Involvement of Protein Kinase A in Oxytocin Neuronal Activity in Rat Dams with Pup Deprivation

Neurochemical Research - Oxytocin (OT) neuronal activity is the key factor for breastfeeding and it can be disrupted by mother-baby separation. To explore cellular mechanisms underlying OT neuronal...     

Offspring performance and female preference of Pagiophloeus tsushimanus (coleoptera: curculionidae) on three Lauraceae tree species: A potential risk of host shift caused by larval experience

The weevil Pagiophloeus tsushimanus Morimoto (Coleoptera: Curculionidae), native to Eastern Asia, is a wood-boring pest that causes severe damage to camphor trees (Cinnamomum sp.) in Shanghai, China. Other Lauraceae tree species that grew sympatrically with this pest in close proximity could face a potential threat. To assess the potential risks of host shift, we explored the phenotypic associations between preference and performance in P. tsushimanus reared on three Lauraceae tree species. In a no-choice experiment offering branches of each plant as diet material and oviposition sites, we found that individuals reared on Cinnamomum camphora (L.) Presl (Laurales: Lauraceae) exhibited the strongest performance with shorter development time, higher survival and growth rate in the immature stage, longer longevity and greater fecundity in adults. In contrast, those on novel Lauraceae tree species (Cinnamomum chekiangensis Nakai and Phoebe chekiangensis Shang) had difficulty completing their whole life cycle due to significantly lower survival and reproduction. In a multiple-choice experiment, C. camphora was established as the preferred host. However, we found that the larval experiences on the non-preferred host plants contributed to an increased preference for that plant species. These results indicated that both the preference-performance hypothesis and the Hopkins’ host selection principle are applicable in this weevil under experimental conditions. It is possible that although the weevil performed poorly on two novel Lauraceae tree species, under favourable conditions their surviving offspring could evolve into a new host-specific population. Consequently, this weevil pest needs to be monitored on these novel Lauraceae tree species.     

Environmental and techno-economic analyses of bio-jet fuel produced from jatropha and castor oilseeds in China

Purpose

Bio-jet fuel derived from energy crops has been promoted by governments around the world through policies such as the Carbon Offsetting and Reduction Scheme for International Aviation. The environmental impact and techno-economic analysis of bio-jet fuel are particularly pertinent to China because China is under huge pressure to reduce emissions, endeavouring to meet bio-economic goals.

Methods

An LCA study was conducted on the production of bio-jet fuel from jatropha and castor by estimating the well-to-wake emissions and its economic impact. The functional unit was 1 MJ of bio-jet fuel, and field survey data was used in inventory analysis. A scenario analysis was performed to measure diverse conditions, including the planting conditions, planting regions, allocation methods, and hydrogen sources. A techno-economic analysis that combined the production costs and co-product credits was performed to calculate the minimum bio-jet fuel selling price (MJSP) based on a plant capacity of 2400 metric tonnes of feedstock per day.

Results and discussion

Compared to the environmental impacts to the fossil jet fuel, the use of biofuel would reduce the majority environmental impacts by 36–85%, when a 1:1 displacement of fossil jet fuel is considered, though the human toxicity potential impact was 100% higher. The scenario analysis indicated that (i) planting castor in harsh and unevenly distributed conditions and jatropha in stable or fertile conditions can leverage their respective advantage; (ii) the global warming potential (GWP) from castor planting in the region of north-east China ranges from 34 to 48 g CO₂ eq/MJ; (iii) the GWP produced through the steam methane reforming process can be reduced by 16–17%, using advances in technological processes. The MJSP for fuel produced from jatropha and castor under the basic scenario is estimated to be 5.68 and 4.66 CNY/kg, respectively, which falls within the current market price range of 4.5–7.5 CNY/kg.

Conclusions

Bio-jet fuel from jatropha and castor oilseeds offers potential environmental benefits if they can reduce fossil jet fuel on an energy-equivalent basis. However, these benefits are likely to be reduced by the rebound effect of the fuel market. Future research is needed to better understand the magnitude of the rebound effect in China and what policy interventions can be implemented to alleviate it. Scenario analysis demonstrated the feasibility and potential of bio-jet fuel development from multiple perspectives and technological progress are conducive to the realization of environmental protection policies.

     

Divergent DNA methylation contributes to duplicated gene evolution and chilling response in tea plants

The tea plant (Camellia sinensis) is a thermophilic cash crop and contains a highly duplicated and repeat-rich genome. It is still unclear how DNA methylation regulates the evolution of duplicated genes and chilling stress in tea plants. We therefore generated a single-base-resolution DNA methylation map of tea plants under chilling stress. We found that, compared with other plants, the tea plant genome is highly methylated in all three sequence contexts, including CG, CHG and CHH (where H = A, T, or C), which is further proven to be correlated with its repeat content and genome size. We show that DNA methylation in the gene body negatively regulates the gene expression of tea plants, whereas non-CG methylation in the flanking region enables a positive regulation of gene expression. We demonstrate that transposable element-mediated methylation dynamics significantly drives the expression divergence of duplicated genes in tea plants. The DNA methylation and expression divergence of duplicated genes in the tea plant increases with evolutionary age and selective pressure. Moreover, we detect thousands of differentially methylated genes, some of which are functionally associated with chilling stress. We also experimentally reveal that DNA methyltransferase genes of tea plants are significantly downregulated, whereas demethylase genes are upregulated at the initial stage of chilling stress, which is in line with the significant loss of DNA methylation of three well-known cold-responsive genes at their promoter and gene body regions. Overall, our findings underscore the importance of DNA methylation regulation and offer new insights into duplicated gene evolution and chilling tolerance in tea plants.     

Transient characteristics of universal cells on human‐induced pluripotent stem cells and their differentiated cells derived from foetal stem cells with mixed donor sources

IntroductionIt is important to prepare ‘hypoimmunogenic’ or ‘universal’ human pluripotent stem cells (hPSCs) with gene‐editing technology by knocking out or in immune‐related genes, because only a few hypoimmunogenic or universal hPSC lines would be sufficient to store for their off‐the‐shelf use. However, these hypoimmunogenic or universal hPSCs prepared previously were all genetically edited, which makes laborious processes to check and evaluate no abnormal gene editing of hPSCs.MethodsUniversal human‐induced pluripotent stem cells (hiPSCs) were generated without gene editing, which were reprogrammed from foetal stem cells (human amniotic fluid stem cells) with mixing 2‐5 allogenic donors but not with single donor. We evaluated human leucocyte antigen (HLA)‐expressing class Ia and class II of our hiPSCs and their differentiated cells into embryoid bodies, cardiomyocytes and mesenchymal stem cells. We further evaluated immunogenic response of transient universal hiPSCs with allogenic mononuclear cells from survival rate and cytokine production, which were generated by the cells due to immunogenic reactions.ResultsOur universal hiPSCs during passages 10‐25 did not have immunogenic reaction from allogenic mononuclear cells even after differentiation into cardiomyocytes, embryoid bodies and mesenchymal stem cells. Furthermore, the cells including the differentiated cells did not express HLA class Ia and class II. Cardiomyocytes differentiated from transient universal hiPSCs at passage 21‐22 survived and continued beating even after treatment with allogenic mononuclear cells.     

Target-specific mutations efficiency at multiple loci of CRISPR/Cas9 system using one sgRNA in soybean

Soybean has a palaeopolyploid genome with nearly 75% of the genes present in multiple copies. Although the CRISPR/Cas9 system has been employed in soybean to generate site-directed mutagenesis, a systematical assessment of mutation efficiency of the CRISPR/Cas9 system for the multiple-copy genes is still urgently needed. Here, we successfully optimize one sgRNA CRISPR/Cas9 system in soybean by testing the efficiency, pattern, specificity of the mutations at multiple loci of GmFAD2 and GmALS. The results showed that simultaneous site-directed mutagenesis of two homoeologous loci by one sgRNA, the mutation frequency in the T0 generation were 64.71% for GmPDS, 60.0% for GmFAD2 and 42.86% for GmALS, respectively. The chimeric and heterozygous mutations were dominant types. Moreover, association of phenotypes with mutation pattern at target loci of GmPDS11 and GmPDS18 could help us further demonstrate that the CRISPR/Cas9 system can efficiently generate target specific mutations at multiple loci using one sgRNA in soybean, albeit with a relatively low transformation efficiency.

     

Cytological and morphology characteristics of natural microsporogenesis within Camellia oleifera

Camellia oleifera is believed to exhibit a complex intraspecific polyploidy phenomenon. Abnormal microsporogenesis can promote the formation of unreduced gametes in plants and lead to sexual polyploidy, so it is hypothesized that improper meiosis probably results in the formation of natural polyploidy in Camellia oleifera. In this study, based on the cytological observation of meiosis in pollen mother cells (PMCs), we found natural 2n pollen for the first time in Camellia oleifera, which may lead to the formation of natural polyploids by sexual polyploidization. Additionally, abnormal cytological behaviour during meiosis, including univalent chromosomes, extraequatorial chromosomes, early segregation, laggard chromosomes, chromosome stickiness, asynchronous meiosis and deviant cytokinesis (monad, dyads, triads), was observed, which could be the cause of 2n pollen formation. Moreover, we confirmed a relationship among the length–width ratio of flower buds, stylet length and microsporogenesis. This result suggested that we can immediately determine the microsporogenesis stages by phenotypic characteristics, which may be applicable to breeding advanced germplasm in Camellia oleifera.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-01002-5.     

mTORC1 activity is supported by spatial association with focal adhesions

The mammalian target of rapamycin complex 1 (mTORC1) integrates mitogenic and stress signals to control growth and metabolism. Activation of mTORC1 by amino acids and growth factors involves recruitment of the complex to the lysosomal membrane and is further supported by lysosome distribution to the cell periphery. Here, we show that translocation of lysosomes toward the cell periphery brings mTORC1 into proximity with focal adhesions (FAs). We demonstrate that FAs constitute discrete plasma membrane hubs mediating growth factor signaling and amino acid input into the cell. FAs, as well as the translocation of lysosome-bound mTORC1 to their vicinity, contribute to both peripheral and intracellular mTORC1 activity. Conversely, lysosomal distribution to the cell periphery is dispensable for the activation of mTORC1 constitutively targeted to FAs. This study advances our understanding of spatial mTORC1 regulation by demonstrating that the localization of mTORC1 to FAs is both necessary and sufficient for its activation by growth-promoting stimuli.