Project description:Cerebral cortical-derived neurosphere cultures were exposed to ethanol to model heavy alcohol exposure during the period of cortical neurogenesis Keywords: Compared differentiated neurospheres pre-exposed to ethanol to untreated differentiated neurospheres
Project description:The fetal cerebral cortical neuroepithelium is a clonal mosaic, wherein populations of neural stem and daughter progenitor cells cycle asynchronously between multiple molecular states to generate cortical plate neurons. We hypothesized that these molecular states within neuroepithelial clonal colonies may be perturbed by fetal teratogens like alcohol, and that analyses of these perturbations may yield clues about mechanisms underlying teratogenesis. Fetal mouse dorsal telencephalon was microdissected at gestational day (GD) 12.5, dispersed single cells cultured for 5 days to yield clonal neurosphere cell aggregates, in either defined control culture media, or with a dose-range of ethanol. We assessed 68 gene transcripts by multiplexed RT-PCR in 264 individual neurospheres, across all treatment conditions. Cluster analysis resulted in the classification of control neurospheres into seven separate categories along a developmental trajectory from neuroepithelial, to transit-amplifying, to neuronal identity. Moreover, smaller control neurospheres were more immature than larger neurospheres. Ethanol exposure resulted in dose-related dissociation between neurosphere size and maturation state, with smaller neurospheres biased towards later maturation states. This pro-maturation effect was particularly pronounced at the highest doses of ethanol. These data suggest that ethanol facilitates neuroepithelial maturation with concurrent loss of stem cells, which may contribute to diminished brain growth.
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:Timed pregnant C57Bl6 mice were exposed to ethanol during a critical period, gestational day 15 to 18, of cerebral cortical development to identify gene expression changes in the cerebral cortex of developing fetus due to this ethanol exposure Keywords: Compared animals exposed to ethanol (alcohol fed group) to a pair-fed control group and both groups were normalized to a control group (animals fed adlibitum)
Project description:Purpose: The goal of this study to use ethanol-exposed human embryonic stem cell (hESC)-derived neural cells as models to investigate microRNA expression changes in the brains of subjects with alcohol use disorder (AUD). Methods: hESCs were differentiated into neural cells (mainly cortical interneurons), which were then cultured in media with or without ethanol (50-100 mM) for 7 days (by duplicate experiments). Total RNAs were extracted from hESC-derived neural cells (with or without ethanol exposure) for small RNA sequencing. The sequence reads were processed using the Comprehensive Analysis Pipeline for miRNA Sequencing Data (CAP-miRseq) workflow. Ethanol-induced miRNA transcriptomic changes were analyzed by the Limma-Voom method. Results: A 7-day ethanol exposure led to differential expression of six miRNAs (absolute FC>2.0 & P<0.05) in hESC-derived cortical interneurons. Three miRNAs were upregulated (>2-fold increase & P<0.05), while three other miRNAs were downregulated (> 2-fold decrease & P < 0.05) due to ethanol exposure. Conclusions: The hESC-derived neural cell model study can partially validate miRNA transcriptomic changes in postmortem brains of subjects with alcohol use disorder.
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:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other