Superior performance of biocomposite nanoparticles PLGA-RES in protecting oocytes against vitrification stimuli.

Irreversible cryogenic damage caused by oocyte vitrification limits its widespread use in female fertility preservation. In recent years, nanoparticles (NPs) have gained great attention as potential alternatives in protecting oocytes against cryoinjuries. In this paper, a novel composite nanoparticle, poly (lactic-co-glycolic acid)-resveratrol (PLGA-RES) was designed to improve the biocompatibility and sustained release properties by encapsulating natural antioxidant RES into PLGA NPs. Firstly, biotoxicity and oxidation resistance of PLGA-RES were determined, and the results showed that PLGA-RES had nontoxic effect on oocyte survival during in vitro maturation (IVM) (97.08% ± 0.24% vs. 98.89% ± 1.11%, p > 0.05). Notably, PLGA-RES even increased maturation (65.10% ± 4.11% vs. 52.85% ± 2.87%, p < 0.05) and blastocyst rate (56.13% ± 1.36% vs. 40.91% ± 5.85%, p < 0.05). Moreover, the reduced reactive oxygen species (ROS) level (13.49 ± 2.30 vs. 34.07 ± 3.30, p < 0.01), increased glutathione (GSH) (44.13 ± 1.57 vs. 37.62 ± 1.79, p < 0.01) and elevated mitochondrial membrane potential (MMP) levels (43.10 ± 1.81 vs. 28.52 ± 1.25, p < 0.01) were observed in oocytes treated with PLGA-RES when compared with that of the control group. Subsequently, the role of PLGA-RES played in oocytes during vitrification was systematically evaluated. The results showed that the addition of PLGA-RES during vitrification and thawing significantly improved the survival rate (80.42% ± 1.97% vs. 75.37% ± 1.3%, p < 0.05). Meanwhile, increased GSH (15.09 ± 0.86 vs. 14.51 ± 0.78, p < 0.01) and mitochondrial membrane potential (22.56 ± 3.15 vs. 6.79 ± 0.60, p < 0.01), decreased reactive oxygen species levels (52.11 ± 2.95 vs. 75.41 ± 7.23, p < 0.05) and reduced mitochondrial abnormality distribution rate (25.00% ± 0.29% vs. 33.33% ± 1.15%, p < 0.01) were assessed in vitrified MII oocytes treated with PLGA-RES. Furthermore, transcriptomic analyses demonstrated that PLGA-RES participated in endocytosis and PI3K/AKT/mTOR pathway regulation, which was verified by the rescued expression of ARRB2 and ULK3 protein after PLGA-RES treatment. In conclusion, PLGA-RES exhibited potent antioxidant activity, and could be used as an efficacious strategy to improve the quality of vitrified oocytes.

Exploring the degradation mechanism of nickel-copper-molybdenum hydrogen evolution catalysts during intermittent operation.

We investigate the dynamic degradation behaviors of a nickel-copper-molybdenum hydrogen evolution catalyst in a liquid and solid polymer electrolyte to figure out its endurance in a renewable energy-driven electrolyzer. A cathode current protection approach is proposed to achieve a durable electrolyzer during intermittent operation.

Integrated transcriptomics and proteomics assay identifies the role of FCGR1A in maintaining sperm fertilization capacity during semen cryopreservation in sheep.

Semen cryopreservation is a promising technology employed in preserving high-quality varieties in animal husbandry and is also widely applied in the human sperm bank. However, the compromised qualities, such as decreased sperm motility, damaged membrane structure, and reduced fertilization competency, have significantly hampered the efficient application of this technique. Therefore, it is imperative to depict various molecular changes found in cryopreserved sperm and identify the regulatory network in response to the cryopreservation stress. In this study, semen was collected from three Chinese Merino rams and divided into untreated (fresh semen, FS) and programmed freezing (programmed freezing semen, PS) groups. After measuring different quality parameters, the ultra-low RNA-seq and tandem mass tag-based (TMT) proteome were conducted in both the groups. The results indicated that the motility (82.63% ± 3.55% vs. 34.10% ± 2.90%, p < 0.05) and viability (89.46% ± 2.53% vs. 44.78% ± 2.29%, p < 0.05) of the sperm in the FS group were significantly higher compared to those in the PS group. In addition, 45 upregulated and 291 downregulated genes, as well as 30 upregulated and 48 downregulated proteins, were found in transcriptomics and proteomics data separately. Moreover, three integrated methods, namely, functional annotation and enrichment analysis, Pearson's correlation analysis, and two-way orthogonal partial least squares (O2PLS) analysis, were used for further analysis. The results suggested that various differentially expressed genes and proteins (DEGs and DEPs) were mainly enriched in leishmaniasis and hematopoietic cell lineage, and Fc gamma receptor Ia (FCGR1A) was significantly downregulated in cryopreserved sperm both at mRNA and protein levels in comparison with the fresh counterpart. In addition, top five genes (FCGR1A, HCK, SLX4, ITGA3, and BET1) and 22 proteins could form a distinct network in which genes and proteins were significantly correlated (p < 0.05). Interestingly, FCGR1A also appeared in the top 25 correlation list based on O2PLS analysis. Hence, FCGR1A was selected as the most potential differentially expressed candidate for screening by the three integrated multi-omics analysis methods. In addition, Pearson's correlation analysis indicated that the expression level of FCGR1A was positively correlated with sperm motility and viability. A subsequent experiment was conducted to identify the biological role of FCGR1A in sperm function. The results showed that both the sperm viability (fresh group: 87.65% ± 4.17% vs. 75.8% ± 1.15%, cryopreserved group: 48.15% ± 0.63% vs. 42.45% ± 2.61%, p < 0.05) and motility (fresh group: 83.27% ± 4.15% vs. 70.41% ± 1.07%, cryopreserved group: 45.31% ± 3.28% vs. 35.13% ± 2.82%, p < 0.05) were significantly reduced in fresh and frozen sperm when FCGR1A was blocked. Moreover, the cleavage rate of embryos fertilized by FCGR1A-blocked sperm was noted to be significantly lower in both fresh (95.28% ± 1.16% vs. 90.44% ± 1.56%, p < 0.05) and frozen groups (89.8% ± 1.50% vs. 82.53% ± 1.53%, p < 0.05). In conclusion, our results revealed that the downregulated membrane protein FCGR1A can potentially contribute to the reduced sperm fertility competency in the cryopreserved sheep sperm.

Antioxidant procyanidin B2 protects oocytes against cryoinjuries via mitochondria regulated cortical tension.

BACKGROUND: Irreversible cryodamage caused by oocyte vitrification limited its wild application in female fertility preservation. Antioxidants were always used to antagonist the oxidative stress caused by vitrification. However, the comprehensive mechanism underlying the protective role of antioxidants has not been studied. Procyanidin B2 (PCB2) is a potent natural antioxidant and its functions in response to vitrification are still unknown. In this study, the effects of PCB2 on vitrified-thawed oocytes and subsequent embryo development were explored, and the mechanisms underlying the protective role of PCB2 were systematically elucidated. RESULTS: Vitrification induced a marked decline in oocyte quality, while PCB2 could improve oocyte viability and further development after parthenogenetic activation. A subsequent study indicated that PCB2 effectively attenuated vitrification-induced oxidative stress, rescued mitochondrial dysfunction, and improved cell viability. Moreover, PCB2 also acts as a cortical tension regulator apart from strong antioxidant properties. Increased cortical tension caused by PCB2 would maintain normal spindle morphology and promote migration, ensure correct meiosis progression and finally reduce the aneuploidy rate in vitrified oocytes. Further study reveals that ATP biosynthesis plays a crucial role in cortical tension regulation, and PCB2 effectively increased the cortical tension through the electron transfer chain pathway. Additionally, PCB2 would elevate the cortical tension in embryo cells at morula and blastocyst stages and further improve blastocyst quality. What's more, targeted metabolomics shows that PCB2 has a beneficial effect on blastocyst formation by mediating saccharides and amino acids metabolism. CONCLUSIONS: Antioxidant PCB2 exhibits multi-protective roles in response to vitrification stimuli through mitochondria-mediated cortical tension regulation.

Proteomic profile of mouse oocytes after vitrification: A quantitative analysis based on 4D label-free technique.

Mature oocyte cryopreservation represents an important trend for future fertility preservation, however, the relatively low efficiency has hampered its clinical application. Proteomic profiling is a method of choice for the exploration of the molecular mechanism underlying cryoinjuries. Here, a systematic comparison of protein expression between fresh and vitrified oocytes was performed based on the 4D label-free technique, an informative method with high sensitivity. Our results indicated that the oocyte survival rate was significantly reduced after vitrification. Proteomic results showed that 32 proteins were up-regulated, while 77 proteins were down-regulated in vitrified oocytes compared with the fresh counterparts. Gene Ontology (GO) functional analysis revealed that differentially expressed proteins (DEPs) were involved in metabolism, mitochondrial function, cytoskeleton and other cell functions. Moreover, proteins that participated in signaling transduction mechanisms were the largest category based on Clusters of Orthologous Groups of protein/EuKaryotic Orthologous Groups (COG/KOG) functional classification. In addition, over-expressed DEPs were enriched for "nucleus", "protein binding", "membrane", "cytoplasm" as well as mitochondrial function. Furthermore, we discovered that the DEPs were clustered in pyruvate metabolism, citric acid (TCA) cycle and glucose metabolism by Protein-Protein Interaction (PPI) network evaluation. In conclusion, our data demonstrate that vitrification induces multi-level damages in oocytes, the dynamic proteomic profiling will provide systematic insights into uncovering the mechanism underlying cryoinjuries.

Procyanidin B2 Protects Aged Oocytes Against Meiotic Defects Through Cortical Tension Modulation.

Defects in meiotic process are the main factors responsible for the decreased developmental competence in aged oocytes. Our recent research indicated that natural antioxidant procyanidin B2 (PCB2) promoted maturation progress in oocytes from diabetic mice. However, the effect of PCB2 on aging-induced chromosome abnormalities and the underlying mechanism have not been explored. Here, we found that PCB2 recovered aging-caused developmental arrest during meiotic maturation, germinal vesicle breakdown (GVBD) rate was significantly higher in aged oocytes treated with PCB2 (P < 0.05). Furthermore, we discovered that cortical mechanics were altered during aging process, cortical tension-related proteins were aberrantly expressed in aged oocytes (P < 0.001). PCB2 supplementation efficaciously antagonized aging-induced decreased cortical tension (P < 0.001). Moreover, PCB2 restored spindle morphology (P < 0.01), maintained proper chromosome alignment (P < 0.05), and dramatically reduced reactive oxygen species (ROS) level (P < 0.05) in aged oocytes. Collectively, our results reveal that PCB2 supplementation is a feasible approach to protect oocytes from reproductive aging, contributing to the improvement of oocytes quality.

Artificially Increasing Cortical Tension Improves Mouse Oocytes Development by Attenuating Meiotic Defects During Vitrification.

Oocyte cryopreservation demonstrates great benefits in the conservation of animal germplasm resources and assisted reproductive technology. However, vitrification causes damages in oocytes, which would lead to the decrease of oocyte quality, and embryonic development post fertilization. Cytoskeleton plays an important role in regulating cell shape, organelle migration, cell division and mechanical signal transduction. Cortical tension is a reflection of the physiological state and contractile ability of cortical cytoskeleton. Appropriate cortical tension is prerequesite for normal oocyte meiosis. In the present study, oocyte cortical tension was examined by evaluating the levels of cortical tension-related protein pERM (Phospho-Ezrin/Radixin/Moesin) and pMRLC (Phospho-Myosin Light Chain 2). We found that the cortical tension of vitrified oocytes was decreased. Increasing cortical tension of vitrified oocytes by adding 10 µg/ml ConA during in vitro culture could significantly improve the polar body extrusion rate and embryo development. Furthermore, increasing the cortical tension could improve spindle positioning, maintain kinetochore-microtubule (KT-MT) attachment, strengthen spindle assembly checkpoint (SAC) activity, and reduce the aneuploidy rate in vitrified oocytes. In conclusion, vitrification induced a remarkable decrease in cortical tension, and increasing the cortical tension could rescue the meiosis defect and improve oocyte quality.

Identifying the heat resistant genes by multi-tissue transcriptome sequencing analysis in Turpan Black sheep.

Heat stress not only affects the physical condition but also affects reproductive performance in sheep. A thorough understanding of the molecular and physiological mechanisms underlying heat stress would certainly improve livestock productivity and provide genetic evaluation ways for heat resistant breeds selection. In this study, 85 Turpan Black sheep, a breed exhibited excellent heat resistance from long-term artificial selection, and 85 heat sensitive Kazakh sheep in Turpan basin were tested for physiological and reproductive performance from July to August in summer. The results showed that the estrus rate was significantly higher in Turpan Black sheep (P < 0.05), while the heart rate and respiratory rate of Turpan Black sheep are significantly lower than that of Kazakh sheep (P < 0.05). Furthermore, to clarify genes participated in heat stress response, the pituitary, ovarian and hepatic tissues from three Turpan Black sheep and three Kazakh sheep were subjected to RNA-seq. The results indicated that 32, 49 and 69 genes were up-regulated, and 39, 60 and 145 genes were down-regulated in pituitary, ovarian and hepatic tissues in Turpan Black sheep compared with that of the Kazakh sheep, respectively. KEGG and gene set enrichment analysis showed that the differentially expressed genes were mainly involved in signal transduction pathways. In particular, the differentially expressed genes in hepar were enriched in the energy metabolism pathway, while the differentially expressed genes in ovarian tissue were enriched in the ovarium steroidogenesis pathway. In conclusion, our results implied that the pituitary-ovary axis might include hepar as downstream targeted organism in heat resistant regulation. Under heat stress, the signals released from pituitary would impact steroidogenesis in ovary, and further alter energy metabolism in hepar. As we know, this is the first comparative study to investigate the gene expression in multi-tissue in sheep under heat stress.

Whole-Genome Resequencing of Worldwide Wild and Domestic Sheep Elucidates Genetic Diversity, Introgression, and Agronomically Important Loci.

Domestic sheep and their wild relatives harbor substantial genetic variants that can form the backbone of molecular breeding, but their genome landscapes remain understudied. Here, we present a comprehensive genome resource for wild ovine species, landraces and improved breeds of domestic sheep, comprising high-coverage (∼16.10×) whole genomes of 810 samples from 7 wild species and 158 diverse domestic populations. We detected, in total, ∼121.2 million single nucleotide polymorphisms, ∼61 million of which are novel. Some display significant (P < 0.001) differences in frequency between wild and domestic species, or are private to continent-wide or individual sheep populations. Retained or introgressed wild gene variants in domestic populations have contributed to local adaptation, such as the variation in the HBB associated with plateau adaptation. We identified novel and previously reported targets of selection on morphological and agronomic traits such as stature, horn, tail configuration, and wool fineness. We explored the genetic basis of wool fineness and unveiled a novel mutation (chr25: T7,068,586C) in the 3'-UTR of IRF2BP2 as plausible causal variant for fleece fiber diameter. We reconstructed prehistorical migrations from the Near Eastern domestication center to South-and-Southeast Asia and found two main waves of migrations across the Eurasian Steppe and the Iranian Plateau in the Early and Late Bronze Ages. Our findings refine our understanding of genome variation as shaped by continental migrations, introgression, adaptation, and selection of sheep.

Replication study and meta-analysis of selected genetic variants and polycystic ovary syndrome susceptibility in Asian population.

PURPOSE: Polycystic ovary syndrome (PCOS) is a highly complex disorder influenced by genetic and environmental factors. Previous association studies have identified multiple PCOS-susceptible loci, but there is no consistent conclusion, which calls for further investigations. METHODS: In the present case-control study, FSHR gene variants (rs2268361, rs6165, and rs6166), LHCGR gene variant (rs13405728), THADA gene variant (rs13429458), DENND1A gene variants (rs10818854 and rs2479106), and INSR gene variants (rs2059807 and rs1799817) were genotyped with Sanger sequencing in a total of 400 PCOS women and 480 healthy women. RESULTS: After Bonferroni correction, our results showed that rs13405728, rs13429458, rs2479106, rs10818854, and rs2059807 were significantly associated with PCOS risk in Chinese women. To improve the statistical strength, a further meta-analysis in Asian population was conducted. Although rs6166 and rs1799817 were not associated with PCOS risk in the present study, they were identified to be strongly associated with PCOS risk in the pooled Koreans and Chinese respectively. No significant association with PCOS risk was consistently found for rs2268361 or rs6165. Moreover, the pooled results further confirmed the significant association with PCOS risk for rs13405728, rs13429458, rs2479106, rs10818854, and rs2059807. CONCLUSIONS: Collectively, the rs6166, rs13405728, rs13429458, rs2479106, rs10818854, rs2059807, and rs1799817 may indeed be the genetic risk factors for PCOS in Asian population, which requires further investigation using larger independent sets of samples in different ethnic populations.

Bioinformatics analysis, codon optimization and expression of ovine pregnancy associated Glycoprotein-7 in HEK293 cells.

Pregnancy-associated glycoproteins (PAGs) are widely used as powerful markers for early pregnancy diagnosis in livestock. To improve expression efficiency of recombinant ovine pregnancy-associated glycoprotein-7 (ovPAG-7) in HEK293 cells, the codon usage bias of the ovPAG-7 gene was analyzed using bioinformatic approaches, after which the DNA sequence encoding ovPAG-7 was designed, synthesized, and expressed in HEK293. The structure and function of ovPAG-7 were predicted using bioinformatics software and online databases. The results showed that the effective number of codons (NEC) of the ovPAG-7 gene was 56.82, indicating that the ovPAG-7 gene was weakly biased. ovPAG-7 gene had 26 biased codons (relative synonymous codon usage (RSCU) > 1), 15 of which were biased towards G/C at the third position. After codon optimization, the codon adaptation index of the ovPAG-7 gene increased from 0.74 to 0.96, and its GC content changed from 46.6 to 58.6%. The amino acid sequence encoded by the optimized gene was entirely consistent with those published in Gen Bank. Western blot analysis indicated that the recombinant ovPAG-7 protein with a relative molecular mass of 48 kDa was successfully expressed in HEK293 cells. The bioinformatics prediction results showed that ovPAG-7 protein contained 3 N-glycosylation sites, 13 B-cell epitopes, and a signal peptide consisting of 15 amino acids at the N terminus. The secondary structure of the ovPAG-7 protein was predicted to consist of random coils (46.85%), extended strands (32.05%), α-helices (16.16%), and ß-turns (4.93%). This study provided a tool for the screening of monoclonal antibodies and functional research on ovPAG-7.

Historical Introgression from Wild Relatives Enhanced Climatic Adaptation and Resistance to Pneumonia in Sheep.

How animals, particularly livestock, adapt to various climates and environments over short evolutionary time is of fundamental biological interest. Further, understanding the genetic mechanisms of adaptation in indigenous livestock populations is important for designing appropriate breeding programs to cope with the impacts of changing climate. Here, we conducted a comprehensive genomic analysis of diversity, interspecies introgression, and climate-mediated selective signatures in a global sample of sheep and their wild relatives. By examining 600K and 50K genome-wide single nucleotide polymorphism data from 3,447 samples representing 111 domestic sheep populations and 403 samples from all their seven wild relatives (argali, Asiatic mouflon, European mouflon, urial, snow sheep, bighorn, and thinhorn sheep), coupled with 88 whole-genome sequences, we detected clear signals of common introgression from wild relatives into sympatric domestic populations, thereby increasing their genomic diversities. The introgressions provided beneficial genetic variants in native populations, which were significantly associated with local climatic adaptation. We observed common introgression signals of alleles in olfactory-related genes (e.g., ADCY3 and TRPV1) and the PADI gene family including in particular PADI2, which is associated with antibacterial innate immunity. Further analyses of whole-genome sequences showed that the introgressed alleles in a specific region of PADI2 (chr2: 248,302,667-248,306,614) correlate with resistance to pneumonia. We conclude that wild introgression enhanced climatic adaptation and resistance to pneumonia in sheep. This has enabled them to adapt to varying climatic and environmental conditions after domestication.

Retroreflection from a single layer of electromagnetic Helmholtz cavities based on magnetic symmetric dipole modes.

We demonstrate a new electromagnetic mode which is formed by the dynamic interaction between a magnetic quadrupole mode and an electric monopole mode in a two-dimensional electromagnetic Helmholtz cavity. It is termed a magnetic symmetric dipole mode since it shares similarity with a magnetic dipole mode in the sense that their radiation is both overwhelmingly dominant in the forward and backward directions with respect to the incident wave. However, the phase distribution in the two radiation directions is symmetric, in stark contrast to the antisymmetry of magnetic dipole modes. When the Helmholtz cavities are arranged in a line, the incident wave will be reflected back to the source, in other words, retroreflection occurs because of the peculiar properties of magnetic symmetric dipole modes. We show that the retroreflection is quite robust against the disorder of the orientation angle of Helmholtz cavities and there exists a wide tolerance for wavelength and the outer radius of the cavity. With low fabrication demands, this might offer a feasible solution for the design of ultrathin retroreflectors towards device miniaturization and the realization of multiplexing holography.

Whole-genome resequencing of wild and domestic sheep identifies genes associated with morphological and agronomic traits.

Understanding the genetic changes underlying phenotypic variation in sheep (Ovis aries) may facilitate our efforts towards further improvement. Here, we report the deep resequencing of 248 sheep including the wild ancestor (O. orientalis), landraces, and improved breeds. We explored the sheep variome and selection signatures. We detected genomic regions harboring genes associated with distinct morphological and agronomic traits, which may be past and potential future targets of domestication, breeding, and selection. Furthermore, we found non-synonymous mutations in a set of plausible candidate genes and significant differences in their allele frequency distributions across breeds. We identified PDGFD as a likely causal gene for fat deposition in the tails of sheep through transcriptome, RT-PCR, qPCR, and Western blot analyses. Our results provide insights into the demographic history of sheep and a valuable genomic resource for future genetic studies and improved genome-assisted breeding of sheep and other domestic animals.

Effect of supplemetation of Zebularine and Scriptaid on efficiency of in vitro developmental competence of ovine somatic cell nuclear transferred embryos.

Somatic cell nuclear transfer (SCNT) technology has been applied in the construction of disease model, production of transgenic animals, therapeutic cloning, and other fields. However, the cloning efficiency remains limited. In our study, to improve SCNT efficiency, brilliant cresyl blue (BCB) staining were chosen to select recipient oocytes. In addition, DNA methyltransferase inhibitor Zebularine (5 nmol/L) and histone deacetylase inhibitor Scriptaid (0.2 µmol/L) were jointly used to treat sheep donor cumulus cells and reconstructed embryo. Moreover, the expression levels of embryonic development-related genes (OCT4, SOX2, H19, IGF2 and Dnmt1) of reconstructed embryo were also detected. Using BCB + oocytes as recipient cell, donor cumulus cells and reconstructed embryos were treated with 5 nmol/L Zebularine and 0.2 µmol/L Scriptaid, the blastocyst rate in Zeb + SCR-SCNT group (28.25%) was significantly higher than SCNT (21.16%) (p < 0.05). Furthermore, results showed that expression levels of OCT4, SOX2, H19, IGF2 and Dnmt1 genes in Zeb + SCR-SCNT embryos were more similar to IVF embryos. Our study proved that 5 nmol/L Zebularine and 0.2 µmol/L Scriptaid treating with sheep donor cumulus cells and reconstructed embryos improved SCNT blastocyst rate and relieve the abnormal expression of embryonic developmental related genes.

The comparison of reproductive hormone receptor expressions of the sheep ovary and hormone concentrations in two Chinese breeds.

The aim of this research was to investigate the changes in reproductive hormone receptor expressions of the ovary and hormone concentrations between oestrous cycle pattern of two different sheep breeds in China. Ovarian tissues were collected from Chinese Merino (Junken type) and Hu sheep with different reproductive states in spring and autumn. Serum samples were assayed for oestrogen (E2), progesterone (P), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations by radioimmunoassay during spring. The ovarian expression of hormone receptors (ERα, ERß, PR, LHR and FSHR) was analysed using real-time reverse transcription polymerase chain reaction (RT-PCR). In Chinese Merino, there was no corpora lutea and ovulation point on the surfaces of ovaries in spring and low basal levels of both LH and P in serum. ERα, ERß and FSHR were expressed significantly higher in Merino ovaries during anoestrus compared with oestrous or luteal phases of Hu sheep (p < 0.05 or p < 0.01). However, both varieties of sheep exhibited a similar tendency to secrete E2 and FSH. Compared with Hu sheep, FSH levels were slightly higher in Merino serum. In Hu sheep, ERα, ERß, FSHR, LHR and PR expressed in luteal phase ovaries during spring were significantly lower (p < 0.05, p < 0.01 or p < 0.001) than autumn. Interestingly, LHR and PR expressed in anoestrous ovaries were similar to that in oestrous phase of both sheep breeds. The above results suggest that seasonal reproductive sheep increased the expression of E2 and FSH receptors in ovary during spring may enhance the effects of E2 and FSH on follicular development. It is likely that this enhancement prevents the ovary from progressing to the luteal phase.

The CXCL12-CXCR4 signaling promotes oocyte maturation by regulating cumulus expansion in sheep.

Gonadotropins and growth factors synergistically regulate folliculogenesis and oocyte development. C-X-C motif chemokine 12 (CXCL12) and its receptor CXCR4 are expressed in ovaries of sheep, cattle and other species, however, roles of this multifunctional signal axis in oocyte maturation are not defined. Using sheep as a model, we examined the expression patterns and functions of the CXCL12-CXCR4 axis during oocyte maturation. CXCL12 and CXCR4 mRNA and protein were present in oocytes and granulosa cells. Relative abundance of CXCR4 transcript was controlled by epidermal growth factor (EGF). Transient inhibition of CXCR4 suppressed oocyte nuclear maturation while supplementing recombination CXCL12 significantly increased percent of oocyte undergone metaphase I phase. Inhibition of CXCR4 function decreased cumulus expansion growth rate. Furthermore, granulosa cell migration was impaired and expression of hyaluronan synthase 2 (HAS2) and hyaluronan binding protein tumor necrosis factor-alpha-induced protein 6 (TNFAIP6) were downregulated by CXCR4 inhibition. These findings revealed a novel role of the CXCL12-CXCR4 signaling in oocyte development in sheep.

Relationship between post-extraction pain and acute pulpitis: a randomised trial using third molars.

INTRODUCTION: The aim of the present study was to examine the relationship between post-extraction pain and acute pulpitis in third molars. METHODS: This study was a randomised controlled trial. Sixty patients requiring removal of a single maxillary third molar with acute pulpitis were included and randomly divided into two groups: group A (n = 30); and group B (n = 30). In group A, third molars were directly extracted, and group B received endodontic therapy (pulp chamber opening and drainage) and underwent extraction 24 hours later, aiming to eliminate the acute inflammation. Another 30 patients requiring removal of a single maxillary third molar and with the same inclusion criteria but without caries or acute pulpitis were recruited into group C, in which the maxillary third molars were also directly extracted. The level of postoperative pain reported each day among the three groups was statistically evaluated. RESULTS: On the first, second and third days after surgery, there was a statistically significant difference between group A and group B and between group A and group C, but there was no statistically significant difference between group B and group C. CONCLUSION: The results of the present study indicate that there is more pain when third molars with acute pulpitis are directly removed compared with the pain level of the removal of third molars without acute pulpitis.

Plant functional traits suggest a change in novel ecological strategies for dominant species in the stages of forest succession.

In forest succession, the ecological strategies of the dominant species that are based on functional traits are important in the determination of both the mechanisms and the potential directions of succession. Thirty-one plots were established in the Loess Plateau region of northern Shaanxi in China. Fifteen leaf traits were measured for the 31 dominant species that represented the six stages of succession, and the traits included four that were related to morphology, seven to stoichiometry and four to physiological ecology. The species from the different successional stages had different patterns of distribution of the traits, and different key traits predicted the turnover of the species during succession. The ash and the cellulose contents were key regulatory factors of species turnover in the early successional communities, and the trait niche forces in sugar and leaf dry mass content might become more important with the progression of succession. When only the three herb stages were considered, a progressive replacement of the ruderal by the competitive-ruderal species occurred in the intermediate stages of succession, which was followed by the stress-tolerant-competitive or the competitive-stress tolerant-ruderal strategists late in the succession. Thus, the different species that occurred in the different stages of succession shared different trait-based ecological strategies. Additionally, these differences occurred concomitantly with a shift toward competitive-stress tolerant-ruderal strategies.

Genetic association and interaction between the IRF5 and TYK2 genes and systemic lupus erythematosus in the Han Chinese population.

OBJECTIVES: The purpose of this case-control study was to investigate whether polymorphisms and gene-gene interactions of the two type I interferon (IFN) genes (IRF5 and TYK2) are the susceptible factors of systemic Lupus erythematosus (SLE) in the Han Chinese population. METHODS: The four variants [rs2004640, rs2070197, rs10954213 and exon6 insertion/deletion (in/de)] of IRF5 gene and five single-nucleotide polymorphisms (SNPs) (rs280500, rs280519, rs2304256, rs8108236, rs12720270) of TYK2 gene were examined in a cohort of 642 SLE patients and 642 healthy controls. Genotyping was conducted using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and confirmed by direct sequencing in 10 % sample randomly. RESULTS: Rs2070197 was not polymorphic in this study, and was excluded in further analysis. Significant association was found for loci on IRF5 (rs2004640: p = 0.0003, p corr = 0.0012) and TYK2 (rs280500: p = 8.83 × 10(-6), p corr = 4.41 × 10(-5); rs2304256: p = 3.71 × 10(-6), p corr = 1.85 × 10(-5); rs8108236: p = 0.0004, p corr = 0.002), but not for other SNPs. Significant association was also observed for genotypes of IRF5 (rs2004640, p = 0.0009, p corr = 0.0036) and TYK2 SNPs (rs280500: p = 5.21 × 10(-5), p corr = 2.61 × 10(-4); rs2304256: p = 7.72 × 10(-6), p corr = 3.86 × 10(-5); rs8108236: p = 0.002, p corr = 0.01). Nevertheless, two haplotypes based on the 3 variants [exon6(in/de), rs10954213, rs2004640] of IRF5 (DAG and IAT) could define protective or susceptibility haplotype in SLE. Similarly, three haplotypes containing 5 SNPs (rs280500, rs280519, rs2304256, rs8108236, rs12720270) of TYK2 (GATAT, AGGAT and GAGGT) may also be associated with SLE in Han Chinese. Additionally, the gene-gene interaction analysis was conducted on the IRF5 and TYK2 SNPs. And a three-way interaction between TYK2 rs280500, rs2304256 and IRF5 rs10954213 and SLE was found (p < 0.0001). CONCLUSIONS: Genetic associations and gene-gene interactions of IRF5 and TYK2 were significantly detected in Han Chinese with SLE. Our results had important implications for future research on the role of type I IFN function in SLE susceptibility.