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
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:A transcriptome study in mouse hematopoietic stem cells was performed using a sensitive SAGE method, in an attempt to detect medium and low abundant transcripts expressed in these cells. Among a total of 31,380 unique transcript, 17,326 (55%) known genes were detected, 14,054 (45%) low-copy transcripts that have no matches to currently known genes. 3,899 (23%) were alternatively spliced transcripts of the known genes and 3,754 (22%) represent anti-sense transcripts from known genes.
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:The Wnt/beta-catenin signalling pathway plays a central role in mammary stem cell homeostasis and in breast cancer. We employed the CD29hiCD24+ cell surface antigens to identify a subpopulation of mammary CSCs from Apc1572T/+, a mouse model for metaplastic breast adenocarcinoma, a subtype of triple-negative breast cancer in man. The MaCSCs are capable of recapitulating tumorigenesis when transplanted at low multiplicities in vivo, and of forming self-renewing organoids in vitro. Expression profiling of the different subpopulations sorted from normal and neoplastic mammary tissues revealed that the normal stem cell compartment is more similar to tumor cells than to their own differentiated progenies. Accordingly, Wnt signaling was found to be activated in the subpopulation encompassing normal mammary stem cells, though to a lesser degree than in the tumor cells. By comparing normal with cancer mouse mammary compartments, we were able to derive a MaCSC-specific signature composed of human orthologous genes able to predict poor survival, relapse and distant metastasis in human breast cancer. Finally, upon intravenous injection, only MaCSCs among the different tumor cell subpopulations are able to form metastatic lesions in a broad spectrum of anatomical sites. Overall, our data indicate that constitutive Wnt signaling activation interferes with mammary stem cell homeostasis leading to metaplasia and basal-like adenocarcinomas. The objective was to compare the: i) expression profiles between normal adult mammary stem cells and tumor cancer stem cells identified by Lin-CD29hiCD24+; ii) expression profile between adult stem cells and their differentiated counterparts both in normal and in tumor tissue to generate a cancer stem cell signature that can be used to compare with mammary human tumor expression data to predict survival and prognosis. To this aim five independent mammary adenocarcinomas from C57BL6/J Apc+/1572T mice and three independently isolated pools of mammary glands from C57BL6/J Apc+/+ mice were employed to sort 10,000 cells of each of the following populations: Lin-, Lin-CD29+CD24+ and Lin-CD29hiCD24+.
Project description:The Wnt/beta-catenin signalling pathway plays a central role in mammary stem cell homeostasis and in breast cancer. We employed the CD29hiCD24+ cell surface antigens to identify a subpopulation of mammary CSCs from Apc1572T/+, a mouse model for metaplastic breast adenocarcinoma, a subtype of triple-negative breast cancer in man. The MaCSCs are capable of recapitulating tumorigenesis when transplanted at low multiplicities in vivo, and of forming self-renewing organoids in vitro. Expression profiling of the different subpopulations sorted from normal and neoplastic mammary tissues revealed that the normal stem cell compartment is more similar to tumor cells than to their own differentiated progenies. Accordingly, Wnt signaling was found to be activated in the subpopulation encompassing normal mammary stem cells, though to a lesser degree than in the tumor cells. By comparing normal with cancer mouse mammary compartments, we were able to derive a MaCSC-specific signature composed of human orthologous genes able to predict poor survival, relapse and distant metastasis in human breast cancer. Finally, upon intravenous injection, only MaCSCs among the different tumor cell subpopulations are able to form metastatic lesions in a broad spectrum of anatomical sites. Overall, our data indicate that constitutive Wnt signaling activation interferes with mammary stem cell homeostasis leading to metaplasia and basal-like adenocarcinomas. The objective was to compare the: i) expression profiles between normal adult mammary stem cells and tumor cancer stem cells identified by Lin-CD29hiCD24+; ii) expression profile between adult stem cells and their differentiated counterparts both in normal and in tumor tissue to generate a cancer stem cell signature that can be used to compare with mammary human tumor expression data to predict survival and prognosis. To this aim five independent mammary adenocarcinomas from C57BL6/J Apc+/1572T mice and three independently isolated pools of mammary glands from C57BL6/J Apc+/+ mice were employed to sort 10,000 cells of each of the following populations: Lin-, Lin-CD29+CD24+ and Lin-CD29hiCD24+.