The mammalian oocyte possesses powerful reprogramming factors, which can reprogram terminally differentiated germ cells (sperm) or somatic cells within a few cell cycles. Although it has been suggested that use of oocyte-derived transcripts may enhance the generation of induced pluripotent stem cells, the reprogramming factors in oocytes are undetermined, and even the identified proteins composition of oocytes is very limited. In the present study, 7,000 mouse oocytes at different developmental stages, including the germinal vesicle stage, the metaphase II (MII) stage, and the fertilized oocytes (zygotes), were collected. We successfully identified 2,781 proteins present in germinal vesicle oocytes, 2,973 proteins in MII oocytes, and 2,082 proteins in zygotes through semiquantitative MS analysis. Furthermore, the results of the bioinformatics analysis indicated that different protein compositions are correlated with oocyte characteristics at different developmental stages. For example, specific transcription factors and chromatin remodeling factors are more abundant in MII oocytes, which may be crucial for the epigenetic reprogramming of sperm or somatic nuclei. These results provided important knowledge to better understand the molecular mechanisms in early development and may improve the generation of induced pluripotent stem cells.germinal vesicle | metaphase II | zygote | protein | reprogramming R eprogramming of patient-specific somatic cells into pluripotent stem cells has attracted wide scientific and public interest because of the great potential value in both research and therapy. Recent advances in induced pluripotent stem cell (iPSC) research have clearly indicated that a small number of transcription factors can reverse the cell fate of differentiated somatic cells; however, the reprogramming process remains slow, and the efficiency is low. Typically, 1% of cells are reprogrammed, but this process requires at least 7 d to 2 wk (1-8). In contrast, reprogramming during somatic cell nuclear transfer (SCNT) occurs within one or two cell cycles and often in a majority of embryos (9-14). The oocytederived transcripts that promote this more efficient reprogramming remain unidentified; however, it has been suggested that their inclusion with the four transcription factors (Oct4, Sox2, Klf4, and c-Myc) may increase the speed and efficiency of the reprogramming process (15). As a step to identification of these factors, this project sought to define the proteome of mouse oocytes at three stages of development, which will also provide us important information on the factors regulating developmental competence of oocytes.During mammalian oogenesis, the oocyte undergoes two cell cycle arrests at the dictyate or germinal vesicle (GV) stage and the metaphase II (MII) stage (16,17). MII oocytes have been widely used to reprogram somatic cell nuclei, because during normal reproduction, sperm and oocyte nuclei are reprogrammed by the MII oocyte to produce totipotent zygotes. By contrast, results from our previous nucl...

AimTo investigate simultaneously the effect of voxel size and fracture width on the accuracy of detecting vertical root fractures (VRFs) in non‐root filled teeth when using cone beam computed tomography.MethodologyFifty‐one of 161 extracted human permanent teeth (16 anterior teeth, 132 premolars and 13 mandibular molars) were selected randomly for VRF induction with two fracture widths. All teeth were scanned with four CBCT units at different voxel sizes provided by the units. Three observers classified the presence or absence of VRF using a 5‐point scale. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the ROC curve (AUC) were calculated. AUCs amongst voxel sizes and between the fracture widths were compared using the Z test. Intra‐ and inter‐observer agreement was assessed using weighted Cohen kappa.ResultsFor the NewTom VGi and ProMax 3D Mid CBCT unit, no significant differences were found amongst voxel sizes for the AUCs, irrespective of the fracture width (P > 0.05). There were significant differences between images scanned with voxel size 250 and 160 μm (P = 0.02), and images scanned with voxel size 250 and 80 μm for AUCs in the narrow VRF group for the 3D Accuitomo 170 unit (P = 0.03). For i‐CAT FLX, significant differences were found between the voxel protocols of 300 μm and of the other three voxel sizes for AUC, sensitivity and NPV (P < 0.05). Significant differences between the wide and the narrow VRF groups for AUCs were found for 3D Accuitomo 170 (P = 0.01) and ProMax 3D Mid (P < 0.01).ConclusionsCone beam computed tomography was accurate for detecting VRF in non‐root filled teeth. Fracture width had an effect on the detection of VRF. The effect of the voxel size on the detection of VRF depended on the CBCT unit used.

Mouse oocytes undergo two successive meiotic divisions to generate one large egg with two small polar bodies. The divisions are essential for preserving the maternal resources to support embryonic development. Although previous studies have shown that some small guanosine triphosphatases, such as RAC, RAN, and CDC42, play important roles in cortical polarization and spindle pole anchoring, no oocytes undergo cytokinesis when the mutant forms of these genes are expressed in mouse oocytes. Here, we show that the ADP-ribosylation factor 1 (ARF1) plays an important role in regulating asymmetric cell division in mouse oocyte meiosis. Microinjection of mRNA of a dominant negative mutant form of Arf1 (Arf1(T31N)) into fully grown germinal vesicle oocytes led to symmetric cell division in meiosis I, generating two metaphase II (MII) oocytes of equal size. Subsequently, the two MII oocytes of equal size underwent the second round of symmetric cell division to generate a four-cell embryo (zygote) when activated parthenogenetically or via sperm injection. Furthermore, inactivation of mitogen-activated protein kinase (MAPK) but not MDK (also known as MEK) has been discovered in the ARF1 mutant oocytes, and this further demonstrated that ARF1, MAPK pathway plays an important role in regulating asymmetric cell division in meiosis I. Similarly, ARF1(T31N)-expressing, superovulated MII oocytes underwent symmetric cell division in meiosis II when activation was performed. Rotation of the MII spindle for 90 degrees was prohibited in ARF1(T31N)-expressing MII oocytes. Taken together, our results suggest that ARF1 plays an essential role in regulating asymmetric cell division in female meiosis.

Character strength-based interventions are an effective positive psychology approach in increasing happiness and reducing depression. However, little is known about whether the character strength-based interventions remain effective over an extended time period of 1 year, and why these activities (e.g., Identifying signature strengths and Using signature strengths in a new way) work. To address these issues, a 1-year randomized controlled intervention was conducted to examine the serial mediating role of strengths knowledge and strengths use. A hundred first-year students were randomly assigned into the intervention and the waiting-list control groups. The intervention group participated in four activities within a 90-min course and was encouraged to continue self-practice of the strengthsrelated activities after the intervention period. Immediate, short-term (i.e., 1 week), and long-term (i.e., 1 year) effectiveness were examined. Participants in the intervention group showed significant increase in thriving and decrease in negative emotional symptoms in the short term, but no effect was found for the control group. The long-term effects of thriving and negative emotional symptoms were insignificant for two experimental groups. Strengths use partially mediated the effectiveness of the intervention, but strengths knowledge did not significantly predict the outcomes. In conclusion, the character strength-based intervention can be an effective approach to improve the mental health of the first-year students. More attention should be paid to strengths use when practitioners design a character strength-based intervention.