCA-Chinese.fhs.umac.mo). Using this data, we performed multi-layered analyses to determine the similarities and differences of BRCA variation between Chinese and non-Chinese ethnic populations. The results show the substantial differences of BRCA data between Chinese and non-Chinese ethnicities. Our study indicates that the current Caucasian population-based BRCA data is not adequate to represent the BRCA status in non-Caucasian populations. Therefore, ethnic-based BRCA standards need to be established to serve for the non-Caucasian populations.

Whole-Genome Sequencing of Brevundimonas diminuta XGC1, Isolated from a Tuberculosis Patient in Gujarat, India.

We report the draft genome of Brevundimonas diminuta strain XGC1, isolated from a tuberculosis-infected patient in Gujarat, India. This study also reveals that the B. diminuta XGC1 strain has acquired mutation to confer resistance to quinolone drugs.