scholarly journals The independent gene amplification of electrophoretically indistinguishable B esterases from the insecticide-resistant mosquito Culex quinquefasciatus

1995 ◽  
Vol 305 (2) ◽  
pp. 651-658 ◽  
Author(s):  
A Vaughan ◽  
M Rodriguez ◽  
J Hemingway

Resistance to organophosphates in Culex mosquitoes is typically associated with increased activity of non-specific esterases. The commonest phenotype involves two elevated esterases, A2 and B2, while some strains have elevation of esterase B1 alone. Overexpression of the two B esterase electromorphs is due to gene amplification. Full-length cDNAs coding for amplified esterase B genes from a resistant Cuban strain (MRES, with amplified B1 esterase) and a Sri Lankan strain (PelRR, with amplified B2 esterase) of C. quinquefasciatus have been sequenced. In addition, a partial-length cDNA coding for a B esterase from an insecticide-susceptible Sri Lankan strain (PelSS) has been sequenced. All the nucleotide sequences and the inferred amino acid sequences show a high level of identify (> 95% at the nucleotide and amino acid level), confirming that they are an allelic series. The two B1 esterase nucleotide sequences (MRES and the previously published TEM-R [Mouches, Pauplin, Agarwal, Lemieux, Herzog, Abadon, Beyssat-Arnaouty, Hyrien, De Saint Vincent, Georghiou and Pasteur (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 2574-2578]) showed the lowest identity, and restriction-fragment-length-polymorphism analysis of the two strains was different. On the basis of these data we suggest that the two electrophoretically identical B1 esterase isoenzymes from California and Cuba have been amplified independently. Alternatively, if amplification has occurred only once, the original amplification has not occurred recently.

2001 ◽  
Vol 45 (9) ◽  
pp. 2559-2562 ◽  
Author(s):  
Rui Kano ◽  
Ken Okabayashi ◽  
Yuka Nakamura ◽  
Shinichi Watanabe ◽  
Atsuhiko Hasegawa

ABSTRACT The expression of the ubiquitin (Ub) gene in dermatophytes was examined for its relation to resistance against the antifungal drug fluconazole. The nucleotide sequences and the deduced amino acid sequences of the Ub gene in Microsporum canis were proven to be 99% similar to those of the Ub gene in Trichophyton mentagrophytes. Expression of mRNA of Ub in M. canisand T. mentagrophytes was enhanced when the fungi were cultured with fluconazole. The antifungal activity of fluconazole against these dermatophytes was increased in the presence of Ub proteasome inhibitor.


2015 ◽  
Vol 45 (12) ◽  
pp. 2197-2200 ◽  
Author(s):  
Thor Vinícius Martins Fajardo ◽  
Monique Bezerra Nascimento ◽  
Marcelo Eiras ◽  
Osmar Nickel ◽  
Gilvan Pio-Ribeiro

ABSTRACT: There is no molecular characterization of Brazilian isolates of Prunus necrotic ringspot virus (PNRSV), except for those infecting peach. In this research, the causal agent of rose mosaic was determined and the movement (MP) and coat (CP) protein genes of a PNRSV isolate from rose were molecularly characterized for the first time in Brazil. The nucleotide and deduced amino acid sequences of MP and CP complete genes were aligned and compared with other isolates. Molecular analysis of the MP and CP nucleotide sequences of a Brazilian PNRSV isolate from rose and others from this same host showed highest identities of 96.7% and 98.6%, respectively, and Rose-Br isolate was classified in PV32 group.


1980 ◽  
Vol 187 (1) ◽  
pp. 65-74 ◽  
Author(s):  
D Penny ◽  
M D Hendy ◽  
L R Foulds

We have recently reported a method to identify the shortest possible phylogenetic tree for a set of protein sequences [Foulds Hendy & Penny (1979) J. Mol. Evol. 13. 127–150; Foulds, Penny & Hendy (1979) J. Mol. Evol. 13, 151–166]. The present paper discusses issues that arise during the construction of minimal phylogenetic trees from protein-sequence data. The conversion of the data from amino acid sequences into nucleotide sequences is shown to be advantageous. A new variation of a method for constructing a minimal tree is presented. Our previous methods have involved first constructing a tree and then either proving that it is minimal or transforming it into a minimal tree. The approach presented in the present paper progressively builds up a tree, taxon by taxon. We illustrate this approach by using it to construct a minimal tree for ten mammalian haemoglobin alpha-chain sequences. Finally we define a measure of the complexity of the data and illustrate a method to derive a directed phylogenetic tree from the minimal tree.


1996 ◽  
Vol 315 (3) ◽  
pp. 807-814 ◽  
Author(s):  
Said MODARESSI ◽  
Bruno CHRIST ◽  
Jutta BRATKE ◽  
Stefan ZAHN ◽  
Tilman HEISE ◽  
...  

In human liver, phosphoenolpyruvate carboxykinase (PCK; EC 4.1.1.32) is about equally distributed between cytosol and mitochondria in contrast with rat liver in which it is essentially a cytosolic enzyme. Recently, the isolation of the gene and cDNA of the human cytosolic enzyme has been reported [Ting, Burgess, Chamberlain, Keith, Falls and Meisler (1993) Genomics 16, 698–706; Stoffel, Xiang, Espinosa, Cox, Le Beau and Bell (1993) Hum. Mol. Genet. 2, 1–4]. It was the goal of this investigation to isolate the cDNA of the human mitochondrial form of hepatic PCK. A human liver cDNA library was screened with a rat cytosolic PCK cDNA probe comprising sequences from exons 2 to 9. A cDNA clone was isolated which had overall a 68% DNA sequence and a 70% deduced amino acid sequence identity with the human cytosolic PCK cDNA. Without the flanking 270 bases (=90 amino acids) each at the 5´ and 3´ end, the sequence identity was 73% on the DNA and 78% on the amino acid level. The isolated cDNA had an open reading frame of 1920 bp; it was 54 bp (equivalent to 18 amino acids) longer than that of human or rat cytosolic PCK cDNA. The isolated cDNA was cloned into the eukaryotic expression vector pcDNAI and transfected into human embryonal kidney cells HEK293; PCK activity was increased by 3-fold in the mitochondria, which normally contain 70% of total PCK activity, but not in the cytosol. The isolated cDNA was also transfected into cultured rat hepatocytes; again, PCK activity was enhanced by about 40-fold in the mitochondria, which normally possess only 10% of total PCK activity, but not in the cytosol. In the rat hepatocytes only the endogenous cytosolic PCK and not the transfected mitochondrial PCK was induced 3-fold with glucagon. Comparison of the amino acid sequences deduced from the isolated cDNA with human and rat cytosolic PCK showed that the additional 18 amino acids were located at the N-terminus of the protein and probably constitute a mitochondrial targeting signal. Northern-blot analyses revealed the human mitochondrial PCK mRNA to be 2.25 kb long, about 0.6 kb shorter than the mRNA of the cytosolic PCK. Primer extension experiments showed that the 5´-untranslated region of mitochondrial PCK mRNA was 134 nucleotides in length.


Author(s):  
Tatyana Tikhomirova ◽  
Maxim Matyunin ◽  
Mikhail Lobanov ◽  
Oxana Galzitskaya

Chaperonin Hsp60, as a protein found in all organisms, is of great interest in medicine, since it is present in many tissues and can be used both as a drug and as an object of targeted therapy. Hence, Hsp60 deserves a fundamental comparative analysis to assess its evolutionary characteristics. It was found that the percent identity of Hsp60 amino acid sequences both within and between phyla was not high enough to identify Hsp60s as highly conserved proteins. In turn, their amino acid composition remained relatively constant. At the same time, the analysis of the nucleotide sequences showed that GC content in the Hsp60 genes was comparable to or greater than the genomic values, which may indicate a high resistance to mutations due to tight control of the nucleotide composition by DNA repair systems. Natural selection plays a dominant role in the evolution of Hsp60 genes. The degree of mutational pressure affecting the Hsp60 genes is quite low, and its direction does not depend on taxonomy. Interestingly, for the Hsp60 genes from Chordata, Arthropoda, and Proteobacteria the exact direction of mutational pressure could not be determined. However, upon further division into classes, it was found that the direction of the mutational pressure for Hsp60 genes from Fish differs from that for other chordates. The direction of the mutational pressure affects the synonymous codon usage bias. The number of high and low represented codons increases with increasing GC content, which can improve codon usage.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Tim Anderson ◽  
Travis J. Wheeler

Abstract Background Pattern matching is a key step in a variety of biological sequence analysis pipelines. The FM-index is a compressed data structure for pattern matching, with search run time that is independent of the length of the database text. Implementation of the FM-index is reasonably complicated, so that increased adoption will be aided by the availability of a fast and flexible FM-index library. Results We present AvxWindowedFMindex (AWFM-index), a lightweight, open-source, thread-parallel FM-index library written in C that is optimized for indexing nucleotide and amino acid sequences. AWFM-index introduces a new approach to storing FM-index data in a strided bit-vector format that enables extremely efficient computation of the FM-index occurrence function via AVX2 bitwise instructions, and combines this with optional on-disk storage of the index’s suffix array and a cache-efficient lookup table for partial k-mer searches. The AWFM-index performs exact match count and locate queries faster than SeqAn3’s FM-index implementation across a range of comparable memory footprints. When optimized for speed, AWFM-index is $$\sim $$ ∼ 2–4x faster than SeqAn3 for nucleotide search, and $$\sim $$ ∼ 2–6x faster for amino acid search; it is also $$\sim $$ ∼ 4x faster with similar memory footprint when storing the suffix array in on-disk SSD storage. Conclusions AWFM-index is easy to incorporate into bioinformatics software, offers run-time performance parameterization, and provides clients with FM-index functionality at both a high-level (count or locate all instances of a query string) and low-level (step-wise control of the FM-index backward-search process). The open-source library is available for download at https://github.com/TravisWheelerLab/AvxWindowFmIndex.


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