Biology subjects

Ye, A. Y.

Publications and source records attributed to Ye, A. Y..

2 recordsLinked to original sources

bioRxiv2020

MosaicBase: A Knowledgebase of Postzygotic Mosaic Variants in Noncancer Diseases and Asymptomatic Human Individuals

Mosaic variants resulting from postzygotic mutations are prevalent in the human genome and play important roles in human diseases. However, except for cancer-related variant collections, there are no collections of mosaic variants in noncancer diseases and asymptomatic individuals. Here, we present MosaicBase (http://mosaicbase.cbi.pku.edu.cn/ or http://49.4.21.8:8000/), a comprehensive database that includes 6,698 mosaic variants related to 269 noncancer diseases and 27,991 mosaic variants identified in 422 asymptomatic individuals. The genomic and phenotypic information for each variant was manually extracted and curated from 383 publications. MosaicBase supports the query of variants with Online Mendelian Inheritance in Man (OMIM) entries, genomic coordinates, gene symbols, or Entrez IDs. We also provide an integrated genome browser for users to easily access mosaic variants and their related annotations within any genomic region. By analyzing the variants collected in MosaicBase, we found that mosaic variants that directly contribute to disease phenotype showed features distinct from those of variants in individuals with a mild or no phenotype in terms of their genomic distribution, mutation signatures, and fraction of mutant cells. MosaicBase will not only assist clinicians in genetic counseling and diagnosis but also provide a useful resource to understand the genomic baseline of postzygotic mutations in the general human population.

bioinformatics↗

bioRxiv2020

CTCF orchestrates long-range cohesin-driven V(D)J recombinational scanning

RAG endonuclease initiates V(D)J recombination in progenitor (pro)-B cells1. Upon binding a recombination center (RC)-based JH, RAG scans upstream chromatin via loop extrusion, potentially mediated by cohesin2-10, to locate Ds and assemble a DJH-based RC11. CTCF looping factor-bound elements (CBEs) within IGCR1 upstream of Ds impede RAG-scanning12-15; but their inactivation allows scanning to proximal VHs where additional CBEs activate rearrangement and impede scanning any further upstream15, 16. Distal VH utilization is thought to involve diffusional RC access following large-scale Igh locus contraction17-23. Here, we test the potential of linear RAG-scanning to mediate distal VH usage in G1-arrested, v-Abl-pro-B cell lines24, 25, which undergo robust D-to-JH but little VH-to-DJH rearrangements, presumably due to lack of locus contraction11, 15. Through an auxin-inducible approach26, 27, we degrade the cohesin-component Rad214, 7, 27 or CTCF7, 9 in these G1-arrested lines, which maintain substantial viability throughout four-day experiments. Rad21 degradation eliminated all V(D)J recombination and RAG-scanning-associated interactions, except RC-located DQ52-to-JH joining in which synapsis occurs by diffusion11. Remarkably, while CTCF degradation suppressed most CBE-based chromatin interactions, it promoted robust RC interactions with, and robust VH-to-DJH joining of, distal VHs, with patterns similar to those of "locus-contracted" primary pro-B cells. Thus, down-modulation of CTCF-bound scanning-impediment activity promotes cohesin-driven RAG-scanning across the 2.7Mb Igh locus.

immunology↗