Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility.
Project description:Aged hematopoietic stem cells (HSCs) display myeloid-biased differentiation and reduced regenerative potential. In this study, we uncover that P-selectin (Selp) marks a subset of aged HSCs with reduced repopulation capacity. This population of HSCs expresses a prominent aging transcriptome. Overexpression of Selp in young HSCs impaired long-term reconstitution potential and repressed erythropoiesis. We show that IL-1β is elevated in aged bone marrow and administration of IL-1β induces expression of Selp and other aging-associated genes in HSCs. Finally, we demonstrate that transplantation of aged HSCs into young recipients restores a young-like transcriptome, specifically by repressing pro-inflammatory pathways, highlighting the important role of the bone marrow microenvironment in HSC aging.
Project description:Evidence indicates that the integrity of in utero embryonic development can influence late life healthy or unhealthy aging. However, specific links between embryonic development and late life aging are not well defined. Histone chaperone HIRA is thought to play a role in both early development and aging. Here, we explore the relationship between HIRA’s roles in development and aging by comparing lineage-specific constitutive and conditional Hira knock out in the murine pigmentary system, with constitutive knock out initiated during embryogenesis and conditional knock out in young adults. Embryonic Hira knockout leads to reduced melanoblast numbers during embryogenesis but wild type numbers of differentiated melanocytes at birth, normally functioning juvenile and young adult melanocyte stem cells (McSCs), and only a very mildly hypopigmented first hair coat. However, on closer analysis of these mice, Hira knockout melanocytic cells of newborn mice exhibit molecular markers characteristic of cell aging and proliferative deficits. As they age, mice with Hira knock out initiated during embryogenesis display marked defects in McSC maintenance and premature hair graying. Importantly, these defects are only observed when HIRA is inactivated during embryogenesis, but not in young adults. This genetic model shows that HIRA function during early development lays a foundation for subsequent maintenance of adult tissue specific stem cells during aging.
Project description:Evidence indicates that the integrity of in utero embryonic development can influence late life healthy or unhealthy aging. However, specific links between embryonic development and late life aging are not well defined. Histone chaperone HIRA is thought to play a role in both early development and aging. Here, we explore the relationship between HIRA’s roles in development and aging by comparing lineage-specific constitutive and conditional Hira knock out in the murine pigmentary system, with constitutive knock out initiated during embryogenesis and conditional knock out in young adults. Embryonic Hira knockout leads to reduced melanoblast numbers during embryogenesis but wild type numbers of differentiated melanocytes at birth, normally functioning juvenile and young adult melanocyte stem cells (McSCs), and only a very mildly hypopigmented first hair coat. However, on closer analysis of these mice, Hira knockout melanocytic cells of newborn mice exhibit molecular markers characteristic of cell aging and proliferative deficits. As they age, mice with Hira knock out initiated during embryogenesis display marked defects in McSC maintenance and premature hair graying. Importantly, these defects are only observed when HIRA is inactivated during embryogenesis, but not in young adults. This genetic model shows that HIRA function during early development lays a foundation for subsequent maintenance of adult tissue specific stem cells during aging.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:We collected whole genome testis expression data from hybrid zone mice. We integrated GWAS mapping of testis expression traits and low testis weight to gain insight into the genetic basis of hybrid male sterility. Gene expression was measured in whole testis from males aged 62-86 days. Samples include 190 first generation lab-bred male offspring of wild-caught mice from the Mus musculus musculus - M. m. domesticus hybrid zone.
Project description:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.
Project description:Muscle stem cells (MuSCs) are required for muscle regeneration. In resting muscles, MuSCs are kept in quiescence. After injury, MuSCs undergo rapid activation, proliferation and differentiation to repair damaged muscles. Age-associated impairments in stem cell functions correlate with a decline in somatic tissue regeneration capacity during aging. However, the mechanisms underlying the molecular regulation of adult stem cell aging remain elusive. Here, we obtained quisecent MuSCs from young, old, geriatric mice for high resolution mass spectrometry Bruker timsTOF Pro. By comparison of young proteome to old MuSCs proteome or geriatric MuSC proteome, we identified the pathways that are differentially during aging.