New vectors derived from pUC18 for cloning and thermal-induced expression in Escherichia coli

We report the construction of two vectors for Escherichia coli: pUC72, for molecular cloning, and pPLT7, for thermal-induced expression. The main feature of pUC72 is a novel polylinker region that includes restriction sites for Nde I and Nco I which provide an ATG codon for proper translation initiation of expressed genes. Vector pPLT7 is ideal for thermo-inducible expression in host cells that carry the cI857 repressor gene. The use of pPLT7 was validated by the successful expression of the genes encoding carp and porcine growth hormones. These vectors provide novel cloning possibilities in addition to simple, non-expensive, high level expression of recombinant proteins in E. coli

Specific discrimination between Taenia saginata and Taenia solium by one step PCR assay and duplex-PCR

Este estudo teve como objetivo a padronização de protocolos e a seleção de novos primers para a identificação espécie-específica de Taenia saginata e Taenia solium através da reação em cadeia da polimerase (PCR) e duplex-PCR. Inicialmente, foram recuperadas seqüências depositadas no GenBank (acesso n° AB020399 para T. saginata e n° AB020395 para T. solium) referentes ao gene da subunidade maior do ribossomo (LSU RNAr) de tenídeos. A partir do alinhamento das seqüências, um primer genérico denominado TBR-3 (5’- ggcttgtttgaatggtttgacg- 3’) foi selecionado de região conservada e, de diferentes regiões semi-conservadas, os primers específicos TBR-4 para T. saginata (5’-cgactcatgaagataaacaaggt-3’) e TBR- 5 (5’-cggtcgaacagaccataaatct-3’) e TBR-6 (5’- gctactacacctaaattctaacc- 3’) para T. solium. Os primers foram avaliados quanto à especificidade através da PCR empregandose DNA total (DNAt) de amostras de cisticercos e proglotes dos parasitos, previamente identificadas por critérios morfológicos. O par de primers TBR-3/TBR-4 permitiu a amplificação específica do fragmento esperado de 328 pb a partir do DNAt de T. saginata. Os pares TBR-3/TBR-5 e TBR-3/TBR-6 permitiram a amplificação, respectivamente, dos fragmentos específicos de 310pb e 286pb a partir do DNAt de T. solium. A identidade dos produtos de PCR foi comprovada comparando-se a seqüência dos amplicons obtidos às seqüências de referência do gene LSU RNAr registrado no GenBank (n° AB020399 e n° AB020395). As reações apresentaram sensibilidade para detecção de até 1fg do DNAt de T. solium e 0,2fg do DNAt de T. saginata. A combinação dos primers TBR-3/TBR-4 e TBR3/TBR-6 e o tamanho dos fragmentos gênicos obtidos permitiram o estabelecimento de ensaios de duplex-PCR, eficaz na detecção simultânea do DNA de T. saginata e T. solium em sistema único de reação. Os primers utilizados não geraram qualquer produto de amplificação cruzada quando testados com DNAt de Taenia hydatigena, Taenia taeniaeformis, Hymenolepis diminuta, Anoplocephala magna, Paranoplocephala mamillana e Moniezia expansa, nem frente ao DNAt dos hospedeiros Homo sapiens, Bos taurus e Sus scrofa.This study was conducted to evaluate a protocol and to select novel primers for the species-specific identification of Taenia saginata and Taenia solium by PCR and duplex- PCR assays. Sequences of the LSU rRNA gene of taenids were obtained from the GenBank (T. saginata access n° AB020399 and T. solium access n° AB020395). The sequences were aligned and then used for primer design. The generic primer TBR3 (5’- ggcttgtttgaatggtttgacg- 3’) was selected from a conserved region. The T. saginata specific primer TBR-4 (5’- cgactcatgaagataaacaaggt-3’) as well as T. solium specific primers TBR-5 (5’-cggtcgaacagaccataaatct-3’) and TBR-6 (5’- gctactacacctaaattctaacc- 3’) were selected from different semiconserved regions. The selected sequences were examined in for similarities with other organisms through the GenBank Blast procedure and experimentally by PCR using total DNA (tDNA)extracted from cysticerci and proglottids from both parasites. The primer pair TBR-3/TBR-4 amplified specific fragments of 328 bp from T. saginata tDNA. The pairs TBR-3/TBR5 and TBR-3/TBR-6 amplified, respectively, the expected and specific fragments of 310bp and 286bp from the T. solium tDNA. Sequencing of the amplicons followed by comparison to GenBank reference sequences confirmed the identities of the PCR products. The detection sensitivity was equivalent to 1fg of T. solium tDNA and 0,2fg of T. saginata tDNA. The combination of primers TBR-3/TBR-4 and TBR3/TBR-6 and the size of amplicons allowed the establishment of a duplex-PCR assay to detect T. saginata and T. solium DNA. No cross reaction was observed with any combination of primers in reactions with tDNA of the parasites Taenia hydatigena, Taenia taeniaeformis, Hymenolepis diminuta, Anoplocephala magna, Paranoplocephala mamillana and Moniezia expansa, nether from the hosts tDNA Homo sapiens, Bos taurus nor Sus scrofa

Dinamic of natural infection in newborn calves exposed to by Babesia bigemina as detected by Polimerase reaction chain

Com o objetivo de estudar por PCR a dinâmica da infecção natural da Babesia bigemina em bezerros criados em sistema extensivo, foram colhidas 266 amostras de sangue de um grupo de 37 bezerros, a partir do nascimento até aproximadamente 165 dias de vida, com intervalo médio de 19 dias entre as colheitas. Distribuíram-se as amostras de acordo com os grupos de diferentes faixas etárias (entre 0 e 15 dias, entre 16 e 30 dias e assim sucessivamente até 165 dias). Do total de 266 amostras, 116 (43,60%) mostraram- se positivas para a PCR. A reação foi capaz de detectar a presença do parasito em todos os intervalos das colheitas e registrou-se o maior número de primo-infecções – 12 em 37 (32,43%) – no período de 31 a 45 dias. Dos 37 bezerros estudados, apenas um apresentou resultado da PCR positivo nos dois grupos de faixa etária inferior a 31 dias. Este animal apresentava dois dias de vida no momento da colheita, sugerindo um caso de transmissão transplacentária de B. bigemina. _______________________________________________________________________________ ABSTRACTWith the objetive of using PCR to study the dynamic of natural infection caused by Babesia bigemina in calves livestock in extensive system, 266 samples of blood were collected from a group of 37 calves from birth to approximately 165 days old. The samples were collected with an average intervale of 19 days and distributed according to age 0 to 15 days old, 16 to 30 days and successively until 165 days. Out of the total of the 266 samples, 116 (43.60%) were PCR positive. The reaction detected the presence of the parasite in all the intervals of collection and most of the prime infection, 12 in 37 (32.43%) were detected in the period between 31 and 45 days. Out of the 37 calves analysed, only one presented a positive PCR result within the two groups aged under 31 days. This animal was two days old at the moment of the collection. This result suggest a case of transplacentary transmission of Babesia bigemina

Production of enzymes for the diagnosis of CoVid-19

Os coronavírus representam um grupo de vírus cujos genomas são baseados em RNA fita simples de sentido positivo (+)ssRNA sendo causadores de diversas infecções respiratórias em humanos, incluindo a COVID-19. O diagnóstico rápido e preciso deste vírus é fundamental para nortear o tratamento da doença. Atualmente, os mais importantes testes de diagnóstico deste vírus são baseadas em imunoensaios (ELISA) ou em testes moleculares (PCR). Por se tratar de um genoma de RNA, a detecção do coronavírus se dá pela RT-PCR que envolve o uso de duas enzimas: transcriptase reversa e Taq DNA polimerase

Biochemical and Structural Characterization of Amy1: An Alpha-Amylase from Cryptococcus flavus Expressed in Saccharomyces cerevisiae

An extracellular alpha-amylase (Amy1) whose gene from Cryptococcus flavus was previously expressed in Saccharomyces cerevisiae was purified to homogeneity (67 kDa) by ion-exchange and molecular exclusion chromatography. The enzyme was activated by NH4+ and inhibited by Cu+2 and Hg+2. Significant biochemical and structural discrepancies between wild-type and recombinant α-amylase with respect to Km values, enzyme specificity, and secondary structure content were found. Far-UV CD spectra analysis at pH 7.0 revealed the high thermal stability of both proteins and the difference in folding pattern of Amy1 compared with wild-type amylase from C. flavus, which reflected in decrease (10-fold) of enzymatic activity of recombinant protein. Despite the differences, the highest activity of Amy1 towards soluble starch, amylopectin, and amylase, in contrast with the lowest activity of Amy1w, points to this protein as being of paramount biotechnological importance with many applications ranging from food industry to the production of biofuels

Cloning, Purification, and Partial Characterization of Bacillus subtilis Urate Oxidase Expressed in Escherichia coli

Urate oxidase (EC 1.7.3.3) is an enzyme involved in purine metabolism which is used in the treatment of gout and as diagnostic reagent for detection of uric acid. In order to produce this enzyme in large quantities for biotechnological purposes, the gene coding for the Bacillus subtilis urate oxidase was cloned and heterologously expressed in Escherichia coli. Time course induction in E. coli showed an induced protein with an apparent molecular mass of ∼60 kDa. Soluble recombinant enzyme was purified in a single-step procedure using Ni-NTA column. The enzyme was purified 2.1-fold with a yield of 56% compared to the crude extract. MALDI-TOF analysis revealed an ion with a mass of 58675 Da which is in agreement with the expected mass of the recombinant protein. The purified enzyme showed an optimal pH and temperature of 8.0 and 37°C, respectively, and retained 90% of its activity after 72 hours of incubation at −20°C and 4°C

Culture of bovine ovarian follicle wall sections maintained the highly estrogenic profile under basal and chemically defined conditions

Follicle cultures reproduce in vitro the functional features observed in vivo. In a search for an ideal model, we cultured bovine antral follicle wall sections (FWS) in a serum-free defined medium (DM) known to induce 17β-estradiol (E2) production, and in a nondefined medium (NDM) containing serum. Follicles were sectioned and cultured in NDM or DM for 24 or 48 h. Morphological features were determined by light microscopy. Gene expression of steroidogenic enzymes and follicle-stimulating hormone (FSH) receptor were determined by RT-PCR; progesterone (P4) and E2 concentrations in the media were measured by radioimmunoassay. DM, but not NDM, maintained an FWS morphology in vitro that was similar to fresh tissue. DM also induced an increase in the expression of all steroidogenic enzymes, except FSH receptor, but NDM did not. In both DM and NDM, there was a gradual increase in P4 throughout the culture period; however, P4 concentration was significantly higher in NDM. In both media, E2 concentration was increased at 24 h, followed by a decrease at 48 h. The E2:P4 ratio was higher in DM than in NDM. These results suggest that DM maintains morphological structure, upregulates the expression of steroidogenic enzyme genes, and maintains steroid production with a high E2:P4 ratio in FWS cultures

Inserção do elemento LINE - 1 no gene C-MYC e imunorreatividade das proteinas C-MYC,p53 , p21 e p27 nos diferentes padrões morfológicos do tumor TVT

O tumor venéreo transmissível canino (TVT) afeta a genitália externa de cães pelo transplante natural de células tumorais viáveis. Assim, esta pesquisa teve como objetivo diagnosticar e caracterizar TVT em padrões morfológicos, identificar a inserção do elemento LINE-1 em gene C-MYC, por meio da reação em cadeia da polimerase (PCR), e avaliar a expressão imuno-histoquímica do C-MYC, p53, p21 e p27. A relação entre C-MYC e as proteínas p53 e a sua interferência na expressão de p21 e p27 foram também estudadas. Para isso, foram utilizadas 20 amostras de ocorrência natural de TVT, submetido a exame citopatológico, histopatológica e imuno-histoquímica e ao diagnóstico molecular de neoplasia. A expressão aumentada do tecido e a correlação entre a C-MYC e as proteínas p53, p21 e p27 indicam redução e/ou perda de funcionalidade na TVT em seu microambiente, com consequente supressão apoptótica, manutenção do crescimento celular e progressão da neoplasia.The canine transmissible venereal tumor (TVT) affects the external genitalia of dogs by the natural transplant of viable tumor cells. Thus, this research aimed to diagnose and characterize TVT morphological patterns, identify the insertion of the LINE-1 element in C-MYC gene, by means of the polymerase chain reaction (PCR), and evaluate the immunohistochemical expression of C-MYC, p53, p21 and p27 proteins. The relationship between C-MYC and p53 proteins and their interference on the expression of p21 and p27 were also studied. For that, 20 samples of naturally occurring TVT were used, subjected to cytopathological, histopathological and immunohistochemical analysis, and to molecular diagnosis of neoplasia. The increased tissue expression and the correlation among C-MYC, p53, p21 and p27 proteins indicate reduction and/or loss of their functionality in the TVT microenvironment, with consequent apoptotic suppression, maintenance of cell growth and progression of neoplasia

Engineering Zymomonas mobilis for the production of xylonic acid from sugarcane bagasse hydrolysate

Sugarcane bagasse is an agricultural residue rich in xylose, which may be used as a feedstock for the production of high-value-added chemicals, such as xylonic acid, an organic acid listed as one of the top 30 value-added chemicals on a NREL report. Here, Zymomonas mobilis was engineered for the first time to produce xylonic acid from sugarcane bagasse hydrolysate. Seven coding genes for xylose dehydrogenase (XDH) were tested. The expression of XDH gene from Paraburkholderia xenovorans allowed the highest production of xylonic acid (26.17 ± 0.58 g L−1) from 50 g L−1 xylose in shake flasks, with a productivity of 1.85 ± 0.06 g L−1 h −1 and a yield of 1.04 ± 0.04 gAX/gX. Deletion of the xylose reductase gene further increased the production of xylonic acid to 56.44 ± 1.93 g L−1 from 54.27 ± 0.26 g L−1 xylose in a bioreactor. Strain performance was also evaluated in sugarcane bagasse hydrolysate as a cheap feedstock, which resulted in the production of 11.13 g L−1 xylonic acid from 10 g L−1 xylose. The results show that Z. mobilis may be regarded as a potential platform for the production of organic acids from cheap lignocellulosic biomass in the context of biorefineries

Draft genome sequence of FT9, a novel Bacillus cereus strain isolated from a Brazilian Thermal Spring

O presente trabalho trata das bactérias formadoras da esporos, incluindo um patógeno presente na intoxicação alimentar e sistêmica e em infecções locais, trazendo uma sequência do genoma FT9