Selected Grantee Publications
A Global Catalog of Whole-Genome Diversity from 233 Primate Species
Kuderna et al., Science. 2023.
https://pubmed.ncbi.nlm.nih.gov/37262161/
Researchers are interested in studying the remarkable diversity of morphology and behavior across primates to answer long‑standing questions in evolutionary and conservation biology. Using whole-genome sequencing, the investigators created a nuclear DNA phylogeny and reassessed evolutionary divergence times among primate clades. They found that intraspecies genetic diversity across families and geographic regions was associated with climate and sociality, but not with extinction risk. Furthermore, mutation rates differed among species, potentially influenced by effective population sizes. Lastly, they identified extensive recurrence of missense mutations that previously were thought to be human specific. Supported by ORIP (P40OD024628).
Early Detection of Pseudocapillaria tomentosa by qPCR in Four Lines of Zebrafish, Danio rerio (Hamilton 1882)
Schuster et al., Journal of Fish Diseases. 2023.
https://onlinelibrary.wiley.com/doi/10.1111/jfd.13773
The intestinal nematode Pseudocapillaria tomentosa in zebrafish (Danio rerio) causes profound intestinal lesions, emaciation, and death and is a promoter of a common intestinal cancer in zebrafish. This nematode has been detected in an estimated 15% of zebrafish laboratories. Adult worms are readily detected about 3 weeks after exposure by either histology or wet mount preparations of the intestine, and larval worms are inconsistently observed in fish before this time. A quantitative PCR (qPCR) test was recently developed to detect the worm in fish and water, and here the authors determined that the test on zebrafish intestines was effective for earlier detection. Supported by ORIP (R24OD010998, P40OD011021).
Leukocyte Tyrosine Kinase (Ltk) Is the Mendelian Determinant of the Axolotl Melanoid Color Variant
Kabangu et al., Genes. 2023.
https://www.mdpi.com/2073-4425/14/4/904
The diversity of color patterns among amphibians is largely explained by the differentiation of a few pigment cell types during development. Mexican axolotls have a variety of color phenotypes, from leucistic to highly melanistic. The melanoid axolotl is a Mendelian variant characterized by large numbers of melanophores, fewer xanthophores, and no iridophores. Studies of melanoid were influential in developing the single-origin hypothesis of pigment cell development, proposing that all three pigment cell types derive from a common progenitor cell, with pigment metabolites playing potential roles in directing the development of organelles that define different pigment cell types. Xanthine dehydrogenase (XDH) activity was identified as a mechanism for the permissive differentiation of melanophores at the expense of xanthophores and iridophores. The authors used bulked segregant RNA-Seq (including a region on chromosome 14q) to screen the axolotl genome for melanoid candidate genes and identify the associated locus. The region 14q contains gephyrin (Gphn), an enzyme that catalyzes the synthesis of the molybdenum cofactor that is required for XDH activity, and Ltk, a cell surface signaling receptor required for iridophore differentiation in zebrafish. Wild-type Ltk crispants present similar pigment phenotypes to melanoid, strongly implicating Ltk as the melanoid locus. The results support the idea of direct fate specification of pigment cells, as well as the single-origin hypothesis of pigment cell development. Supported by ORIP (P40OD019794, R24OD010435, R24OD021479).
Effect of the Snake Venom Component Crotamine on Lymphatic Endothelial Cell Responses and Lymph Transport
Si et al., Microcirculation. 2023.
https://onlinelibrary.wiley.com/doi/10.1111/micc.12775
The pathology of snake envenomation is closely tied to the severity of edema in the tissue surrounding the area of the bite. This study focused on one of the most abundant venom components in North American viper venom, crotamine, and the effects it has on the cells and function of the lymphatic system. The authors found that genes that encode targets of crotamine are highly present in lymphatic tissues and cells and that there is a differential distribution of those genes that correlates with phasic contractile activity. They found that crotamine potentiates calcium flux in human dermal lymphatic endothelial cells in response to stimulation with histamine and shear stress—but not alone—and that it alters the production of nitric oxide in response to shear, as well as changes the level of F-actin polymerization of those same cells. Crotamine alters lymphatic transport of large molecular weight tracers to local lymph nodes and is deposited within the node, mostly in the immediate subcapsular region. Results suggest that snake venom components may have an impact on the function of the lymphatic system and provide new targets for improved therapeutics to treat snakebites. Supported by ORIP (P40OD010960).
A Live Dengue Virus Vaccine Carrying a Chimeric Envelope Glycoprotein Elicits Dual DENV2–DENV4 Serotype-Specific Immunity
Young et al., Nature Communications. 2023.
https://pubmed.ncbi.nlm.nih.gov/36914616/
Dengue vaccine development is challenging because some virus-specific antibodies are protective, whereas others are implicated in enhanced viral replication and more severe disease. Current dengue tetravalent vaccines contain four live attenuated serotypes formulated to induce balanced protective immunity. To simplify live-virus vaccine design, investigators identified co-evolutionary constraints inherent in flavivirus virion assembly. They found that the chimeric virus replicated efficiently in vitro and in vivo and that a single inoculation induced type-specific neutralizing antibodies in male macaques. These findings can be applied to the development of bivalent live dengue vaccines that induce independent immunity to multiple serotypes. Supported by ORIP (P40OD012217) and NIAID.
Evolution of the Nitric Oxide Synthase Family in Vertebrates and Novel Insights in Gill Development
Annona et al., Proceedings of the Royal Society B. 2022.
https://www.doi.org/10.1098/rspb.2022.0667
Nitric oxide (NO) plays essential roles in biological systems, including cardiovascular homeostasis, neurotransmission, and immunity. Knowledge of NO synthases (NOS) is substantial, but the origin of nos gene orthologues in fishes, with respect to tetrapods, remains largely unknown. The recent identification of nos3 in the spotted gar, considered lost in this lineage, prompted the authors to explore nos gene evolution. Here, they report that nos2 experienced several lineage-specific gene duplications and losses. Additionally, nos3 was found to be lost independently in two teleost lineages, Elopomorpha and Clupeocephala. Further, the expression of at least one nos paralogue in gills of developing shark, bichir, sturgeon, and gar, but not in gills of lamprey, suggests nos expression in the gill might have arisen in the last common ancestor of gnathostomes. These results provide a framework for further research on the role of nos genes. Supported by ORIP (P40OD019794, R01OD011116).
Large Comparative Analyses of Primate Body Site Microbiomes Indicate That the Oral Microbiome Is Unique Among All Body Sites and Conserved Among Nonhuman Primates
Asangba et al., Microbiology Spectrum. 2022.
https://www.doi.org/10.1128/spectrum.01643-21
Microbiomes are critical to host health and disease, but large gaps remain in the understanding of the determinants, coevolution, and variation of microbiomes across body sites and host species. Thus, researchers conducted the largest comparative study of primate microbiomes to date by investigating microbiome community composition at eight distinct body sites in 17 host species. They found that the oral microbiome is unique in exhibiting notable similarity across primate species while being distinct from the microbiomes of all other body sites and host species. This finding suggests conserved oral microbial niche specialization, despite substantial dietary and phylogenetic differences among primates. Supported by ORIP (P51OD010425, P51OD011107, P40OD010965, R01OD010980), NIA, NIAID, and NICHD.
Natural Disaster and Immunological Aging in a Nonhuman Primate
Watowich et al., PNAS. 2022.
https://www.pnas.org/content/119/8/e2121663119
Weather-related disasters can exacerbate existing morbidities and increase mortality risk. Researchers examined Hurricane Maria’s impact on immune cell gene expression in large, age-matched, cross-sectional samples from free-ranging rhesus macaques (Macaca mulatta) living on an isolated island. Hurricane Maria was significantly associated with differential expression of 4% of immune-cell-expressed genes and was correlated with age-associated alterations in gene expression, in addition to expression of key immune genes, dysregulated proteostasis networks, and greater expression of inflammatory immune cell-specific marker genes. These findings illuminate that natural disasters might become biologically embedded and contribute to earlier onset of disease and death. Supported by ORIP (P40OD012217), NIA, NIMH.
HDAC Inhibitor Titration of Transcription and Axolotl Tail Regeneration
Voss et al., Frontiers in Cell and Development Biology. 2021.
https://pubmed.ncbi.nlm.nih.gov/35036404/
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. These results implicate HDAC activity as a transcriptional mechanism that operates across cell types to regulate the alternative expression of genes that associate with regenerative success versus failure outcomes. Supported by ORIP (P40OD019794, R24OD010435, R24OD021479), NICHD, and NIGMS.
Deep Learning Is Widely Applicable to Phenotyping Embryonic Development and Disease
Naert et al., Development. 2021.
https://pubmed.ncbi.nlm.nih.gov/34739029/
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. Supported by ORIP (P40OD010997, R24OD030008), NICHD, NIDDK, and NIMH.