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The discovery of RNAs (for example, messenger RNAs, non-coding RNAs) in sperm has opened the possibility that sperm may function by delivering additional paternal information aside from solely providing the DNA 1 . Increasing evidence now suggests that sperm small non-coding RNAs (sncRNAs) can mediate intergenerational transmission of paternally acquired phenotypes, including mental stress2,3 and metabolic disorders4-6. How sperm sncRNAs encode paternal information remains unclear, but the mechanism may involve RNA modifications. Here we show that deletion of a mouse tRNA methyltransferase, DNMT2, abolished sperm sncRNA-mediated transmission of high-fat-diet-induced metabolic disorders to offspring. Dnmt2 deletion prevented the elevation of RNA modifications (m5C, m2G) in sperm 30-40 nt RNA fractions that are induced by a high-fat diet. Also, Dnmt2 deletion altered the sperm small RNA expression profile, including levels of tRNA-derived small RNAs and rRNA-derived small RNAs, which might be essential in composing a sperm RNA 'coding signature' that is needed for paternal epigenetic memory. Finally, we show that Dnmt2-mediated m5C contributes to the secondary structure and biological properties of sncRNAs, implicating sperm RNA modifications as an additional layer of paternal hereditary information.

Increasing evidence indicates that metabolic disorders in offspring can result from the father's diet, but the mechanism remains unclear. In a paternal mouse model given a high-fat diet (HFD), we showed that a subset of sperm transfer RNA-derived small RNAs (tsRNAs), mainly from 5' transfer RNA halves and ranging in size from 30 to 34 nucleotides, exhibited changes in expression profiles and RNA modifications. Injection of sperm tsRNA fractions from HFD males into normal zygotes generated metabolic disorders in the F1 offspring and altered gene expression of metabolic pathways in early embryos and islets of F1 offspring, which was unrelated to DNA methylation at CpG-enriched regions. Hence, sperm tsRNAs represent a paternal epigenetic factor that may mediate intergenerational inheritance of diet-induced metabolic disorders.

In rodent species, the ovary and the end of oviduct are encapsulated by a thin membrane called ovarian bursa. The biological functions of ovarian bursa remain unexplored despite its structural arrangement in facilitating oocytes transport into oviduct. In the present study, we observed a rapid fluid accumulation and reabsorption within the ovarian bursa after ovarian stimulation (PMSG-primed hCG injection), suggesting that the ovarian bursa might play an active role in regulating local fluid homeostasis around the timing of ovulation. We hypothesized that the aquaporin proteins, which are specialized channels for water transport, might be involved in this process. By screening the expression of aquaporin family members (Aqp1-9) in the ovarian tissue and isolated ovarian bursa (0, 1, 2 and 5 h after hCG injection), we found that AQP2 and AQP5 mRNA showed dynamic changes after hCG treatment, showing upregulation at 1-2 h followed by gradually decrease at 5 h, which is closely related with the intra-bursa fluid dynamics. Further immunofluorescence examinations of AQP2 and AQP5 in the ovarian bursa revealed that AQP2 is specifically localized in the outer layer (peritoneal side) while AQP5 localized in the inner layer (ovarian side) of the bursa, such cell type specific and spatial-temporal expressions of AQP2 and 5 support our hypothesis that they might be involved in efficient water transport through ovarian bursa under ovulation related hormonal regulation. The physiological significance of aquaporin-mediated water transport in the context of ovarian bursa still awaits further clarification.

Abstract: Quantum-chemical calculations on some linear or non-linear C28H20 and C36H24 isomers composed of hexaprismane cages which are parallel or perpendicular to each other have been performed using density functional theory (DFT) method. The electronic structures, thermal energies, and vertical ionization potential as well as vertical electron affinity of various isomers have been obtained at the B3LYP/6-31G(d,p) level. And some meaningful conclusions have been speculated. Meanwhile, the present paper has also computed the enthalpies of formation for different isomers so as to evaluate their stability from a thermodynamic point of view. It has been concluded that the linear isomer in which the hexaprismane cages are perpendicular is more stable and has smaller enthalpy of formation. [ABSTRACT FROM AUTHOR]

Abstract: This paper assesses the potential of natural Chinese clinoptilolite for ammonia removal from aqueous solution. In batch study, the effects of relevant parameters, such as contact time, pH and initial ammonia concentration were examined, respectively. The results show that although contact time needs at least 4h in order to attain exchange equilibrium, ammonia removal by clinoptilolite occurs rapidly within the first 15min of contact time; the pH has an effect on ammonia removal efficiency as it can influence both the character of the exchanging ions and the clinoptilolite itself; the ammonia removal capacity of clinoptilolite increases with the increase of initial ammonia concentration. In column study, clinoptilolite bed was exhausted at different flow velocities and ammonia breakthrough capacity of clinoptilolite bed was calculated. Furthermore, the optimum regeneration conditions were considered. The results show that flow velocity can affect breakthrough capacity of clinoptilolite by changing hydraulic retention time and the volume of 15–20BV of 0.5mol/L sodium chloride solution at pH 11–12 is sufficient for complete regeneration of clinoptilolite in column. [Copyright &y& Elsevier]

Abstract: Quantum-chemical calculations on some possible isomers of C24O derived from C24 have been performed using density functional theory (DFT) method. The geometric structures, relative energies and electronic structures of various C24O isomers at the ground state have been calculated at the B3LYP/6-31G(d) level. And the 1,4-C24O(I) isomer was found to be the most stable geometry where the oxygen atom was added to the longest carbonnd derived from the C24 (D6) isomer in the present paper. Based on the optimized neutral geometries at B3LYP/6-31G(d), the vertical ionization potential and vertical electron affinity have been analyzed. Meanwhile, the vibrational frequencies and IR spectrum of various C24O isomers have been obtained. [Copyright &y& Elsevier]

The growth and differentiation of neurons are critical events in the establishment of proper neuron connectivity and function. Planarians have a remarkable ability to completely regenerate a functional nervous system from a pluripotent stem cell population. Thus, planarians provide a powerful model to identify genes required for neuronal differentiation in vivo. The Wnt/Ca 2+ signaling pathway is crucial for cancer development, arousing inflammatory responses, and neurodegeneration. We analyzed the expression patterns and RNAi phenotypes for members of the Wnt/Ca 2+ signaling pathway in the planarian, Dugesia japonica. The expression of DjWnt5a, DjPLC-β, DjCamKII, and DjCaln during regeneration was surprisingly similar and revealing in the regenerated brain. RNAi knockdown of DjWnt5a, DjPLC-β, DjCamKII, and DjCaln led to defects in regenerated brains including brain partial deletions, incompact phenotypes at the posterior of the new brain, and lateral branches, which could not regenerate. Furthermore, the expressions of GAD and the number of GABAergic neurons decreased. Together, these results suggest that the Wnt/Ca 2+ signaling pathway is required for GABAergic neuron regeneration., (© 2020 Federation of American Societies for Experimental Biology.)

Distribution of the tributyltin (TBT) between egg-phosphatidylcholine membranes (liposome) and water under different pH and a comparison between the partition of TBT into lipid membranes and into octanol were studied. The distribution of this compound into both lipid membranes and octanol increased with pH. The major difference was that at lower pH, where ionized TBT dominated distribution was greater into lipid membranes compared to that of octanol. At high pH, where TBT predominates as neutral species, the distribution ratios were very similar in the octanol and the liposome-water system. These differences can be attributed to the properties of the biomembrane. The results indicated that the liposome-water partition model appears to be a better molecular descriptor for ionogenic organic compounds.