Comparative transcriptome analysis of male and female flowers in Spinacia oleracea L.

BACKGROUND: Dioecious spinach (Spinacia oleracea L.), a commercial and nutritional vegetable crop, serves as a model for studying the mechanisms of sex determination and differentiation in plants. However, this mechanism is still unclear. Herein, based on PacBio Iso-seq and Illumina RNA-seq data, comparative transcriptome analysis of male and female flowers were performed to explore the sex differentiation mechanism in spinach. RESULTS: Compared with published genome of spinach, 10,800 transcripts were newly annotated; alternative splicing, alternative polyadenylation and lncRNA were analyzed for the first time, increasing the diversity of spinach transcriptome. A total of 2965 differentially expressed genes were identified between female and male flowers at three early development stages. The differential expression of RNA splicing-related genes, polyadenylation-related genes and lncRNAs suggested the involvement of alternative splicing, alternative polyadenylation and lncRNA in sex differentiation. Moreover, 1946 male-biased genes and 961 female-biased genes were found and several candidate genes related to gender development were identified, providing new clues to reveal the mechanism of sex differentiation. In addition, weighted gene co-expression network analysis showed that auxin and gibberellin were the common crucial factors in regulating female or male flower development; however, the closely co-expressed genes of these two factors were different between male and female flower, which may result in spinach sex differentiation. CONCLUSIONS: In this study, 10,800 transcripts were newly annotated, and the alternative splicing, alternative polyadenylation and long-noncoding RNA were comprehensively analyzed for the first time in spinach, providing valuable information for functional genome study. Moreover, candidate genes related to gender development were identified, shedding new insight on studying the mechanism of sex determination and differentiation in plant.

Comparison of cusp-overlap projection and standard three-cusp coplanar view during self-expanding transcatheter aortic valve replacement: A systematic review and meta-analysis.

Objective: Permanent pacemaker implantation (PPI) is a common complication after transcatheter aortic valve replacement (TAVR). Recently, the cusp-overlap projection (COP) technique was thought to be a feasible method to reduce PPI risk. However, the evidence is still relatively scarce. Therefore, this meta-analysis was performed to compare COP and standard three-cusp coplanar (TCC) projection technique. Methods: PubMed and EMBASE databases were systematically searched for relevant literature published from the inception (EMBASE from 1974 and PubMed from 1966) to 16 April 2022, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary outcome of interest was post-operative (including in-hospital and 30-day) PPI. Results: Total of 3,647 subjects from 11 studies were included in this meta-analysis. Of those, 1,453 underwent self-expanding TAVR using COP and 2,194 using TCC technique. In a pooled analysis, the cumulative PPI incidence was 9.3% [95% confidence interval (CI): 6.9-11.7%] and 18.9% (95% CI: 15.5-22.3%) in the COP group and TCC group, respectively. The application of the COP technique was associated with a significant PPI risk reduction (I2 = 40.3% and heterogeneity Chi-square p = 0.070, random-effects OR: 0.49, 95% CI: 0.36-0.66, p < 0.001). A higher implantation depth was achieved in the COP group compared with the TCC group [standardized mean difference (SMD) = -0.324, 95% CI: (-0.469, -0.180)]. There was no significant difference between the two groups in second valve implantation, prosthesis pop-out, fluoroscopic time, post-operative left bundle branch block, mortality, stroke, moderate/severe paravalvular leakage, mean gradient, and length of hospital stay. However, radiation doses were higher in the COP group [SMD = 0.394, 95% CI: (0.216, 0.572), p < 0.001]. Conclusion: In self-expanding TAVR, the application of the cusp overlap projection technique was associated with a lower risk of PPI compared with the standard TCC technique. Systematic review registration: [https://inplasy.com/inplasy-2022-4-0092/], identifier [INPLASY202240092].

Development of signature-tagged mutagenesis in Riemerella anatipestifer to identify genes essential for survival and pathogenesis.

Riemerella anatipestifer causes epizootic infectious disease in ducks, geese, turkeys and other birds, and serious economic losses especially to the duck industry. However, little is known about the molecular basis of its pathogenesis. In this study, signature-tagged transposon mutagenesis based on Tn4351 was developed in R. anatipestifer to identify genes essential for survival and pathogenesis. Seventeen tagged Tn4351 random mutation libraries of the R. anatipestifer strain WJ4 containing 5100 mutants were screened for survive using a duckling infection model. Twenty mutants that could not be recovered from the infected ducklings, were identified, and 17 mutated genes were identified by inverse PCR or genome-walking PCR. Of these genes, FIP52_03215, FIP52_04350 and FIP52_09345, were inserted into two mutant strains, and FIP52_03215 and FIP52_03175 were found exclusively on the chromosome of serotype 1 R. anatipestifer strains. Twelve out of 17 genes encoding for proteins were predicted to be involved in amino acid, nucleotide, coenzyme, or lipid transport and metabolism, one gene was predicted to be involved in signal transduction, one gene was predicted to be involved in DNA replication, recombination and repair, the other three genes had an unknown function. Animal experiments showed that the virulence of mutants 16-284, 7-295, 24-231, 9-232 and 19-214 were significantly attenuated compared to that of the wild-type WJ4. Moreover, the median lethal dose of mutant 16-284 was greater than 1010 CFU, and its virulence to ducklings was partially restored when it was complemented with the shuttle expression plasmid pRES-FIP52_09345. The results in this study will be helpful to further study the molecular mechanisms of the pathogenesis of R. anatipestifer infection.

Complete Genome Sequence of Riemerella anatipestifer Serotype 10 Strain HXb2.

The complete genome sequence of highly virulent Riemerella anatipestifer strain HXb2 was determined. The genome consisted of a single circular chromosome of 2,425,237 bp containing 2,383 putative open reading frames (ORFs), 9 rRNA operons, and 40 tRNA genes.