Project description:Transcriptional profiling of the antennae of adult honeybee workers with a dsx stop/stop mutation and wild-type workers was performed by RNA-Seq. Gene expression of the dsx stop/stop and wild type female workers was compared.
Project description:Within a mutatgenesis screen, we identified the new recessive mouse mutant KTA48 with a kinky tail, white spots on coat and with small eyes. Aim of the actual study was the molecular characterization of the mutant and the functional consequences of the mutation. We mapped the mutation to mouse chromosome 12 within a critical interval of 2.4 Mb between the markers D12Mit171 and D12Mit270; sequence analysis of Pxdn revealed a T->A mutation at position 3816 (T3816A) resulting in a premature stop codon (Cys1272X) in teh perosidasin domain. Histological analysis revealed variable, but severe defects in teh eye including all major ocular tissues (cornea, lens and retina). These findings demonstrate severe clinical findings of a recessive mutation affecting peroxidasin. Total RNA obtained from homozygote embryos E12.5 and wildtype embryos E12.5, each sample include 4 eyes of two embryos
Project description:Here, we first establish an easy Multi-Stop system to simultaneously inactivate genes involved in DNA methylation and demethylation in zygotes through introduction of the stop codon by hA3A-eBE-Y130F-mediated base editor (BE). While Multi-Stop-derived Dnmt-null embryos display embryonic lethal due to gastrulation failure. Moreover, mutation combinations between Tet and Dnmt families show severe embryonic lethal and Dnmt1 or Dnmt3a/3b is indispensable for mouse gastrulation. Then WGBS and RNA-seq analysis of different mutant embryos reveals genes jointly maintained by Dnmt1 and Dnmt3a/3b that are critical for gastrulation.
Project description:The genetic code that specifies the identity of amino acids incorporated into proteins during protein synthesis is almost universally conserved. Mitochondrial translation, however, exhibits deviations from the standard genetic code including reassigning of two arginine codons to stop codons. Translation termination at these non-canonical stop codons requires a protein factor to release the newly synthesized polypeptide chain. Currently it is not known how, and by which release factor, these stop codons are recognized. Here, we used biochemical experiments on knockout mutants in human cells in combination with cryo-electron microscopy to establish that the unusual mitochondrial release factor 1 (mtRF1) detects the non-canonical stop codons. We show that loss of this factor leads to stalling of mitochondrial ribosomes on non-canonical stop codons. As a result, reduced levels of cytochrome C oxidase subunit 1 of the oxidative phosphorylation complex IV are synthesized leading to a defect in mitochondrial respiration. We further show that binding of mtRF1 to the decoding center of the ribosome stabilizes a highly unusual distortion in the mRNA conformation and that the ribosomal RNA importantly participates in the specific recognition of the non-canonical stop codons.
Project description:The genetic code that specifies the identity of amino acids incorporated into proteins during protein synthesis is almost universally conserved. Mitochondrial translation deviates from the standard genetic code which includes the reassignment of two arginine codons into stop codons {Jukes, 1993 #438}. Translation termination at these non-canonical stop codons requires a protein factor to release the newly synthesized polypeptide chain, however, the identity of this factor is not known currently{Nadler, 2021 #406}. Here, we used gene editing and ribo-profiling in combination with cryo-electron microscopy to establish that the unusual mitochondrial release factor 1 (mtRF1) detects the non-canonical stop codons. We show that loss of mtRF1 leads to stalling of mitochondrial ribosomes on non-canonical stop codons and consequent reduced translation of cytochrome C oxidase subunit 1 that results in decreased mitochondrial respiration. We show that binding of mtRF1 to the decoding center of the ribosome stabilizes a highly unusual distortion in the mRNA conformation and that the ribosomal RNA importantly participates in the specific recognition of the non-canonical stop codons.
2023-03-21 | GSE216979 | GEO
Project description:Somatic Mutation Screen of Clear Cell RCC
| PRJNA120083 | ENA
Project description:Severe soft tissue infection caused by a non-hemolytic Streptococcus pyogenes strain with a premature stop mutation in sagC gene