Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Protein & Cell ; (12): 102-119, 2022.
Artigo em Inglês | WPRIM | ID: wpr-922497

RESUMO

The use of two inhibitors of Mek1/2 and Gsk3β (2i) promotes the generation of mouse diploid and haploid embryonic stem cells (ESCs) from the inner cell mass of biparental and uniparental blastocysts, respectively. However, a system enabling long-term maintenance of imprints in ESCs has proven challenging. Here, we report that the use of a two-step a2i (alternative two inhibitors of Src and Gsk3β, TSa2i) derivation/culture protocol results in the establishment of androgenetic haploid ESCs (AG-haESCs) with stable DNA methylation at paternal DMRs (differentially DNA methylated regions) up to passage 60 that can efficiently support generating mice upon oocyte injection. We also show coexistence of H3K9me3 marks and ZFP57 bindings with intact DMR methylations. Furthermore, we demonstrate that TSa2i-treated AG-haESCs are a heterogeneous cell population regarding paternal DMR methylation. Strikingly, AG-haESCs with late passages display increased paternal-DMR methylations and improved developmental potential compared to early-passage cells, in part through the enhanced proliferation of H19-DMR hypermethylated cells. Together, we establish AG-haESCs that can long-term maintain paternal imprints.

2.
Ciênc. rural (Online) ; 51(7): e20200627, 2021. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1249540

RESUMO

ABSTRACT: This study evaluated the viability of Nellore cloned calves derived from somatic cell nuclear transfer (SCNT) and compare their viability with animals of the same breed derived from in vitro fertilization (IVF). Thus, two groups were formed. Group I (GI) consisted of 10 calves derived from SCNT and group II (GII) consisted of 10 calves derived from IVF. The differences detected between the groups were in the physical examination of the respiratory tract in GI, which represented the most common clinical-pathological disturbances. The Apgar index score indicated that 80% of GI animals were depressed and all had pale mucous membranes. Thus, anemia was reported in GI. In GII, this started at 12 h of life and was probably caused by an iron deficiency. Moreover, total calcium and ionized calcium levels were higher in GI immediately after birth. These alterations probably resulted in a high incidence of mortality in GI, reaching 90% of the calves, whereas mortality was only 20% for the calves in GII. In conclusion, cloned calves, which were derived from SCNT, had physiological and metabolic alterations after delivery, leading to a higher mortality rate during the perinatal period.


RESUMO: O objetivo deste trabalho foi avaliar a viabilidade de bezerros da raça Nelore oriundos da técnica da transferência nuclear de células somáticas (TNCS), no período pós natal imediato, comparando-a com animais desta mesma raça, oriundos de fertilização in vitro (FIV). Para tanto, os animais foram alocados em dois grupos, a saber: Grupo I (GI) - 10 animais frutos de TNCS; e, Grupo II (GII) - 10 animais oriundos de FIV. Nos respectivos bezerros, todos obtidos por cesariana, foram realizadas as avaliações físicas, escore de APGAR, bem como coleta de amostras de sangue nos momentos 0 (ao nascimento), às 2, 4, 6 e 12 horas de vida, a fim de avaliar os resultados de eritrograma, análises bioquímicas e hormonais, comparando-os entre os grupos e momentos. Nos animais que vieram a óbito foi realizada a necropsia para investigar a causa mortis. As diferenças observadas foram em relação aos achados clínico-patológicos, envolvendo, principalmente, o sistema respiratório caracterizado por bradpneia associada à dispneia, e a presença de edema e atelectasia pulmonar observadas no GI. Ademais, após a colostragem notou-se que 80% dos animais avaliados não foram capazes de manter a glicemia sendo mais evidentes nos animais do GII, possivelmente devido à hiperinsulinemia que se manifestou neste grupo ao longo de todo o período experimental. A anemia após o nascimento foi evidente no grupo de bezerros clonados ao longo de todo período de avaliação ao contrário dos bezerros oriundos de GII, a qual foi observada somente às 12 horas de vida, sendo, possivelmente, de origem ferropriva. Casos de hipercalcemia foram denotados nos animais do GI ao nascimento, sendo possivelmente associados à asfixia perinatal. Estas alterações, em conjunto, levaram a uma taxa de mortalidade de 90% dos animais do GI e de 20% dos bezerros do GII. Conclui-se que os animais oriundos da TNCS apresentam alterações fisiológicas e metabólicas após o nascimento, responsáveis, em grande parte, pela maior taxa de óbitos dentro do período perinatal.

3.
Artigo | IMSEAR | ID: sea-195743

RESUMO

The term animal cloning refers to an asexual mean of reproduction to produce genetically identical copies of any animal without the use of sperm. In India, the cloning of buffalo is well established and clones of the Murrah, the best dairy breed of buffalo, have been produced. The most acclaimed example is the restoration of progeny-tested breeding bull by isolating somatic cells from frozen doses of semen, which were stored for more than a decade in the semen bank. Buffalo bull cloning is considered the best available option to reproduce declared proven bulls and their semen would contribute to accomplishing the demand of ever-growing frozen semen, which is the prime requirement of conventional breeding. This article highlights the importance of buffalo bull cloning and its current status in India.

4.
Artigo | IMSEAR | ID: sea-195742

RESUMO

The reproductive cloning in buffalo in India has been started using a simplified somatic cell nuclear transfer technique named handmade cloning. Since the birth of first cloned female buffalo in 2009, a number of buffalo clones have been produced in India by utilizing different types of donor cells such as ear cells, embryonic stem cells, semen somatic cells and urine somatic cells. The use of buffalo cloning on a large scale is restricted due to low pregnancy rates and poor calf survival. Considerable attempts have been made to improve the overall buffalo cloning efficiency, particularly by modifying epigenetic reprogramming of cloned embryos. Previous studies have demonstrated that chemical epigenetic modifiers such as trichostatin A and 5-aza-2'-deoxycytidine, m-carboxycinnamic acid bishydroxamide can be used to treat donor somatic cells and reconstructed fused embryos to correct the epigenetic reprogramming to enhance the overall cloning efficiency in terms of live birth rates.

5.
The Malaysian Journal of Pathology ; : 1-15, 2017.
Artigo em Inglês | WPRIM | ID: wpr-630950

RESUMO

The human oral microbiome has been known to show strong association with various oral diseases including oral cancer. This study attempts to characterize the community variations between normal, oral potentially malignant disorders (OPMD) and cancer associated microbiota using 16S rDNA sequencing. Swab samples were collected from three groups (normal, OPMD and oral cancer) with nine subjects from each group. Bacteria genomic DNA was isolated in which full length 16S rDNA were amplified and used for cloned library sequencing. 16S rDNA sequences were processed and analysed with MOTHUR. A core oral microbiome was identified consisting of Firmicutes, Proteobacteria, Fusobacteria, Bacteroidetes and Actinobacteria at the phylum level while Streptococcus, Veillonella, Gemella, Granulicatella, Neisseria, Haemophilus, Selenomonas, Fusobacterium, Leptotrichia, Prevotella, Porphyromonas and Lachnoanaerobaculum were detected at the genus level. Firmicutes and Streptococcus were the predominant phylum and genus respectively. Potential oral microbiome memberships unique to normal, OPMD and oral cancer oral cavities were also identified. Analysis of Molecular Variance (AMOVA) showed a significant difference between the normal and the cancer associated oral microbiota but not between the OPMD and the other two groups. However, 2D NMDS showed an overlapping of the OPMD associated oral microbiome between the normal and cancer groups. These findings indicated that oral microbes could be potential biomarkers to distinguish between normal, OPMD and cancer subjects.

6.
Journal of Veterinary Science ; : 563-567, 2016.
Artigo em Inglês | WPRIM | ID: wpr-167761

RESUMO

Somatic cell nuclear transfer allows generation of genetically identical animals using donor cells derived from animals with particular traits. To date, few studies have investigated whether or not these cloned dogs will show identical behavior patterns. To address this question, learning, memory and exploratory patterns were examined using six cloned dogs with identical nuclear genomes. The variance of total incorrect choice number in the Y-maze test among cloned dogs was significantly lower than that of the control dogs. There was also a significant decrease in variance in the level of exploratory activity in the open fields test compared to age-matched control dogs. These results indicate that cloned dogs show similar cognitive and exploratory patterns, suggesting that these behavioral phenotypes are related to the genotypes of the individuals.


Assuntos
Animais , Cães , Humanos , Células Clonais , Genoma , Genótipo , Aprendizagem , Memória , Fenótipo , Doadores de Tecidos
7.
Journal of Veterinary Science ; : 407-411, 2016.
Artigo em Inglês | WPRIM | ID: wpr-148726

RESUMO

In 2007, seven detector dogs were produced by somatic cell nuclear transfer using one nuclear donor dog, then trained and certified as excellent detector dogs, similar to their donor. In 2011, we crossed a cloned male and normal female by natural breeding and produced ten offspring. In this study, we investigated the puppies' temperaments, which we later compared with those of the cloned parent male. The results show that the cloned male had normal reproductive abilities and produced healthy offspring. All puppies completed narcotic detector dog training with a success rate for selection of 60%. Although the litter of cloned males was small in this study, a cloned male dog bred by natural mating produced puppies that later successfully completed the training course for drug detection. In conclusion, cloning an elite dog with superior genetic factors and breeding of the cloned dog was found to be a useful method to efficiently procure detector dogs.


Assuntos
Animais , Cães , Feminino , Humanos , Masculino , Cruzamento , Células Clonais , Clonagem de Organismos , Métodos , Pais , Temperamento , Doadores de Tecidos
8.
Journal of Veterinary Science ; : 89-96, 2016.
Artigo em Inglês | WPRIM | ID: wpr-110761

RESUMO

Recent developments in genome editing technology using meganucleases demonstrate an efficient method of producing gene edited pigs. In this study, we examined the effectiveness of the transcription activator-like effector nuclease (TALEN) system in generating specific mutations on the pig genome. Specific TALEN was designed to induce a double-strand break on exon 9 of the porcine α1,3-galactosyltransferase (GGTA1) gene as it is the main cause of hyperacute rejection after xenotransplantation. Human decay-accelerating factor (hDAF) gene, which can produce a complement inhibitor to protect cells from complement attack after xenotransplantation, was also integrated into the genome simultaneously. Plasmids coding for the TALEN pair and hDAF gene were transfected into porcine cells by electroporation to disrupt the porcine GGTA1 gene and express hDAF. The transfected cells were then sorted using a biotin-labeled IB4 lectin attached to magnetic beads to obtain GGTA1 deficient cells. As a result, we established GGTA1 knockout (KO) cell lines with biallelic modification (35.0%) and GGTA1 KO cell lines expressing hDAF (13.0%). When these cells were used for somatic cell nuclear transfer, we successfully obtained live GGTA1 KO pigs expressing hDAF. Our results demonstrate that TALEN-mediated genome editing is efficient and can be successfully used to generate gene edited pigs.


Assuntos
Animais , Humanos , Antígenos CD55/genética , Linhagem Celular , Quebras de DNA de Cadeia Dupla , Éxons/genética , Galactosiltransferases/genética , Edição de Genes/veterinária , Técnicas de Inativação de Genes , Técnicas de Transferência Nuclear , Suínos , Nucleases dos Efetores Semelhantes a Ativadores de Transcrição/genética
9.
Journal of Veterinary Science ; : 509-516, 2015.
Artigo em Inglês | WPRIM | ID: wpr-207353

RESUMO

Transvaginal ultrasound-guided follicle aspiration is one method of obtaining recipient oocytes for equine somatic cell nuclear transfer (SCNT). This study was conducted: (1) to evaluate the possibility of oocyte aspiration from pre-ovulatory follicles using a short disposable needle system (14-G) by comparing the oocyte recovery rate with that of a long double lumen needle (12-G); (2) to investigate the developmental competence of recovered oocytes after SCNT and embryo transfer. The recovery rates with the short disposable needle vs. the long needle were not significantly different (47.5% and 35.0%, respectively). Twenty-six SCNT embryos were transferred to 13 mares, and one mare delivered a live offspring at Day 342. There was a perfect identity match between the cloned foal and the cell donor after analysis of microsatellite DNA, and the mitochondrial DNA of the cloned foal was identical with that of the oocyte donor. These results demonstrated that the short disposable needle system can be used to recover oocytes to use as cytoplasts for SCNT, in the production of cloned foals and for other applications in equine embryology


Assuntos
Humanos , Células Clonais , DNA , DNA Mitocondrial , Transferência Embrionária , Embriologia , Estruturas Embrionárias , Cavalos , Competência Mental , Repetições de Microssatélites , Agulhas , Recuperação de Oócitos , Oócitos , Doadores de Tecidos
10.
Journal of Veterinary Science ; : 241-244, 2015.
Artigo em Inglês | WPRIM | ID: wpr-86392

RESUMO

Somatic cell nuclear transfer (SCNT) is a cost-effective technique for producing transgenic pigs. However, abnormalities in the cloned pigs might prevent use these animals for clinical applications or disease modeling. In the present study, we generated several cloned pigs. One of the pigs was found to have intrapancreatic ectopic splenic tissue during histopathology analysis although this animal was grossly normal and genetically identical to the other cloned pigs. Ectopic splenic tissue in the pancreas is very rare, especially in animals. To the best of our knowledge, this is the first such report for cloned pigs.


Assuntos
Animais , Animais Geneticamente Modificados , Coristoma/patologia , Clonagem de Organismos , Técnicas de Transferência Nuclear/veterinária , Pâncreas , Esplenopatias/patologia , Suínos , Doenças dos Suínos/patologia , Porco Miniatura
11.
Journal of Veterinary Science ; : 405-407, 2011.
Artigo em Inglês | WPRIM | ID: wpr-186139

RESUMO

Recently, the world's first transgenic dogs were produced by somatic cell nuclear transfer. However, cellular senescence is a major limiting factor for producing more advanced transgenic dogs. To overcome this obstacle, we rejuvenated transgenic cells using a re-cloning technique. Fibroblasts from post-mortem red fluorescent protein (RFP) dog were reconstructed with in vivo matured oocytes and transferred into 10 surrogate dogs. One puppy was produced and confirmed as a re-cloned dog. Although the puppy was lost during birth, we successfully established a rejuvenated fibroblast cell line from this animal. The cell line was found to stably express RFP and is ready for additional genetic modification.


Assuntos
Animais , Feminino , Masculino , Animais Geneticamente Modificados , Clonagem de Organismos/métodos , Cães/genética , Trato Gastrointestinal/metabolismo , Regulação da Expressão Gênica , Rim/metabolismo , Fígado/metabolismo , Proteínas Luminescentes/genética , Pulmão/metabolismo , Miocárdio/metabolismo , Técnicas de Transferência Nuclear/veterinária , Baço/metabolismo , Traqueia/metabolismo
12.
Journal of Veterinary Science ; : 83-89, 2011.
Artigo em Inglês | WPRIM | ID: wpr-47185

RESUMO

Somatic cell nuclear transfer (SCNT) is considered to be a critical tool for propagating valuable animals. To determine the productivity calves resulting from embryos derived with different culture media, enucleated oocytes matured in vitro were reconstructed with fetal fibroblasts, fused, and activated. The cloned embryos were cultured in modified synthetic oviduct fluid (mSOF) or a chemically defined medium (CDM) and developmental competence was monitored. After 7 days of culturing, the blastocysts were transferred into the uterine horn of estrus-synchronized recipients. SCNT embryos that were cultured in mSOF or CDM developed to the blastocysts stages at similar rates (26.6% vs. 22.5%, respectively). A total of 67 preimplantational stage embryos were transferred into 34 recipients and six cloned calves were born by caesarean section, or assisted or natural delivery. Survival of transferred blastocysts to live cloned calves in the mSOF and the CDM was 18.5% (to recipients), 9.6% (to blastocysts) and 42.9% (to recipients), 20.0% (to blastocysts), respectively. DNA analysis showed that all cloned calves were genetically identical to the donor cells. These results demonstrate that SCNT embryos cultured in CDM showed higher viability as judged by survival of the calves that came to term compared to blastocysts derived from mSOF cultures.


Assuntos
Animais , Bovinos , Feminino , Gravidez , Blastocisto/fisiologia , Clonagem de Organismos/métodos , Meios de Cultura/química , Técnicas de Cultura Embrionária , Transferência Embrionária , Desenvolvimento Embrionário , Fertilização in vitro/veterinária , Técnicas de Transferência Nuclear/veterinária
13.
Braz. j. vet. res. anim. sci ; 47(6): 447-453, 2010. ilus
Artigo em Português | LILACS | ID: lil-589857

RESUMO

Os mecanismos de morte em animais clonados a partir de células somáticas são poucos elucidados. Malformações de órgãos, alterações de tamanho e peso desses animais foram anomalias já descritas, porém em casos isolados. Desse modo, estudos nos níveis anátomo e histopatológicos são de suma importância para ajudar a compreensão dos fatores responsáveis pelos altos índices de insucessos com a utilização da TNCS (transferência nuclear de células somáticas). Assim, o presente trabalho foi realizado com o objetivo de descrever, por meio de exames anatomopatológicos, as alterações presentes em um grupo de animais gerados por TNCS, que vieram a óbito entre 1 e 19 dias de vida. Esse experimento foi realizado entre os anos de 2004 e 2008 na fazenda Tambaú, cidade de Tambaú, Estado de São Paulo. No total foram gerados 21 animais da raça Nelore (Bos indicus), sendo que 11 vieram a óbito e dez apresentaram boa evolução clínica no período perinatal. Foram realizadas as necropsias dos animais e posterior análise histopatológica de tecidos alterados. Esse estudo mostrou alta prevalência de alterações cardiopulmonares, que provavelmente foram determinantes nos mecanismos de morte dos animais. Dentre essas alterações a hipertensão pulmonar e modificações hemodinâmicas diagnosticadas através do exame histopatológico foram as mais frequentes.


The death mechanisms in cloned animals are not well elucidated. There are few cases describing organ malformation, size and weight alterations in these animals. Pathologic studies are necessary to understand the high level of unsuccessful results using the NTSC (nuclear transfer somatic cell) technique. The present study was carried out to describe alterations present in a group of animals generated by NTSC technique that deceased between 0 to 19 days of life, using anatomopathologic examination. This experiment was conducted at Tambaú Farm in São Paulo State between years 2004 and 2008. Initially there were twenty one Nelore breed Bos indicus animals, but 11 of them deceased and ten survived and showed satisfactory clinical evolution in perinatal period. Animals necropsies and histopathologic analyses where performed. The results revealed a high prevalence of cardiopulmonary alterations, which were predominantly lung hypertension and hemodynamic profile changes, revealed by histopathologic analyses.


Assuntos
Animais , Bovinos , Bovinos , Patologia , Técnicas de Transferência Nuclear/veterinária
14.
Pesqui. vet. bras ; 29(10): 779-787, out. 2009. ilus
Artigo em Português | LILACS | ID: lil-537583

RESUMO

O objetivo deste trabalho foi comparar as fusões carunculares em gestações de conceptos não clonados (CNC) e conceptos clonados (CC). Os CNC foram divididos segundo o período de gestação em Grupo I (2-3 meses, n=9), Grupo II (4-6 meses, n=9), Grupo III (7-8 meses, n=10) e Grupo IV (9 meses, n=7). Os CC formaram o Grupo V (9 meses, n=4). As carúnculas foram observadas macroscopicamente (número e dimensões: comprimento, largura e altura), microscopicamente e submetidas à análise estatística (5 por cento de significância). Observaram-se três tipos de fusões carunculares macroscópicas: ovais (morfologicamente normais); duas carúnculas adjacentes unidas e do tipo lobuladas, caracterizadas por regiões com várias carúnculas unidas apresentando falsa fusão ou deformação do parênquima caruncular. O comprimento das carúnculas foi de 1,55±0,57; 2,45±0,55; 4,66±2,00 e 5,72±1,90cm para os Grupos I, II, III e IV, respectivamente. Quanto à altura, as carúnculas apresentaram um crescimento linear durante a gestação e foram de 0,40±0,15; 0;57±0,21; 1,00±0,48 e 1,80±0,91cm, para os respectivos Grupos I, II, III e IV. A largura das carúnculas foi semelhante entre os Grupos I e II (0,97±0,30 e 1,42±0,71cm) e os Grupos III e IV (2,68±1,22 e 3,52±1,16cm). Quando o Grupo V foi comparado ao Grupo IV, as carúnculas do Grupo V apresentaram maior comprimento (5,72±1,90 vs. 7,88±2,13cm) e largura (3,52±1,16 vs. 4,93±1,46cm), porém foram semelhantes em altura (1,80±0,91 e 2,25±0,67cm). Verificou-se que em gestações de CC, as carúnculas apresentaram maior desenvolvimento que em gestações de CNC. As carúnculas fusionadas apresentaram medidas estatisticamente semelhantes às isoladas em todos os parâmetros e grupos. Sob microscopia de luz, observou-se a formação de um eixo estromal, da base da carúncula ao ápice da fissura fusional, de constituição histológica semelhante ao estroma endometrial. Também foram ineditamente definidos três formatos microscópicos: fusão propriamente ...


The objective of the study was to compare the characteristics of the caruncular fusion in gestations of non-cloned and cloned conceptuses. The non-cloned conceptuses were divided according to the gestation period: Group I (2 to 3 months; n=9), II (4 to 6; n=9); III (7 to 8; n=10) and IV (9 n=7). The cloned conceptuses formed the Group V: 9 months; n=4. The caruncles were observed macroscopically (number and dimensions: length, width and height), microscopically and submitted to statistical analysis (5 percent of significance). We observed three types of macroscopic caruncular fusions: oval (morphologically normal); two united adjacent caruncles and the lobulated type, characterized by regions with several united caruncles presenting a false fusion or deformation of the caruncular parenchyma. The length of the caruncles was 1.55±0.57; 2.45±0.55; 4.66±2.0 and 5.72±1.90cm for the groups I, II, III, IV respectively. As for the height, the caruncles presented a lineal growth during the gestation: 0.40±0.15; 0.57±0.21; 1.0±0.48 and 1.80±0.91cm, for the respective groups I, II, III and IV. The width of the caruncles was similar between the groups I and II (0.97±0.30 e 1.42±0.71cm) and the groups III and IV (2.68±1.22 and 3.52±1.16cm). When the group V was compared to the IV, the caruncles of the group V presented a larger length (5.72±1.90 vs. 7.88±.13cm) and width (3.52±1.16 vs. 4.93±1.46cm), however they were similar in height (1.80±0.91 and 2.25±0.67cm). We verified that in gestations of cloned conceptuses the caruncles presented a larger development than in gestations of non-cloned conceptuses. The fusioned caruncles presented measurements statistically similar to the isolated ones in all the parameters and groups. Under light microscopy, we observed the formation of a stromal axis from the basis of the caruncle to the apex of the fusional fissure, with the histological constitution similar to the endometrial stroma. Three microscopic shapes ...


Assuntos
Animais , Feminino , Gravidez , Bovinos , Clonagem de Organismos/veterinária , Placenta/anatomia & histologia , Placenta/anormalidades , Placenta/crescimento & desenvolvimento , Placenta/embriologia , Bovinos/embriologia , Desenvolvimento Fetal
15.
Journal of Veterinary Science ; : 243-245, 2005.
Artigo em Inglês | WPRIM | ID: wpr-128171

RESUMO

Inbred strains of pig become indispensable for a wide range of biological studies. In biomedical science, it is generally accepted that somatic cell nuclear transfer(SCNT)technology with inbreed strain of pig is essential for xenotransplantation. In this study, we observed the anal atresia in a cloned pig which was derived from fetal fibroblast of inbreed miniature pig. A presumptive anal site of the cloned pig was excised and the rectum was sutured to apposed skin for treatment. This cloned piglet seemed to be normal with healthy status after surgery. This report can be useful for the treatment of anal atresia of cloned piglets.


Assuntos
Animais , Feminino , Animais Geneticamente Modificados/cirurgia , Anus Imperfurado/genética , Clonagem de Organismos , Predisposição Genética para Doença , Suínos/anormalidades
16.
Journal of Pharmaceutical Analysis ; (6): 104-107, 2000.
Artigo em Chinês | WPRIM | ID: wpr-621842

RESUMO

ObjectiveTo test what length is needed for polyamine binding both intrinsic gate and pore docking site to block the cloned strong inwardly rectifying channel (Kir2. 1 channel). Methods The effect of alkylamine analogues (DA 5, DA 8, DA 10 and DA 12) and the competitive interaction of polyamine toxin, philanthotoxin (PhTx), on expressed Kir 2. 1channel in Xenopus oocytes were examined by using giant excised inside-out patch-clamp technique. ResultsThe results showed that along with the increase of the length of DAs ,the value of Kd decreased and the high affinity binding increased gradually. However,PhTx had the strongest effect on interfering the DA10 binding between intrinsic gate and pore docking site and had a less effect on DA12. Conclusion DA10 may be the right length for polyamine to block the channel. And maybe there is a hydrophobic interaction between DA12 and C-terminal domain of this channel, which then stabilize the DA12 binding between these two points and decrease the effect of PhTx on DA12.

17.
Chinese Medical Ethics ; (6)1995.
Artigo em Chinês | WPRIM | ID: wpr-521445

RESUMO

cloned human have been put forward from gestation to practice study,but the cloning will face many problems about society ,ethic and law,such as family,prepotency or low birth,social identity,population etc.All should be solved by the means of the social control including morality policy and law,etc.

18.
Journal of Environment and Health ; (12)1993.
Artigo em Chinês | WPRIM | ID: wpr-536430

RESUMO

During the last decade a lot of new learning about asthma was arisen along with the development of modern immunology and molecular biology,and asthma had been one hotspot in the studies of molecular biological and administer medical field.One of the new viewpoints was that airway neurogenic inflammation took important role in asthma development.For years scholars had suspected that airborne pollutants had an synergistic effect on the attack of asthma and could cause asthma attack,but they did not know the molecular mechanism.In 1991 Denish scholar Nielsen GD advanced a new hypothesis that airway irritation was mediated by capsaicin receptor.The pathological process included a molecular chain of message transfer as air pollutants_capsaicin receptor_Ca2+_substance P_neurokinin receptor.Airway neurogenic inflammation was the result of activation of the receptors.In 1997 American scholar Caterina MJ and his colleagues successfully obtained the cloned capsaicin receptor in expressing cells,this will make Nielsen GD's hypothesis living.

19.
J Biosci ; 1986 June; 10(2): 277-281
Artigo em Inglês | IMSEAR | ID: sea-160642

RESUMO

Two Escherichia coli clones expressing Mycobacterium tuberculosis antigens were isolated from a gene-bank in the plasmid vector pBR 325. 'Western blot' analysis revealed the presence of a unique protein band of molecular weight 68,000 and 38,000, respectively in cellextracts from each clone. The 68,000 dalton antigen was found to be expressed on Escherichia coli outer surface. Plasmid DNA from a third clone could confer leucine independence on two different leu Β mutants of Escherichia coli but not on mutants in other leu genes, pointing to the possibility ofgenetic complementation. Thus, Mycobacterium tuberculosis DNA is capable of expression in Escherichia coli.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA