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N,N-dimethylformamide (DMF) is a widely-used solvent for the synthesis of synthetic fibers such as polyacrylonitrile fiber, and can also be used to make medicine. Although this organic solvent has multipurpose applications, its biological toxicity cannot be ignored and its impact on mammalian reproduction remains largely unexplored. Our study found that DMF exposure inhibited oocyte maturation and fertilization ability. Transcriptomic analysis indicated that DMF exposure changed the expression of genes and transposable elements in oocytes. Subcellular structure examination found that DMF exposure caused mitochondrial dysfunction, abnormal aggregation of mitochondria and decreased mitochondrial membrane potential in mouse oocytes. Its exposure also caused abnormal distribution of Golgi apparatus and endoplasmic reticulum which formed large number of clusters. In addition, oxidative stress occurs in oocytes exposed to DMF, which was manifested by an increase in the level of reactive oxygen species. We found that DMF exposure induced disordered spindle and chromosomes abnormality. Meanwhile, we examined various histone modification levels in oocytes exposed to DMF and found that DMF exposure reduced H3K9me3, H3K9ac, H3K27ac, and H4K16ac levels in mouse oocytes. Moreover, DMF-treated oocytes failed to form pronuclei after fusion with normal sperm. Collectively, DMF exposure caused mitochondrial damage, oxidative stress, spindle assembly and chromosome arrangement disorder, leading to oocyte maturation arrest and fertilization failure.

An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is leading to an unprecedented worldwide health crisis. SARS‐CoV‐2 cell entry depends on ACE2 and TMPRSS2. Our objectives are to analysis the expression profile of ACE2 and TMPRSS2 in human spermatogenic cells, follicle cells, and preimplantation embryos, thereby providing mechanistic insights into viral entry and viral impact on reproduction. We found that ACE2 is mainly expressed during gametogenesis in spermatogonia and oocytes of antral follicles, granulosa cells of antral follicles and pre‐ovulatory follicles, while TMPRSS2 almost has no expression in spermatogenic cells, oocytes or granulosa cells. In preimplantation embryos, ACE2 is expressed in early embryos before eight‐cell stage, and trophectoderm of late blastocysts, while TMPRSS2 initiates its robust expression in late blastocyst stage. ACE2 and TMPRSS2 only show significant co‐expression in trophectoderm of late blastocysts in all above cell types. We speculate that trophectoderm of late blastocysts is susceptible to SARS‐CoV‐2, and that the chance of SARS‐CoV‐2 being passed on to offspring through gametes is very low. Therefore, we propose that fertility preservation for COVID‐19 patients is relatively safe and rational. We also recommend embryo cryopreservation and embryo transfer into healthy recipient mother at cleavage stage instead of blastocyst stage. Moreover, we unexpectedly found that co‐expression pattern of ACE2 and TMPRSS2 in oocytes and preimplantation embryos in human, rhesus monkey and mouse are totally different, so animal models have significant limitations for evaluating transmission risk of SARS‐CoV‐2 in reproduction.

Gastric cancer is a common and high‐incidence malignant gastro‐intestinal cancer that seriously threatens human life. Evidence suggests that microRNAs (miRNAs) play an essential role in regulating the occurrence and development of gastric cancer, but the possible mechanisms and effects remain to be further explored. In the present study, a new tumour suppresser function of miR‐484 was identified in gastric cancer. The expression of miR‐484 was obviously decreased, and the expression of CCL‐18 was obviously increased in gastric cancer tissues and cell lines. In addition, upregulation of miR‐484 suppressed cell proliferation, migration and invasion, and induced cell cycle arrest in G1 phase and cell apoptosis in gastric cancer cells. Besides, miR‐484 mimics could block the PI3K/AKT signalling pathway. Moreover, CCL‐18 was confirmed as a direct target of miR‐484 by binding its 3′‐UTR, and over‐expression of CCL‐18 could restore the effects of miR‐484 on the growth and metastasis of gastric cancer. Finally, in vivo experiments showed that over‐expression of miR‐484 inhibited the subcutaneous tumorigenicity of gastric cancer cells, and the inhibition was blocked after over‐expression of CCL‐18. To conclude, miR‐484 expression was downregulated in gastric cancer tissues and cells and played an anti‐cancer role in the occurrence and development of gastric cancer, which may be achieved by inhibiting the expression of transcription factor CCL‐18 and blocking the PI3K/AKT pathway.

(E)-2-(hetero)arylethenesulfonyl fluorides and (E,E)-1,3-dienylsulfonyl fluorides are bis-electrophiles and rare members of the sulfonyl fluoride family with limited information being known of their reactivity and synthetic utility. The direct annulation reaction of these 2-substituted ethenesulfonyl fluorides with medicinally important enolizable pyrazolones and 1,3-dicarbonyl compounds utilizing catalytic DBU in DCM under mild conditions leads to over 50 structurally diverse δ-sultone fused heterocycles with a pyrazolone ring or a cyclic enone, respectively, in good to excellent yield. The double bond at the 1-position adjacent to the sulfonyl fluoride group in 1,3-dienylsulfonyl fluoride is the chemoselective site of reactivity but is less reactive than the double bond of arylethenesulfonyl fluoride. High turnover and robustness of construction for these fused heterocycles, including the novel fused pyrazolone δ-sultone heterocycle series, may make compounds like these attractive to drug discovery, development and material science.

A new coordination polymer, [Zn(L)(1,2-bdc)(H2O)]·1.5H2O (1) (L = N,N′,N′′-tris(3-pyridyl)-1,3,5-benzenetricarboxamide, 1,2-bdc = 1,2-benzenedicarboxylic acid), has been synthesized through the hydrothermal method and characterized by elemental analysis, IR, single-crystal X-ray diffraction. It crystallizes in triclinic, space group P -1, a = 7.403(3) A, b = 13.900(5) A, c = 17.317(6) A, α = 71.591(5)°, β = 88.225(5)°, γ = 75.940(5)°, V = 1638.1(10) A 3, Z = 2, C32H27ZnN6O9.5, Mr = 712.97, Dc = 1.445 g/cm3, F(000) = 734, GOOF = 0.968. In this structure, each two bdc2- ligands connect two Zn(II) atoms to form a four-membered ring with two L ligands acting as the two arms of the four-membered ring. The adjacent four-membered rings are further extended to a 3D supramolecular structure by hydrogen bonding interactions and π-π stacking. Moreover, the luminescent property has also been investigated.

Accurate mitotic regulation is as important as intrinsic DNA repair for maintaining genomic stability. It is believed that these two cellular mechanisms are interconnected with DNA damage. DNA-PKcs is a critical component of the non-homologous end-joining pathway of DNA double-stranded break repair, and it was recently discovered to be involved in mitotic processing. However, the underlying mechanism of DNA-PKcs action in mitotic control is unknown. Here, we demonstrated that depletion of DNA-PKcs led to the dysregulation of mitotic progression in response to DNA damage, which eventually resulted in multiple failures, including failure to segregate sister chromatids and failure to complete cytokinesis, with daughter cells becoming fused again. The depletion of DNA-PKcs resulted in a notable failure of cytokinesis, with a high incidence of multinucleated cells. There were also cytoplasmic bridges containing DNA that continuously connected the daughter cells after DNA damage was induced. Phosphorylated DNA-PKcs (T2609) colocalizes with PLK1 throughout mitosis, including at the centrosomes from prophase to anaphase and at the kinetochores from prometaphase to metaphase, with accumulation at the midbody during cytokinesis. Importantly, DNA-PKcs was found to associate with PLK1 in the mitotic phase, and the depletion of DNA-PKcs resulted in the overexpression of PLK1 due to increased protein stability. However, deficiency in DNA-PKcs attenuated the recruitment of phosphorylated PLK1 to the midbody but not to the kinetochores and centrosomes. Our results demonstrate the functional association of DNA-PKcs with PLK1, especially in chromosomal segregation and cytokinesis control.

A Pd-catalyzed Suzuki cross-coupling of arylboronic acids with Yagupolskii-Umemoto reagents was explored. In contrary to trifluoromethylations, the Pd-catalyzed reaction of R-B(OH)2 and [Ar2 SCF3 ](+) [OTf](-) provided the arylation products (R-Ar) in good to high yields. The reaction confirms that the S-Ar bonds of [Ar2 SCF3 ](+) [OTf](-) can be readily cleaved in the presence of Pd complexes. The relatively electron-poor aryl groups of asymmetric [Ar(1) Ar(2) SCF3 ](+) [OTf](-) salts are more favorably transferred compared to the electron-rich ones. This reaction represents the first report of utilization of [Ar2 SCF3 ](+) [OTf](-) as arylation reagents in organic synthesis.

1. The mechanisms that prevent competition (conflict) between the recipient and co-operative actor in co-operative systems remain one of the greatest problems for evolutionary biology. Previous hypotheses suggest that self-restraint, dispersal or spatial constraints can prevent direct competition for local resources or any other common resources, thereby maintaining stable co-operation interactions. In this study, we use the obligate fig-fig-wasp mutualism to examine whether the above mechanisms can maintain stable co-operation sufficiently between figs and fig wasps. 2. Our data on obligate co-operation between figs (Ficus racemosa Linn.) and fig wasps (Ceratoslen fusciceps Mayr) show that the number of viable seeds of figs is positively correlated with the number of pollinator offspring when the number of vacant female flowers is high while the foundress number is low (two foundresses). Meanwhile, they are negatively correlated when the number of vacant female flowers is low and the number of foundresses is increased manually (eight foundresses). The correlation coefficient between viable seeds and wasp offspring (galls) depends on vacant female flower availability. 3. Our data suggest that the interaction between figs and fig wasps is conditional, and that they co-operate when local resource availability is plentiful but are in conflict when local resource availability is limited. The self-restraint, dispersal and spatial heterogeneity previously hypothesized in maintaining stable co-operation cannot sufficiently prevent the symbionts from utilizing more local resources at the expense of the recipients. The conflict, which can disrupt the co-operation interaction, exists after the local resource is saturated with symbionts. The repression of symbiont increase, therefore repressing the utilization of local resources in the conflict period, is crucial in the maintenance and evolution of co-operation.

(E)-Bis(phosphonium)ethylenes were synthesized from aryl-, alkyl-, and arylalkylphosphines under solvent-free conditions using TfOCH2CF2H as reagent. The reaction allows for a convenient access to vinylenebis(trialkylphosphonium) salts in good to high yields.