Project description:Copper (Cu) is not only one of the essential trace elements for animal body, but also an important nutrient component for normal physiology and metabolism of animal reproductive system. Lack or excess of copper will directly or indirectly affect animal reproductive activities. However, the effect of copper on reproductive performance of boars and sows has not been studied and the effect of excessive Copper addition on reproductive performance of sows is even less, and the molecular mechanism is poorly understood. Here, we document that copper has the negative effects on the oocyte maturation and Organelle function. We show that copper exposure perturbs the porcine oocyte meiotic maturation and impair the spindle/chromosome structure, displaying an obviously defective spindle assembly, and abnormal distribution of actin dynamics and cortical granules. In addition, single-cell transcriptome analysis identifies target effectors of copper in porcine oocytes, which was further demonstrated that copper exposure affects the distribution and function of mitochondria, and high ROS levels, DNA damage, and early apoptosis in porcine oocytes. Collectively, we demonstrate that copper exposure causes abnormalities in mitochondrial function and distribution, resulting in increased oxidative stress ROS levels, DNA damage and apoptosis, ultimately leading to decreased quality of porcine oocytes.
Project description:Copper (Cu) is an essential trace element for animals, and also an important nutritional component for the normal physiology and metabolism of animal reproductive systems. An excess or lack of Cu will directly or indirectly affect animal reproductive activities. However, the effect of Cu, in particular excessive Cu, on the reproductive performance of sows has not been studied. Here, we report that excessive Cu had negative effects on oocyte maturation and organelle functions. We showed that Cu exposure perturbed porcine oocyte meiotic maturation and impaired spindle/chromosome structure, resulting in a defective spindle assembly, as well as the abnormal distribution of actin dynamics and cortical granules. In addition, single-cell transcriptome analysis identified the target effectors of Cu actions in porcine oocytes, further demonstrating that Cu exposure affects the mitochondrial distribution and function, leading to the high levels of reactive oxygen species, DNA damage, and early apoptosis of porcine oocytes. These findings demonstrate that Cu exposure causes abnormalities in the mitochondrial distribution and function, resulting in the increased oxidative stress and levels of reactive oxygen species, DNA damage, and apoptosis, ultimately leading to a decreased porcine oocyte quality.
Project description:Comparison of gene expresion profile of 4 SC clones and 4 SI clones at different time points defined a stabilization competency signiture required for successful reprogramming mRNA profilling 4 SI clones at 5 time points, 4 SC clones at 6 time points, and 3 feeder samples.
Project description:Comparison of gene expresion profile of 4 SC clones and 4 SI clones at different time points defined a stabilization competency signiture required for successful reprogramming
Project description:Chromosome aneuploidy increases in oocytes with maternal age, and is considered the leading cause for the increased incidence of infertility, miscarriage, and birth defects. Using mRNA-Sequencing of oocytes from 12 month old mouse versus 3 month young mouse, we identified a spindle assembly checkpoint gene, BubR1, whose expression was significantly decreased. We employed a mRNA microinjection based approach to increase BubR1 expression in aging oocytes. We find that increased expression of BubR1 protects against aneuploidy and chromosome misalignment in aging oocytes. After in vitro fertilization, the embryos derived from BubR1 increased expression aging oocytes exhibited chromosome stability as robust as those of the young ones. Furthermore, following embryo transfer, these embryos showed greatly improved developmental competency, with comparable levels of full-term development to those of the young ones. These results indicate that the decline in oocyte quality may be reversible and could lead to treatments that prolong female fertility. Examination of the effect of maternal aging on the mRNA expression in the mature oocytes of the female mice. Naturally ovulated mature oocytes (MII stage) were collected from 6 young (3 month) and 6 aging (12 month) female mice (3 oocytes per mice, 18 oocytes for each group).
Project description:Lactating cows experience transient metabolic stresses during postpartum which results in abnormal concentrations of non-esterified fatty acids and beta-hydroxybutyrate that can impact oocyte maturation and ultimately reproductive success. We hypothesize that metabolic challenges in lactating cows influence DNA methylation changes of the oocyte affecting genes involved in oocyte developmental competency. Therefore, we compared whole genome bisultfite sequencing (wgbs) of the oocytes collected from 5-6 week (early) or 9-10 week (mid) post-partum against that of oocytes from nulliparous heifers as metabolically unchallenged condition control. Bisulfite-Seq DNA libraries were generated from pooled oocytes using an EZ DNA methylation-direct kit and Pico-Methyl seq library preparation kit (Zymo Research), and parallel sequenced using the illumina HiSeq2500 system.
Project description:To identify genes which are differentially expressed in Corynebacterium glutamicum in the absence of copper, we performed DNA microarray analyses of cells cultivated under copper starvation conditions compared to copper sufficiency.
Project description:Chromosome aneuploidy increases in oocytes with maternal age, and is considered the leading cause for the increased incidence of infertility, miscarriage, and birth defects. Using mRNA-Sequencing of oocytes from 12 month old mouse versus 3 month young mouse, we identified a spindle assembly checkpoint gene, BubR1, whose expression was significantly decreased. We employed a mRNA microinjection based approach to increase BubR1 expression in aging oocytes. We find that increased expression of BubR1 protects against aneuploidy and chromosome misalignment in aging oocytes. After in vitro fertilization, the embryos derived from BubR1 increased expression aging oocytes exhibited chromosome stability as robust as those of the young ones. Furthermore, following embryo transfer, these embryos showed greatly improved developmental competency, with comparable levels of full-term development to those of the young ones. These results indicate that the decline in oocyte quality may be reversible and could lead to treatments that prolong female fertility.
Project description:The dynamic transcriptional regulation and interactions of human germlines and surrounding somatic cells during folliculogenesis remains unknown. Using RNA-Seq analysis of human oocytes and corresponding granulosa cells (GCs) spanning five follicular stages, we revealed unique features in transcriptional machinery, transcription factor networks and reciprocal interactions in human oocytes and GCs that displayed developmental-stage-specific expression patterns. Notably, we identified specific gene signatures of two cell types in particular developmental stage that may reflect developmental competency and ovarian reserve. Additionally, we uncovered key pathways that may concert germline-somatic interactions and drive the transition of primordial-to-primary follicle which represents follicle activation. Thus, our work provides key insights into the crucial features of the transcriptional regulation in the stepwise folliculogenesis and offers important clues for improving follicle recruitment in-vivo and restoring fully competent oocytes in-vitro.