Sequence Diversity Analyses of an Improved Rhesus Macaque Genome Enhance its Biomedical Utility
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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.
Estrogen Acts Through Estrogen Receptor 2b to Regulate Hepatobiliary Fate During Vertebrate Development
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During liver development, bipotent progenitor cells differentiate into hepatocytes and biliary epithelial cells to ensure a functional liver. The developmental cues controlling the differentiation of committed progenitors into these cell types are not completely understood. These authors report an essential role for estrogenic regulation in vertebrate liver development to affect hepatobiliary fate decisions.
Intra-Strain Genetic Variation of Platyfish (Xiphophorus maculatus) Strains Determines Tumorigenic Trajectory
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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.
Epidemiological and Molecular Characterization of a Novel Adenovirus of Squirrel Monkeys After Fatal Infection During Immunosuppression
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Adenoviruses frequently cause upper respiratory tract infections, often causing disseminated disease in immunosuppressed patients. A novel adenovirus was identified, squirrel monkey adenovirus 1 (SqMAdV-1), as the cause of a fatal infection in an immunocompromised squirrel monkey (Saimiri boliviensis). A nucleotide polymorphism at the stop codon of the DNA polymerase gene results in a 126 amino acid extension at the carboxy terminus. A single adenovirus variant, SqMAdV-3, has similarity to tufted capuchin (Sapajus apella) adenoviruses.
3-D Printed Customizable Vitrification Devices for Preservation of Genetic Resources of Aquatic Species
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Sperm vitrification as an alternative approach to conventional cryopreservation allows quick and low-cost sample preservation and is suitable for small-bodied aquatic species with miniscule testis, fieldwork at remote locations, and small-scale freezing for research purposes. Tiersch et al. report the developing of operational prototypes of 3-dimensional (3-D) printed vitrification devices. This study demonstrated the feasibility of developing standardized low-cost devices fabricated by 3-D printing with functions including vitrification, volume control, labeling, protection, and storage.
HDAC Inhibitor Titration of Transcription and Axolotl Tail Regeneration
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New patterns of gene expression are enacted and regulated during tissue regeneration. Romidepsin, an FDA-approved HDAC inhibitor, potently blocks axolotl embryo tail regeneration by altering initial transcriptional responses to injury. Regeneration inhibitory concentrations of romidepsin increased and decreased the expression of key genes. Single-nuclei RNA sequencing at 6 HPA illustrated that key genes were altered by romidepsin in the same direction across multiple cell types.
Deep Learning Is Widely Applicable to Phenotyping Embryonic Development and Disease
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Genome editing simplifies the generation of new animal models for congenital disorders. The authors illustrate how deep learning (U-Net) automates segmentation tasks in various imaging modalities. They demonstrate this approach in embryos with polycystic kidneys (pkd1 and pkd2) and craniofacial dysmorphia (six1). They provide a library of pre-trained networks and detailed instructions for applying deep learning to datasets and demonstrate the versatility, precision, and scalability of deep neural network phenotyping on embryonic disease models.
A Novel Non-Human Primate Model of Pelizaeus-Merzbacher Disease
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Pelizaeus-Merzbacher disease (PMD) in humans is a severe hypomyelinating disorder of the central nervous system (CNS) linked to mutations in the proteolipid protein-1 (PLP1) gene. Investigators report on three spontaneous cases of male neonatal rhesus macaques (RMs) with clinical symptoms of hypomyelinating disease. Genetic analysis revealed that the parents of these related RMs carried a rare, hemizygous missense variant in exon 5 of the PLP1 gene.
Whole-Organism 3D Quantitative Characterization of Zebrafish Melanin by Silver Deposition Micro-CT
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This research team combined micro-computed tomography (CT) with a novel application of ionic silver staining to characterize melanin distribution in whole zebrafish larvae. The resulting images enabled whole-body, computational analyses of regional melanin content and morphology. Normalized micro-CT reconstructions of silver-stained fish consistently reproduced pigment patterns seen by light microscopy and allowed direct quantitative comparisons of melanin content.
IL-21 Enhances Influenza Vaccine Responses in Aged Macaques with Suppressed SIV Infection
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Aging with HIV is associated with low-grade systemic inflammation, immune senescence, and impaired antibody (Ab) responses to such vaccines as influenza (flu). Researchers investigated the role of interleukin (IL)-21, a CD4 T follicular helper cell regulator, on flu vaccine Ab response in rhesus macaques in the context of age and controlled simian immunodeficiency virus (SIV) mac239 infection.