3-ketoacyl-CoA synthase 7 from Xanthoceras sorbifolium seeds is a crucial regulatory enzyme for nervonic acid biosynthesis.

Nervonic acid (C24:1) is a very-long-chain fatty acid that plays an imperative role in human brain development and other health benefits. In plants, 3-ketoacyl-CoA synthase (KCS) is the key rate-limiting enzyme for C24:1 biosynthesis. Xanthoceras sorbifolium is a valuable oil-producing economic woody species with abundant C24:1 in seed oils, but the key KCS gene responsible for C24:1 accumulation remains unknown. In this work, a correlation analysis between the transcript profiles of KCS and dynamic change of C24:1 content in developing seeds of X. sorbifolium were conducted to screen out three members of KCS, namely XsKCS4, XsKCS7 and XsKCS8, potentially involved in C24:1 biosynthesis. Of which, the XsKCS7 was highly expressed in developing seeds, while XsKCS4 and XsKCS8 displayed the highest expression in fruits and flowers, respectively. Overexpression of XsKCS4, XsKCS7 and XsKCS8 in yeast Saccharomyces cerevisiae and plant Arabidopsis thaliana indicated that only XsKCS7 possessed the ability to facilitate the biosynthesis of C24:1. These findings collectively suggested that XsKCS7 played a crucial role in specific regulation of C24:1 biosynthesis in X. sorbifolium seeds.

Effect of sustained measurable residue disease negativity and post-remission treatment selection on the prognosis of acute lymphoblastic leukemia in adults.

BACKGROUND: To explore the effects of monitoring measurable residual disease and post-remission treatment selection on the clinical outcomes of B-cell acute lymphoblastic leukemia (B-ALL) in adults. METHODS: Between September 2010 and January 2022, adult patients with B-ALL who received combination chemotherapy, with or without allogeneic hematopoietic stem cell transplantation (allo-HSCT), were included in the retrospective study, which was approved by the Ethics Committee and the observation of Declaration of Helsinki conditions. RESULTS: One hundred and forty-three B-ALL patients achieved complete remission (CR) were included in the study, of whom 94 patients (65.7%) received allo-HSCT in first complete remission (CR1). Multivariate analysis showed that the most powerful factors affecting OS were transplantation (hazard ratio [HR] = 0.540, p = 0.037) and sustained measurable residue disease (MRD) negativity (HR = 0.508, p = 0.037). The subgroup analysis showed that the prognosis of the allo-HSCT group was better than that of the chemotherapy group, regardless of whether MRD was negative or positive after two courses of consolidation therapy. After consolidation therapy, the prognosis of patients with positive MRD remained significantly better in the allo-HSCT group than in the chemotherapy group. However, no significant difference was observed in the prognosis between the allo-HSCT and chemotherapy groups with negative MRD after consolidation therapy. CONCLUSIONS: B-ALL patients who achieve sustained MRD negativity during consolidation therapy have excellent long-term outcomes even without allo-HSCT. Allo-HSCT is associated with a significant benefit in terms of OS and DFS for patients who were with positive MRD during consolidation therapy.

Vaccination Shortens the Negative Nucleic Acid Conversion Time of the Older Population: A Retrospective Cohort Study of 73,456 Asymptomatic and Mild Patients with COVID-19 in Shanghai.

Purpose: To explore the influencing factors to predict the negative nucleic acid conversion time and ORF1ab gene CT value changes in patients with asymptomatic and mild COVID-19. Patients and Methods: A total of 73,456 patients with asymptomatic and mild COVID-19 admitted to the Mobile Cabin Hospital in Shanghai from April 3 to April 23, 2022 were selected as the research objects. Epidemiological, clinical, and laboratory data were collected. Correlation analysis was performed. Results: In patients <18 years old and ≥65 years old, COVID-19 vaccine can shorten the negative nucleic acid conversion time, which is reflected in the lower median or 75% quantile (P<0.001, P<0.05). In patients with underlying diseases, the negative nucleic acid conversion time of booster vaccination and complete vaccination was lower than that of non-vaccinated group (P<0.001, P<0.05). In patients ≤18 years of age or >65 years of age, patients with comorbidity and patients with symptoms, compared with patients 18-65 years of age, patients without comorbidity and patients without symptoms, there was a greater difference in the rate of rise of CT values between vaccinated and unvaccinated patients (P<0.05). Conclusion: The time of nucleic acid conversion to negative in patients with asymptomatic and mild COVID-19 is affected by age, comorbidity, and first nucleic acid CT value. Vaccination could shorten the negative nucleic acid conversion time of the older population, those with complications or symptoms. The vaccination of older patients does not increase the risk of symptoms.

Genome-wide association analysis identifies a candidate gene controlling seed size and yield in Xanthoceras sorbifolium Bunge.

Yellow horn (Xanthoceras sorbifolium Bunge) is a woody oilseed tree species whose seed oil is rich in unsaturated fatty acids and rare neuronic acids, and can be used as a high-grade edible oil or as a feedstock for biodiesel production. However, the genetic mechanisms related to seed yield in yellow horn are not well elucidated. This study identified 2 164 863 SNP loci based on 222 genome-wide resequencing data of yellow horn germplasm. We conducted genome-wide association study (GWAS) analysis on three core traits (hundred-grain weight, single-fruit seed mass, and single-fruit seed number) that influence seed yield for the years 2022 and 2020, and identified 399 significant SNP loci. Among these loci, the Chr10_24013014 and Chr10_24012613 loci caught our attention due to their consistent associations across multiple analyses. Through Sanger sequencing, we validated the genotypes of these two loci across 16 germplasms, confirming their consistency with the GWAS analysis results. Downstream of these two significant loci, we identified a candidate gene encoding an AP2 transcription factor protein, which we named XsAP2. RT-qPCR analysis revealed high expression of the XsAP2 gene in seeds, and a significant negative correlation between its expression levels and seed hundred-grain weight, as well as single-fruit seed mass, suggesting its potential role in the normal seed development process. Transgenic Arabidopsis lines with the overexpressed XsAP2 gene exhibited varying degrees of reduction in seed size, number of seeds per silique, and number of siliques per plant compared with wild-type Arabidopsis. Combining these results, we hypothesize that the XsAP2 gene may have a negative regulatory effect on seed yield of yellow horn. These results provide a reference for the molecular breeding of high-yielding yellow horn.