Project description:Mouse oocytes control cumulus cell metabolic processes that are deficient in the oocytes themselves and this delegation is necessary for oocyte development. Oocyte-derived bone morphogenetic factor 15 (BMP15) and growth differentiation factor 9 (GDF9) appear to be key regulators of follicular development. The effect of these factors on cumulus cell function before the preovulatory surge of luteinizing hormone (LH) was assessed by analysis of the transcriptomes of cumulus cells from wildtype (WT), Bmp15-/-, and Bmp15-/- Gdf9+/- double mutant (DM) mice using microarray analysis. The biological themes associated with the most highly-affected transcripts were identified using bioinformatic approaches, IPA and GenMAPP/MAPPFinder. There were 5,332, 7,640, and 2,651 transcripts identified to be significantly changed in the comparisons of Bmp15-/- vs. WT, DM vs. WT, and DM vs. Bmp15-/- respectively by the criteria of FC (fold change) p <0.01. Among theses changed transcripts, 744 were commonly changed in all three pair-wise comparisons, and hence were considered to be the most highly affected transcripts by mutation of Bmp15 and Gdf9. IPA Analyses revealed that metabolism was the major theme associated with the most highly-changed transcripts: glycolysis and sterol biosynthesis were the two most significantly affected pathways. Most of the transcripts encoding enzymes for sterol biosynthesis were down-regulated in both mutant cumulus cells and in WT cumulus cell after oocytectomy. Similarly, there was a reduction of de novo-synthesized cholesterol in these cumulus cells. This suggests that oocytes regulate cumulus cell metabolism, particularly sterol biosynthesis, by promoting the expression of corresponding transcripts. Furthermore, in WT-mice, Mvk, Pmvk, Fdps, Sqle, Cyp51, Sc4mol, and Ebp, which encode enzymes in the sterol biosynthetic pathway, were found to be expressed robustly in cumulus cells, but expression was barely detectable in oocytes. Levels of de novo-synthesized cholesterol were significantly higher in cumulusâenclosed oocytes than denuded oocytes. These results indicate that mouse oocytes are deficient in their ability to synthesize cholesterol and require cumulus cells to provide them with products of the sterol biosynthetic pathway. Oocyte-derived BMP15 and GDF9 may promote this metabolic pathway in cumulus cells as compensation for their own deficiencies. Experiment Overall Design: Three sets of independent cumulus cell samples were collected for each genotype (wild type, Bmp15-/-, and Bmp15-/-Gdf9+/-) of mice, and were used for the array study as shown below. Experiment Overall Design: Array Genotype Sample Experiment Overall Design: GC_430_2_GES05_0161_033105_1.CEL WT 1 Experiment Overall Design: GC_430_2_GES05_0162_033105_1.CEL WT 2 Experiment Overall Design: GC_430_2_GES05_0163_033105_1.CEL WT 3 Experiment Overall Design: GC_430_2_GES05_0164_033105_1.CEL Bmp15-/- 4 Experiment Overall Design: GC_430_2_GES05_0165_033105_1.CEL Bmp15-/- 5 Experiment Overall Design: GC_430_2_GES05_0166_033105_1.CEL Bmp15-/- 6 Experiment Overall Design: GC_430_2_GES05_0167_033105_1.CEL DM 7 Experiment Overall Design: GC_430_2_GES05_0168_033105_1.CEL DM 8 Experiment Overall Design: GC_430_2_GES05_0169_033105_1.CEL DM 9
Project description:Mouse oocytes control cumulus cell metabolic processes that are deficient in the oocytes themselves and this delegation is necessary for oocyte development. Oocyte-derived bone morphogenetic factor 15 (BMP15) and growth differentiation factor 9 (GDF9) appear to be key regulators of follicular development. The effect of these factors on cumulus cell function before the preovulatory surge of luteinizing hormone (LH) was assessed by analysis of the transcriptomes of cumulus cells from wildtype (WT), Bmp15-/-, and Bmp15-/- Gdf9+/- double mutant (DM) mice using microarray analysis. The biological themes associated with the most highly-affected transcripts were identified using bioinformatic approaches, IPA and GenMAPP/MAPPFinder. There were 5,332, 7,640, and 2,651 transcripts identified to be significantly changed in the comparisons of Bmp15-/- vs. WT, DM vs. WT, and DM vs. Bmp15-/- respectively by the criteria of FC (fold change) p <0.01. Among theses changed transcripts, 744 were commonly changed in all three pair-wise comparisons, and hence were considered to be the most highly affected transcripts by mutation of Bmp15 and Gdf9. IPA Analyses revealed that metabolism was the major theme associated with the most highly-changed transcripts: glycolysis and sterol biosynthesis were the two most significantly affected pathways. Most of the transcripts encoding enzymes for sterol biosynthesis were down-regulated in both mutant cumulus cells and in WT cumulus cell after oocytectomy. Similarly, there was a reduction of de novo-synthesized cholesterol in these cumulus cells. This suggests that oocytes regulate cumulus cell metabolism, particularly sterol biosynthesis, by promoting the expression of corresponding transcripts. Furthermore, in WT-mice, Mvk, Pmvk, Fdps, Sqle, Cyp51, Sc4mol, and Ebp, which encode enzymes in the sterol biosynthetic pathway, were found to be expressed robustly in cumulus cells, but expression was barely detectable in oocytes. Levels of de novo-synthesized cholesterol were significantly higher in cumulus–enclosed oocytes than denuded oocytes. These results indicate that mouse oocytes are deficient in their ability to synthesize cholesterol and require cumulus cells to provide them with products of the sterol biosynthetic pathway. Oocyte-derived BMP15 and GDF9 may promote this metabolic pathway in cumulus cells as compensation for their own deficiencies. Keywords: Gdf9, Bmp15, cumulus cells, transcriptome, metabolism, sterol biosynthesis, genotype comparison, microarray, ingenuity pathways analyses.
Project description:Follicle stimulating hormone (FSH) and epidermal growth factor (EGF) are currently used on cumulus-oocyte complexes to mimic the luteinizing hormone surge in vitro and induce oocyte maturation and cumulus expansion. We have previously shown that addition of exogenous recombinant growth differentiation factor 9 (GDF9) during oocyte in vitro maturation led to an improvement of oocyte quality, as shown by an increased blastocyst percentage and fetal survival. Our objective was to characterize the effect of FSH/EGF and GDF9 treatments on mouse cumulus cells expression profile by microarray analysis. Cumulus-oocyte complexes (COCs) were recovered from 21 to 26 day old female 129/SV mice, 44 hours post equine chorionic gonadotropin treatment (eCG (5 IU)). For the microarray experiment whole COCs were treated with 293H control medium (0.125% v/v), with 20 ng/ml GDF9 or with a combination of 50 mIU/ml FSH and 10 ng/ml EGF. After 8 hours of in vitro maturation, COCs were denuded by gentle pipetting, the oocytes were removed and the cumulus cells centrifuged and extracted RNA analysed by microarray.
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: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:To characterize the genetic basis of hybrid male sterility in detail, we used a systems genetics approach, integrating mapping of gene expression traits with sterility phenotypes and QTL. We measured genome-wide testis expression in 305 male F2s from a cross between wild-derived inbred strains of M. musculus musculus and M. m. domesticus. We identified several thousand cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into eleven ‘hotspots,’ seven of which co-localize with QTL for sterility phenotypes identified in the cross. The number and clustering of trans eQTL - but not cis eQTL - were substantially lower when mapping was restricted to a ‘fertile’ subset of mice, providing evidence that trans eQTL hotspots are related to sterility. Functional annotation of transcripts with eQTL provides insights into the biological processes disrupted by sterility loci and guides prioritization of candidate genes. Using a conditional mapping approach, we identified eQTL dependent on interactions between loci, revealing a complex system of epistasis. Our results illuminate established patterns, including the role of the X chromosome in hybrid sterility.
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: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.