Project description:Thyroid hormone has a positive effect on endochondral bone growth. Few studies have looked at the interaction between thyroid hormone exposures and intramembranous bone derived cells. We used microarray as one tool to determine the gene expression profile of intramembranous (calvarial) derived murine pre-osteoblsts after thyroxine exposure.
Project description:Thyroid hormone has a positive effect on endochondral bone growth. Few studies have looked at the interaction between thyroid hormone exposures and intramembranous bone derived cells. We used microarray as one tool to determine the gene expression profile of intramembranous (calvarial) derived murine pre-osteoblsts after thyroxine exposure. We isolated whole RNA from MC3T3-E1 cells treated with proliferation media or proliferation media with thyroxine at a dose of 10^-6 mol./liter for 3 or 7 days in culture. We then used an Affymetrix array and compared expression profiles between control and experimental treatments.
Project description:Recently, serotonin and serotonin reuptake inhibitor (SSRI) drugs have been shown to have an effect on the development and maintenance of bone. However, little is known about its role in craniofacial development. We used microarray as one tool to determine the gene expression profile of intramembranous (calvarial) derived murine pre-osteoblasts after citalopram (SSRI) exposure.
Project description:Thyroid hormone is know to effect growth and development. However little is know about the hormone thyroxine's effect on craniofacial growth and suture development. We used microarray as one tool to determine gene expression profile of wild type and craniosynostotic (Twist 1 +/-) suture cells after thyroxine exposure. We isolated whole RNA from Wild type C57BL6 and Twist 1 +/- suture derived calvarial cells and treated with proliferation media and with thyroxine 10^-6 mol/liter for 3 or 7 days in culture. We then used an Affymetrix array and compared expression profiles between control and experimental treatments.
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:Background: It has widely been observed that young children are capable of reossifying large calvarial defects, while adults lack this endogenous tissue-engineering capacity. The ability of juvenile animals to regenerate calvarial defects has been investigated in multiple animal models, including mice. In this study, the authors used cDNA microarrays to investigate the expression of osteogenesis-associated genes upstream and downstream of Runx2 in juvenile and adult mouse calvaria. Methods: Nonsuture-associated parietal bone discs were harvested from 6-day-old (n = 50) and 60-day-old (n = 35) male CD-1 mice. After separation of the underlying dura mater and overlying pericranium, the calvarial discs were snap-frozen and RNA was extracted from pooled samples of calvaria for microarray analysis. Genes analyzed included cytokines, receptors, and cell-surface and matrix proteins both upstream and downstream of Runx2. Results: Genes associated with the Runx2 pathway had notably higher levels in the juvenile versus adult calvaria. All genes except for osteocalcin were expressed at least twofold higher in the juvenile calvaria. This pattern was validated with quantitative real-time polymerase chain reaction. In addition, mRNA for potent osteoinductive growth factors was present at higher levels in the juvenile compared with the adult calvaria. Conclusions: These findings reflect a genomic environment of active osteoblast differentia-tion and ossification in the juvenile calvaria compared with the adult aquiescent calvarial tissue. These data suggest that a decreased osteogenic potential of adult calvarial osteoblasts may, in part, explain the inability of adult animals to heal calvarial defects.
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.