Project description:The product of the Bmal1 locus is an essential component of the circadian clock that plays important roles in various aspects of reproductive biology, and its disruption results in infertility. In an effort to identify the identity of the tissue specific clock that is responsible for this infertility, we used the steroidogenic factor-1 (Sf1) promoter to drive Cre-mediated recombination and genetically delete Bmal1 within cells of the reproductive axis. We show that Bmal1 within the reproductive axis of females is essential for normal fertility through its role in maintaining implantation, but is not required for normal estrous cycling. At the root of this biology appears to be a defect in the regulation of ovarian steroidogenic acute regulator (StAR) and its role in maintaining progesterone synthesis. This conclusion is based upon three observations. First, that deletion of Bmal1 within the reproductive axis leads to lower levels of StAR mRNA, and lower progesterone levels. Second, that progesterone supplementation of these conditional mutants rescues implantation. Third, transplantation of wild type ovaries into Bmal1 reproductive axis mutants results in 100% fertility. Our study suggests that ovarian Bmal1 is an essential peripheral clock governing implantation and fertility in female mice. Ten week old female Bmal1fxfx mice positive or negative for Cre-recombinase driven by the sf-1 promoter, housed in 12 hour light:12 dark, ad lib feeding and drinking conditions were sacrificed at ZT12 on 3.5dpc (3.5 days post copulation). For each array analysis, a pool of 3 RNA samples from 3 individual Bmal1fx/fxCresf-1 ovaries labeled with cy3 were co-hybridized with a pool of 3 RNA samples from Bmal1fx/fx ovaries labeled with cy5, according to Agilent protocols.
Project description:The product of the Bmal1 locus is an essential component of the circadian clock that plays important roles in various aspects of reproductive biology, and its disruption results in infertility. In an effort to identify the identity of the tissue specific clock that is responsible for this infertility, we used the steroidogenic factor-1 (Sf1) promoter to drive Cre-mediated recombination and genetically delete Bmal1 within cells of the reproductive axis. We show that Bmal1 within the reproductive axis of females is essential for normal fertility through its role in maintaining implantation, but is not required for normal estrous cycling. At the root of this biology appears to be a defect in the regulation of ovarian steroidogenic acute regulator (StAR) and its role in maintaining progesterone synthesis. This conclusion is based upon three observations. First, that deletion of Bmal1 within the reproductive axis leads to lower levels of StAR mRNA, and lower progesterone levels. Second, that progesterone supplementation of these conditional mutants rescues implantation. Third, transplantation of wild type ovaries into Bmal1 reproductive axis mutants results in 100% fertility. Our study suggests that ovarian Bmal1 is an essential peripheral clock governing implantation and fertility in female mice.
Project description:The product of the Bmal1 locus is an essential component of the circadian clock that plays important roles in various aspects of reproductive biology,and when disrupted results in infertility. In an effort to establish the identity of the tissue specific clock that is responsible for this infertility, we used the steroidogenic factor-1 (Sf1) promoter to drive Cre-mediated recombination and genetically delete Bmal1 within cells of the reproductive axis. We show that Bmal1 within the reproductive axis of females is essential for normal fertility through its role in maintaining implantation, but is not required for normal estrous cycling. At the root of this biology appears to be a defect in the ovaries, including regulation of ovarian lipid biosynthetic or metabolic processes and their roles in maintaining progesterone synthesis. This conclusion is based upon three observations. First, that deletion of Bmal1 within the reproductive axis reducesleads to affected transcripts in steroidogenic pathways for the LH receptor , and lowers progesterone levels. Second, that progesterone supplementation of these conditional mutants rescues implantation. Third, transplantation of wild type ovaries into Bmal1 reproductive axis mutants rescues fertility. Our study demonstrates the significance of ovarian Bmal1 as an overriding influence in experimental models of infertility. A time series was performed in time-mated C57Bl/6J mice to identiy oscillating transcripts. During the peak and trough of the majority of transcripts (ZT0 and ZT12) samples from Bmal1fx/fx Sf1Cre mice and control litermates as well and global Bmal1 nulls were also analyzed. The tissue types (ovary, pituitary) are not comparable.
Project description:The product of the Bmal1 locus is an essential component of the circadian clock that plays important roles in various aspects of reproductive biology,and when disrupted results in infertility. In an effort to establish the identity of the tissue specific clock that is responsible for this infertility, we used the steroidogenic factor-1 (Sf1) promoter to drive Cre-mediated recombination and genetically delete Bmal1 within cells of the reproductive axis. We show that Bmal1 within the reproductive axis of females is essential for normal fertility through its role in maintaining implantation, but is not required for normal estrous cycling. At the root of this biology appears to be a defect in the ovaries, including regulation of ovarian lipid biosynthetic or metabolic processes and their roles in maintaining progesterone synthesis. This conclusion is based upon three observations. First, that deletion of Bmal1 within the reproductive axis reducesleads to affected transcripts in steroidogenic pathways for the LH receptor , and lowers progesterone levels. Second, that progesterone supplementation of these conditional mutants rescues implantation. Third, transplantation of wild type ovaries into Bmal1 reproductive axis mutants rescues fertility. Our study demonstrates the significance of ovarian Bmal1 as an overriding influence in experimental models of infertility.
Project description:Analysis of Ubb knockout mouse testes at 7, 4, 21, and 28 dpp. Ubiquitin (Ub) is an essential protein found in all eukaryotic cells and plays important roles in a variety of cellular functions including germ cell development. Targeted disruption of the polyubiquitin gene Ubb results in male and female infertility in mice with germ cells arrested at meiotic prophase I. Whole testes from wild-type (WT) and Ubb−/− (KO) mice were harvested at 7, 14, 21, and 28 days postpartum. Total RNA was extracted and hybridized to Affymetrix Mouse Genome 430 2.0 arrays.
Project description:Analysis of Ubb knockout mouse testes at 7, 4, 21, and 28 dpp. Ubiquitin (Ub) is an essential protein found in all eukaryotic cells and plays important roles in a variety of cellular functions including germ cell development. Targeted disruption of the polyubiquitin gene Ubb results in male and female infertility in mice with germ cells arrested at meiotic prophase I.
Project description:miR-29a/b1 was reported to be involved in the regulation of reproductive function in female mice, but the underlying molecular mechanisms were not clear. In this study, female mice lacking miR-29a/b1 showed a delay in vaginal opening, irregular estrus cycles, ovulation disorder and infertility. However, the development of egg was normal in mutant mice and the ovulation disorder could be rescued by the superovulation treatment. The plasma level of luteinizing hormone (LH) was significantly lower in the mutant mice. Using iTRAQ coupled with LC-MS/MS, we found that the deficiency of miR-29a/b1 in mice resulted in an abnormal expression of a number of proteins involved in vesicular transport and secretion in the pituitary gland. The miR-29a/b1 targeting gene Dnmt3a and Hdac4 were up-regulated in the pituitary of miR-29a/b1 knockout mice suggesting that these two epigenetic writers may be the upstream causes for these phenotype changes due to miR-29a/b1 deficiency. These findings demonstrated that miR-29a/b1 is indispensable for the function of the reproductive axis through regulating LH secretion in the pituitary gland.
Project description:Estrogen receptor α (ERα) is a nuclear transcription factor crucial for the female reproductive function. We previously reported that mice lacking epithelial ERα in the epithelial cells of female reproductive tract (Wnt7aCre+;Esr1fl/fl, conditional knockout or cKO) were infertile, in part, due to an implantation defect. To determine if oviductal dysfunction also contributed to their infertility, we examined the fertilization rates and embryo development in vivo during the first few days of pregnancy. At 0.5 days post coitum (dpc), cKO females had significantly fewer zygotes than wild type control littermates (WT). At 1.5 dpc, cKO females had no 2-cell embryos at all; only dead oocytes or embryos and empty zona pellucidas were observed. These results indicate that lack of ERα in the oviductal epithelium resulted in alterations in the oviductal microenvironment that were detrimental to the embryos. Microarray analysis revealed dramatic differences in gene expression between cKO and WT oviducts collected at 0.5 dpc and significant but less dramatic differences at 1.5 dpc. These findings indicate that signaling via epithelial ERα is essential to generate an oviductal milieu supportive of fertilization and embryo development.and may have implications for infertility in women. The oviduct samples were collected from female reproductive tract epithelial ER α knockout (cKO) and wild type control littermates (WT) at days 1 and 2 of pregnancy (0.5 and 1.5 days post coitum). Each experimental group contains 4 replicates. Gene expression analysis was conducted by using Agilent Whole Mouse Genome 4�44 multiplex format oligo arrays (no. 014868; Agilent Technologies, Santa Clara, CA)
Project description:Obesity and liver diseases are associated with the disruption of the circadian clock that orchestrates mammalian physiology to optimize nutrient metabolism and storage. We show here that the activity of the circadian clock regulator BMAL1 is perturbed during liver fibrosis in humans. To understand the impact of BMAL1 perturbation in obesity and liver diseases, we assessed the impact of a high fat diet or leptin deficiency on Bmal1 knockout mice. While Bmal1 knockout mice were prone to obesity, they were protected against insulin resistance, hepatic steatosis, inflammation, and fibrosis. In addition to direct transcriptional regulation of metabolic programs by BMAL1, we show that adaptation disruption of the growth hormone and sex hormone pathways plays a critical role in this protection. Similar endocrine perturbations correlate with the development of liver fibrosis in humans, but were absent in hepatocyte specific Bmal1 knockout mice. This suggestsing that systemic endocrine perturbation associated with circadian disruptionthe disruption of BMAL1 activity is critical for the pathogenesis of metabolic and liver diseases.