Loss-of-function of KMT5B leads to neurodevelopmental disorder and impairs neuronal development and neurogenesis

Autism spectrum disorder(ASD)is a group of neurodevelopmental disorders that cause severe social,communication,and behavioral problems.Recent studies show that the variants of a histone methyltransferase gene KMT5B cause neurodevelopmental disorders(NDDs),including ASD,and the knockout of Kmt5b in mice is embryonic lethal.However,the detailed genotype-phenotype correlations and functional effects of KMT5B in neurodevelopment are unclear.By targeted sequencing of a large Chinese ASD cohort,analyzing published genome-wide sequencing data,and mining literature,we curated 39 KMT5B variants identified from NDD individuals.A genotype-phenotype correlation analysis for 10 individuals with KMT5B pathogenic variants reveals common symptoms,including ASD,intellectual disability,languages problem,and macrocephaly.In vitro knockdown of the expression of Kmt5b in cultured mouse primary cortical neurons leads to a decrease in neuronal dendritic complexity and an increase in dendritic spine density,which can be rescued by expression of human KMT5B but not that of pathogenic de novo missense mutants.In vivo knockdown of the Kmt5b expression in the mouse embryonic cerebral cortex by in utero electroporation results in decreased proliferation and accelerated migration of neural progenitor cells.Our findings reveal essential roles of histone methyltransferase KMT5B in neuronal development,prenatal neurogenesis,and neuronal migration.

Bombyx mori U-shaped regulates the melanization cascade and immune response via binding with the Lozenge protein

Zinc finger protein,an important transcription factor,regulates gene expression associated with various physiological and pathological processes.U-shaped,belong to the Friend of GATA(FOG)transcription factor,plays a crucial role in hematopoiesis by interacting with the GATA transcription factor as a co-factor.However,little is known about its functions in insects.In the present study,a U-shaped cDNA was identified and characterized from the silkworm Bombyx mori and its potential roles in innate immunity investigated.The predicted silkworm U-shaped amino acid sequence contained a classical nuclear localization signal(NLS)motif“GESSPKRRRR”at position 45CU459,and arginine residues at position 456 and 478 are the critical sites of the NLS.U-shaped mRNA was detected in all tested tissues of the B.mori;however,the highest levels were found in the hemocytes.U-shaped mRNA expression levels were upregulated in the hemocyte after the Escherichia coli and Staphylococcus aureus challenge.Furthermore,U-shaped knockdown significantly reduced the melanization process and suppressed the expression of melanization-associated genes,including PPO1,PPO2,PPAE and BAEE.In addition,U-shaped interacts with Lozenge protein to regulate the innate immune response of the insect.Our results revealed that U-shaped binds directly to Lozenge protein to modulate the melanization process and innate immune responses in silkworm.