Análisis molecular y filogenético del genotipo F de Chlamydia trachomatis aislados en México en 2011 / Molecular and phylogenetic analysis of the F genotype of Chlamydia trachomatis isolated in Mexico in 2011

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.

Novel primer designing and PCR-AFLP approach for an expeditious detection of coliforms in potable waters

Molecular techniques involving 16S rRNA gene have long been proved to be a mainstay of sequence-based bacterial analysis and enhance the competence of bacterial removal in drinking water and food. The main goal of this analysis was to reduce the time of detection of total coliforms by developing 16S rRNA based DNA markers by targeting variable region in the 16S rRNA gene position of V2 and V9. Coliform specific primers (189F and 1447R) were designed to amplify total coliform with an amplicon size of 1300 bp. The PCR product was later digested with Hind III and BseRI (restriction enzymes) to differentiate the type of contamination caused by fecal and non-fecal coliforms respectively. The digested amplicons were run on agarose gel electrophoresis and contamination levels were estimated based on the respective band pattern. This method can be applicable to know the coliform contamination levels of potable waters, in food and beverage industries within a short period of time. To our knowledge, this is the first report on newly designed primers which not only amplify coliform bacteria, followed by various restriction digestions of these amplicons but also provides unique band patterns to identify coliforms at genus level.

Restriction enzymes and their use in molecular biology: An overview

Restriction enzymes have been identified in the early 1950s of the past century and have quickly become key players in themolecular biology of DNA. Forty years ago, the scientists whose pioneering work had explored the activity and sequencespecificity of these enzymes, contributing to the definition of their enormous potential as tools for DNA characterization,mapping and manipulation, were awarded the Nobel Prize. In this short review, we celebrate the history of these enzymes inthe light of their many different uses, as these proteins have accompanied the history of DNA for over 50 years representingactive witnesses of major steps in the field

Genomic comparisons of Rhizobium species using in silico AFLP-PCR, endonuclease restriction, and AMPylating enzymes

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.

Identification of deer blood by PCR-RFLP method / 中草药

Objective To establish a polymerase chain reaction coupled with restriction fragment length polymorphism (PCR-RFLP) method which can identify deer blood. Methods We analyzed DNA sequences of cytochrome b (cytb) from different species (i.e. sika deer, red deer, pig, ox, sheep, and duck) and selected two DNA restriction enzymes of EcoRV and MseI to distinguish deer from other species and to sika deer from red deer, respectively. Genomic DNA of every sample was extracted by blood genomic DNA extraction kit. After PCR of cytb fragment, digestion by EcoRV or MseI was conducted and the results were analyzed. The capacity of this method to identify different proportional blood mix from different species also was determined. Results Using the PCR-RFLP method, EcoRV digestion made two fragments of 287 bp and 185 bp in deer, but no digestion in other species; MesI digestion made two fragments of 281 bp and 191 bp in sika deer, but three fragments of 281 bp, 126 bp, and 65 bp in red deer. The 191 bp fragment was a characteristic marker of sika deer, and the 126 bp was for red deer. The minimum detected proportion added to blood of deer with other sample was 3%, 6% of sika deer with red deer. Conclusion A PCR-RFLP method according to the sequences of cytb gene is established. This method can identify the blood of sika deer rapidly and conveniently.

Biomolecular computers with multiple restriction enzymes

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.

Its2 para la identificación de califóridos (diptera: calliphoridae) de importancia forense en colombia / ITS2 for the Identification of Calliphoridae (Diptera: Calliphoridae) of Forensic Importance in Colombia

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.

Utilidad del bandeo cromosómico con la enzima ALU I para la identificación de zonas metiladas en cáncer de mama / Utility of chromosome banding with ALU I enzyme for identifying methylated areas in breast cancer

El cáncer es un conjunto de trastornos que comparten la característica común de un crecimiento celular descontrolado, teniendo la facultad de comenzar en las células, generando dos procesos sucesivos: el aumento de la proliferación celular (tumor o neoplasia) y la capacidad invasiva de estas células, proliferando y colonizando otros tejidos (metástasis). La metilación del DNA es un proceso epigenético que recurrentemente ha sido involucrado como un factor importante en la patogenia de esta enfermedad el cual participa en la regulación de la expresión génica directamente al impedir la unión de factores de trascripción, e indirectamente propiciando la estructura “cerrada” de la cromatina. El objetivo de este trabajo fue determinar regiones hipermetiladas en muestras de extendidos cromosómicos mediante la utilización de la endonucleasa de restricción Alu I y relacionar estas regiones con sitios de localización de genes supresores de tumores relacionados con el cáncer de mama. Se analizaron 60 muestras de sangre periférica de mujeres con diagnóstico de cáncer de mama a las cuales se les realizó cultivo celular; los extendidos cromosómicos fueron teñidos con Giemsa previamente digeridos con la enzima Alu I. Se observaron cromosomas con regiones centroméricas y no centroméricas teñidas en el 37% de los casos, comprobándose que en el 95,46% de los casos existen genes asociados descritos, como metilados en cáncer de mama. Ejemplo de ellos son los localizados en los cromosomas 1q, 2q, 6q, y regiones centroméricas no teñidas usualmente como en los cromosomas 3, 4, 8, 13, 14, 15, y 17. Se sugiere la importancia de esta técnica ya que permite la visualización total del genoma, pudiendo localizar genes metilados relacionados con cáncer de mama y, de esta manera dirigir la terapia de forma específica, logrando una mejor respuesta terapéutica.

Cancer is a group of disorders characterized by uncontrolled cell growth which is produced by two successive events: increased cell proliferation (tumor or neoplasia) and the invasive capacity of these cells (metastasis). DNA methylation is an epigenetic process which has been involved as an important pathogenic factor of cancer. DNA methylation participates in the regulation of gene expression, directly, by preventing the union of transcription factors, and indirectly, by promoting the “closed” structure of the chromatine. The objectives of this study were to identify hypermethyled chromosomal regions through the use of restriction Alu I endonuclease, and to relate cytogenetically these regions with tumor suppressive gene loci. Sixty peripheral blood samples of females with breast cancer were analyzed. Cell cultures were performed and cytogenetic spreads, previously digested with Alu I enzyme, were stained with Giemsa. Chromosomal centromeric and not centromeric regions were stained in 37% of cases. About 96% of stained hypermethyled chromosomal regions (1q, 2q, 6q) were linked with methylated genes associated with breast cancer. In addition, centromeric regions in chromosomes 3, 4, 8, 13, 14, 15 and 17, usually unstained, were found positive to digestion with Alu I enzime and Giemsa staining. We suggest the importance of this technique for the global visualization of the genome which can find methylated genes related to breast cancer, and thus lead to a specific therapy, and therefore a better therapeutic response.

Progressive De Novo DNA Methylation at the Pa Promotor of the Abl Genein the Bcr-Abl Locus during the Course of Chronic Myelogenous Leukemia / 대한임상병리학회지

BACKGROUND: In most cases of chronic myelogenous leukemia (CML), one of the two abl promotors (Pa) is nested within the bcr-abl hybrid gene and should be able to transcribe the 6-kb normal abl mRNA from the Philadelphia chromosome. However, 6-kb transcript is present only in CML cell lines containing a normal abl allele. Since the nested Pa in the bcr-abl hybrid gene is contained within a CpG island, de novo methylation of Pa CpG islands may cause silencing of the c-abl gene. In this study, using a polymerase chain reaction (PCR) and methylation-sensitive restriction enzymes, we investigated the methylation status of the nested Pa CpG islands in the bcr-abl hybrid gene at two stages of CML and the usefulness of it as a disease progression marker. METHODS: Genomic DNA was extracted from the preserved bone marrow smear slides of ten CML patients, at chronic phase and blast crisis respectively. K-562 cell line and normal peripheral lymphocytes as a negative control were also used. The extracted genomic DNA was digested with methylation-sensitive restriction enzymes and methylation-insensitive restriction enzymes, respectively, followed by PCR amplification for Pa promotor and electrophoresed for detection of 171 bp PCR products. RESULTS: The patients were transformed from chronic phase to blast crisis during 11-60 months after initial diagnosis. The patients displayed the following three types of methylation patterns. A, no methylation; B, partial methylation; C, complete methylation. All cases of chronic phase showed pattern A, but three cases of blast crisis were pattern B and seven cases, pattern C. CONCLUSIONS: De novo DNA Methylation at the Pa promotor of the abl gene in the bcr-abl hybrid gene is a distinct and common molecular event in blast crisis of CML. Since the process of Pa CpG methylation is of a progressive nature, Pa methylation pattern may be used as a molecular marker for progression of CML to blast crisis.