High vigor seeds have greater yield potential than those with low vigor; however, long-term storage leads to a decline in this trait. The objective of this study was to identify quantitative trait loci (QTLs) for seed vigor-related traits under artificial aging conditions using a high-density genetic linkage map of wheat (Triticum aestivum) and mine the related candidate genes. A doubled haploid population, derived from a cross between Hanxuan 10 × Lumai 14, was used as the experimental material. Six controlled-environment treatments were set up, i.e. the seeds were aged for 0, 24, 36, 48, 60, and 72 h at a high temperature (48 °C) and under high humidity (relative humidity 100%). Eight traits including seed germination percentage, germination energy, germination index, seedling length, root length, seedling weight, vigor index, and simple vigor index were measured. With the prolongation of artificial aging treatment, these traits showed a continuous downward trend and significant correlations were observed between most of them. A total of 49 additive QTLs for seed vigor-related traits were mapped onto 12 chromosomes (1B, 2D, 3A, 3B, 3D, 4A, 4D, 5A, 5B, 5D, 6D, and 7A); and each one accounted for 6.01-17.18% of the phenotypic variations. Twenty-five pairs of epistatic QTLs were detected on all chromosomes, except for 5D, 6A, and 7D, and each epistasis accounted for 7.35-26.06% of the phenotypic variations. Three additive QTL hot spots were found on chromosomes 5A, 5B, and 5D, respectively. 13 QTLs, QGEe5B, QGIe5B, QSLc5B, QSLd5B, QSLf5B, QRLd5B, QRLe5B, QRLf5B, QVId5B, QVIe5B, QVIf5B, QSVId5B, and QSVIe5B, were located in the marker interval AX-94643729 ~ AX-110529646 on 5B and the physical interval 707,412,449-710,959,479 bp. Genes including TRAESCS5B01G564900, TRAESCS5B01G564200, TRAESCS5B01G562600, TraesCS5B02G562700, TRAESCS5B01G561300, TRAESCS5B01G561400, and TRAESCS5B01G562100, located in this marker interval, were found to be involved in regulating the processes of carbohydrate and lipid metabolism, transcription, and cell division during the germination of aging seeds, thus they were viewed as candidate genes for seed viability-related traits. These findings provide the basis for the seed-based cloning and functional identification of related candidate genes for seed vigor.

In recent years, the population of men who have sex with men (MSM) constitute a major group for HIV transmission in China. A total of 340 newly reported HIV-infected MSM were recruited proportionally from ten prefectures across Zhejiang province between January and December in 2013. Partial pol gene was amplified and sequenced. Phylogenetic relationship, transmission network and genotypic drug resistance analyses were performed on 311 sequences. HIV-1 subtypes including CRF01_AE (55.9%), CRF07_BC (37.6%), subtype B (1.9%), CRF55_01B (1.3%), CRF68_01B (0.3%), CRF08_BC (0.3%) and URFs (2.6%) were identified. A higher proportion of CRF07_BC and other subtypes existed in the >35 years group, while a higher proportion of CRF01_AE was present in the young group (<35 years). Low prevalence of transmitted drug resistance was found (3.9%, 12/311). Strains with Hangzhou imprints were diffused across the full phylogenetic tree. Moreover, Hangzhou represented the dominant proportion of local HIV transmission (72.0%) and cross-regional transmission (62.4%) based on the provincial transmission network and possessed the largest number of nodes with ≥50 edges, accounting for 50.0% (10/20). The complexity of HIV subtypes and an intertwined network was noticed in MSM in Zhejiang province. Hangzhou likely plays a central regional role in the intra-provincial spread of HIV.

DNA-based sensors can detect disease biomarkers, including acetone and ethanol for diabetes and H2S for cardiovascular diseases. Before experimenting on thousands of potential DNA segments, we conduct full atomistic steered molecular dynamics (SMD) simulations to screen the interactions between different DNA sequences with targeted molecules to rank the nucleobase sensing performance. We study and rank the strength of interaction between four single DNA nucleotides (Adenine (A), Guanine (G), Cytosine (C), and Thymine (T)) on single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) with acetone, ethanol, H2S and HCl. By sampling forward and reverse interaction paths, we compute the free-energy profiles of eight systems for the four targeted molecules. We find that dsDNA react differently than ssDNA to the targeted molecules, requiring more energy to move the molecule close to DNA as indicated by the potential of mean force (PMF). Comparing the PMF values of different systems, we obtain a relative ranking of DNA base for the detection of each molecule. Via the same procedure, we could generate a library of DNA sequences for the detection of a wide range of chemicals. A DNA sensor array built with selected sequences differentiating many disease biomarkers can be used in disease diagnosis and monitoring.

Patients with diabetes are more likely to be infected with Coronavirus disease 2019 (COVID-19), and the risk of death is significantly higher than ordinary patients. Dipeptidyl peptidase-4 (DPP4) is one of the functional receptor of human coronavirus. Exploring the relationship between diabetes mellitus targets and DPP4 is particularly important for the management of patients with diabetes and COVID-19. We intend to study the protein interaction through the protein interaction network in order to find a new clue for the management of patients with diabetes with COVID-19. Diabetes mellitus targets were obtained from GeneCards database. Targets with a relevance score exceeding 20 were included, and DPP4 protein was added manually. The initial protein interaction network was obtained through String. The targets directly related to DPP4 were selected as the final analysis targets. Importing them into String again to obtain the protein interaction network. Module identification, gene ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis were carried out respectively. The impact of DPP4 on the whole network was analyzed by scoring the module where it located. 43 DPP4-related proteins were finally selected from the diabetes mellitus targets and three functional modules were found by the cluster analysis. Module 1 was involved in insulin secretion and glucagon signaling pathway, module 2 and module 3 were involved in signaling receptor binding. The scoring results showed that LEP and apoB in module 1 were the highest, and the scores of INS, IL6 and ALB of cross module associated proteins of module 1 were the highest. DPP4 is widely associated with key proteins in diabetes mellitus. COVID-19 may affect DPP4 in patients with diabetes mellitus, leading to high mortality of diabetes mellitus combined with COVID-19. DPP4 inhibitors and IL-6 antagonists can be considered to reduce the effect of COVID-19 infection on patients with diabetes.

Xenotransplantation (cross-species transplantation) using genetically-engineered pig organs offers a potential solution to address persistent organ shortage. Current evaluation of porcine genetic modifications is to monitor the nonhuman primate immune response and survival after pig organ xenotransplantation. This measure is an essential step before clinical xenotransplantation trials, but it is time-consuming, costly, and inefficient with many variables. We developed an efficient approach to quickly examine human-to-pig xeno-immune responses in vitro. A porcine endothelial cell was characterized and immortalized for genetic modification. Five genes including GGTA1, CMAH, β4galNT2, SLA-I α chain, and β2-microglobulin that are responsible for the production of major xenoantigens (αGal, Neu5Gc, Sda, and SLA-I) were sequentially disrupted in immortalized porcine endothelial cells using CRISPR/Cas9 technology. The elimination of αGal, Neu5Gc, Sda, and SLA-I dramatically reduced the antigenicity of the porcine cells, though the cells still retained their ability to provoke human natural killer cell activation. In summary, evaluation of human immune responses to genetically modified porcine cells in vitro provides an efficient method to identify ideal combinations of genetic modifications for improving pig-to-human compatibility, which should accelerate the application of xenotransplantation to humans.

Microcosms containing DDT spiked-sediment, Tubifex tubifex and carp (Cyprinus carpio) were constructed to simulate a freshwater system. The accumulation, elimination and toxic effects of DDT (p,p'-DDT, o,p'-DDT), and its metabolites DDD (p,p'-DDD, o,p'-DDD) and DDE (p,p'-DDE, o,p'-DDE) were studied in T. tubifex and carp. Tissue/organ distributions of DDTs were also investigated in carp. The bioaccumulation and elimination of DDT differed in T. tubifex, carp and its tissues/organs. Unimodal or bimodal distributions were observed, and the concentrations of DDT metabolites (DDD and p,p'-DDE) increased over time. The carp organ with the highest concentrations of DDTs (DDT, DDD and DDE) was the gill. The largest mass distribution of DDTs was also in gill, followed by muscle and gastrointestinal tract. Maximum levels of DDTs in whole carp and carp muscle were 161 and 87 ng/g, respectively; therefore, the levels of DDTs observed in carp in this study were insufficient to constitute a health concern if present in fish for human consumption. Significant changes were observed in some biomarkers, including superoxide dismutase, catalase, glutathione-S-transferase, glutathione, and carboxylesterase, in T. tubifex and carp tissues during DDT exposure. Tissue-specific accumulation of DDTs in carp can be a key indicator of exposure to environmentally relevant concentrations.