Bta-miR-301a targets ACVR1 to influence cleavage time and blastocyst formation rate of early embryos in cattle.

Accumulating evidence indicates that paternally-derived miRNAs play a crucial role in the development of early embryos and are regarded as the key factor in the successful development of somatic cell cloned embryos. In our previous study, bta-miR-301a was found to be highly expressed in bovine sperm, and was delivered into oocytes during fertilization. In this study, bioinformatics, dual luciferase reporter assays, rescue experiments and gain- and loss-of-function experiments indicated that ACVR1 is the target gene of bta-miR-301a in early bovine embryos. By microinjecting bta-miR-301a mimic into embryos of parthenogenetic or somatic cell nuclear transfer, we observed that bta-miR-301a prolonged the first cleavage time of the embryos and increased the blastocyst formation rate. Thus, this study provides preliminary evidence that bta-miR-301a influences remodeling of the microfilament skeleton, prolongs the first cleavage time, and improves the developmental competence of embryos by negatively regulating ACVR1 translation.

Inhibition of HSP90AA1 induces abnormalities in bovine oocyte maturation and embryonic development.

In brief: HSP90AA1 is a ubiquitous molecular chaperone that can resist cellular stress, such as oxidative stress and apoptosis, and mediate the efficacy and protein folding of normal cells during heat stress, as well as many other functions. This study further reveals the role of HSP90AA1 in bovine oocyte maturation and early embryonic development. Abstract: HSP90AA1, a highly abundant and ubiquitous molecular chaperone, plays important roles in various cellular processes including cell cycle control, cell survival, and hormone signaling pathways. In this study, we investigated the functions of HSP90AA1 in bovine oocyte and early embryo development. We found that HSP90AA1 was expressed at all stages of development, but was mainly located in the cytoplasm, with a small amount distributed in the nucleus. We then evaluated the effect of HSP90AA1 on the in vitro maturation of bovine oocytes using tanespimycin (17-AAG), a highly selective inhibitor of HSP90AA1. The results showed that inhibition of HSP90AA1 decreased nuclear and cytoplasmic maturation of oocytes, disrupted spindle assembly and chromosome distribution, significantly increased acetylation levels of α-tubulin in oocytes and affected epigenetic modifications (H3K27me3 and H3K27ac). In addition, H3K9me3 was increased at various stages during early embryo development. Finally, the impact of HSP90AA1 on early embryo development was explored. The results showed that inhibition of HSP90AA1 reduced the cleavage and blastocyst formation rates, while increasing the fragmentation rate and decreasing blastocyst quality. In conclusion, HSP90AA1 plays a crucial role in bovine oocyte maturation as well as early embryo development.

Dynamic functional network connectivity analysis in schizophrenia based on a spatiotemporal CPD framework.

Objective.Dynamic functional network connectivity (dFNC), based on data-driven group independent component (IC) analysis, is an important avenue for investigating underlying patterns of certain brain diseases such as schizophrenia. Canonical polyadic decomposition (CPD) of a higher-way dynamic functional connectivity tensor, can offer an innovative spatiotemporal framework to accurately characterize potential dynamic spatial and temporal fluctuations. Since multi-subject dFNC data from sliding-window analysis are also naturally a higher-order tensor, we propose an innovative sparse and low-rank CPD (SLRCPD) for the three-way dFNC tensor to excavate significant dynamic spatiotemporal aberrant changes in schizophrenia.Approach.The proposed SLRCPD approach imposes two constraints. First, the L1regularization on spatial modules is applied to extract sparse but significant dynamic connectivity and avoid overfitting the model. Second, low-rank constraint is added on time-varying weights to enhance the temporal state clustering quality. Shared dynamic spatial modules, group-specific dynamic spatial modules and time-varying weights can be extracted by SLRCPD. The strength of connections within- and between-IC networks and connection contribution are proposed to inspect the spatial modules. K-means clustering and classification are further conducted to explore temporal group difference.Main results.82 subject resting-state functional magnetic resonance imaging (fMRI) dataset and opening Center for Biomedical Research Excellence (COBRE) schizophrenia dataset both containing schizophrenia patients (SZs) and healthy controls (HCs) were utilized in our work. Three typical dFNC patterns between different brain functional regions were obtained. Compared to the spatial modules of HCs, the aberrant connections among auditory network, somatomotor, visual, cognitive control and cerebellar networks in 82 subject dataset and COBRE dataset were detected. Four temporal states reveal significant differences between SZs and HCs for these two datasets. Additionally, the accuracy values for SZs and HCs classification based on time-varying weights are larger than 0.96.Significance.This study significantly excavates spatio-temporal patterns for schizophrenia disease.

The effect of L-carnitine supplementation during in vitro maturation on oocyte maturation and somatic cloned embryo development.

The quality of the recipient cytoplasm was reported as a crucial factor in maintaining the vitality of SCNT embryos and SCNT efficiency for dairy cows. Compared with oocytes matured in vivo, oocytes matured in vitro showed abnormal accumulation and metabolism of cytoplasmic lipids. L-carnitine treatment was found to control fatty acid transport into the mitochondrial ß-oxidation pathway, which improved the process of lipid metabolism. The results of this study show that 0.5 mg/ml L-carnitine significantly reduced the cytoplasmic lipid content relative to control. No significant difference was observed in the rate of oocyte nuclear maturation, but the in vitro developmental competence of SCNT embryos was improved in terms of increased blastocyst production and lower apoptotic index in the L-carnitine treatment group. In addition, the pregnancy rate with SCNT embryos in the treatment group was significantly higher than in the control group. In conclusion, the present study demonstrated that adding L-carnitine to the maturation culture medium could improve the developmental competence of SCNT embryos both in vitro and in vivo by reducing the lipid content of the recipient cytoplasm.

Folic acids promote in vitro maturation of bovine oocytes by inhibition of ferroptosis via upregulated glutathione and downregulated Fe2+ accumulation.

Bovine embryos by in vitro fertilization have become the primary source of commercial embryo transfers globally. However, the developmental capacity of in vitro maturation (IVM) oocytes is considerably lower than that of in vivo maturation (IVO) oocytes, owing to the production of reactive oxygen species (ROS) via mitochondrial metabolism, which was higher in IVM oocytes than in IVO oocytes. To avoid the negative effects of ROS on embryo quality, folic acid (FA) was supplemented directly into the IVM medium to antagonize ROS production, however, the mechanisms remain unknown. In the present study, five levels of FA (0, 25, 50, 100, and 200 µM) were supplemented into the bovine oocyte culture medium. The maturation, cleavage, and blastocyst formation rates increased by 8.95 %, 6.94 %, and 4.36 %, respectively, in the 50 µM group compared to the 0 µM group. Moreover, 7904 differential genes were identified between 0 µM and 50 µM groups by transcriptome sequencing, and they were mainly enriched in 8 pathways. The glutathione, ROS, and Fe2+ levels in oocytes were found to be associated with ferroptosis. Our results revealed that 50 µM FA promoted the IVM of bovine oocytes and affected the expression of genes involved in the ferroptosis pathway. The downregulation of TFR1 and STEAP3 led to a decrease in intracellular Fe2+ accumulation, and the upregulation of GCL increased oocyte GSH levels, thereby reducing the production of ROS in the ferroptosis pathway. Our study provides a new insight into the molecular mechanisms by which FA promotes bovine oocyte development in vitro.

Sperm-borne lncRNA loc100847420 improves development of early bovine embryos.

Long non-coding RNAs (lncRNAs) act as competing endogenous RNAs (ceRNAs) that play a significant role in bovine embryo development; but the influence of sperm-borne lncRNA on the preimplantation development of bovine embryos has not been reported in detail. In this study, we aimed to clarify how sperm-borne lncRNAs can act to regulate early development of bovine embryos. Utilizing high-throughput sequencing technology and quantitative real-time PCR (qPCR), we found that the lncRNA, loc100847420, was highly enriched in bovine sperm and was carried into the oocyte during fertilization. Introduction of wild-type loc100847420 had no effect on cleavage rate of parthenogenetic embryos compared with injection of mutant loc100847420 (70.58 ± 2.85% vs 70.46 ± 1.98%, p > 0.05), but significantly improved the blastocyst rate (33.67 ± 2.40% vs 28.35 ± 3.06%, p < 0.05), total numbers of cells (p < 0.05), numbers of inner cell mass (ICM) cells (p < 0.05) and numbers of trophoblast (TE) cells (p < 0.05). In summary, the sperm-borne lncRNA, loc100847420, can improve the developmental potential of early bovine embryos.

Effect of ACY-1215 on cytoskeletal remodeling and histone acetylation in bovine somatic cell nuclear transfer embryos.

The latest studies indicated that in addition to alterations in abnormal chromosome epigenetic modifications, the abnormal cytoskeletal changes are also an important cause for the developmental failure of somatic cell nuclear transfer (SCNT) embryos. In the present study, the effects of ACY-1215, a specific inhibitor of HDAC6, on the acetylation of α-tubulin, histone epigenetic modification, spindle formation and embryonic development of early bovine SCNT embryos were studied. The results showed that acetylation of α-tubulin, H3K9, and H4K16 was significantly lower in SCNT embryos than in vitro fertilization (IVF) embryos. After ACY-1215 treatment, the acetylation level of α-tubulin, H3K9, and H4K16 of SCNT embryos was closer to that of IVF embryos. ACY-1215 treatment reduced spindle abnormalities, delayed the time of first cleavage of embryos, increased the total cell number and trophectoderm cells numbers, and reduced apoptosis in SCNT blastocysts. ACY-1215 regulated the process of embryonic epigenetic modification and cytoskeletal protein acetylation, corrected abnormal development of SCNT embryos, and improved SCNT embryonic development potential.