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In the department of Boyacá, Colombia, agriculture stands as one of the primary economic activities. However, the escalating utilization of pesticides within this sector has sparked concern regarding its potential correlation with elevated risks of genotoxicity, chromosomal alterations, and carcinogenesis. Furthermore, pesticides have been associated with a broad spectrum of genetic polymorphisms that impact pivotal genes involved in pesticide metabolism and DNA repair, among other processes. Nonetheless, our understanding of the genotoxic effects of pesticides on the chromosomes (as biomarkers of effect) in exposed farmers and the impact of genetic polymorphisms (as susceptibility biomarkers) on the increased risk of chromosomal damage is still limited. The aim of our study was to evaluate chromosomal alterations, chromosomal instability, and clonal heterogeneity, as well as the presence of polymorphic variants in the GSTP1 and XRCC1 genes, in peripheral blood samples of farmers occupationally exposed to pesticides in Aquitania, Colombia, and in an unexposed control group. Our results showed statistically significant differences in the frequency of numerical chromosomal alterations, chromosomal instability, and clonal heterogeneity levels between the exposed and unexposed groups. In addition, we also found a higher frequency of chromosomal instability and clonal heterogeneity in exposed individuals carrying the heterozygous GSTP1 AG and XRCC1 (exon 10) GA genotypes. The evaluation of chromosomal alterations and chromosomal instability resulting from pesticide exposure, combined with the identification of polymorphic variants in the GSTP1 and XRCC1 genes, and further research involving a larger group of individuals exposed to pesticides could enable the identification of effect and susceptibility biomarkers. Such markers could prove valuable for monitoring individuals occupationally exposed to pesticides.

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Resumen Antecedentes: Chlamydia trachomatis es la bacteria que se detecta con mayor frecuencia en las infecciones de transmisión sexual. Se han identificado 20 genotipos de C. trachomatis mediante el gen ompA y varias genovariantes mediante el análisis de polimorfismo de un solo nucleótido (SNP). En México, el genotipo F es el más frecuente. Objetivo: Identificar la existencia de subtipos del genotipo F. Método: Se analizaron siete cepas del genotipo F de C. trachomatis aisladas en 2011, mediante secuenciación de nucleótidos y mapeo con enzimas de restricción. Resultados: El análisis de SNP mostró dos cepas con el mismo SNP en el nucleótido 288 (C288T), mientras que con enzimas de restricción se identificó una variante con diferente RFLP (polimorfismo de la longitud de fragmentos de restricción) cuando se tratan con la mezcla de enzimas HinfI y TaqI. Conclusión: En México se encuentran dos subtipos del genotipo F y solo las enzimas de restricción HinfI y TaqI pueden identificar la existencia de uno de estos genotipos F.

Abstract Background: Chlamydia trachomatis is the most frequently identified bacterium in sexually transmitted infections. Twenty C. trachomatis genotypes have been determined using the ompA gene and several genovariants by single nucleotide polymorphism (SNP) analysis. In Mexico, the F genotype is the most frequent. Objective: To identify subtypes of the F genotype. Method: Seven C. trachomatis genotype F strains isolated in 2011 were analyzed by nucleotide sequencing and restriction enzyme mapping. Results: SNP analysis showed two strains with the same SNP at nucleotide 288 (C288T), while with res-triction enzymes, a variant with different RFLP (restriction fragment length polymorphism) was identified when treated with the mixture of HinfI and TaqI enzymes. Conclusion: In Mexico, there are two subtypes of F, and only with restriction enzymes HinfI and TaqI can identify one of the genovariants of the F genotype.

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The use of LEGO® bricks in the higher education classroom has increased in the last two decades. This is no different in the STEM classroom and several disciplines, including physics, chemistry, and biology, have all made use of LEGO® bricks in some way to create models for active learning activities. Currently, the discipline to make the greatest use of LEGO® bricks is chemistry; only limited examples exist in biochemistry and the molecular life sciences. Here, we present the use of a LEGO® brick modelling activity in the introductory biochemistry classroom during the teaching of metabolism. We present student comments on the activity and the models that were generated by the students. Additionally, we focus on other instructor and project student-designed models for the teaching of ATP synthesis, gene regulation and restriction digestion. Interestingly, both the gene regulation and restriction digest activities were generated with the help of undergraduate students or recent graduates, by applying a backward design approach. This case study seeks to encourage more molecular life science educators to adopt the use of LEGO® bricks in their classrooms to engage in more active learning.

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The aim of this study was to produce high yield of a local bacterial alkaline protease in the yeast system because the scientific involvement of microorganisms in enzyme production is still not given enough attention in Saudi Arabia. Soil samples were collected from the rhizosphere of some desert plants in Saudi Arabia. Ninety-three alkaline protease producing bacterial isolates were recovered on skimmed-milk agar at pH 9.4 and 45°C for 48 hr. Isolate D9 obtained from the rhizosphere of Heliotropium digynum at Dhahran City was the most potent isolate in respect to enzyme productivity (184.6 U/ml). The full gene of alkaline protease was amplified and showed the expected size (1300 bp). Restriction enzymes analysis also verified the integrity of the PCR product. The sequence of the protease gene revealed an open reading frame of 1329 nt correspond to the full length of the protease gene of isolate D9 encoding a 443 aa protein. After ligation of the amplified gene by the TA cloning method, digestion with appropriate restriction enzymes confirmed the integrity of the cloned gene. The insert was prepared by two PCRs that were conducted with a pair of primers specifically designed for this purpose. The digested and purified cloning vector pRS426/GAL1p-207-Glu-MS was ligated with the insert then transformed into various strains of Saccharomyces cerevisiae via the electroporation method. Maximum protease expression was done by recombinant OS303 in galactose containing media (145.5 U/ml) with an approximately 2-fold increase when compared with the wild OS303 strain., this may be due to ability to activate gal operon.

O objetivo deste estudo foi produzir alto rendimento de uma protease alcalina bacteriana local no sistema de leveduras, já que o envolvimento científico de microrganismos na produção de enzimas ainda não recebe atenção suficiente na Arábia Saudita. Amostras de solo foram coletadas da rizosfera de algumas plantas do deserto na Arábia Saudita. Noventa e três isolados bacterianos produtores de protease alcalina foram recuperados em ágar de leite desnatado a pH 9,4 e 45°C por 48 horas. O isolado D9 obtido da rizosfera de Heliotropium digynum na cidade de Dhahran foi o mais potente em relação à produtividade da enzima (184,6 U/ml). O gene completo da protease alcalina foi amplificado e apresentou o tamanho esperado (1300 pb). A análise de enzimas de restrição também verificou a integridade do produto de PCR. A sequência do gene da protease revelou uma fase de leitura aberta de 1329 nt, correspondendo ao comprimento total do gene da protease do isolado D9 que codifica uma proteína 443 aa. Após a ligação do gene amplificado pelo método de clonagem TA, a digestão com enzimas de restrição apropriadas confirmou a integridade do gene clonado. A inserção foi preparada por dois PCRs que foram conduzidos com um par de primers projetados especificamente para esta finalidade. O vetor de clonagem digerido e purificado pRS426/GAL1p-207-Glu-MS foi ligado com a inserção e então transformado em várias cepas de Saccharomyces cerevisiae por meio do método de eletroporação. A expressão máxima da protease foi feita por OS303 recombinante em meio contendo galactose (145,5 U/ml) com um aumento de aproximadamente duas vezes quando comparado com a cepa OS303 selvagem, e isso pode ser por causa da capacidade de ativar o operon gal.

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The advent of new DNA sequencing technologies leads to a dramatic increase in the number of available genome sequences and therefore of target genes with potential for functional analysis. The insertion of these sequences into proper expression vectors requires a simple an efficient cloning method. In addition, when expressing a target protein, quite often it is necessary to evaluate different DNA constructs to achieve a soluble and homogeneous expression of the target with satisfactory yields. The development of new molecular methods made possible the cloning of a huge number of DNA sequences in a high-throughput manner, necessary for meeting the increasing demands for soluble protein expression and characterization. In this chapter several molecular methods suitable for high-throughput cloning are reviewed.

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Background: The whole-genome sequences of nine Rhizobium species were evaluated using different in silico molecular techniques such as AFLP-PCR, restriction digest, and AMPylating enzymes. The entire genome sequences were aligned with progressiveMauve and visualized by reconstructing phylogenetic tree using NTSYS pc 2.11X. The "insilico.ehu.es" was used to carry out in silico AFLP-PCR and in silico restriction digest of the selected genomes. Post-translational modification (PTM) and AMPylating enzyme diversity between the proteome of Rhizobium species were determined by novPTMenzy. Results: Slight variations were observed in the phylogeny based on AFLP-PCR and PFGE and the tree based on whole genome. Results clearly demonstrated the presence of PTMs, i.e., AMPylation with the GS-ATasE (GlnE), Hydroxylation, Sulfation with their domain, and Deamidation with their specific domains (AMPylating enzymes) GS-ATasE (GlnE), Fic, and Doc (Phosphorylation); Asparagine_hydroxylase and Collagen_prolyl_lysyl_hydroxylase; Sulfotransferase; and CNF (Cytotoxic Necrotizing Factors), respectively. The results pertaining to PTMs are discussed with regard to functional diversities reported in these species. Conclusions: The phylogenetic tree based on AFLP-PCR was slightly different from restriction endonuclease- and PFGE-based trees. Different PTMs were observed in the Rhizobium species, and the most prevailing type of PTM was AMPylation with the domain GS-ATasE (GlnE). Another type of PTM was also observed, i.e., Hydroxylation and Sulfation, with the domains Asparagine_hydroxylase and Collagen_prolyl_lysyl_hydroxylase and Sulfotransferase, respectively. The deamidation type of PTM was present only in Rhizobium sp. NGR234. How to cite: Qureshi MA, Pervez MT, Babar ME, et al. Genomic comparisons of Rhizobium species using in silico AFLP-PCR, endonuclease restrictions and ampylating enzymes.

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Abstract The development of conventional, silicon-based computers has several limitations, including some related to the Heisenberg uncertainty principle and the von Neumann "bottleneck". Biomolecular computers based on DNA and proteins are largely free of these disadvantages and, along with quantum computers, are reasonable alternatives to their conventional counterparts in some applications. The idea of a DNA computer proposed by Ehud Shapiro's group at the Weizmann Institute of Science was developed using one restriction enzyme as hardware and DNA fragments (the transition molecules) as software and input/output signals. This computer represented a two-state two-symbol finite automaton that was subsequently extended by using two restriction enzymes. In this paper, we propose the idea of a multistate biomolecular computer with multiple commercially available restriction enzymes as hardware. Additionally, an algorithmic method for the construction of transition molecules in the DNA computer based on the use of multiple restriction enzymes is presented. We use this method to construct multistate, biomolecular, nondeterministic finite automata with four commercially available restriction enzymes as hardware. We also describe an experimental applicaton of this theoretical model to a biomolecular finite automaton made of four endonucleases.

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La entomología forense es una disciplina que utiliza insectos para obtener información útil en la determinación del intervalo postmortem (IPM). Las moscas de la familia Calliphoridae son muy utilizadas en entomología forense, sin embargo, su identificación a nivel de especie puede dificultarse cuando el individuo se encuentra incompleto o en estadio inmaduro. En el presente trabajo, se evaluó el potencial de la región ITS2 del genoma nuclear para la identificación de especies de Calliphoridae en Colombia utilizando tres aproximaciones: comparando distancias genéticas utilizando la metodología de códigos de barra, haciendo una reconstrucción filogenética, y con enzimas de restricción (PCR-RFLPs). Se secuenciaron un total de 520 pb en 44 individuos pertenecientes a 16 especies. Se calcularon los valores de distancia intraespecífica e interespecíficas utilizando el modelo K2P. Los valores de distancia intraespecífica oscilaron entre 0 y 0,252 %, mientras que las distancias interespecíficas fluctuaron entre 3,6 y 18,9 %, evidenciándose que esta técnica puede ser utilizada como código de barras genético en la identificación de especies de la familia Calliphoridae. Tanto en los análisis de Neighbour-Joining como en los análisis bayesianos el 90 % de los géneros presentan una monofilia sustentada en probabilidad posterior de 0,89 a 1. En todos los casos la especie Blepharicnema splendens agrupa con el género Lucilia. Con base en las secuencias obtenidas se utilizó la aplicación NEBCutter para identificar cuatro enzimas de restricción las cuales se probaron en el laboratorio y se comprobó su utilidad para la identificación rápida de especies de Calliphoridae en Colombia.

Forensic entomology is a discipline that uses insects to obtain useful information for the determination of the postmortem interval (PMI). Flies of the family Calliphoridae are extensively used for this purpose, however, the identification of these flies can be difficult when the individual is not an adult or when it is incomplete. In the present work, we tested the utility of the ITS2 region of the nuclear genome for the identification of Calliphoridae species in Colombia using three approaches: comparing genetic distances using the barcoding methodology, with a phylogenetic reconstruction, and with PCR-RFLPs. We sequenced 520 bp in 44 individuals belonging to 16 species of califorids. Intraspecific and interspecific distance values were calculated using the K2P model. The intraspecific distance values ranged between 0 and 0.252 %, while the interspecific distance values ranged between 3.6 and 18.9 %, indicating that this gene can be used as a genetic barcode for the identification of species of the Calliphoridae family. Both the Neighbour-Joining and Bayesian analyses recovered 90 % of the genera as monophyletic, with pp values between 0.89 and 1. Blepharicnema splendens was always recovered within the Lucilia genera. Based on the obtained sequences we used the NEBCutter application to identify four restriction enzymes that cut in a differential way and generated useful patterns for the identification of the species. The enzymes were successfully tested and confirmed the utility of this technique as a fast way to identify species of Calliphoridae in Colombia.

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The gram negative facultative bacterium P. salmonis is the etiological agent of Salmonid Rickettsial Septicaemia (SRS), a severe disease that causes important economic losses in the global salmon farmer industry. Despite efforts to control this disease, the high frequency of new epizootic events indicate that the vaccine and antibiotics treatments have limited effectiveness, therefore the preventive and diagnostic approaches must be improved. A comparison of several methodologies for SRS diagnostic indicate differences in their specificity and its capacity to detect other bacteria coexisting with P. salmonis in culture media (contamination) and fish samples (coinfection), aspects relevant for research, vaccine development and clinical diagnostic. By computer-simulation analyses, we identified a group of restriction enzymes that generate unique P. salmonis 16S rDNA band patterns, distinguishable from all other bacteria. From this information, we designed and developed a PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) assay, which was validated using 16S rDNA universal primers and restriction enzyme PmaCI for the amplification and digestion, respectively. Experimental validation was performed by comparing the restriction pattern of P. salmonis with the restriction patterns generated by bacteria that cohabit with P. salmonis (fish bacterial isolates and culture media contaminants). Our results indicate that the restriction enzyme selection pipeline was suitable to design a more specific, sensible, faster and cheaper assay than the currently used P. salmonis detection methodologies.

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A total of 65 Bacillus thuringiensis (Bt) isolates were subjected to analysis of genetic relationship using fAFLP (fluorescent Fragment Length Polymorphism), in order to determine the genetic diversity within a group of Bt strains. 26 strains from different subspecies were identified as it follows: 9 kindly provided by the USDA (United States Department of Agriculture), 9 kindly provided by the Institute Pasteur and eight from Embrapa Maize and Sorghum Bt Collection, and 39 strains with no subspecies information also from Embrapa's Bt Collection. DNA sample was double digested with restriction enzymes EcoRI and MseI, and the fragments were linked to adapters. Selective amplification reactions were performed using five primer combinations and the amplified fragments were separated by gel electrophoresis on an ABI377 sequencer. Genetic distances were obtained by the complement of the Jaccard coefficient and the groups were performed by the UPGMA method. Five primer combinations generated 495 scorable fragments and 483 were found to be polymorphic. Out of 26 subspecies, strains 344 and T09 (B. thuringiensis subsp. tolworthi) showed the highest similarity (15%), while isolates HD3 B. thuringiensis subsp finitimus and T24 B. thuringiensis subsp neoleonensis were the most genetically distant (92%). B. thuringiensis isolates with no subspecies identification, found in samples from Goiás State showed higher similarity forming a group with an average distance of 6%, and the closest subspecies to this group was B. thuringiensis subsp thuringiensis (HD2) with 52% of similarity. This similarity may be due to the fact that these organism exchange genetic material by conjugation, and it is relatively common to have evolutionary characteristics of their ancestors.