Trans-splicing as a Novel Mechanism to Explain Interallelic Complementation in Drosophila

AbstractTwo mutant alleles of the same gene, each located in one of the two homologous chromosomes, may in some instances restore the wild-type function of the gene. This is the case with certain combinations of mutant alleles in the mod(mdg4) gene. This gene encodes several different proteins, including Mod(mdg4)2.2, a component of the gypsy insulator. This protein is encoded by two separate transcription units that can be combined in a trans-splicing reaction to form the mature Mod(mdg4)2.2-encoding RNA. Molecular characterization of complementing alleles shows that they affect the two different transcription units. Flies homozygous for each allele are missing the Mod(mdg4)2.2 protein, whereas wild-type trans-heterozygotes are able to synthesize almost normal levels of the Mod(mdg4)2.2 product. This protein is functional as judged by its ability to form a functional insulator complex. The results suggest that the interallelic complementation in the mod(mdg4) gene is a consequence of trans-splicing between two different mutant transcripts. A conclusion from this observation is that the trans-splicing reaction that takes place between transcripts produced on two different mutant chromosomes ensures wild-type levels of functional protein.

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Molecular Characterization of the CytochromebGene andIn VitroAtovaquone Susceptibility of Plasmodium falciparum Isolates from Kenya

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.03956-14 ◽

2015 ◽

Vol 59 (3) ◽

pp. 1818-1821 ◽

Cited By ~ 6

Author(s):

Luicer A. Ingasia ◽

Hoseah M. Akala ◽

Mabel O. Imbuga ◽

Benjamin H. Opot ◽

Fredrick L. Eyase ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Genetic Polymorphism ◽

Molecular Characterization ◽

Mutant Allele ◽

Inhibitory Concentration ◽

Wild Type Allele ◽

Wild Type ◽

Western Kenya ◽

Content Type

ABSTRACTThe prevalence of a genetic polymorphism(s) at codon 268 in the cytochromebgene, which is associated with failure of atovaquone-proguanil treatment, was analyzed in 227Plasmodium falciparumparasites from western Kenya. The prevalence of the wild-type allele was 63%, and that of the Y268S (denoting a Y-to-S change at position 268) mutant allele was 2%. There were no pure Y268C or Y268N mutant alleles, only mixtures of a mutant allele(s) with the wild type. There was a correlation between parasite 50% inhibitory concentration (IC50) and parasite genetic polymorphism; mutant alleles had higher IC50s than the wild type.

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In Vitro Molecular Characterization of RNA–Proteins Interactions During Initiation of Translation of a Wild-Type and a Mutant Coxsackievirus B3 RNAs

Molecular Biotechnology ◽

10.1007/s12033-012-9592-x ◽

2012 ◽

Vol 54 (2) ◽

pp. 515-527 ◽

Cited By ~ 4

Author(s):

Amira Souii ◽

Manel Ben M’hadheb-Gharbi ◽

Mahjoub Aouni ◽

Jawhar Gharbi

Keyword(s):

Molecular Characterization ◽

Coxsackievirus B3 ◽

Wild Type ◽

Initiation Of Translation ◽

Proteins Interactions

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Inheritance and Molecular Characterization of a Novel Mutated AHAS Gene Responsible for the Resistance of AHAS-Inhibiting Herbicides in Rapeseed (Brassica napus L.)

International Journal of Molecular Sciences ◽

10.3390/ijms21041345 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1345

Author(s):

Qianxin Huang ◽

Jinyang Lv ◽

Yanyan Sun ◽

Hongmei Wang ◽

Yuan Guo ◽

...

Keyword(s):

Brassica Napus ◽

Molecular Characterization ◽

Herbicide Resistance ◽

Acetohydroxyacid Synthase ◽

Cross Resistance ◽

Single Point Mutation ◽

Wild Type ◽

Brassica Napus L ◽

Herbicide Resistant

The use of herbicides is an effective and economic way to control weeds, but their availability for rapeseed is limited due to the shortage of herbicide-resistant cultivars in China. The single-point mutation in the acetohydroxyacid synthase (AHAS) gene can lead to AHAS-inhibiting herbicide resistance. In this study, the inheritance and molecular characterization of the tribenuron-methyl (TBM)-resistant rapeseed (Brassica napus L.) mutant, K5, are performed. Results indicated that TBM-resistance of K5 was controlled by one dominant allele at a single nuclear gene locus. The novel substitution of cytosine with thymine at position 544 in BnAHAS1 was identified in K5, leading to the alteration of proline with serine at position 182 in BnAHAS1. The TBM-resistance of K5 was approximately 100 times that of its wild-type ZS9, and K5 also showed cross-resistance to bensufuron-methyl and monosulfuron-ester sodium. The BnAHAS1544T transgenic Arabidopsis exhibited higher TBM-resistance than that of its wild-type, which confirmed that BnAHAS1544T was responsible for the herbicide resistance of K5. Simultaneously, an allele-specific marker was developed to quickly distinguish the heterozygous and homozygous mutated alleles BnAHAS1544T. In addition, a method for the fast screening of TBM-resistant plants at the cotyledon stage was developed. Our research identified and molecularly characterized one novel mutative AHAS allele in B. napus and laid a foundation for developing herbicide-resistant rapeseed cultivars.

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Molecular Characterization of Genes Coding for Wild-Type and Sulfonylurea-Resistant Acetolactate Synthase in the Cyanobacterium Synechococcus PC C7942

Zeitschrift für Naturforschung C ◽

10.1515/znc-1990-0541 ◽

1990 ◽

Vol 45 (5) ◽

pp. 538-543 ◽

Cited By ~ 6

Author(s):

D. Friedberg ◽

J. Seijffers

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Amino Acid Sequence ◽

Molecular Characterization ◽

Amino Acid Level ◽

Acetolactate Synthase ◽

Mutant Gene ◽

Wild Type ◽

E Coli

We present here the isolation and molecular characterization of acetolactate synthase (ALS) genes from the cyanobacterium Synechococcus PCC7942 which specify a sulfonylurea-sensitive enzyme and from the sulfonylurea-resistant mutant SM3/20, which specify resistance to sulfonylurea herbicides. The ALS gene was cloned and mapped by complementation of an Escherichia coli ilv auxotroph that requires branched-chain amino acids for growth and lacks ALS activity. The cyanobacterial gene is efficiently expressed in this heterologous host. The ALS gene codes for 612 amino acids and shows high sequence homology (46%) at the amino acid level with ALS III of E. coli and with the tobacco ALS. The resistant phenotype is a consequence of proline to serine substitution in residue 115 of the deduced amino acid sequence. Functional expression of the mutant gene in wild-type Synechococcus and in E. coli confirmed that this amino-acid substitution is responsible for the resistance. Yet the deduced amino-acid sequence as compared with othjer ALS proteins supports the notion that the amino-acid context of the substitution is important for the resistance.

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Cellular and molecular characterization of mammary tumor development in wild type and adiponectin deficient MMTV-PyVT mice

10.5353/th_b5071264 ◽

2013 ◽

Author(s):

Chun-to Leung

Keyword(s):

Molecular Characterization ◽

Mammary Tumor ◽

Tumor Development ◽

Wild Type

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Molecular Characterization of eutF Mutants ofSalmonella typhimurium LT2 Identifies eutFLesions as Partial-Loss-of-Function tonB Alleles

Journal of Bacteriology ◽

10.1128/jb.181.2.368-374.1999 ◽

1999 ◽

Vol 181 (2) ◽

pp. 368-374 ◽

Cited By ~ 4

Author(s):

Michael G. Thomas ◽

George A. O’Toole ◽

Jorge C. Escalante-Semerena

Keyword(s):

Amino Acid ◽

Molecular Characterization ◽

Immunoblot Analysis ◽

Phenotypic Characterization ◽

Loss Of Function ◽

Wild Type ◽

Partial Loss ◽

Acid Addition ◽

Fusion Site

ABSTRACT The eutF locus of Salmonella typhimuriumLT2 was identified as a locus necessary for the utilization of ethanolamine as a sole carbon source. Initial models suggested that EutF was involved in either ethanolamine transport or was a transcriptional regulator of an ethanolamine transporter. Phenotypic characterization of eutF mutants suggested EutF was somehow involved in 1,2-propanediol, propionate, and succinate utilization. Here we provide evidence that two alleles defining the eutFlocus, Δ903 and eutF1115, are partial-loss-of-function tonB alleles. Both mutations were complemented by plasmids containing a wild-type allele of theEscherichia coli tonB gene. Immunoblot analysis using TonB monoclonal antibodies detected a TonB fusion protein in strains carrying eutF alleles. Molecular analysis of the Δ903 allele identified a deletion that resulted in the fusion of the 3′ end of tonB with the 3′ end oftrpA. In-frame translation of the tonB-trpAfusion resulted in the final 9 amino acids of TonB being replaced by a 45-amino-acid addition. We isolated a derivative of a strain carrying allele Δ903 that regained the ability to grow on ethanolamine as a carbon and energy source. The molecular characterization of the mutation that corrected the Eut−phenotype caused by allele Δ903 showed that the new mutation was a deletion of two nucleotides at the tonB-trpAfusion site. This deletion resulted in a frameshift that replaced the 45-amino-acid addition with a 5-amino-acid addition. This change resulted in a TonB protein with sufficient activity to restore growth on ethanolamine and eut operon expression to nearly wild-type levels. It was concluded that the observed EutF phenotypes were due to the partial loss of TonB function, which is proposed to result in reduced cobalamin and ferric siderophore transport in an aerobic environment; thus, the eutF locus does not exist.

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