Pub Date : 1997-12-01DOI: 10.1590/S0100-84551997000400032
C. R. Machado, C. Menck
Several human genetic syndromes have long been recognized to be defective in DNA repair mechanisms. This was first discovered by Cleaver (1968), who showed that cells from patients with xeroderma pigmentosum (XP) were defective for the ability to remove ultraviolet (UV)-induced lesions from their genome. Since then, new discoveries have promoted DNA repair studies to one of the most exciting areas of molecular biology. The present work intends to give a brief summary of the main known human genetic diseases related to DNA repair and how they may be linked to acquired diseases such as cancer
{"title":"Human DNA repair diseases: From genome instability to cancer","authors":"C. R. Machado, C. Menck","doi":"10.1590/S0100-84551997000400032","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400032","url":null,"abstract":"Several human genetic syndromes have long been recognized to be defective in DNA repair mechanisms. This was first discovered by Cleaver (1968), who showed that cells from patients with xeroderma pigmentosum (XP) were defective for the ability to remove ultraviolet (UV)-induced lesions from their genome. Since then, new discoveries have promoted DNA repair studies to one of the most exciting areas of molecular biology. The present work intends to give a brief summary of the main known human genetic diseases related to DNA repair and how they may be linked to acquired diseases such as cancer","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116728373","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400020
J. Viana, C. Cruz
Sao apresentados os estimadores dos coeficientes de sete indices de selecao, que levam em consideracao o valor fenotipico do individuo e o desempenho medio de sua familia, e discute-se o uso destes indices em teste de geracao precoce, no melhoramento de plantas autogamas. Nao ha clara superioridade de nenhum indice, embora alguns apresentem um ou mais aspectos negativos, como favorecer a selecao de planta excepcional em familia de desempenho inferior, em detrimento de planta com desempenho desejavel, em familia superior
{"title":"Combined selection in early generation testing of self-pollinated plants","authors":"J. Viana, C. Cruz","doi":"10.1590/S0100-84551997000400020","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400020","url":null,"abstract":"Sao apresentados os estimadores dos coeficientes de sete indices de selecao, que levam em consideracao o valor fenotipico do individuo e o desempenho medio de sua familia, e discute-se o uso destes indices em teste de geracao precoce, no melhoramento de plantas autogamas. Nao ha clara superioridade de nenhum indice, embora alguns apresentem um ou mais aspectos negativos, como favorecer a selecao de planta excepcional em familia de desempenho inferior, em detrimento de planta com desempenho desejavel, em familia superior","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121940279","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400011
Ivana Camilia da Silva, Marco Antonio Del Lama
Five bovine milk protein polymorphisms were studied in Zebuine cattle raised in Brazil, through horizontal electrophoresis on starch gel containing urea and 2-mercaptoethanol, using basic and acidic buffer systems. Allelic frequencies for a-La, b-Lg, aS1-Cn, b-Cn and k-Cn loci were estimated in six Gyr herds (N = 283), six Guzerat herds (N = 205), one Nelore herd (N = 17) and one Sindi herd (N = 22), all from Sao Paulo or Minas Gerais State, Brazil. Genotypic frequencies observed for each locus and breed studied are in accordance with the assumption of genetic equilibrium, demonstrating absence of high inbreeding levels for the breeds tested. The FST value found indicated significant genetic differentiation among breeds; however, the Gyr and Guzerat herds showed significantly different gene frequencies. Genetic distance estimates among zebuine breeds studied and the Holstein breed, taken as a reference for a taurine breed, showed strong differences between these two racial groups
{"title":"Milk protein polymorphisms in Brazilian Zebu cattle","authors":"Ivana Camilia da Silva, Marco Antonio Del Lama","doi":"10.1590/S0100-84551997000400011","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400011","url":null,"abstract":"Five bovine milk protein polymorphisms were studied in Zebuine cattle raised in Brazil, through horizontal electrophoresis on starch gel containing urea and 2-mercaptoethanol, using basic and acidic buffer systems. Allelic frequencies for a-La, b-Lg, aS1-Cn, b-Cn and k-Cn loci were estimated in six Gyr herds (N = 283), six Guzerat herds (N = 205), one Nelore herd (N = 17) and one Sindi herd (N = 22), all from Sao Paulo or Minas Gerais State, Brazil. Genotypic frequencies observed for each locus and breed studied are in accordance with the assumption of genetic equilibrium, demonstrating absence of high inbreeding levels for the breeds tested. The FST value found indicated significant genetic differentiation among breeds; however, the Gyr and Guzerat herds showed significantly different gene frequencies. Genetic distance estimates among zebuine breeds studied and the Holstein breed, taken as a reference for a taurine breed, showed strong differences between these two racial groups","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126676345","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400027
G. Passos, M. Lefranc
The human immunoglobulin lambda variable locus (IGLV) is mapped at chromosome 22 band q11.1-q11.2. The 30 functional germline v-lambda genes sequenced untill now have been subgrouped into 10 families (Vl1 to Vl10). The number of Vl genes has been estimated at approximately 70. This locus is formed by three gene clusters (VA, VB and VC) that encompass the variable coding genes (V) responsible for the synthesis of lambda-type Ig light chains, and the Jl-Cl cluster with the joining segments and the constant genes. Recently the entire variable lambda gene locus was mapped by contig methodology and its one- megabase DNA totally sequenced. All the known functional V-lambda genes and pseudogenes were located. We screened a human genomic DNA cosmid library and isolated a clone with an insert of 37 kb (cosmid 8.3) encompassing four functional genes (IGLV7S1, IGLV1S1, IGLV1S2 and IGLV5a), a pseudogene (VlA) and a vestigial sequence (vg1) to study in detail the positions of the restriction sites surrounding the Vl genes. We generated a high resolution restriction map, locating 31 restriction sites in 37 kb of the VB cluster, a region rich in functional Vl genes. This mapping information opens the perspective for further RFLP studies and sequencing
{"title":"A 37-kb restriction map of the human immunoglobulin lambda variable locus, VB cluster, harboring four functional genes and two non-coding V l sequences","authors":"G. Passos, M. Lefranc","doi":"10.1590/S0100-84551997000400027","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400027","url":null,"abstract":"The human immunoglobulin lambda variable locus (IGLV) is mapped at chromosome 22 band q11.1-q11.2. The 30 functional germline v-lambda genes sequenced untill now have been subgrouped into 10 families (Vl1 to Vl10). The number of Vl genes has been estimated at approximately 70. This locus is formed by three gene clusters (VA, VB and VC) that encompass the variable coding genes (V) responsible for the synthesis of lambda-type Ig light chains, and the Jl-Cl cluster with the joining segments and the constant genes. Recently the entire variable lambda gene locus was mapped by contig methodology and its one- megabase DNA totally sequenced. All the known functional V-lambda genes and pseudogenes were located. We screened a human genomic DNA cosmid library and isolated a clone with an insert of 37 kb (cosmid 8.3) encompassing four functional genes (IGLV7S1, IGLV1S1, IGLV1S2 and IGLV5a), a pseudogene (VlA) and a vestigial sequence (vg1) to study in detail the positions of the restriction sites surrounding the Vl genes. We generated a high resolution restriction map, locating 31 restriction sites in 37 kb of the VB cluster, a region rich in functional Vl genes. This mapping information opens the perspective for further RFLP studies and sequencing","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128591428","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400006
D. Selivon, J. S. Morgante, A. Perondini
Variations in egg length were observed for two populations of cryptic species of Anastrepha fraterculus (Wiedemann). The eggs of type I flies were smaller than those of type II individuals. For both types, in regard to yolk mass extrusion, four classes of embryos were detected. Class 1: embryos that extrude masses at both extremities; class 2: embryos in which extrusion occurs only at the anterior pole; class 3: embryos that eliminate mass only at the posterior pole, and class 4: embryos that do not extrude any mass. Embryo class frequencies were similar for populations belonging to the same type, but different between types. Individual females may produce eggs from different embryo classes, but for any given female the pattern remains constant during a long period of oviposition. Variation in size of the extruded masses was similar for both populations. Individual females produced embryos with a small range of mass diameters, and different females produced masses of different mean size. However, individual mass size remained constant during oviposition. The results suggest the existence of genetic components involved in the control of this unusual process. Larvae of both types presented, just before eclosion, similar unusual behaviors: they ingest the anterior extruded mass, rotate 180°, absorb the posterior mass and eclose near the posterior pole. Data show that cryptic A. fraterculus type I and type II differs in regard to egg size as well as to the phenomenon of yolk mass extrusion
{"title":"Egg size, yolk mass extrusion and hatching behavior in two cryptic speciesof Anastrepha fraterculus (Wiedemann) (Diptera, Tephritidae)","authors":"D. Selivon, J. S. Morgante, A. Perondini","doi":"10.1590/S0100-84551997000400006","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400006","url":null,"abstract":"Variations in egg length were observed for two populations of cryptic species of Anastrepha fraterculus (Wiedemann). The eggs of type I flies were smaller than those of type II individuals. For both types, in regard to yolk mass extrusion, four classes of embryos were detected. Class 1: embryos that extrude masses at both extremities; class 2: embryos in which extrusion occurs only at the anterior pole; class 3: embryos that eliminate mass only at the posterior pole, and class 4: embryos that do not extrude any mass. Embryo class frequencies were similar for populations belonging to the same type, but different between types. Individual females may produce eggs from different embryo classes, but for any given female the pattern remains constant during a long period of oviposition. Variation in size of the extruded masses was similar for both populations. Individual females produced embryos with a small range of mass diameters, and different females produced masses of different mean size. However, individual mass size remained constant during oviposition. The results suggest the existence of genetic components involved in the control of this unusual process. Larvae of both types presented, just before eclosion, similar unusual behaviors: they ingest the anterior extruded mass, rotate 180°, absorb the posterior mass and eclose near the posterior pole. Data show that cryptic A. fraterculus type I and type II differs in regard to egg size as well as to the phenomenon of yolk mass extrusion","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121529098","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400004
V. Valiati, V. Valente
Drosophila paulistorum populations colonizing the urban area of Porto Alegre, southern Brazil, were studied with the objective of characterizing their chromosomal polymorphism in this new environment. Despite being geographically and ecologically marginal and the fact that the colonization of the urban area seems to be a recent event, the populations showed a large number of inversions on all chromosome arms. Differences regarding inversion frequencies and percentage of heterozygosis were found when we compared the samples with respect to geographical, microenvironmental and temporal aspects. Such differences, however, could be attributed to both selective and stochastic factors
{"title":"Chromosomal polymorphism in urban populations of Drosophila paulistorum","authors":"V. Valiati, V. Valente","doi":"10.1590/S0100-84551997000400004","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400004","url":null,"abstract":"Drosophila paulistorum populations colonizing the urban area of Porto Alegre, southern Brazil, were studied with the objective of characterizing their chromosomal polymorphism in this new environment. Despite being geographically and ecologically marginal and the fact that the colonization of the urban area seems to be a recent event, the populations showed a large number of inversions on all chromosome arms. Differences regarding inversion frequencies and percentage of heterozygosis were found when we compared the samples with respect to geographical, microenvironmental and temporal aspects. Such differences, however, could be attributed to both selective and stochastic factors","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114375099","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400003
A. Ruíz, J. Ranz, M. Cáceres, C. Segarra
Uma revisao de nosso recente trabalho sobre a evolucao cromossomica do grupo de especies de Drosophila repleta e apresentada. A maioria dos estudos refere-se ao complexo de especies buzzatii, um conjunto monofiletico de 12 especies que habitam os desertos da America do Sul e das Indias Ocidentais. Uma analise estatistica do comprimento e da distribuicao do ponto de quebra de 86 inversoes paracentricas observadas neste complexo mostrou que o comprimento da inversao e um carater selecionado. Inversoes raras sao geralmente pequenas, enquanto que inversoes evolucionariamente bem sucedidas, fixas e polimorficas, sao predominantemente de tamanho medio. Ha tambem uma correlacao negativa entre o comprimento e o numero de inversoes por especie. Finalmente, a distribuicao dos pontos de quebra nas inversoes ao longo do cromossomo 2 nao e aleatoria, com regioes cromossomicas que acumulam ate 8 pontos de quebra (possiveis "pontos quentes"). O mapeamento genico comparativo tambem foi usado para investigar a organizacao molecular e a evolucao dos cromossomos. Usando hibridizacao in situ, 26 genes foram precisamente localizados nos cromossomos da glândula salivar de D. repleta e D. buzzatii; outros 9 foram identificados por tentativa. Os resultados sao completamente consistentes com as homologias cromossomicas correntemente aceitas entre D. repleta e D. melanogaster, nao se encontrando evidencias de translocacoes reciprocas ou inversoes pericentricas. A comparacao do mapa genico do cromossomo 2 de D. repleta com o do cromossomo homologo 3R de D. melanogaster mostra uma extensa reorganizacao atraves de inversoes paracentricas e permite estimar uma taxa de evolucao para este cromossomo de cerca de 1 inversao fixada por milhao de anos.
{"title":"Chromosomal evolution and comparative gene mapping in the Drosophila repleta species group","authors":"A. Ruíz, J. Ranz, M. Cáceres, C. Segarra","doi":"10.1590/S0100-84551997000400003","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400003","url":null,"abstract":"Uma revisao de nosso recente trabalho sobre a evolucao cromossomica do grupo de especies de Drosophila repleta e apresentada. A maioria dos estudos refere-se ao complexo de especies buzzatii, um conjunto monofiletico de 12 especies que habitam os desertos da America do Sul e das Indias Ocidentais. Uma analise estatistica do comprimento e da distribuicao do ponto de quebra de 86 inversoes paracentricas observadas neste complexo mostrou que o comprimento da inversao e um carater selecionado. Inversoes raras sao geralmente pequenas, enquanto que inversoes evolucionariamente bem sucedidas, fixas e polimorficas, sao predominantemente de tamanho medio. Ha tambem uma correlacao negativa entre o comprimento e o numero de inversoes por especie. Finalmente, a distribuicao dos pontos de quebra nas inversoes ao longo do cromossomo 2 nao e aleatoria, com regioes cromossomicas que acumulam ate 8 pontos de quebra (possiveis \"pontos quentes\"). O mapeamento genico comparativo tambem foi usado para investigar a organizacao molecular e a evolucao dos cromossomos. Usando hibridizacao in situ, 26 genes foram precisamente localizados nos cromossomos da glândula salivar de D. repleta e D. buzzatii; outros 9 foram identificados por tentativa. Os resultados sao completamente consistentes com as homologias cromossomicas correntemente aceitas entre D. repleta e D. melanogaster, nao se encontrando evidencias de translocacoes reciprocas ou inversoes pericentricas. A comparacao do mapa genico do cromossomo 2 de D. repleta com o do cromossomo homologo 3R de D. melanogaster mostra uma extensa reorganizacao atraves de inversoes paracentricas e permite estimar uma taxa de evolucao para este cromossomo de cerca de 1 inversao fixada por milhao de anos.","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129105290","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400008
W. E. Kerr
The first experiments on sex determination in bees began with Dzierzon, Meves, Nachtsheim, Paulcke, Petrunkewitsch, Manning. Whiting, (1943) found multiple alleles in Bracon xo that are the Rosetta stone of sex determination in Hymenoptera. Whiting also discovered that some species of microhymenoptera do not possess xo sex alleles. Therefore, Hymenoptera apparently presents two types of sex determination superimposed on haplodiploidy. In the panmictic groups hemizygous (xo1, xo2,... xon) and homozygous (xo1xo1, xo2xo2... xonxon) are males while heterozygous (xo1xo2, ... xon-1xon) are females. There is no such series of xon in endogamous Hymenoptera, since the constant elimination of diploid males would be damaging to the population and the mutation of xo to xon would be quickly eliminated. Besides the Whiting hypothesis, four others are discussed. The new hypothesis of genomic imprinting, of Beukeboom, is eliminated since: a) spermatozoa that develop within the egg produce male tissue; b) telitokous parthenogenesis due to the fusion of two haploid cells develop into females; c) last instar larvae treated with juvenile hormone become queens. The Cunha and Kerr hypothesis (female determining genes are totally or partially additive and male determination is totally or partially nonadditive) explains all known cases. The xo is a female determining gene. Sex determination in social bees led to the gradual evolution of two systems of caste determination: one in which queens and workers are similar and males are very different (Apinae), and another in which workers and males are very similar and both very different from the queens (Meliponinae). This second system in stingless bees implies that many of the mutations that improve worker capacities also affect the males that will carry out some activities that in Apis are clearly female ones. Ten of these activities are described.
{"title":"Sex determination in honey bees (Apinae and Meliponinae) and its consequences","authors":"W. E. Kerr","doi":"10.1590/S0100-84551997000400008","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400008","url":null,"abstract":"The first experiments on sex determination in bees began with Dzierzon, Meves, Nachtsheim, Paulcke, Petrunkewitsch, Manning. Whiting, (1943) found multiple alleles in Bracon xo that are the Rosetta stone of sex determination in Hymenoptera. Whiting also discovered that some species of microhymenoptera do not possess xo sex alleles. Therefore, Hymenoptera apparently presents two types of sex determination superimposed on haplodiploidy. In the panmictic groups hemizygous (xo1, xo2,... xon) and homozygous (xo1xo1, xo2xo2... xonxon) are males while heterozygous (xo1xo2, ... xon-1xon) are females. There is no such series of xon in endogamous Hymenoptera, since the constant elimination of diploid males would be damaging to the population and the mutation of xo to xon would be quickly eliminated. Besides the Whiting hypothesis, four others are discussed. The new hypothesis of genomic imprinting, of Beukeboom, is eliminated since: a) spermatozoa that develop within the egg produce male tissue; b) telitokous parthenogenesis due to the fusion of two haploid cells develop into females; c) last instar larvae treated with juvenile hormone become queens. The Cunha and Kerr hypothesis (female determining genes are totally or partially additive and male determination is totally or partially nonadditive) explains all known cases. The xo is a female determining gene. Sex determination in social bees led to the gradual evolution of two systems of caste determination: one in which queens and workers are similar and males are very different (Apinae), and another in which workers and males are very similar and both very different from the queens (Meliponinae). This second system in stingless bees implies that many of the mutations that improve worker capacities also affect the males that will carry out some activities that in Apis are clearly female ones. Ten of these activities are described.","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129576798","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400021
C. Pacheco, J. I. R. Júnior, Cosme Damião
Data of corn ear production (kg/ha) of 196 half-sib progenies (HSP) of the maize population CMS-39 obtained from experiments carried out in four environments were used to adapt and assess the BLP method (best linear predictor) in comparison with to the selection among and within half-sib progenies (SAWHSP). The 196 HSP of the CMS-39 population developed by the National Center for Maize and Sorghum Research (CNPMS-EMBRAPA) were related through their pedigree with the recombined progenies of the previous selection cycle. The two methodologies used for the selection of the twenty best half-sib progenies, BLP and SAWHSP, led to similar expected genetic gains. There was a tendency in the BLP methodology to select a greater number of related progenies because of the previous generation (pedigree) than the other method. This implies that greater care with the effective size of the population must be taken with this method. The SAWHSP methodology was efficient in isolating the additive genetic variance component from the phenotypic component. The pedigree system, although unnecessary for the routine use of the SAWHSP methodology, allowed the prediction of an increase in the inbreeding of the population in the long term SAWHSP selection when recombination is simultaneous to creation of new progenies.
{"title":"Using the best linear predictor (BLP) in the selection between and among half-sib progenies of the CMS-39 maize population","authors":"C. Pacheco, J. I. R. Júnior, Cosme Damião","doi":"10.1590/S0100-84551997000400021","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400021","url":null,"abstract":"Data of corn ear production (kg/ha) of 196 half-sib progenies (HSP) of the maize population CMS-39 obtained from experiments carried out in four environments were used to adapt and assess the BLP method (best linear predictor) in comparison with to the selection among and within half-sib progenies (SAWHSP). The 196 HSP of the CMS-39 population developed by the National Center for Maize and Sorghum Research (CNPMS-EMBRAPA) were related through their pedigree with the recombined progenies of the previous selection cycle. The two methodologies used for the selection of the twenty best half-sib progenies, BLP and SAWHSP, led to similar expected genetic gains. There was a tendency in the BLP methodology to select a greater number of related progenies because of the previous generation (pedigree) than the other method. This implies that greater care with the effective size of the population must be taken with this method. The SAWHSP methodology was efficient in isolating the additive genetic variance component from the phenotypic component. The pedigree system, although unnecessary for the routine use of the SAWHSP methodology, allowed the prediction of an increase in the inbreeding of the population in the long term SAWHSP selection when recombination is simultaneous to creation of new progenies.","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123172474","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 : 1997-12-01DOI: 10.1590/S0100-84551997000400016
M. M. Itoyama, H. E. Bicudo, J. Cordeiro
The effect of two concentrations of caffeine (1500 mg/ml and 2500 mg/ml) on mitotic indices of Drosophila prosaltans was analyzed in larval brain cells. Although the differences detected between treated and control cells were not significant, the percentages obtained suggest a possible effect of caffeine in slowing the process of cell division
{"title":"Effects of caffeine on mitotic index in Drosophila prosaltans (Diptera)","authors":"M. M. Itoyama, H. E. Bicudo, J. Cordeiro","doi":"10.1590/S0100-84551997000400016","DOIUrl":"https://doi.org/10.1590/S0100-84551997000400016","url":null,"abstract":"The effect of two concentrations of caffeine (1500 mg/ml and 2500 mg/ml) on mitotic indices of Drosophila prosaltans was analyzed in larval brain cells. Although the differences detected between treated and control cells were not significant, the percentages obtained suggest a possible effect of caffeine in slowing the process of cell division","PeriodicalId":340356,"journal":{"name":"Brazilian Journal of Genetics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122699444","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}
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