Data-driven control of oscillator networks with population-level measurement.

Controlling complex networks of nonlinear limit-cycle oscillators is an important problem pertinent to various applications in engineering and natural sciences. While in recent years the control of oscillator populations with comprehensive biophysical models or simplified models, e.g., phase models, has seen notable advances, learning appropriate controls directly from data without prior model assumptions or pre-existing data remains a challenging and less developed area of research. In this paper, we address this problem by leveraging the network's current dynamics to iteratively learn an appropriate control online without constructing a global model of the system. We illustrate through a range of numerical simulations that the proposed technique can effectively regulate synchrony in various oscillator networks after a small number of trials using only one input and one noisy population-level output measurement. We provide a theoretical analysis of our approach, illustrate its robustness to system variations, and compare its performance with existing model-based and data-driven approaches.

Cell-cell communications shape tumor microenvironment and predict clinical outcomes in clear cell renal carcinoma.

BACKGROUND: Cell-cell communications of various cell populations within tumor microenvironment play an essential role in primary tumor growth, metastasis evolution, and immune escape. Nevertheless, comprehensive investigation of cell-cell communications in the ccRCC (Clear cell renal carcinoma) microenvironment and how this interplay affects prognosis still remains limited. METHODS: Intercellular communications were characterized by single-cell data. Firstly, we employed "CellChat" package to characterize intercellular communications across all types of cells in microenvironment in VHL mutated and non-mutated samples from 8 patients, respectively. And pseudotime trajectory analyses were performed with monocle analyses. Finally clinical prognosis and immunotherapy efficacy with different landscapes of intercellular interplay are evaluated by TCGA-KIRC and immunotherapy cohort. RESULTS: Firstly, the VHL phenotype may be related to the intercellular communication landscape. And trajectory analysis reveals the potential relationship of cell-cell communication molecules with T cells and Myeloid cells differentiation. Furthermore, those molecules also correlate with the infiltration of T cells and Myeloid cells. A tumor cluster with highly expressed ligands was defined by quantitative analysis and transcription factor enrichment analysis, which was identified to be pivotal for intercellular communications in tumor microenvironment. Finally, bulk data indicates bulk that different clusters with different intercellular communications have significant predictive value for prognosis and distinguished immunotherapy efficiency. CONCLUSIONS: The intercellular communication landscapes of VHL wild and VHL mutant ccRCC vary. Intercellular communications within the tumor microenvironment also influence T cell and myeloid cell development and infiltration, as well as predict clinical prognosis and immunotherapy efficacy in ccRCC.

The copper-catalyzed oxidation of arylmethyl triazines with H2O toward the oxidant-free synthesis of aroyl triazines.

We report an efficient copper-catalyzed dehydrogenation method for the synthesis of aroyl triazines from arylmethyl triazines with water in the absence of additional oxidants or hydrogen acceptors. The use of substrates with both electron-donating and electron-withdrawing groups resulted in moderate to good yields. Using liquid chromatography-mass spectrometry, 18O-labeled-water reactions and hydrogen capture experiments confirmed that water was the only oxygen donor and hydrogen was the by-product. This oxidation strategy provides a new approach for the synthesis of aroyl triazines with a broad substrate scope.

Intrafollicular spontaneous parthenogenetic development of dromedary camel oocytes.

Dromedary camel oocytes are unique in their capability for intrafollicular and in vitro spontaneous parthenogenetic activation (SPA) and development. This study was designed for (a) observing the incidence of SPA and development of dromedary camel oocytes retrieved from ovaries; (b) assessing intrafollicular development of dromedary camel oocytes using histological examination; (c) evaluating the abilities of dromedary camel oocytes to mature, SPA, and develop in vitro; and (d) identifying the transcript abundance of Cdx2 messenger RNA (mRNA) expression in different stages of SPA and developed camel embryos. The results revealed that 2.33% of oocytes retrieved from dromedary camel ovaries were SPA and developed to blastocyst stage. Serial sections of dromedary camel ovaries also demonstrated the presence of 1.4 SPA and parthenotes per ovary, which included from two-cell to the blastocysts with demarcated trophectoderm and inner cell mass layers. A total of 2.6% in vitro matured dromedary camel oocytes developed into morulae. The SPA and developed dromedary embryos expressed transcript abundance for Cdx2 mRNA with the highest (p < .05) at the blastocyst. The present work determines for the first time the intrafollicular oocytes from the dromedary camel display SPA, and the parthenotes can develop into blastocysts and expressing Cdx2 mRNA.

A Meta-Analysis of Abnormal Glucose Metabolism in First-Episode Drug-Naive Schizophrenia.

BACKGROUND: Patients with schizophrenia exhibit a higher mortality rate compared with the general population. This mortality has been attributed predominantly by the high risk of type 2 diabetes mellitus in the patients. We aimed to assess the inherent risk of glucose metabolism abnormalities in first-episode drug-naive schizophrenia. SUBJECTS AND METHODS: We searched English database (PubMed, EMBASE, MEDLINE, Cochrane Library databases) and Chinese database (Wan Fang Data, CBM disc, VIP, and CNKI) from their inception until Jul 2018 for case-control studies examining glucose metabolism abnormalities. Measurements, such as fasting plasma glucose levels, fasting plasma insulin levels, insulin resistance and HbA1c levels in first-episode antipsychotic-naive patients were used to test for prediabetes. Standardized/weighted mean differences and 95% confidence intervals were calculated and analyzed. RESULTS: 19 studies (13 in English and 6 in Chinese) consisting of 1065 patients and 873 controls were included. Fasting plasma glucose levels (95% CI; 0.02 to 0.29; P=0.03), 2 h plasma glucose levels after an OGTT (95% CI; 0.63 to 1.2; P<0.00001), fasting plasma insulin levels (95% CI; 0.33 to 0.73; P<0.00001), insulin resistance (95% CI; 0.29 to 0.6; P<0.00001) in patients with first-episode schizophrenia were significant elevated. There was no significant difference in HbA1c level (95% CI; -0.34 to 0.18; P=0.54) in patients with first-episode schizophrenia compared with controls. CONCLUSIONS: This meta-analysis showed that glucose metabolism was impaired in patients with first-episode schizophrenia. Higher quality studies with larger samples are warranted to confirm these findings.

Roles of interferon-stimulated gene 15 protein in bovine embryo development.

Interferon (IFN)-stimulated gene 15 (ISG15) is one of several proteins induced by conceptus-derived Type I or II IFNs in the uterus, and is implicated as an important factor in determining uterine receptivity to embryos in ruminants. But little is known about the role the ISG15 gene or gene product plays during embryo development. In the present study, both the expression profile and function of ISG15 were investigated in early bovine embryos in vitro. ISG15 mRNA was detectable in Day 0, 2, 6 and 8 bovine embryos, but IFN-τ (IFNT) mRNA only appeared from Day 6. This means that embryonic expression of ISG15 on Days 0 and 2 was not induced by embryonic IFNT. However, ISG15 mRNA expression paralleled the expression of IFNT mRNA in Day 6 and 8 embryos. ISG15-lentivirus interference plasmid (ISG15i) was injected into 2-cell embryos to knockdown ISG15 expression. This resulted in decreases in the proportion of hatching blastocysts, the diameter of blastocysts and cell number per diameter of blastocysts compared with control embryos. In addition, ISG15i inhibited IFNT, Ets2 (E26 oncogene homolog 2) mRNA and connexion 43 protein expression in Day 8 blastocysts, whereas exogenous IFNT treatment (100ngmL-1, from Day 4 to Day 8) improved ISG15 mRNA and connexion 43 protein expression. In conclusion, it appears that ISG15 is involved in early bovine embryo development and that it regulates IFNT expression in the blastocyst.

Inhibition of NF-κB promotes autophagy via JNK signaling pathway in porcine granulosa cells.

The transcription factor nuclear factor-κB (NF-κB) plays an important role in diverse processes, including cell proliferation and differentiation, apoptosis and inflammation. However, the role of NF-κB in porcine follicle development is not clearly elucidated. In this study, we demonstrated that follicle stimulating hormone (FSH) increased the level of inhibitor of NF-κB (IκB) protein and promoted the cytoplasmic localization of p65, indicating that FSH inhibits the activation of NF-κB in porcine granulosa cells. Moreover, inhibition of NF-κB by FSH or another specific inhibitor of NF-κB, pyrrolidine dithiocarbamate (PDTC), could activate JNK signaling and enhance autophagic activity in porcine granulosa cells. Knockdown of RelA (p65) Subunit of NF-κB by RNA interference abrogated the activation of JNK signaling pathway and the increase of autophagic protein expression by FSH. Meanwhile, the functional significance of FSH or PDTC-mediated autophagy were further investigated. Our results demonstrated that the increased autophagy promoted progesterone secretion in porcine granulosa cells. Blockage of autophagy by chloroquine obviated the FSH or PDTC-induced progesterone production. Taken together, these results indicate that inhibition of NF-κB increased autophagy via JNK signaling, and promote steroidogenesis in porcine granulosa cells. Our results provide new insights into the regulation and function of autophagy in mammalian follicle development.

Recombinant bovine interferon-τ enhances in vitro development of bovine embryos by upregulating expression of connexin 43 and E-cadherin.

Interferon-τ (IFNT), produced in ruminants by embryonic trophoblastic cells before implantation, is involved in the maternal recognition of pregnancy. It is a pleiotropic molecule that alters the synthesis of endometrial proteins and inhibits the proliferation of some cells. The present study investigated the effects of recombinant bovine IFNT on the development of early-stage bovine embryos and the molecular mechanism underlying this effect. This study demonstrated that expression of mRNA encoding type I IFN receptor subunits was detectable from d 4 to 8 in in vitro fertilized (IVF) bovine embryos. A considerable number of IVF (n = 1,941) and parthenogenetic activated (n = 1,552) bovine embryos demonstrated that supplementing the culture medium with IFNT (100 ng/mL) produced a greater percentage of blastocysts, and the total cell number within the resulting blastocysts was higher. In addition, IFNT upregulated the expression levels of both mRNA and protein for connexin 43 (GJA1) and E-cadherin (CDH1) and expression levels for granulocyte-macrophage colony-stimulating factor and insulin-like growth factor 2 mRNA but not for their proteins in d 8 embryos. However, IFNT inhibited mRNA expression for leukemia inhibitory factor (LIF), LIF receptor α, and the sodium/potassium-transporting ATPase subunit ß-1. We concluded that IFNT promoted the development of bovine embryos by upregulating the expression of GJA1 and CDH1. Thus, supplementing embryo cultures or transfer medium with IFNT may stimulate embryo development and improve embryo transfer efficiency.

Follicle-stimulating hormone regulates pro-apoptotic protein Bcl-2-interacting mediator of cell death-extra long (BimEL)-induced porcine granulosa cell apoptosis.

The pro-apoptotic protein Bim (B-cell lymphoma-2 (Bcl-2)-interacting modulator of cell death) has recently been identified and shown to promote cell death in response to several stimuli. In this report, we investigated the role of Bim in porcine follicular atresia. Initially, Bim cDNA was cloned and characterized from porcine ovarian tissue. Porcine Bim had three alternative splicing variants (Bim-extra long, Bim-long, and Bim-short), all containing the consensus Bcl-2 homology 3 domain. We then found the Bim-extra long (Bim(EL)) protein, the most abundant isoform of Bim, was strongly expressed and co-localized with apoptotic (TUNEL-positive) granulosa cells from porcine atretic follicles. Furthermore, overexpression of Bim(EL) triggered apoptosis in granulosa cells. In primary granulosa cell cultures under basal conditions, we observed that Bim(EL) expression was dampened by treatment with follicle-stimulating hormone (FSH). The role of the PI3K/Akt pathway in the regulation of repression was clarified by the use of the PI3K inhibitor, LY294002, and by transfection with Akt siRNA. Forkhead Box Protein O3a (FoxO3a), a well defined transcriptional activator of Bim, was phosphorylated at Ser-253 and inactivated after FSH stimulation. Also, FSH abolished FoxO3a nuclear accumulation in response to LY294002. Finally, chromatin immunoprecipitation assays demonstrated that FoxO3a directly bound and activated the bim promoter. Taken together, we conclude that Bim(EL) induces porcine granulosa cell apoptosis during follicular atresia, and its expression is regulated by FSH via the PI3K/Akt/FoxO3a pathway.

Oocyte-secreted growth differentiation factor 9 inhibits BCL-2-interacting mediator of cell death-extra long expression in porcine cumulus cell.

Oocyte-secreted factors (OSFs) maintain the low incidence of cumulus cell apoptosis. In this report, we described that the presence of oocytes suppressed the expression of proapoptotic protein BCL-2-interacting mediator of cell death-extra long (BIMEL) in porcine cumulus cells. Atretic (terminal deoxynucleotidyl transferase dUTP nick end labeling-positive) cumulus cells strongly expressed BIMEL protein. The healthy cumulus- oocyte complex exhibited a low BIMEL expression in cumulus cell while the removal of oocyte led to an about 2.5-fold (P < 0.5) increased expression in oocytectomized complex (OOX). Coculturing OOXs with denuded oocytes decreased BIMEL expression to the normal level. The similar expression pattern could also be achieved in OOXs treated with exogenous recombinant mouse growth differentiation factor 9 (GDF9), a well-characterized OSF. This inhibitory action of GDF9 was prevented by the addition of a phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002. Luciferase assay further demonstrated that BIM gene expression was forkhead box O3a (FOXO3a)-dependent because mutation of FOXO3a-binding site on the BIM promoter inhibited luciferase activities. Moreover, the activity of BIM promoter encompassing the FOXO3a-binding site could be regulated by GDF9. Additionally, we found that GDF9 elevated the levels of phosphorylated AKT and FOXO3a, and this process was independent of the SMAD signal pathway. Taken together, we concluded that OSFs, particularly GDF9, maintained the low level of BIMEL expression in cumulus cell through activation of the PI3K/FOXO3a pathway.

The disturbances of endoplasmic reticulum calcium homeostasis caused by increased intracellular reactive oxygen species contributes to fragmentation in aged porcine oocytes.

Accumulating evidence indicates that cellular and molecular abnormalities occur during oocyte aging, including fragmentation, increases in intracellular reactive oxygen species (ROS), and abnormal Ca(2+) oscillations. The objective of the present study was to characterize the relationships between intracellular ROS, Ca(2+) homeostasis of endoplasmic reticulum (ER), and fragmentation in aged porcine MII oocytes. Prolonged culture (36 h) of porcine oocytes resulted in elevated intracellular ROS level, impaired ER Ca(2+) homeostasis (i.e., Ca(2+) storage, Ca(2+) rising patterns after electroactivation, and the cluster distribution of ER), and increased fragmentation rates. However, when the porcine oocytes were treated with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl ester), an intracellular Ca(2+) chelator, the fragmentation was significantly inhibited during in vitro aging. In order to pursue the underlying mechanisms, H2O2 and cycloheximide (CHX) were used to artificially increase or inhibit, respectively, the intracellular ROS levels in aged porcine oocytes during in vitro culture. The results demonstrated that incubation of porcine MII oocytes with H2O2 damaged the ER clusters and the Ca(2+) regulation of ER, leading to a high proportion of fragmented oocytes. In contrast, CHX, an intracellular inhibitor of ROS generation, prevented both increase of ROS level and damage of the ER Ca(2+) homeostasis in porcine oocytes during aging, resulting in low fragmentation rate. We conclude that the increased intracellular ROS damaged the ER clusters and ER Ca(2+) homeostasis, resulting in a disorder in ooplasmic free Ca(2+), which caused the fragmentations seen in porcine MII oocytes during aging.

Data-Driven Control of Neuronal Networks with Population-Level Measurement.

Controlling complex networks of nonlinear neurons is an important problem pertinent to various applications in engineering and natural sciences. While in recent years the control of neural populations with comprehensive biophysical models or simplified models, e.g., phase models, has seen notable advances, learning appropriate controls directly from data without any model assumptions remains a challenging and less developed area of research. In this paper, we address this problem by leveraging the network's local dynamics to iteratively learn an appropriate control without constructing a global model of the system. The proposed technique can effectively regulate synchrony in a neuronal network using only one input and one noisy population-level output measurement. We provide a theoretical analysis of our approach and illustrate its robustness to system variations and its generalizability to accommodate various physical constraints, such as charge-balanced inputs.

[Effect of gingival biotype on total crown repair and gingival crevicular fluid inflammatory factors].

PURPOSE: To explore the effect of thick and thin sputum on the restoration of oral anterior teeth and the index of gingival crevicular fluid. METHODS: A study was conducted on 80 patients (130 teeth) who underwent full-ceramic crown treatment for anterior tooth restoration in Jiangnan University Affiliated Hospital 's oral clinic. The patients were divided into thick gingival type (42 cases, 67 teeth) and thin gingival type (38 cases, 63 teeth) according to their gingival biotype. The two groups were compared before and after the restoration with improved plaque index (mPI), modified bleeding index (mBI), probing depth (PD), clinical evaluation score of oral prosthesis, tumor necrosis factor-alpha (TNF-alpha) and IL-1 ß(interleukin-1ß) in gingival crevicular fluid. Statistical analysis was performed with SPSS 21.0 software package. RESULTS: Before treament, there were no significant differences in mPI, mBI and PD between the two groups (P＞0.05); 12 months after treament, mPI, mBI and PD of the thin gingiva group were significantly lower than those of the thick gingiva group(P＜0.05). Before treament, there were no significant differences in TNF-α and IL-1ß levels in gingival crevicular fluid between the two groups(P＞0.05); 12 months after treament, TNF-α and IL-1ß levels of the thin gingiva group were significantly lower than those of the thick gingiva group(P＜0.05). Six months after treament, there were no significant differences in prosthesis integrity, marginal adaptation, color matching, periodontal health status and secondary caries scores between the two groups (P＞0.05); 12 months after treament, the marginal adaptation, periodontal health status and secondary caries scores of the thick gingiva group were significantly higher than those of the thin gingiva group(P＜0.05); the marginal discoloration score of the thick gingiva group was significantly lower than that of the thin gingiva group at 6 months and 12 months after treament(P＜0.05). CONVLUSIONS: The thin sputum type is more conducive to repairing the oral cavity after treatment, and is beneficial to the maintenance of oral health condition after repair. The gingival index of the thick sputum type patient will be significantly increased after repair, and the risk of gingival inflammation is increased. The aesthetic effect is better than the thin sputum type.

Data-Efficient Inference of Nonlinear Oscillator Networks.

Decoding the connectivity structure of a network of nonlinear oscillators from measurement data is a difficult yet essential task for understanding and controlling network functionality. Several data-driven network inference algorithms have been presented, but the commonly considered premise of ample measurement data is often difficult to satisfy in practice. In this paper, we propose a data-efficient network inference technique by combining correlation statistics with the model-fitting procedure. The proposed approach can identify the network structure reliably in the case of limited measurement data. We compare the proposed method with existing techniques on a network of Stuart-Landau oscillators, oscillators describing circadian gene expression, and noisy experimental data obtained from Rössler Electronic Oscillator network.

Differential expression pattern of ISG15 in different tissue explants and cells induced by various interferons.

Interferon stimulated gene 15 (ISG15), an ubiquitin cross-reactive protein, can conjugate to target proteins. Unlike ubiquitination, protein modification by ISG15 does not target protein for degradation, but enhances the cellular response to interferon (IFN), which plays a key role in antiviral responses. In this study, Western blot and/or immunocytochemistry were performed to explore the ISG15 expression patterns in explants of bovine endometrium, mammary gland and kidney, as well as Madin-Darby bovine kidney (MDBK), endometrial and mammary cells stimulated by IFN-α, -ß, and -τ. Western blot indicated that there are differential minimum antiviral units among recombinant bovine interferon-α (rbIFN-α, 10(2) IU/mL), rbIFN-ß (10(3) IU/mL) and rbIFN-τ (10(4) IU/mL) in regard to stimulating saturation expression of free and ISG15-conjugated proteins by MDBK cells and endometrial and mammary explants. These results were further confirmed through immunocytochemical analysis of MDBK, endometrial and mammary cells. For the first time it has been shown that the expression pattern of ISG15-conjugated proteins occurs in a tissue-specific manner. Furthermore, the present findings provide the first evidence of 10- to 100-fold differences in minimum antiviral units of rbIFN-α, rbIFN-ß, and rbIFN-τ in regard to stimulating saturation expression of ISG15.

The progress of small-molecules and degraders against BCR-ABL for the treatment of CML.

Chronic myeloid leukemia (CML) is a malignant disease of the hematopoietic system with crucial pathogenic protein named BCR-ABL, which endangers the life of patients severely. As a milestone of targeted drug, Imatinib has achieved great success in the treatment of CML. Nevertheless, inevitable drug resistance of Imatinib has occurred frequently in clinical due to the several mutations in the BCR-ABL kinase. Subsequently, the second-generation of tyrosine kinase inhibitors (TKIs) against BCR-ABL was developed to address the mutants of Imatinib resistance, except T315I. To date, the third-generation of TKIs targeting T315I has been developed for improving the selectivity and safety. Notably, the first allosteric inhibitor has been in market which could overcome the mutations in ATP binding site effectively. Meanwhile, some advanced technology, such as proteolysis-targeting chimeras (PROTAC) based on different E3 ligand, are highly expected to overcome the drug resistance by selectively degrading the targeted proteins. In this review, we summarized the current research progress of inhibitors and degraders targeting BCR-ABL for the treatment of CML.

The synthesis of anticancer sulfonated indolo[2,1-a]isoquinoline and benzimidazo[2,1-a]isoquinolin-6(5H)-ones derivatives via a free radical cascade pathway.

A facile CuBr2 induced radical relay addition/cyclization of activated alkenes with substituted-thiosulfonates has been achieved, leading to a broad range of sulfonated indolo[2,1-a]isoquinolines and benzimidazo[2,1-a]isoquinolin-6(5H)-ones in moderate to good yields. In particular, some compounds exhibit bioactivity against cancer cell lines. This protocol shows advantages of low-cost, base-free, simple operation, and broad functional group tolerance.

Effects of melatonin on in vitro development of mouse two-cell embryos cultured in HTF medium.

Melatonin is capable of improving the developmental capacity of ovine, porcine and bovine embryos in vitro. However, whether melatonin possesses similar benefits to the in vitro mouse embryonic development has yet to be determined. In this study, we assessed the effects of various concentrations of melatonin (10-13 to 10-3 M) on the in-vitro development of mouse embryos cultured in HTF medium for 96 hr; embryos cultured without melatonin were used as control. The in vitro development of mouse two-cell embryos significantly benefited from treatment with melatonin in a concentration-dependent manner. The effects of melatonin on the rates of blastocyst formation, hatching/hatched blastocysts and cell number per blastocyst were bi-phasic; all significantly increased by melatonin at 10-13 to 10-5 M and decreased by melatonin at 10-3 M. Maximal benefit of melatonin on in vitro mouse 2-cell embryo development was achieved at a concentration of 10-9 M. In comparison to control, 10-9 M melatonin increased blastocyst formation rate from 48.08 +/- 5.25% to 82.08 +/- 2.34% (p < 0.05), hatched blastocyst rate from 25.65 +/- 11.79% to 66.47 +/- 4.94% (p < 0.05), and cell number per blastocyst 62.71 +/- 5.97 to 77.91 +/- 10.63 (p < 0.05). Thus, our datas demonstrated firstly that melatonin has beneficial effects on the in vitro development of 2-cell mouse embryos cultured in HTF medium.

Melatonin exists in porcine follicular fluid and improves in vitro maturation and parthenogenetic development of porcine oocytes.

This study focused on the effect of melatonin on in vitro maturation of porcine oocytes and their parthenogenetic embryonic development. Melatonin was measured in porcine follicular fluid of follicles of different sizes in the same ovary. Melatonin exists in follicular fluid, and the concentration is approximately 10(-11) m. Its concentration decreased as the diameter of follicle increased, which suggests an effect of melatonin on oocyte maturation. Therefore, immature oocytes were cultured in vitro in maturation medium supplemented with melatonin (10(-11), 10(-9), 10(-7), 10(-5) and 10(-3) m) or without melatonin. The oocytes at maturation stage were collected and activated. The parthenogenetic embryos were cultured and observed in medium supplemented with or without melatonin. Fresh immature oocytes without melatonin treatment were used as control. When only maturation medium was supplemented with 10(-9) m melatonin, the cleavage rate, blastocyst rate and the cell number of blastocyst (70 +/- 4.5%, 28 +/- 2.4% and 50 +/- 6.5%) were significantly higher (P < 0.05) than that of controls; when only culture medium was supplemented with melatonin, the highest cleavage rate, blastocyst rate and the cell number of blastocyst was observed at 10(-7) m melatonin, which were significantly higher than that of controls (P < 0.05). The best results (cleavage rates 79 +/- 8.4%, blastocyst rates 35 +/- 6.7%) were obtained when both the maturation and culture medium were supplemented with 10(-9) m melatonin respectively (P < 0.05). In conclusion, exogenous melatonin at the proper concentration may improve the in vitro maturation of porcine oocytes and their parthenogenetic embryonic development. Further research is needed to identify the effect of melatonin on in vitro and in vivo oocyte maturation and embryo development in porcine.

Abnormal changes in mitochondria, lipid droplets, ATP and glutathione content, and Ca(2+) release after electro-activation contribute to poor developmental competence of porcine oocyte during in vitro ageing.

The present study aims to investigate major changes in porcine oocytes during ageing in vitro. After the oocytes were cultured for 44, 56, 68 and 80 h, changes to porcine oocytes in ultrastructure, mitochondrial distribution, glutathione (GSH) and ATP content, Ca(2+) release patterns and developmental competence after electro-activation were observed. Mitochondria were evenly distributed in oocytes at 44 h, aggregated in clusters or in peripheral cytoplasm at 68 h and dimly dispersed throughout ooplasm at 80 h. Mitochondrial shape during ageing was also observed by transmission electron microscopy (TEM) at the same time intervals. Most mitochondria were spherical at 44 h, and became elongated when the culture time was extended to 68 h and 80 h. Moreover, mitochondrial clustering became increasingly loose from 56 h. Lipid droplets in oocytes appeared prominent and electron-dense at 44 h, but electron density was lost at 56 h. Lipid droplets were solidified as of 68 h. There was an age-dependent decrease in ATP content per oocyte. Glutathione content per oocyte decreased significantly and remained lower after 56 h. Amplitudes of [Ca(2+)] rise decreased dramatically following 56 h, and the time required for [Ca(2+)] to plateau became shorter after electro-activation with prolonged culture time. Cleavage and blastocyst rates of aged oocytes progressively decreased, while the fragmentation rate gradually increased after electro-activation. It is concluded that abnormal changes in mitochondria, lipid droplets, Ca(2+) release after electro-activation, and ATP and GSH content in oocytes during ageing may result in poor developmental competence of parthenotes.