Project description:Brain structure and function are sexually dimorphic. As neuroscience research has largely focused on the male brain and behavior, the female brain and, in particular, its inherent dynamics have been left underexplored. During the mammalian reproductive period, the female brain is exposed to fluctuating hormone levels over the cycles known as menstrual (in humans) or estrous (in rodents). Variation in estradiol levels has been shown to affect synaptic plasticity in the female brain, including changes in dendritic spine density systematically across the estrous cycle. Female emotionality and cognitive function vary with physiologically fluctuating sex hormone levels. However, the molecular mechanisms underlying the dynamic nature of the female brain structure and function are currently unknown. Here we show that neuronal chromatin organization in the female ventral hippocampus of mouse is dynamic and fluctuates across the estrous cycle. We find changes in chromatin organization associated with the transcriptional activity of nearby genes important for neuronal function, neurotransmission, synapse formation, and behavior. We also link these chromatin dynamics to variation in anxiety-like behavior and to fluctuations in dendritic spine and synaptic density in the ventral hippocampus. In terms of chromatin structure, within-female and between-sex variation are of similar magnitudes, emphasizing the importance of accounting for fluctuating sex-hormone levels in females in the studies of the brain epigenome and behavior. These results provide critical insights into the mechanisms underlying sex-hormone and sex-dependent variation in adult brain structure and function. The study also has implications for better understanding of sex-biased disorders such as depression and anxiety which are strongly associated with sex-hormone status in females and are twice as prevalent in women than in men. This study establishes a foundation for the development of sex-specific approaches to treat sex-biased neuropsychiatric disorders including depression and anxiety disorders.
Project description:We analyzed the transcriptome of the C57BL/6J mouse hypothalamus, hippocampus, neocortex, and cerebellum to determine estrous cycle-specific changes in these four brain regions. We found almost 16,000 genes are present in one or more of the brain areas but only 210 genes, ~1.3%, are significantly changed as a result of the estrous cycle. The hippocampus has the largest number of differentially expressed genes (DEGs) (82), followed by the neocortex (76), hypothalamus (63), and cerebellum (26). Most of these DEGs (186/210) are differentially expressed in only one of the four brain regions. A key finding is the unique expression pattern of growth hormone (Gh) and prolactin (Prl). Gh and Prl are the only DEGs to be expressed during only one stage of the estrous cycle (metestrus). To gain insight into the function of the DEGs, we examined gene ontology and phenotype enrichment and found significant enrichment for genes associated with myelination, hormone stimulus, and abnormal hormone levels. Additionally, 61 of the 210 DEGs are known to change in response to estrogen in the brain. 50 genes differentially expressed as a result of the estrous cycle are related to myelin and oligodendrocytes and 12 of the 63 DEGs in the hypothalamus are oligodendrocyte- and myelin-specific genes. This transcriptomic analysis reveals that gene expression in the female mouse brain is remarkably stable during the estrous cycle and demonstrates that the genes that do fluctuate are functionally related.
Project description:Males and females often differ on propensity for a substance use disorder (SUD), etiology and clinical manifestation of SUD, and response to SUD treatment strategies (Riley et al 2018). The fluctuation of sex-related hormones in the brain and/or circulation may contribute to some of these differences. For example, estradiol activity has been associated with sensitivity to drugs of abuse (Tonn Eisinger et al 2018) and vulnerability to SUD (Anker and Carroll 2011). In particular, estrogen can affect the dopamine system in brain and this may contribute to differences in the etiology and the clinical manifestation of SUD (Bobzean et al 2014). Without direct association with SUD, others have shown that stage of the estrous cycle influences RNA transcription levels and splicing in particular brain regions (Duclot and Kabbaj 2015; DiCarlo et al 2017). What has not been thoroughly explored is whether genetic factors can modify the effect of estrous cycle on RNA transcript and ultimately, whether the interaction of these two factors can influence the sex-related differences in SUD vulnerability.
Project description:The hippocampus is a critical brain region for coordinating learning, memory, and behavior. In adult females, the estrus cycle alters these functions through the activity of steroids hormones, with well-characterized effects on cellular physiology and behavior. However,the molecular genetic basis of these outcomes has not been systematically explored. In order to better understand the role of sex and the estrous cycle in the hippocampus, we profiled the transcriptome of hippocampi from female mice in each stage of the estrus cycle, along with those of males. We identify only subtle sex differences in gene expression between the sexes on average, yet comparing males to individual estrous stages reveals ~100 genes deviating from male expression patterns at one point in their cyclic fluctuations across estrous cycle. These estrus-responsive genes are especially enriched in oligodendrocytes and glycinergic neurons, and are potentially regulated downstream of estrogen receptor repressed pathways. To further understand our previous observations of female- and estrous-specific behavioral outcomes in knockout of Cnih3, we performed the same profiling in the knockout strain. Surprisingly, Cnih3 knockouts showed far broader transcriptomic differences between estrous cycle stages and males, despite very subtle within-group-across-genotype expression changes. We show that Cnih3 knockout drives expression changes in opposing directions between males and all points of the estrous cycle, extensively accentuating the magnitude of sex-differential hippocampal gene expression compared to wild-types. We thus provide a novel resource characterizing estrous-specific gene expression patterns in the adult hippocampus, which can provide insights into mechanisms of sex differential neuropsychiatric functions and dysfunctions, and identify a role for Cnih3 in buffering the female brain against the transcriptional effects of estrous.
Project description:This study attempted to reveal the profile of the oviductal gene expression at each stage of estrous cycle by microarray analyses The oviductal tissue was separately collected at four stages of the estrous cycle, i.e., proestrus, estrus, metestrus, and diestrus.
Project description:The uterus, a female reproductive organ regulated by the sex hormones estrogen and progesterone, undergoes periodic cyclical changes. The estrous cycle refers to the reproductive cycle in non-primate mammalian females. During the mouse estrous cycle, the uterus undergoes various physiological changes as a result of dynamic hormonal changes. Accurate regulation of these changes is crucial for the establishment of a successful pregnancy. Notably, estrogen plays an important role in the regulation of the proestrus and estrus stages of the estrous cycle. Family with sequence similarity 3 (Fam3) is a cytokine-like gene family with four members: Fam3a, Fam3b, Fam3c, and Fam3d. Expression and regulation of the Fam3 family members in mouse uterine physiology remain largely unknown. Therefore, this study aimed to investigate the expression of Fam family members in the uterus during the estrous cycle and evaluate its regulation by estrogen using a mouse model. Analysis of mouse uterine RNA sequencing data revealed upregulated expression of Fam3b, Fam3c, and Fam3d during the proestrus and estrus stages. Fam3d expression was dynamically regulated during the estrous cycle, with high expression levels during the proestrus and estrus stages. To investigate whether Fam3d expression is regulated by estrogen, we administered estradiol (E2) to ovariectomized mice at different time points. Fam3d expression was highest 24 h after E2 injection, suggesting that estrogen plays a crucial role in regulating Fam3d expression. Furthermore, inhibition experiments using the estrogen receptor alpha (ERα) antagonist ICI revealed that estrogen regulates Fam3d expression through the ERα-mediated pathway. Immunofluorescence staining demonstrated that FAM3D was exclusively expressed in the luminal and glandular epithelia but not in the stroma. Additionally, FAM3D was predominantly localized in the cytoplasm, particularly in the apical region, and not in the nucleus. These findings provide valuable insights into the potential role of Fam3d in the uterus and lay the groundwork for future research on its function and significance in uterine physiology.
Project description:To investigate the impact of the reproductive cycle on adipose tissue, we analyzed transcriptome profiling across the entire estrous cycle in the adipose tissue of female mice.
Project description:Saliva is considered as the best source for biomarker-discovery studies, since it is a non-invasive method when compared to other body sources. Usually, buffalo cannot express their estrus signs precisely. Hence, there is a need for concise methods to detect the time of estrus to ensure the success in artificial insemination. Therefore, we have established a reference proteome map on buffalo whole saliva during estrous cycle in order to document the estrus-specific proteins using SDS-PAGE and mass spectrometry. The present findings conclude that the proteomic approach adopted to identify the proteins from buffalo saliva around estrous cycle may provide a new tool for screening the estrus phase.
Project description:Female mammalian brains exhibit sex-hormone-driven plasticity during the reproductive period. Evidence implicates the role of chromatin dynamics in gene regulation underlying this plasticity. However, whether ovarian hormones impact higher-order chromatin organization in post-mitotic neurons in vivo is unknown. Here, we mapped 3D genome of ventral hippocampal neurons across the estrous cycle and by sex in mice. In females, we found cycle-driven dynamism in 3D chromatin organization, including in estrogen-response-elements-enriched X-chromosome compartments, autosomal CTCF loops, and enhancer-promoter interactions. With rising estrogen levels, the female 3D genome becomes more similar to males. Cyclical enhancer-promoter interactions are partially associated with gene expression and enriched for brain disorder-relevant genes. Our study reveals unique 3D genome dynamics in the female brain relevant to female-specific gene regulation, neuroplasticity, and disease risk.