Selected Grantee Publications
Sequence Diversity Analyses of an Improved Rhesus Macaque Genome Enhance its Biomedical Utility
Warren et al., Science. 2020.
https://science.sciencemag.org/content/370/6523/eabc6617
Investigators sequenced and assembled an Indian-origin female rhesus macaque (RM) genome using a multiplatform genomics approach that included long-read sequencing, extensive manual curation, and experimental validation to generate a new comprehensive annotated reference genome. As a result, 99.7% of the gaps in the earlier draft genome are now closed, and more than 99% of the genes are represented. Whole-genome sequencing of 853 RMs of both sexes identified 85.7 million single-nucleotide variants and 10.5 million indel variants, including potentially damaging variants in genes associated with human autism and developmental delay. The improved assembly of segmental duplications, new lineage-specific genes and expanded gene families provide a framework for developing noninvasive NHP models for human disease, as well as studies of genetic variation and phenotypic consequences. Supported by ORIP (P51OD011106, P51OD011107, P51OD011132, P51OD011104, U42OD024282, U42OD010568, R24OD011173, R24OD021324, R24OD010962), NHGRI, NIMH, NHLBI, and NIGMS.
Imbalance of Regulatory and Cytotoxic SARS-CoV-2-Reactive CD4+ T Cells in COVID-19
Meckiff et al., Cell. 2020.
https://pubmed.ncbi.nlm.nih.gov/33096020/
It is not clear why COVID-19 is deadly in some people and mild in others. To understand the underlying mechanism, investigators studied the contribution of CD4+ T cells in immune responses to SARS-CoV-2 infection. They analyzed single-cell transcriptomic data of >100,000 viral antigen-reactive CD4+ T cells from 40 COVID-19 patients. In hospitalized patients compared to non-hospitalized patients, they found increased proportions of cytotoxic follicular helper cells (TFH) and cytotoxic T helper (TH) cells responding to SARS-CoV-2 and reduced proportion of SARS-CoV-2-reactive regulatory T cells (TREG). Importantly, in hospitalized COVID-19 patients, a strong cytotoxic TFH response was observed early in the illness, which correlated negatively with antibody levels to SARS-CoV-2 spike protein. Polyfunctional TH1 and TH17 cell subsets were underrepresented in the repertoire of SARS-CoV-2-reactive CD4+ T cells compared to influenza-reactive CD4+ T cells. Together, these analyses provided insights into the gene expression patterns of SARS-CoV-2-reactive CD4+ T cells in distinct disease severities. Supported by ORIP (S10RR027366, S10OD025052), NIAID, NHLBI, and NIGMS.
A Frog with Three Sex Chromosomes that Co-Mingle Together in Nature: Xenopus tropicalis Has a Degenerate W and a Y that Evolved from a Z Chromosome
Furman et al., PLOS Genetics. 2020.
https://pubmed.ncbi.nlm.nih.gov/33166278/
Genetic systems governing sexual differentiation vary among species. Furman et al. investigated a frog with three sex chromosomes, the Western clawed frog, Xenopus tropicalis. They demonstrate that natural populations from the western and eastern edges of Ghana have a young Y chromosome, and that a male-determining factor on this Y chromosome is in a similar genomic location as a previously known female-determining factor on the W chromosome. Their findings are consistent with theoretical expectations associated with recombination suppression on sex chromosomes and demonstrate that several characteristics of old and established sex chromosomes can arise well before they become cytogenetically distinguished. Supported by ORIP (P40OD010997) and NICHD.
Intra-Strain Genetic Variation of Platyfish (Xiphophorus maculatus) Strains Determines Tumorigenic Trajectory
Lu et al., Frontiers in Genetics . 2020.
https://www.frontiersin.org/articles/10.3389/fgene.2020.562594/full
Xiphophorus interspecies hybrids represent a valuable model system to study heritable tumorigenesis. Although the ancestors of the two X. maculatus parental lines, Jp163 A and Jp163 B, were siblings produced by the same mother, backcross interspecies hybrid progeny between X. hellerii and X. maculatus Jp163 A develop spontaneous melanoma initiating at the dorsal fin due to a regulator encoded by the X. maculatus genome; the backcross hybrid progeny with X. hellerii or X. couchianus and Jp163 B exhibit melanoma on their flanks. Comparative genomic analyses revealed genetic differences are associated with pathways highlighting fundamental cellular functions. Disruption of these baselines may give rise to spontaneous or inducible tumorigenesis. Supported by ORIP (R24OD011120), NCI, and NIGMS.