Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300007
M. Reigosa, S. Soloneski, C. F. Garcia, M. Larramendy
Foi estudado o efeito de co-culturas com concentracoes variadas de celulas sanguineas vermelhas (RBCs) suinas e humanas na frequencia basal de trocas de cromatides irmas (SCEs) e na progressao do ciclo celular em culturas de plasma de porco (PLCs) e culturas leucocitarias do sangue total (WBCs). Nao foi observada nenhuma variacao na frequencias de SCEs entre os controles de WBC e PLC em porcos. A adicao de RBCs de suinos e humanos a PLCs nao modificou a frequencia basal de SCEs. Por outro lado, a proliferacao celular foi mais lenta em PLCs que em WBCs. A adicao de RBCs humanas ou suinas a PLCs acelerou a progressao do ciclo celular de linfocitos suinos. Quando RBCs foram adicionadas a PLCs, a concentracao e a sequencia temporal da incorporacao de RBC afetaram a progressao do ciclo celular de linfocitos suinos. Quando adicionadas doses de RBCs suinas ou humanas equivalentes aquelas presentes em WBCs, imediatamente apos estimulacao da PLC, a cinetica do ciclo celular foi similar a das WBCs. Periodos mais curtos de co-incubacao ou uma reducao na dose de RBCs causaram uma progressao do ciclo celular intermediaria entre os valores de PLCs e WBCs. Assim, RBCs suinas e humanas modularam a progressao do ciclo celular in vitro de linfocitos suinos em uma maneira dependente da dose e do tempo, e a frequencia basal baixa de SCEs de linfocitos suinos independe da presenca ou nao de eritrocitos na cultura
{"title":"Erythrocytes modulate cell cycle progression but not the baseline frequency of sister chromatid exchanges in pig lymphocytes","authors":"M. Reigosa, S. Soloneski, C. F. Garcia, M. Larramendy","doi":"10.1590/S0100-84551997000300007","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300007","url":null,"abstract":"Foi estudado o efeito de co-culturas com concentracoes variadas de celulas sanguineas vermelhas (RBCs) suinas e humanas na frequencia basal de trocas de cromatides irmas (SCEs) e na progressao do ciclo celular em culturas de plasma de porco (PLCs) e culturas leucocitarias do sangue total (WBCs). Nao foi observada nenhuma variacao na frequencias de SCEs entre os controles de WBC e PLC em porcos. A adicao de RBCs de suinos e humanos a PLCs nao modificou a frequencia basal de SCEs. Por outro lado, a proliferacao celular foi mais lenta em PLCs que em WBCs. A adicao de RBCs humanas ou suinas a PLCs acelerou a progressao do ciclo celular de linfocitos suinos. Quando RBCs foram adicionadas a PLCs, a concentracao e a sequencia temporal da incorporacao de RBC afetaram a progressao do ciclo celular de linfocitos suinos. Quando adicionadas doses de RBCs suinas ou humanas equivalentes aquelas presentes em WBCs, imediatamente apos estimulacao da PLC, a cinetica do ciclo celular foi similar a das WBCs. Periodos mais curtos de co-incubacao ou uma reducao na dose de RBCs causaram uma progressao do ciclo celular intermediaria entre os valores de PLCs e WBCs. Assim, RBCs suinas e humanas modularam a progressao do ciclo celular in vitro de linfocitos suinos em uma maneira dependente da dose e do tempo, e a frequencia basal baixa de SCEs de linfocitos suinos independe da presenca ou nao de eritrocitos na cultura","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117250992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300011
A. M. Waldschmidt, T. Salomão, E. G. Barros, L. Campos
O objetivo deste trabalho foi o de testar tres protocolos de extracao de DNA utilizados para Apis, plantas e fungos, visando determinar um que seja eficiente para extracao de DNA de Melipona quadrifasciata. Esses metodos diferem nas concentracoes de componentes especificos do tampao de extracao. Os resultados obtidos mostraram que a metodologia recomendada para extracao de DNA de Apis nao e adequada para a extracao de DNA de M. quadrifasciata. Entretanto, com pequenas modificacoes, este metodo, bem como aquele utilizado para a extracao de DNA de plantas e fungos, mostrou-se eficiente para a extracao de DNA desta abelha sem ferrao, tanto de individuos adultos como de larvas
{"title":"Extraction of genomic DNA from Melipona quadrifasciata (Hymenoptera: Apidae, Meliponinae)","authors":"A. M. Waldschmidt, T. Salomão, E. G. Barros, L. Campos","doi":"10.1590/S0100-84551997000300011","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300011","url":null,"abstract":"O objetivo deste trabalho foi o de testar tres protocolos de extracao de DNA utilizados para Apis, plantas e fungos, visando determinar um que seja eficiente para extracao de DNA de Melipona quadrifasciata. Esses metodos diferem nas concentracoes de componentes especificos do tampao de extracao. Os resultados obtidos mostraram que a metodologia recomendada para extracao de DNA de Apis nao e adequada para a extracao de DNA de M. quadrifasciata. Entretanto, com pequenas modificacoes, este metodo, bem como aquele utilizado para a extracao de DNA de plantas e fungos, mostrou-se eficiente para a extracao de DNA desta abelha sem ferrao, tanto de individuos adultos como de larvas","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121438978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300016
Ana C. Vello Dantas, J. B. M. Filho, M. Alleoni
Foram utilizadas seis variedades de milho braquitico em cruzamento dialelico. As variedades, hibridos e testemunhas (quatro hibridos braquiticos) foram avaliadas em solucao nutritiva em casa de vegetacao em blocos completamente casualizados com tres repeticoes em duas epocas. Os seguintes caracteres foram avaliados 28 dias apos a semeadura: peso total da planta, peso da parte aerea, peso total de raizes, peso de raizes seminais, peso de raizes nodais, numero total de raizes, numero de raizes seminais e numero de raizes nodais. Foram tomadas dez plantas por parcela e todas as analises foram realizadas com medias de parcelas. No esquema dialelico o peso total da planta foi assim distribuido: 57,6% para a parte aerea, 15,4% para raizes seminais e 27,0% para raizes nodais. O numero total de raizes foi assim distribuido: 36,7% para raizes seminais e 63,3% para raizes nodais. Aproximadamente as mesmas relacoes foram observadas para as testemunhas. A heterose media foi muito baixa e nao significante para todos os caracteres. Os outros componentes da heterose (heterose de variedade e heterose especifica) tambem nao se mostraram importantes como fontes de variacao. Os resultados gerais levaram a concluir que a acao genica nao aditiva nao e importante como fonte de variacao para os caracteres da parte aerea e do sistema radicular em plantas jovens. Os coeficientes de correlacao positivos para as combinacoes de caracteres indicam que eles estao em maior ou menor grau sob o controle do mesmo sistema poligenico
{"title":"Diallel cross analysis for young plants of brachytic maize (Zea mays L.) varieties","authors":"Ana C. Vello Dantas, J. B. M. Filho, M. Alleoni","doi":"10.1590/S0100-84551997000300016","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300016","url":null,"abstract":"Foram utilizadas seis variedades de milho braquitico em cruzamento dialelico. As variedades, hibridos e testemunhas (quatro hibridos braquiticos) foram avaliadas em solucao nutritiva em casa de vegetacao em blocos completamente casualizados com tres repeticoes em duas epocas. Os seguintes caracteres foram avaliados 28 dias apos a semeadura: peso total da planta, peso da parte aerea, peso total de raizes, peso de raizes seminais, peso de raizes nodais, numero total de raizes, numero de raizes seminais e numero de raizes nodais. Foram tomadas dez plantas por parcela e todas as analises foram realizadas com medias de parcelas. No esquema dialelico o peso total da planta foi assim distribuido: 57,6% para a parte aerea, 15,4% para raizes seminais e 27,0% para raizes nodais. O numero total de raizes foi assim distribuido: 36,7% para raizes seminais e 63,3% para raizes nodais. Aproximadamente as mesmas relacoes foram observadas para as testemunhas. A heterose media foi muito baixa e nao significante para todos os caracteres. Os outros componentes da heterose (heterose de variedade e heterose especifica) tambem nao se mostraram importantes como fontes de variacao. Os resultados gerais levaram a concluir que a acao genica nao aditiva nao e importante como fonte de variacao para os caracteres da parte aerea e do sistema radicular em plantas jovens. Os coeficientes de correlacao positivos para as combinacoes de caracteres indicam que eles estao em maior ou menor grau sob o controle do mesmo sistema poligenico","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121445623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300012
M. Pastori, A. Fenocchio, P. A. López
Thirty-six specimens of Schizodon nasutus (Anostomidae-Characiformes) from the middle Parana River (Posadas, Argentina) were analyzed cytogenetically. The karyotype of this species was similar to those described for this species in the literature. C-banding technique showed a rich heterochromatic pattern relative to other Anostomidae species. The NORs were located on one chromosome pair in terminal position and showed a very marked size heteromorphism. A microchromosome was observed with a frequency of about 20% in the sample studied. This additional element was punctiform, negative C-band, and constant in all metaphase plates of the seven carriers. The present study is the first karyotypic approach to Schizodon nasutus from Argentina and the first description of microchromosome in Anostomidae
{"title":"First description of microchromosome in the Anostomidae fish Schizodon nasutus from Argentina","authors":"M. Pastori, A. Fenocchio, P. A. López","doi":"10.1590/S0100-84551997000300012","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300012","url":null,"abstract":"Thirty-six specimens of Schizodon nasutus (Anostomidae-Characiformes) from the middle Parana River (Posadas, Argentina) were analyzed cytogenetically. The karyotype of this species was similar to those described for this species in the literature. C-banding technique showed a rich heterochromatic pattern relative to other Anostomidae species. The NORs were located on one chromosome pair in terminal position and showed a very marked size heteromorphism. A microchromosome was observed with a frequency of about 20% in the sample studied. This additional element was punctiform, negative C-band, and constant in all metaphase plates of the seven carriers. The present study is the first karyotypic approach to Schizodon nasutus from Argentina and the first description of microchromosome in Anostomidae","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121462745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300017
G. A. Torres, S. N. Parentoni, M. A. Lopes, E. Paíva
The objective of this study was to identify restriction fragment length polymorphism (RFLP) markers linked to QTLs that control aluminum (Al) tolerance in maize. The strategy used was bulked segregant analysis (BSA) and the genetic material utilized was an F2 population derived from a cross between the Al-susceptible inbred line L53 and Al-tolerant inbred line L1327. Both lines were developed at the National Maize and Sorghum Research Center - CNPMS/EMBRAPA. The F2 population of 1554 individuals was evaluated in a nutrient solution containing a toxic concentration of Al and relative seminal root length (RSRL) was used as a phenotypic measure of tolerance. The RSRL frequency distribution was continuous, but skewed towards Al-susceptible individuals. Seedlings of the F2 population which scored the highest and the lowest RSRL values were transplanted to the field and subsequently selfed to obtain F3 families. Thirty F3 families (15 Al-susceptible and 15 Al-tolerant) were evaluated in nutrient solution, using an incomplete block design, to identify those with the smallest variances for aluminum tolerance and susceptibility. Six Al-susceptible and five Al-tolerant F3 families were chosen to construct one pool of Al-susceptible individuals, and another of Al-tolerant, herein referred as "bulks", based on average values of RSRL and genetic variance. One hundred and thirteen probes were selected, with an average interval of 30 cM, covering the 10 maize chromosomes. These were tested for their ability to discriminate the parental lines. Fifty-four of these probes were polymorphic, with 46 showing codominance. These probes were hybridized with DNA from the two contrasting bulks. Three RFLPs on chromosome 8 distinguished the bulks on the basis of band intensity. DNA of individuals from the bulks was hybridized with these probes and showed the presence of heterozygous individuals in each bulk. These results suggest that in maize there is a region related to aluminum tolerance on chromosome 8
{"title":"A search for RFLP markers to identify genes for aluminum tolerance in maize","authors":"G. A. Torres, S. N. Parentoni, M. A. Lopes, E. Paíva","doi":"10.1590/S0100-84551997000300017","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300017","url":null,"abstract":"The objective of this study was to identify restriction fragment length polymorphism (RFLP) markers linked to QTLs that control aluminum (Al) tolerance in maize. The strategy used was bulked segregant analysis (BSA) and the genetic material utilized was an F2 population derived from a cross between the Al-susceptible inbred line L53 and Al-tolerant inbred line L1327. Both lines were developed at the National Maize and Sorghum Research Center - CNPMS/EMBRAPA. The F2 population of 1554 individuals was evaluated in a nutrient solution containing a toxic concentration of Al and relative seminal root length (RSRL) was used as a phenotypic measure of tolerance. The RSRL frequency distribution was continuous, but skewed towards Al-susceptible individuals. Seedlings of the F2 population which scored the highest and the lowest RSRL values were transplanted to the field and subsequently selfed to obtain F3 families. Thirty F3 families (15 Al-susceptible and 15 Al-tolerant) were evaluated in nutrient solution, using an incomplete block design, to identify those with the smallest variances for aluminum tolerance and susceptibility. Six Al-susceptible and five Al-tolerant F3 families were chosen to construct one pool of Al-susceptible individuals, and another of Al-tolerant, herein referred as \"bulks\", based on average values of RSRL and genetic variance. One hundred and thirteen probes were selected, with an average interval of 30 cM, covering the 10 maize chromosomes. These were tested for their ability to discriminate the parental lines. Fifty-four of these probes were polymorphic, with 46 showing codominance. These probes were hybridized with DNA from the two contrasting bulks. Three RFLPs on chromosome 8 distinguished the bulks on the basis of band intensity. DNA of individuals from the bulks was hybridized with these probes and showed the presence of heterozygous individuals in each bulk. These results suggest that in maize there is a region related to aluminum tolerance on chromosome 8","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126492090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300001
D. Orengo, E. Hauschteck-Jungen, F. Mestres
A line of one-winged Drosophila subobscura was studied. The absent wing is substituted by a bulky structure with macro and microchaetes, showing a thoracic appearance. Genetic crosses showed that there is no way to select for the trait by simple crossing. The number of one-winged flies in the various generations was always low. In one case a wingless fly was also obtained. The trait presents an unknown genetic pattern.
{"title":"One-winged Drosophila subobscura: a phenotype with an obscure genetic basis","authors":"D. Orengo, E. Hauschteck-Jungen, F. Mestres","doi":"10.1590/S0100-84551997000300001","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300001","url":null,"abstract":"A line of one-winged Drosophila subobscura was studied. The absent wing is substituted by a bulky structure with macro and microchaetes, showing a thoracic appearance. Genetic crosses showed that there is no way to select for the trait by simple crossing. The number of one-winged flies in the various generations was always low. In one case a wingless fly was also obtained. The trait presents an unknown genetic pattern.","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130335327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300005
E. Revaldaves, E. Renesto, M. F. P. S. Machado
The genetic variability of the "curimba", Prochilodus lineatus, from three locations in the Parana river basin, was investigated by starch gel electrophoresis. A total of 160 specimens were analyzed for 19 enzymes, 12 of which permitted successful interpretation of electrophoretic patterns. Eighteen loci were identified and six of them proved to be polymorphic (EST-1*, EST-2*, IDH-1*, PGM-1*, PGM-2*, LDH-2*). Mean heterozygosity was considered high (13%) by comparison with the literature. A low level of differentiation was found among subpopulations, with mean FST = 0.018. Values of genetic distance and genetic identity suggest that, at least along this stretch of the river, P. lineatus comprises a single breed with high gene flow. This analysis has important implications for fishery management, aquaculture, and conservation of the stocks
{"title":"Genetic variability of Prochilodus lineatus (Characiformes, Prochilodontidae) in the upper Paraná river","authors":"E. Revaldaves, E. Renesto, M. F. P. S. Machado","doi":"10.1590/S0100-84551997000300005","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300005","url":null,"abstract":"The genetic variability of the \"curimba\", Prochilodus lineatus, from three locations in the Parana river basin, was investigated by starch gel electrophoresis. A total of 160 specimens were analyzed for 19 enzymes, 12 of which permitted successful interpretation of electrophoretic patterns. Eighteen loci were identified and six of them proved to be polymorphic (EST-1*, EST-2*, IDH-1*, PGM-1*, PGM-2*, LDH-2*). Mean heterozygosity was considered high (13%) by comparison with the literature. A low level of differentiation was found among subpopulations, with mean FST = 0.018. Values of genetic distance and genetic identity suggest that, at least along this stretch of the river, P. lineatus comprises a single breed with high gene flow. This analysis has important implications for fishery management, aquaculture, and conservation of the stocks","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122813785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300022
D. F. Ferreira, G. S. P. Rezende
Exact correlation coefficients between a canonical variate and measured traits were derived to evaluate genetic divergence among varieties. This method allows the plant breeder to determine which traits contribute significantly to genetic divergence and, also, to identify the most important among them. An example is presented, related to a trial where 28 varieties of maize were evaluated for two traits
{"title":"Use of canonical variates in genetic divergence studies","authors":"D. F. Ferreira, G. S. P. Rezende","doi":"10.1590/S0100-84551997000300022","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300022","url":null,"abstract":"Exact correlation coefficients between a canonical variate and measured traits were derived to evaluate genetic divergence among varieties. This method allows the plant breeder to determine which traits contribute significantly to genetic divergence and, also, to identify the most important among them. An example is presented, related to a trial where 28 varieties of maize were evaluated for two traits","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127503296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300009
C. Grisolia, Í. Ferrari
O herbicida metolachlor foi avaliado quanto ao seu potencial genotoxico. Em camundongos nao houve inducao de micronucleos nos eritrocitos policromaticos de medula ossea; entretanto, com a dose mais forte de 40 mg/kg peso por 48 h, observaram-se efeitos citotoxicos atraves da queda acentuada na porcentagem de eritrocitos policromaticos em relacao aos normocromaticos. O metolachlor tambem nao induziu aberracoes cromossomicas em linfocitos humanos quando tratados in vitro, porem na concentracao de 2,0 mg/ml de meio ocorreu queda no indice mitotico, demonstrando a toxidez do tratamento. Para se estudar os efeitos genotoxicos de possiveis metabolitos do metolachlor, ratos Wistar foram tratados com duas doses de 50 mg/kg com um intervalo de 24 h. Uma hora apos o ultimo tratamento, seus plasmas foram coletados atraves de puncao cardiaca e adicionados as culturas de linfocitos humanos. Os resultados tambem demonstraram efeitos citotoxicos mas nao de mutagenicidade
{"title":"In vitro and in vivo studies demonstrate non-mutagenicity of the herbicide metolachlor","authors":"C. Grisolia, Í. Ferrari","doi":"10.1590/S0100-84551997000300009","DOIUrl":"https://doi.org/10.1590/S0100-84551997000300009","url":null,"abstract":"O herbicida metolachlor foi avaliado quanto ao seu potencial genotoxico. Em camundongos nao houve inducao de micronucleos nos eritrocitos policromaticos de medula ossea; entretanto, com a dose mais forte de 40 mg/kg peso por 48 h, observaram-se efeitos citotoxicos atraves da queda acentuada na porcentagem de eritrocitos policromaticos em relacao aos normocromaticos. O metolachlor tambem nao induziu aberracoes cromossomicas em linfocitos humanos quando tratados in vitro, porem na concentracao de 2,0 mg/ml de meio ocorreu queda no indice mitotico, demonstrando a toxidez do tratamento. Para se estudar os efeitos genotoxicos de possiveis metabolitos do metolachlor, ratos Wistar foram tratados com duas doses de 50 mg/kg com um intervalo de 24 h. Uma hora apos o ultimo tratamento, seus plasmas foram coletados atraves de puncao cardiaca e adicionados as culturas de linfocitos humanos. Os resultados tambem demonstraram efeitos citotoxicos mas nao de mutagenicidade","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127915755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1997-09-01DOI: 10.1590/S0100-84551997000300018
M. Grando, M. I. Moraes-Fernandes
This article discusses, from the standpoint of cellular biology, the deterministic and indeterministic androgenesis theories. The role of the vacuole and of various types of stresses on deviation of the microspore from normal development and the point where androgenetic competence is acquired are examined. Based on extensive literature review and data on wheat studies from our laboratory, a model for androgenetic capacity of pollen grain is proposed. A two point deterministic model for in vitro androgenesis is our proposal for acquisition of androgenetic potential of the pollen grain: the first switch point would be early meiosis and the second switch point the uninucleate pollen stage, because the elimination of cytoplasmatic sporophytic determinants takes place at those two strategic moments. Any abnormality in this process allowing the maintenance of sporophytic informational molecules results in the absence of establishment of a gametophytic program, allowing the reactivation of the embryogenic process
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