Paternal chromosome elimination of inducer triggers induction of double haploids in Brassica napus

A synthetic octoploid rapeseed, Y3380, induces maternal doubled haploids when used as a pollen donor to pollinate plant. However, the mechanism underlying doubled haploid formation remains elusive. We speculated that double haploid induction occurs as the inducer line’s chromosomes pass to the maternal egg cell, and the zygote is formed through fertilization. In the process of zygotic mitosis, the paternal chromosome is specifically eliminated. Part of the paternal gene might have infiltrated the maternal genome through homologous exchange during the elimination process. Then, the zygote haploid genome doubles (early haploid doubling, EH phenomenon), and the doubled zygote continues to develop into a complete embryo, finally forming doubled haploid offspring. To test our hypothesis, in the current study, the octoploid Y3380 line was back bred with the 4122-cp4-EPSPS exogenous gene used as a marker into hexaploid Y3380-cp4-EPSPS as paternal material to pollinate three different maternal materials. The fertilization process of crossing between the inducer line and the maternal parent was observed 48 h after pollination, and the fertilization rate reached 97.92% and 98.72%. After 12 d of pollination, the presence of cp4-EPSPS in the embryo was detected by in situ PCR, and at 13–23 d after pollination, the probability of F1 embryos containing cp4-EPSPS gene was up to 97.27%, but then declined gradually to 0% at 23–33 d. At the same time, the expression of cp4-EPSPS was observed by immunofluorescence in the 3rd to 29th day embryo. As the embryos developed, cp4-EPSPS marker genes were constantly lost, accompanied by embryonic death. After 30 d, the presence of cp4-EPSPS was not detected in surviving embryos. Meanwhile, SNP detection of induced offspring confirmed the existence of double haploids, further indicating that the induction process was caused by the loss of specificity of the paternal chromosome. The tetraploid-induced offspring showed infiltration of the induced line gene loci, with heterozygosity and homozygosity. Results indicated that the induced line chromosomes were eliminated during embryonic development, and the maternal haploid chromosomes were synchronously doubled in the embryo. These findings support our hypothesis and lay a theoretical foundation for further localization or cloning of functional genes involved in double haploid induction in rapeseed

Neutrino Physics with JUNO

The Jiangmen Underground Neutrino Observatory (JUNO), a 20 kton multi-purposeunderground liquid scintillator detector, was proposed with the determinationof the neutrino mass hierarchy as a primary physics goal. It is also capable ofobserving neutrinos from terrestrial and extra-terrestrial sources, includingsupernova burst neutrinos, diffuse supernova neutrino background, geoneutrinos,atmospheric neutrinos, solar neutrinos, as well as exotic searches such asnucleon decays, dark matter, sterile neutrinos, etc. We present the physicsmotivations and the anticipated performance of the JUNO detector for variousproposed measurements. By detecting reactor antineutrinos from two power plantsat 53-km distance, JUNO will determine the neutrino mass hierarchy at a 3-4sigma significance with six years of running. The measurement of antineutrinospectrum will also lead to the precise determination of three out of the sixoscillation parameters to an accuracy of better than 1\%. Neutrino burst from atypical core-collapse supernova at 10 kpc would lead to ~5000inverse-beta-decay events and ~2000 all-flavor neutrino-proton elasticscattering events in JUNO. Detection of DSNB would provide valuable informationon the cosmic star-formation rate and the average core-collapsed neutrinoenergy spectrum. Geo-neutrinos can be detected in JUNO with a rate of ~400events per year, significantly improving the statistics of existing geoneutrinosamples. The JUNO detector is sensitive to several exotic searches, e.g. protondecay via the $p\to K^++\bar\nu$ decay channel. The JUNO detector will providea unique facility to address many outstanding crucial questions in particle andastrophysics. It holds the great potential for further advancing our quest tounderstanding the fundamental properties of neutrinos, one of the buildingblocks of our Universe

Efficient purification and concentration of viruses from a large body of high turbidity seawater

Marine viruses are the most abundant entities in the ocean and play crucial roles in the marine ecological system. However, understanding of viral diversity on large scale depends on efficient and reliable viral purification and concentration techniques. Here, we report on developing an efficient method to purify and concentrate viruses from large body of high turbidity seawater. The developed method characterizes with high viral recovery efficiency, high concentration factor, high viral particle densities and high-throughput, and is reliable for viral concentration from high turbidity seawater. Recovered viral particles were used directly for subsequent analysis by epifluorescence microscopy, transmission electron microscopy and metagenomic sequencing. Three points are essential for this method: • The sampled seawater (>150 L) was initially divided into two parts, water fraction and settled matter fraction, after natural sedimentation. • Both viruses in the water fraction concentrated by tangential flow filtration (TFF) and viruses isolated from the settled matter fraction were considered as the whole viral community in high turbidity seawater. • The viral concentrates were re-concentrated by using centrifugal filter device in order to obtain high density of viral particles

Dynamic Changes in MMP1 and TIMP1 in the Antifibrotic Process of Dahuang Zhechong Pill in Rats with Liver Fibrosis

On the basis of carbon tetrachloride (CCl4)induced liver fibrosis in rats, this study aims to investigate the dynamic changes in matrix metalloproteinase 1 (MMP1) and the tissue inhibitor of metalloproteinase 1 (TIMP1) in the antifibrotic process of Dahuang Zhechong Pill (DHZCP). A total of 50 male Sprague Dawley rats, aged 8 weeks, were randomly divided into 3 groups: the control group, the model group (the group treated with CCl4), and the treatment group (the group treated with CCl4 and DHZCP). Rats were sacrificed at Weeks 4 and 8. Liver tissues were separated for RNA sequencing and bioinformatics analysis. Real-time PCR, Western blot analysis, and histological staining were conducted to confirm the gene expression and pathological change in liver tissues. Compared with control group, rats in model group showed poor mental state and slow weight gain. The liver tissues of the rats in the model group exhibited a damaged hepatic lobule structure, fibrous connective tissue hyperplasia, and inflammatory cell infiltration among the hyperplastic tissues. DHZCP could significantly improve the appearance of rats and alleviate CCl4-induced fibrosis. Compared to model group, 798 differentially expressed mRNAs were found in the treatment group, of which 120 were up-regulated and 678 were down-regulated. Differentially expressed mRNAs between the CCl4-induced group and the DHZCP-treated group were mainly focused on the following KEGG pathways: focal adhesion, phagosome, tight junction, and ECM–receptor interactions. Relative to those in the control group, MMP1 was downregulated, whereas, TIMP1 and Col1A1 were upregulated in the CCl4-induced group at Weeks 4 and 8. DHZCP could reverse MMP1, TIMP1, and Col1A1 expression.DHZCP protects against liver injury and exerts an antifibrotic effect on liver fibrosis induced by CCl4 in rats. Its mechanism may be related to the upregulation of MMP1, downregulation of TIMP1, and promotion of collagen degradation