Denaturing Gradient Gel Analysis of Single-Base Substitutions at a MouseAdenine Phosphoribosyltransferase Splice Acceptor Site

1989 ◽  
Vol 2 (4) ◽  
pp. 217-225 ◽  
Author(s):  
Stephen R. Dlouhy ◽  
Dennis A. Schaff ◽  
James A. Trofatter ◽  
Hsiao-Sheng Liu ◽  
Peter J. Stambrook ◽  
...  
Keyword(s):  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Splice Acceptor ◽  
Single Base ◽  
Base Substitutions

scholarly journals Adenine Base-Editing-Mediated Exon Skipping Induces Gene Knockout in Cultured Pig Cells

2021 ◽  
Author(s):  
Xiang-xing Zhu ◽  
Jia-sheng Pan ◽  
Tao Lin ◽  
Ye-cheng Yang ◽  
Qiu-yan Huang ◽  
...  
Keyword(s):  
Genetic Modification ◽  
Gene Knockout ◽  
Exon Skipping ◽  
Splice Acceptor Site ◽  
Splice Donor Site ◽  
Acceptor Site ◽  
Splice Acceptor ◽  
Single Base ◽  
Base Editing ◽  
Adenine Base

Abstract Gene-knockout pigs have important applications in agriculture and medicine. Compared with CRISPR/Cas9, Adenine base editor (ABE) convert single A·T pairs to G·C pairs in the genome without generating DNA double-strand breaks, and this method has higher accuracy and biosafety in pig genetic modification. However, the application of ABE in pig gene knockout is limited by protospacer-adjacent motif (PAM) sequences and the base-editing window. Alternative mRNA splicing is an important mechanism underlying the formation of proteins with diverse functions in eukaryotes. Spliceosome recognizes the conservative sequences of splice donors and acceptors in a precursor mRNA. Mutations in these conservative sequences induce exon skipping, leading to proteins with novel functions or to gene inactivation due to frameshift mutations. In this study, adenine base-editing-mediated exon skipping was used to expand the application of ABE in the generation of gene knockout pigs. We first constructed a modified “all-in-one” ABE vector suitable for porcine somatic cell transfection that contained an ABE for single-base editing and an sgRNA expression cassette. The “all-in-one” ABE vector induced efficient sgRNA-dependent A-to-G conversions in porcine cells during single base-editing of multiple endogenous gene loci. Subsequently, an ABE system was designed for single adenine editing of the conservative splice acceptor site (AG sequence at the 3’ end of the intron 5) and splice donor site (GT sequence at the 5’ end of the intron 6) in the porcine gene GHR; this method achieved highly efficient A-to-G conversion at the cellular level. Then, porcine single-cell colonies carrying a biallelic A-to-G conversion in the splice acceptor site in the intron 5 of GHR were generated. RT-PCR indicated exon 6 skipped at the mRNA level. Western blotting revealed GHR protein loss, and gene sequencing showed no sgRNA-dependent off-target effects. These results demonstrate accurate adenine base-editing-mediated exon skipping and gene knockout in porcine cells. This is the first proof-of-concept study of adenine base-editing-mediated exon skipping for gene regulation in pigs, and this work provides a new strategy for accurate and safe genetic modification of pigs for agricultural and medical applications.

scholarly journals Adenine Base-Editing-Mediated Exon Skipping Induces Gene Knockout in Cultured Pig Cells

2021 ◽  
Author(s):  
XIANGXING ZHU ◽  
Jia-sheng Pan ◽  
Tao Lin ◽  
Ye-cheng Yang ◽  
Qiu-yan Huang ◽  
...  
Keyword(s):  
Genetic Modification ◽  
Gene Knockout ◽  
Exon Skipping ◽  
Splice Acceptor Site ◽  
Splice Donor Site ◽  
Acceptor Site ◽  
Splice Acceptor ◽  
Single Base ◽  
Base Editing ◽  
Adenine Base

Abstract Gene-knockout pigs have important applications in agriculture and medicine. Compared with CRISPR/Cas9, Adenine base editor (ABE) convert single A·T pairs to G·C pairs in the genome without generating DNA double-strand breaks, and this method has higher accuracy and biosafety in pig genetic modification. However, the application of ABE in pig gene knockout is limited by protospacer-adjacent motif (PAM) sequences and the base-editing window. Alternative mRNA splicing is an important mechanism underlying the formation of proteins with diverse functions in eukaryotes. Spliceosome recognizes the conservative sequences of splice donors and acceptors in a precursor mRNA. Mutations in these conservative sequences induce exon skipping, leading to proteins with novel functions or to gene inactivation due to frameshift mutations. In this study, adenine base-editing-mediated exon skipping was used to expand the application of ABE in the generation of gene knockout pigs. We first constructed a modified “all-in-one” ABE vector suitable for porcine somatic cell transfection that contained an ABE for single-base editing and an sgRNA expression cassette. The “all-in-one” ABE vector induced efficient sgRNA-dependent A-to-G conversions in porcine cells during single base-editing of multiple endogenous gene loci. Subsequently, an ABE system was designed for single adenine editing of the conservative splice acceptor site (AG sequence at the 3’ end of the intron 5) and splice donor site (GT sequence at the 5’ end of the intron 6) in the porcine gene GHR; this method achieved highly efficient A-to-G conversion at the cellular level. Then, porcine single-cell colonies carrying a biallelic A-to-G conversion in the splice acceptor site in the intron 5 of GHR were generated. RT-PCR indicated exon 6 skipped at the mRNA level. Western blotting revealed GHR protein loss, and gene sequencing showed no sgRNA-dependent off-target effects. These results demonstrate accurate adenine base-editing-mediated exon skipping and gene knockout in porcine cells. This is the first proof-of-concept study of adenine base-editing-mediated exon skipping for gene regulation in pigs, and this work provides a new strategy for accurate and safe genetic modification of pigs for agricultural and medical applications.

scholarly journals Splice-acceptor site mutation in p53 gene of hu888 zebrafish line

2014 ◽  
Vol 56 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Alicja Piasecka ◽  
Paweł Brzuzan ◽  
Maciej Woźny ◽  
Sławomir Ciesielski ◽  
Dariusz Kaczmarczyk
Keyword(s):  
P53 Gene ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Splice Acceptor ◽  
Site Mutation ◽  
Splice Acceptor Site Mutation

scholarly journals Procyclic acidic repetitive protein (PARP) genes located in an unusually small alpha-amanitin-resistant transcription unit: PARP promoter activity assayed by transient DNA transfection of Trypanosoma brucei.

1990 ◽  
Vol 10 (7) ◽  
pp. 3492-3504 ◽  
Author(s):  
G Rudenko ◽  
S Le Blancq ◽  
J Smith ◽  
M G Lee ◽  
A Rattray ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Transcription Unit ◽  
Splice Acceptor Site ◽  
Acceptor Site ◽  
Nucleotide Position ◽  
Splice Acceptor ◽  
Transcription Analysis ◽  
Alpha Amanitin ◽  
Single Promoter ◽  
Repetitive Protein

At least one of the procyclic acidic repetitive protein (PARP or procyclin) loci of Trypanosoma brucei is a small (5- to 6-kilobase) polycistronic transcription unit which is transcribed in an alpha-amanitin-resistant manner. Its single promoter, as mapped by run-on transcription analysis and UV inactivation of transcription, is located immediately upstream of the first alpha-PARP gene. Transcription termination occurs in a region approximately 3 kilobases downstream of the beta-PARP gene. The location of the promoter was confirmed by its ability to direct transcription of the bacterial chloramphenicol acetyltransferase gene in insect-form (procyclic) T. brucei. The putative PARP promoter is located in the region between the 3' splice acceptor site (nucleotide position 0) and nucleotide position -196 upstream of the alpha-PARP genes. Regulatory regions influencing the levels of PARP expression may be located further upstream. We conclude that a single promoter, which is located very close to the 3' splice acceptor site of the alpha-PARP genes, directs the transcription of a small, polycistronic, and alpha-amanitin-resistant transcription unit.

Sign in / Sign up

Export Citation Format

Share Document