Project description:The oviducts play a critical role in gamete and embryo transport, as well as supporting fertilization and early embryo development. Progesterone receptor (PGR) is a transcription factor highly expressed in oviductal cells, while it’s activating ligand, progesterone (P4), surges to peak levels as ovulation approaches. P4 is known to regulate oviduct cilia beating and muscular contractions in vitro, but how PGR may mediate this in vivo is poorly understood. We used PGR-knockout (PRKO) mice to determine how PGR regulates oviductal function during the periovulatory period, in particular oviductal transport and embryo support. We used microarrays to identify putative PGR-regulated genes in the oviduct during the periovulatory period, a time when the oviduct is preparing to receive the newly-ovulated COC. The mutant strain used in this experiment were PRlacZ knock-in mice which originated from Assoc Prof John Lydon, Baylor College of Medicine, Houston TX, USA. The lacZ insertion results in disruption of transcription of both isoforms of PGR (Ismail et al, 2002, Mol Endocrinol 16:2475-2489), and therefore mice homozygous for the lacZ insertion are a phenocopy of the knockout strain described by Lydon et al. (1995, Genes Dev. 9:2266-2278) and are hereafter referred to as PRKO. Heterozygous mice (PR+/-) are a phenocopy of WT and have normal fertility (Ismail et al, 2002) and are therefore appropriate controls. Whole oviducts were collected from pre-pubertal PRKO and PR+/- mice 8 h after a standard protocol for hormonal induction of ovulation. Day 21-23 old mice were injected i.p. with 5IU of equine chorionic gonadotropin (eCG) to stimulate follicle growth, followed 44-47 h later by i.p. injection of 5 IU of human chorionic gonadotropin (hCG) to trigger ovulatory processes. Oviducts from 15 animals were collected per genotype, with oviducts from 3 animals pooled per sample for a total of n = 5 samples per genotype.
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: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