Expression analysis of eight amphioxus genes involved in the Wnt/β-catenin signaling pathway

The Wnt/β-catenin signaling pathway plays a crucial role in the embryonic development of metazoans. Although the pathway has been studied extensively in many model animals, its function in amphioxus, the most primitive chordate, remains largely uncharacterized. To obtain basic data for functional analysis, we identified and isolated seven genes （Lrp5/6, Dvl, APC, Ckla, CklS, Gsk3β, and Gro） of the Wnt/β-catenin signaling pathway from the amphioxus （Branchiostoma floridae） genome. Phylogenetic analysis revealed that amphioxus had fewer members of each gene family than that found in vertebrates. Whole-mount in situ hybridization showed that the genes were maternally expressed and broadly distributed throughout the whole embryo at the cleavage and blastula stages. Among them, Dvl was expressed asymmetrically towards the animal pole, while the others were evenly distributed in all blastomeres. At the mid-gastrula stage, the genes were specifically expressed in the primitive endomesoderm, but displayed different patterns. When the embryo developed into the neurula stage, the gene expressions were mainly detected in either paraxial somites or the tail bud. With the development of the embryo, the expression levels further decreased gradually and remained only in some pharyngeal regions or the tail bud at the larva stage. Our results suggest that the Wnt/β-catenin pathway might be involved in amphioxus somite formation and posterior growth, but not in endomesoderm specification.

Insufficiency of Mrpl40 disrupts testicular structure and semen parameters in a murine model

Approximately 31%of patients with 22q11.2 deletion syndrome(22q11.2DS)have genitourinary system disorders and 6%of them have undescended testes.Haploinsufficiency of genes on chromosome 22q11.2 might contribute to the risk of 22q11.2DS.In this study,we used mice with single-allele deletion in mitochondrial ribosomal protein L4o(Mrpl40-)as models to investigate the function of Mrpl40 in testes and spermatozoa development.The penetrance of cryptorchidism in Mrpl40+-mice was found to be higher than that in wild-type(WT)counterparts.Although the weight of testes was not significantly different between the WT and Mrpl40+-mice,the structure of seminiferous tubules and mitochondrial morphology was altered in the Mrpl40+-mice.Moreover,the concentration and motility of spermatozoa were significantly decreased in the Mrpl4O+-mice.In addition,data-independent acquisition mass spectrometry indicated that the expression of genes associated with male infertility was altered in Mrpl40+-testes.Our study demonstrated the important role of Mrpl40 in testicular structure and spermatozoa motility and count.These findings suggest that Mrpl4o is potentially a novel therapeutic target for cryptorchidism and decreased motility and count of spermatozoa.

Clinical characteristics of Kawasaki disease and concurrent pathogens during isolation in COVID-19 pandemic

Background The aim of this study is to explore the characteristics of Kawasaki disease(KD)and concurrent pathogens due to a stay-at-home isolation policy during coronavirus disease 2019(COVID-19)epidemic.Methods All patients with KD admitted between February and April in 2015-2020,were classified into before(group 1,in 2015-2019)and after(group 2,in 2020)isolation groups.A total of 4742 patients[with KD(m=98)and non-KD(n=4644)]referred to Mycoplasma pneumoniae(MP)and virus detection were analyzed in 2020.Clinical characteristics,laboratory data,and 13 pathogens were analyzed retrospectively.Results Group 2 had a significantly increased incidence of KD(0.11%)with 107 patients compared to that of group 1(0.03%)with 493 patients.The comparisons of oral mucosal change,strawberry tongue,desquamation of the fingertips,cervical lymphadenopathy and neutrophil percentage decreased in group 2 compared to group 1.The infection rate of MP increased significantly in group 2(34.7%)compared to group 1(19.3%),while the positive rate of viruses decreased significantly in group 2(5.3%)compared to group 1(14.3%).In 2020,the positive rate of MP infection increased significantly in patients with KD compared to the increase in patients with non-KD.The infection rate of MP for younger children aged less than 3 years old was higher in group 2 than in group 1.Conclusion Compared with the characteristics of KD from 2015 to 2019 years,the incidence of KD was increased in 2020 and was accompanied by a high incidence of MP infection,especially in younger children(less than 3 years old)during the isolation due to COVID-19 pandemic.