Genomic insights into biased allele loss and increased gene numbers after genome duplication in autotetraploid Cyclocarya paliurus.

BACKGROUND: Autopolyploidy is a valuable model for studying whole-genome duplication (WGD) without hybridization, yet little is known about the genomic structural and functional changes that occur in autopolyploids after WGD. Cyclocarya paliurus (Juglandaceae) is a natural diploid-autotetraploid species. We generated an allele-aware autotetraploid genome, a chimeric chromosome-level diploid genome, and whole-genome resequencing data for 106 autotetraploid individuals at an average depth of 60 × per individual, along with 12 diploid individuals at an average depth of 90 × per individual. RESULTS: Autotetraploid C. paliurus had 64 chromosomes clustered into 16 homologous groups, and the majority of homologous chromosomes demonstrated similar chromosome length, gene numbers, and expression. The regions of synteny, structural variation and nonalignment to the diploid genome accounted for 81.3%, 8.8% and 9.9% of the autotetraploid genome, respectively. Our analyses identified 20,626 genes (69.18%) with four alleles and 9191 genes (30.82%) with one, two, or three alleles, suggesting post-polyploid allelic loss. Genes with allelic loss were found to occur more often in proximity to or within structural variations and exhibited a marked overlap with transposable elements. Additionally, such genes showed a reduced tendency to interact with other genes. We also found 102 genes with more than four copies in the autotetraploid genome, and their expression levels were significantly higher than their diploid counterparts. These genes were enriched in enzymes involved in stress response and plant defense, potentially contributing to the evolutionary success of autotetraploids. Our population genomic analyses suggested a single origin of autotetraploids and recent divergence (~ 0.57 Mya) from diploids, with minimal interploidy admixture. CONCLUSIONS: Our results indicate the potential for genomic and functional reorganization, which may contribute to evolutionary success in autotetraploid C. paliurus.

Different rates of pollen and seed gene flow cause branch-length and geographic cytonuclear discordance within Asian butternuts.

Topological cytonuclear discordance is commonly observed in plant phylogenetic and phylogeographic studies, yet few studies have attempted to detect two other forms of cytonuclear discordance (branch length and geographical) and to uncover the causes of the discordance. We used the whole nuclear and chloroplast genome data from 80 individual Asian butternuts to reveal the pattern and processes of cytonuclear discordance. Our findings indicate that the chloroplast genome had substantially deeper divergence (branch-length discordance) and a steeper cline in the contact zone (geographic discordance) compared with the nuclear genome. After various hypothesis have been tested, the results suggest that incomplete lineage sorting, positive selection and cytonuclear incompatibility are probably insufficient to explain this pattern. However, isolation-by-distance analysis and gene flow estimation point to a much higher level of gene flow by pollen compared with by seeds, which may have slowed down lineage divergence and mediated wider contact for nuclear genome compared with the chloroplast genome. Altogether, this study highlights a critical role of sex-biased dispersal in causing discordance between the nuclear and plastid genome of Asian butternuts. Given its ubiquity among plants, asymmetric gene flow should be given a high priority in future studies of cytonuclear discordance.

StMBF1c positively regulates disease resistance to Ralstonia solanacearum via it's primary and secondary upregulation combining expression of StTPS5 and resistance marker genes in potato.

Multiprotein bridging factor 1 (MBF1) is a transcription coactivator that has a general defense response to pathogens. However, the regulatory mechanisms of MBF1 resistance bacterial wilt remain largely unknown. Here, the role of StMBF1c in potato resistance to Ralstonia solanacearum infection was characterized. qRT-PCR assays indicated that StMBF1c could was elicited by SA, MJ and ABA and the time-course expression pattern of the StMBF1c gene induced by R. solanacearum was found to be twice significant upregulated expression during the early and middle stages of bacterial wilt. Combined with the co-expression analysis of disease-resistant marker genes, gain-of-function and loss-of-function assays demonstrated that StMBF1c was associated with defence priming. Overexpression or silencing the MBF1c could enhance plants resistance or sensitivity to R. solanacearum through inducing or reducing NPR and PR genes related to SA signal pathway. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) experiment results confirmed the interaction of StMBF1c with StTPS5 which played a key role in ABA signal pathway in potato. It is speculated that by combining StTPS5 and resistance marker genes, StMBF1c is activated twice to participate in potato bacterial wilt resistance, in which EPI, PTI involved.

[The influence of elective course of emergency treatment for medical students on the cultivation of first aid knowledge and skill of cardio-pulmonary resuscitation].

OBJECTIVE: To investigate the influence of elective course of emergency treatment for medical students on the cultivation of first aid knowledge and skills of cardio-pulmonary resuscitation. METHODS: Senior students major in medicine of our university were randomly divided into observation group and contrast group with 30 students in each group according to whether an elective course of emergency treatment was given or not. All of them then received a test of first aid knowledge and cardio-pulmonary resuscitation skills. RESULTS: The theoretical exam scores in observation group and contrast group were respectively 78.5+/-9.1 and 46.7+/-15.6. The scores in observation group were significantly higher than that in contrast group (P < 0.01). Cardio-pulmonary resuscitation skills scores in observation group and contrast group were respectively 7.32+/-0.83 and 6.63+/-0.91. The scores in observation group were significantly higher than that in contrast group (P < 0.01). The number of failure for closed cardiac massage in 60 times in observation group and contrast group was respectively 5.06+/-0.58 and 5.77+/-0.63. The number of mouth to mouth artificial respiration in 4 times in observation group and contrast group was 0.92+/-0.16 and 1.10+/-0.17, respectively. There were notable differences in the number of failure in resuscitation maneuvers between two groups (both P < 0.01), observation group being obviously poorer than contrast group. CONCLUSION: An elective course of emergency treatment given to medical students plays an important role in the cultivation of first aid knowledge and skills in cardio-pulmonary resuscitation. It is therefore necessary that emergency medicine is included as a required course in medical college.

[Effects of rosiglitazone on inflammatory reaction and insulin resistance in obese patients with newly diagnosed type 2 diabetes].

OBJECTIVE: To study the effect of rosiglitazone on serum high-sensitivity C-reactive protein (hs-CRP), interleukin-1beta (IL-1beta), IL-6, tumor necrosis factor-alpha (TNF-alpha) and insulin resistance in obese patients with newly diagnosed type 2 diabetes. METHODS: This study involved 118 patients with newly diagnosed type 2 diabetes and obesity, who were randomly assigned into two groups for a 12-week treatment with rosiglitazone (4 mg/day, group A) or sulfonylureas (group B). Serum hs-CRP, IL-1beta, IL-6, TNF-alpha, fasting plasma glucose (FPG) and fasting insulin (FINS) were measured before and after the treatment. Insulin resistance index was calculated according to the HOMA Model. RESULTS: In group A, rosiglitazone treatment resulted in significantly reduced serum hs-CRP, IL-1beta, IL-6, TNF-alpha, FPG and insulin resistance index (P<0.01). No difference in FPG was found between the two groups after the treatment (P>0.05), but serum hs-CRP, IL-1beta, IL-6, TNF-alpha and insulin resistance index were significantly lower in group A than in group B (P<0.05). CONCLUSION: Rosiglitazone can decrease FPG, reduce the inflammation reaction and improve insulin resistance in obese patients with type 2 diabetes.