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‣ Análise genética de caracteres quantitativos em milho com o delineamento III e marcadores moleculares.; Genetic analisys of quantitative traits in maize by using the design III and moleculars markers.

Silva, Adelmo Resende da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/05/2002 Português
Relevância na Pesquisa
47.63364%
Caracteres importantes em espécies vegetais estão, em sua maior parte, sob o controle de vários locos gênicos, denominados locos de caracteres quantitativos (QTLs). A expressão fenotípica desses caracteres produz uma distribuição contínua de valores devido à segregação genotípica, aos efeitos ambientais e à interação genótipos por ambientes. Com o advento dos marcadores moleculares e de modelos estatístico-genéticos adequados tornou-se possível a detecção e o mapeamento de regiões cromossômicas que controlam estes caracteres. Este trabalho foi realizado para analisar caracteres quantitativos em uma população de milho tropical com os objetivos: (1) obter estimativas das variâncias genéticas aditiva e de dominância, e do grau médio de dominância; (2) construção de um mapa genético utilizando marcador molecular do tipo microssatélite; (3) detecção de QTLs e estimação de seus efeitos genéticos, e de suas interações com ambientes, utilizando o delineamento III. Neste trabalho foram utilizadas 250 progênies F2:3 retrocruzadas para ambos os genitores, totalizando 500 progênies, que foram avaliadas em seis ambientes para a obtenção de dados fenotípicos. Foi realizada a genotipagem com 140 marcadores moleculares para as 250 plantas F2 genitoras. O mapa genético foi construído utilizando o programa MAPMAKER/EXP V.3.0. Os componentes das variâncias genéticas e o grau de dominância dos caracteres foram estimados utilizando-se o delineamento III. A detecção de QTLs e as estimativas de seus efeitos genéticos foram efetuados utilizando a metodologia de Cockerham & Zeng (1996). Os resultados das análises de variâncias evidenciaram sobredominância para produção de grãos e dominância parcial para os outros nove caracteres. Por causa do desequilíbrio de ligação nesta população...

‣ Uso do delineamento III com marcadores moleculares para a análise genética da produção de grãos e seus componentes em milho.; Use of the design III with molecular markers for the genetic analysis of grain yield and its components in maize.

Aguiar, Aurelio Mendes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 18/11/2003 Português
Relevância na Pesquisa
67.17984%
O delineamento III foi proposto para estimar as variâncias aditivas e de dominância e o grau médio de dominância de caracteres quantitativos. Com o advento dos marcadores moleculares, Cockerham & Zeng (1996) desenvolveram uma metodologia genético-estatística associando o delineamento III com marcadores moleculares. Esta metodologia foi proposta visando estimar, com o uso de quatro contrastes ortogonais, os efeitos aditivos, dominantes e epistáticos dos QTLs ligados a marcadores moleculares. O objetivo desta pesquisa foi usar ambas as metodologias para análise genética da produção de grãos, componentes da produção e número de ramificações do pendão em uma população referência F2 de milho. Duzentos e cinqüenta progênies F2:3 foram retrocruzadas com ambas linhagens genitoras, dando origem a 500 progênies de retrocruzamento. Estas progênies foram alocadas em cinco látices 10x10 e avaliadas em seis ambientes em três estações experimentais próximas a Piracicaba, SP, com duas repetições por ambientes. Estimativas de variância aditiva e de dominância, assim como o grau médio de dominância dos caracteres avaliados, apresentaram magnitudes similares às reportadas em populações de milho temperado para todos os caracteres. Estimativas do grau médio de dominância foram inferiores a um para o diâmetro da espiga...

‣ Genetic epidemiology of fecal egg excretion during Schistosoma mansoni infection in an endemic area in Minas Gerais, Brazil

Bethony,J; Gazzinelli,A; Lopes,A; Pereira,W; Alves-Oliveira,LF; Willams-Blangero,S; Blangero,J; LoVerde,PT; Corrêa-Oliveira,R
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2001 Português
Relevância na Pesquisa
57.314707%
There is considerable variation in the level of fecal egg excretion during Schistosoma mansoni infections. Within a single endemic area, the distribution of egg counts is typically overdispersed, with the majority of eggs excreted coming from a minority of residents. The purpose of this study was to quantify the influence of genetic factors on patterns of fecal egg excretion in a rural study sample in Brazil. Individual fecal egg excretions, expressed in eggs per gram of feces, were determined by the Kato-Katz method on stool samples collected on three different days. Detailed genealogic information was gathered at the time of sampling, which allowed assignment of 461 individuals to 14 pedigrees containing between 3 and 422 individuals. Using a maximum likelihood variance decomposition approach, we performed quantitative genetic analyses to determine if genetic factors could partially account for the observed pattern of fecal egg excretion. The quantitative genetic analysis indicated that between 21-37% of the variation in S. mansoni egg counts was attributable to additive genetic factors and that shared environment, as assessed by common household, accounted for a further 12-21% of the observed variation. A maximum likelihood heritability (h²) estimate of 0.44 ± 0.14 (mean ± SE) was found for the 9...

‣ Quantitative genetic analysis of methylxanthines and phenolic compounds in mate progenies

Cardozo Junior,Euclides Lara; Donaduzzi,Carmen Maria; Ferrarese-Filho,Osvaldo; Friedrich,Juliana Cristhina; Gonela,Adriana; Sturion,José Alfredo
Fonte: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira Publicador: Embrapa Informação Tecnológica; Pesquisa Agropecuária Brasileira
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2010 Português
Relevância na Pesquisa
56.893716%
The objective of this work was to determine the contents of methylxanthines, caffeine and theobromine, and phenolic compounds, chlorogenic and caffeic acids, in 51 mate progenies (half-sib families) and estimate the heritability of genetic parameters. Mate progenies were from five Brazilian municipalities: Pinhão, Ivaí, Barão de Cotegipe, Quedas do Iguaçu, and Cascavel. The progenies were grown in the Ivaí locality. The contents of the compounds were obtained by high performance liquid chromatography (HPLC). The estimation of genetic parameters by the restricted maximum likelihood (REML) and the prediction of genotypic values via best linear unbiased prediction (BLUP) were obtained by the Selegen - REML/BLUP software. Caffeine (0.248-1.663%) and theobromine (0.106-0.807%) contents were significantly different (p<0.05) depending on the region of origin, with high individual heritability (ĥ²>0.5). The two different progeny groups determined for chlorogenic (1.365-2.281%) and caffeic (0.027-0.037%) acid contents were not significantly different (p<0.05) depending on the locality of origin. Individual heritability values were low to medium for chlorogenic (ĥ²<0.4) and caffeic acid (ĥ²<0.3). The content of the compounds and the values of genetic parameters could support breeding programs for mate.

‣ A quantitative genetic analysis of male sexual traits distinguishing the sibling species Drosophila simulans and D. sechellia.

Macdonald, S J; Goldstein, D B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1999 Português
Relevância na Pesquisa
57.0192%
A quantitative trait locus (QTL) genetic analysis of morphological and reproductive traits distinguishing the sibling species Drosophila simulans and D. sechellia was carried out in a backcross design, using 38 markers with an average spacing of 8.4 cM. The direction of QTL effects for the size of the posterior lobe was consistent across the identified QTL, indicating directional selection for this trait. Directional selection also appears to have acted on testis length, indicating that sexual selection may have influenced many reproductive traits, although other forms of directional selection cannot be ruled out. Sex comb tooth number exhibited high levels of variation both within and among isofemale lines and showed no evidence for directional selection and, therefore, may not have been involved in the early speciation process. A database search for genes associated with significant QTL revealed a set of candidate loci for posterior lobe shape and size, sex comb tooth number, testis length, tibia length, and hybrid male fertility. In particular, decapentaplegic (dpp), a gene known to influence the genital arch, was found to be associated with the largest LOD peak for posterior lobe shape and size.

‣ A quantitative genetic analysis of nuclear-cytoplasmic male sterility in structured populations of Silene vulgaris.

Taylor, D R; Olson, M S; McCauley, D E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/2001 Português
Relevância na Pesquisa
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Gynodioecy, the coexistence of functionally female and hermaphroditic morphs within plant populations, often has a complicated genetic basis involving several cytoplasmic male-sterility factors and nuclear restorers. This complexity has made it difficult to study the genetics and evolution of gynodioecy in natural populations. We use a quantitative genetic analysis of crosses within and among populations of Silene vulgaris to partition genetic variance for sex expression into nuclear and cytoplasmic components. We also use mitochondrial markers to determine whether cytoplasmic effects on sex expression can be traced to mitochondrial variance. Cytoplasmic variation and epistatic interactions between nuclear and cytoplasmic loci accounted for a significant portion of the variation in sex expression among the crosses. Source population also accounted for a significant portion of the sex ratio variation. Crosses among populations greatly enhanced the dam (cytoplasmic) effect, indicating that most among-population variance was at cytoplasmic loci. This is supported by the large among-population variance in the frequency of mitochondrial haplotypes, which also accounted for a significant portion of the sex ratio variance in our data. We discuss the similarities between the population structure we observed at loci that influence sex expression and previous work on putatively neutral loci...

‣ A Thurstonian Model for Quantitative Genetic Analysis of Ranks: A Bayesian Approach

Gianola, Daniel; Simianer, Henner
Fonte: Copyright © 2006 by the Genetics Society of America Publicador: Copyright © 2006 by the Genetics Society of America
Tipo: Artigo de Revista Científica
Publicado em /11/2006 Português
Relevância na Pesquisa
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A fully Bayesian method for quantitative genetic analysis of data consisting of ranks of, e.g., genotypes, scored at a series of events or experiments is presented. The model postulates a latent structure, with an underlying variable realized for each genotype or individual involved in the event. The rank observed is assumed to reflect the order of the values of the unobserved variables, i.e., the classical Thurstonian model of psychometrics. Parameters driving the Bayesian hierarchical model include effects of covariates, additive genetic effects, permanent environmental deviations, and components of variance. A Markov chain Monte Carlo implementation based on the Gibbs sampler is described, and procedures for inferring the probability of yet to be observed future rankings are outlined. Part of the model is rendered nonparametric by introducing a Dirichlet process prior for the distribution of permanent environmental effects. This can lead to potential identification of clusters of such effects, which, in some competitions such as horse races, may reflect forms of undeclared preferential treatment.

‣ Quantitative genetic analysis of embryo heterosis in faba bean (Vicia faba L.)

Dieckmann, S.; Link, Wolfgang
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
67.19347%
Seeds, i.e. embryos, may be genetically different from either of their parents and moreover may express their own heterosis. The objective was to genetically analyse embryo heterosis for their own weight (i.e. seed weight) in comparison with their seedlings’ heterosis, taking the large-seeded crop (Vicia faba L.) as model. A specific diallel mating scheme was used, based on four parental lines, creating 76 seed genotypes in generations P, F1, F2 and BC. Mature seed weight was assessed for these embryo genotypes in 3 years at one German location, and young plant biomass yield of seedlings emerging from these seeds in two greenhouse experiments. The quantitative genetic analysis showed an average of 10.6% mid-parent heterosis for mature seed weight and 14.5% mid-parent heterosis for juvenile biomass. In both traits, the embryos contributed markedly and significantly via their own genes to the genetic variation. For mature embryo weight heterosis, apparently the parental difference in seed weight was decisive, whereas for juvenile biomass heterosis, genetic unrelatedness of parents had priority.

‣ Propensity score analysis in the Genetic Analysis Workshop 17 simulated data set on independent individuals

Lin, Chen Min; Sathirapongsasuti, Fah J; Kerner, Berit
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 29/11/2011 Português
Relevância na Pesquisa
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Genetic Analysis Workshop 17 provided simulated phenotypes and exome sequence data for 697 independent individuals (209 case subjects and 488 control subjects). The disease liability in these data was influenced by multiple quantitative traits. We addressed the lack of statistical power in this small data set by limiting the genomic variants included in the study to those with potential disease-causing effect, thereby reducing the problem of multiple testing. After this adjustment, we could readily detect two common variants that were strongly associated with the quantitative trait Q1 (C13S523 and C13S522). However, we found no significant associations with the affected status or with any of the other quantitative traits, and the relationship between disease status and genomic variants remained obscure. To address the challenge of the multivariate phenotype, we used propensity scores to combine covariates with genetic risk factors into a single risk factor and created a new phenotype variable, the probability of being affected given the covariates. Using the propensity score as a quantitative trait in the case-control analysis, we again could identify the two common single-nucleotide polymorphisms (C13S523 and C13S522). In addition...

‣ From Structure to Systems: High-Resolution, Quantitative Genetic Analysis of RNA Polymerase II

Braberg, Hannes; Jin, Huiyan; Moehle, Erica A.; Chan, Yujia A.; Wang, Shuyi; Shales, Michael; Benschop, Joris J.; Morris, John H.; Qiu, Chenxi; Hu, Fuqu; Tang, Leung K.; Fraser, James S.; Holstege, Frank C.P.; Hieter, Philip; Guthrie, Christine; Kaplan, C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
57.0192%
RNA polymerase II (RNAPII) lies at the core of dynamic control of gene expression. Using 53 RNAPII point mutants, we generated a point mutant epistatic miniarray profile (pE-MAP) comprising ~60,000 quantitative genetic interactions in Saccharomyces cerevisiae. This analysis enabled functional assignment of RNAPII subdomains and uncovered connections between individual regions and other protein complexes. Using splicing microarrays and mutants that alter elongation rates in vitro, we found an inverse relationship between RNAPII speed and in vivo splicing efficiency. Furthermore, the pE-MAP classified fast and slow mutants that favor upstream and downstream start site selection, respectively. The striking coordination of polymerization rate with transcription initiation and splicing suggests that transcription rate is tuned to regulate multiple gene expression steps. The pE-MAP approach provides a powerful strategy to understand other multifunctional machines at amino acid resolution.

‣ Applying Quantitative Genetic Methods to Primate Social Behavior

Blomquist, Gregory E.; Brent, Lauren J. N.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
47.56856%
Increasingly, behavioral ecologists have applied quantitative genetic methods to investigate the evolution of behaviors in wild animal populations. The promise of quantitative genetics in unmanaged populations opens the door for simultaneous analysis of inheritance, phenotypic plasticity, and patterns of selection on behavioral phenotypes all within the same study. In this article, we describe how quantitative genetic techniques provide studies of the evolution of behavior with information that is unique and valuable. We outline technical obstacles for applying quantitative genetic techniques that are of particular relevance to studies of behavior in primates, especially those living in noncaptive populations, e.g., the need for pedigree information, non-Gaussian phenotypes, and demonstrate how many of these barriers are now surmountable. We illustrate this by applying recent quantitative genetic methods to spatial proximity data, a simple and widely collected primate social behavior, from adult rhesus macaques on Cayo Santiago. Our analysis shows that proximity measures are consistent across repeated measurements on individuals (repeatable) and that kin have similar mean measurements (heritable). Quantitative genetics may hold lessons of considerable importance for studies of primate behavior...

‣ Quantitative Genetic Analysis of Insecticide Resistance: Variation in Fenvalerate Tolerance in a Diamondback Moth (Lepidoptera: Plutellidae) Population

Tabashnik, Bruce E.; Cushing, Nancy L.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica Formato: text/html
Português
Relevância na Pesquisa
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Tolerance to the pyrethroid fenvalerate in a diamondback moth, Plutella xylostella (L.), population was analyzed by quantitative genetic techniques. F1 offspring of field-collected individuals were reared in the laboratory as full sibling families and tested for tolerance to fenvalerate residues. Mortality varied extensively among families, indicating a genetic component. Variation in mortality at 48 h was essentially continuous and not significantly different from a normal distribution, suggesting that the heritable variation is polygenic. Heritability of fenvalerate tolerance was approximately.≤:0.20. Result from probit analysis suggest that substantial variation in insecticide tolerance is common within insect populations. Quantitative genetic techniques may be useful for estimating the genetic component of variation in tolerance within populations.

‣ Genetic analysis of quantitative phenotypes in AD and MCI: imaging, cognition and biomarkers

Shen, Li; Thompson, Paul M.; Potkin, Steven G.; Bertram, Lars; Farrer, Lindsay A.; Foroud, Tatiana M.; Green, Robert C.; Hu, Xiaolan; Huentelman, Matthew J.; Kim, Sungeun; Kauwe, John S. K.; Li, Qingqin; Liu, Enchi; Macciardi, Fabio; Moore, Jason H.; Muns
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
47.56171%
The Genetics Core of the Alzheimer’s Disease Neuroimaging Initiative (ADNI), formally established in 2009, aims to provide resources and facilitate research related to genetic predictors of multidimensional Alzheimer’s disease (AD)-related phenotypes. Here, we provide a systematic review of genetic studies published between 2009 and 2012 where either ADNI APOE genotype or genome-wide association study (GWAS) data were used. We review and synthesize ADNI genetic associations with disease status or quantitative disease endophenotypes including structural and functional neuroimaging, fluid biomarker assays, and cognitive performance. We also discuss the diverse analytical strategies used in these studies, including univariate and multivariate analysis, meta-analysis, pathway analysis, and interaction and network analysis. Finally, we perform pathway and network enrichment analyses of these ADNI genetic associations to highlight key mechanisms that may drive disease onset and trajectory. Major ADNI findings included all the top 10 AD genes and several of these (e.g., APOE, BIN1, CLU, CR1, and PICALM) were corroborated by ADNI imaging, fluid and cognitive phenotypes. ADNI imaging genetics studies discovered novel findings (e.g., FRMD6) that were later replicated on different data sets. Several other genes (e.g....

‣ Quantitative genetic analysis of methylxanthines and phenolic compounds in mate progenies.

CARDOZO JUNIOR, E. L.; DONADUZZI, C. M.; FERRARESE-FILHO, O.; FRIEDRICH, J. C.; GONELA, A.; STURION, J. A.
Fonte: Pesquisa Agropecuaria brasileira., Brasília, v.45, n.2, p.171-177, fev. 2010 Publicador: Pesquisa Agropecuaria brasileira., Brasília, v.45, n.2, p.171-177, fev. 2010
Tipo: Artigo em periódico indexado (ALICE)
Português
Relevância na Pesquisa
56.893716%
Abstract ?The objective of this work was to determine the contents of methylxanthines, caffeine and theobromine, and phenolic compounds, chlorogenic and caffeic acids, in 51 mate progenies (half-sib families) and estimate the heritability of genetic parameters. Mate progenies were from five Brazilian municipalities: Pinhão, Ivaí, Barão de Cotegipe, Quedas do Iguaçu, and Cascavel. The progenies were grown in the Ivaí locality. The contents of the compounds were obtained by high performance liquid chromatography (HPLC). The estimation of genetic parameters by the restricted maximum likelihood (REML) and the prediction of genotypic values via best linear unbiased prediction (BLUP) were obtained by the Selegen - REML/BLUP software. Caffeine (0.248?1.663%) and theobromine (0.106?0.807%) contents were significantly different (p<0.05) depending on the region of origin, with high individual heritability (^h2>0.5). The two different progeny groups determined for chlorogenic (1.365?2.281%) and caffeic (0.027?0.037%) acid contents were not significantly different (p<0.05) depending on the locality of origin. Individual heritability values were low to medium for chlorogenic (^h2<0.4) and caffeic acid (^h2<0.3). The content of the compounds and the values of genetic parameters could support breeding programs for mate.; 2010

‣ The genetic improvement of wheat and barley for reproductive frost tolerance.

Reinheimer, Jason
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010 Português
Relevância na Pesquisa
57.049053%
The aim of the research reported in this thesis was to identify genetic variation for Reproductive Frost Tolerance (RFT) in barley, characterise the genetic basis of the observed tolerance and devise and execute a strategy to incorporate the tolerance into germplasm adapted to Australian production environments. Effects of wheat chromosome regions syntenous to the barley RFT loci were also investigated. A field based screening nursery was developed to characterise barley germplasm for RFT. A diverse collection of international barley germplasm was screened for RFT to identify barley genotypes exhibiting better levels of RFT than what was available in Australian cultivated germplasm. Three lines were identified as having an increased level of RFT and populations derived from these three lines were used to QTL map RFT traits. One QTL was common between the three populations and a second QTL was common between 2 of the populations. These two loci were found to control a reduction in Frost Induced Sterility (FIS) and frost induced grain damage. One of the barley QTL spanned the vernalisation response gene and vegetative frost tolerance locus vrn-H1/Fr-H1. The syntenous genomic regions in hexaploid wheat were investigated to determine if they had an effect on RFT. Two sets of wheat germplasm containing variation for winter/spring alleles of vrn-A1...

‣ Genetic analysis of tolerance to the root lesion nematode Pratylenchus neglectus in the legume Medicago littoralis

Oldach, K.H.; Peck, D.M.; Nair, R.M.; Sokolova, M.; Harris, J.; Bogacki, P.; Ballard, R.
Fonte: Biomed Central Publicador: Biomed Central
Tipo: Artigo de Revista Científica
Publicado em //2014 Português
Relevância na Pesquisa
57.10239%
BACKGROUND: The nematode Pratylenchus neglectus has a wide host range and is able to feed on the root systems of cereals, oilseeds, grain and pasture legumes. Under the Mediterranean low rainfall environments of Australia, annual Medicago pasture legumes are used in rotation with cereals to fix atmospheric nitrogen and improve soil parameters. Considerable efforts are being made in breeding programs to improve resistance and tolerance to Pratylenchus neglectus in the major crops wheat and barley, which makes it vital to develop appropriate selection tools in medics. RESULTS: A strong source of tolerance to root damage by the root lesion nematode (RLN) Pratylenchus neglectus had previously been identified in line RH-1 (strand medic, M. littoralis). Using RH-1, we have developed a single seed descent (SSD) population of 138 lines by crossing it to the intolerant cultivar Herald. After inoculation, RLN-associated root damage clearly segregated in the population. Genetic analysis was performed by constructing a genetic map using simple sequence repeat (SSR) and gene-based SNP markers. A highly significant quantitative trait locus (QTL), QPnTolMl.1, was identified explaining 49% of the phenotypic variation in the SSD population. All SSRs and gene-based markers in the QTL region were derived from chromosome 1 of the sequenced genome of the closely related species M. truncatula. Gene-based markers were validated in advanced breeding lines derived from the RH-1 parent and also a second RLN tolerance source...

‣ Quantitative genetic analysis of subspecific differences in body shape in the snail-feeding carabid beetle Damaster blaptoides

Konuma, J; Sota, T; Chiba, S
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
57.115586%
A dimorphic pattern of macrocephalic (wide, short) and stenocephalic (narrow, long) body shapes is observed in snail-feeding carabid beetles globally. The former exhibits high performance in crushing snail shells with powerful jaws, whereas the latter specializes in eating snails' soft body directly by inserting the head into the shell. In the snail-feeding species Damaster blaptoides, the subspecies D. b. capito has a wide, short forebody, and D. b. fortunei has a narrow, long forebody. They exhibit distinct morphologies despite their geographic and phylogenetic proximity. To examine the genetic basis of the morphological differences between these two subspecies, we conducted quantitative genetic analyses by crossing these subspecies and producing F1 and backcross hybrids. The hybrids had body shapes intermediate between the parental subspecies. The variation between wide, short and narrow, long forebodies was based on negative genetic correlations between width and length of the head and thorax. Between one and eight genetic factors were involved in the morphological differences between subspecies. We suggest that the morphological integration of forebody parts in a small number of loci has facilitated the marked morphological diversification between subspecies of D. blaptoides.

‣ Genetic Studies of Physiological Traits with Their Application to Sleep Apnea

Lee, D. Y.; Hanis, C.; Bell, G. I.; Aguilar, D. A.; Redline, S.; Below, J.; Xiong, M. M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/10/2014 Português
Relevância na Pesquisa
57.27093%
Advances of modern sensing and sequencing technologies generate a deluge of high dimensional space-temporal physiological and next-generation sequencing (NGS) data. Physiological traits are observed either as continuous random functions, or on a dense grid and referred to as function-valued traits. Both physiological and NGS data are highly correlated data with their inherent order, spacing, and functional nature which are ignored by traditional summary-based univariate and multivariate regression methods designed for quantitative genetic analysis of scalar trait and common variants. To capture morphological and dynamic features of the data and utilize their dependent structure, we propose a functional linear model (FLM) in which a trait curve is modeled as a response function, the genetic variation in a genomic region or gene is modeled as a functional predictor, and the genetic effects are modeled as a function of both time and genomic position (FLMF) for genetic analysis of function-valued trait with both GWAS and NGS data. By extensive simulations, we demonstrate that the FLMF has the correct type 1 error rates and much higher power to detect association than the existing methods. The FLMF is applied to sleep data from Starr County health studies where oxygen saturation were measured in 22...

‣ A quantitative genetic analysis of hibernation emergence date in a wild population of Columbian ground squirrels

Lane, J.E.; Kruuk, Loeske; Charmantier, A.; Murie, J.O.; Coltman, D.W.; Buoro, M.; Raveh, S.; Dobson, F.S.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Português
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The life history schedules of wild organisms have long attracted scientific interest, and, in light of ongoing climate change, an understanding of their genetic and environmental underpinnings is increasingly becoming of applied concern. We used a multi-generation pedigree and detailed phenotypic records, spanning 18years, to estimate the quantitative genetic influences on the timing of hibernation emergence in a wild population of Columbian ground squirrels (Urocitellus columbianus). Emergence date was significantly heritable [h2=0.22±0.05 (in females) and 0.34±0.14 (in males)], and there was a positive genetic correlation (rG=0.76±0.22) between male and female emergence dates. In adult females, the heritabilities of body mass at emergence and oestrous date were h2=0.23±0.09 and h2=0.18±0.12, respectively. The date of hibernation emergence has been hypothesized to have evolved so as to synchronize subsequent reproduction with upcoming peaks in vegetation abundance. In support of this hypothesis, although levels of phenotypic variance in emergence date were higher than oestrous date, there was a highly significant genetic correlation between the two (rG=0.98±0.01). Hibernation is a prominent feature in the annual cycle of many small mammals...

‣ Fatores genéticos na variação inter-fratrias das componentes do somatótipo; Genetic and environmental factors in the variability of somatotype components of siblings

Maia, José António Ribeiro; Vasques, Catarina; Lopes, Vítor Pires; Seabra, André; Garganta, Rui; Pereira, Simonete; Fermino, Rogério César
Fonte: Universidade de São Paulo. Escola de Educação Física e Esporte Publicador: Universidade de São Paulo. Escola de Educação Física e Esporte
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 01/03/2007 Português
Relevância na Pesquisa
57.073613%
Esta pesquisa pretende determinar a influência de fatores genéticos e ambientais na variação inter-fratrias nas componentes do somatótipo, bem como apresentar, de modo didático, um conjunto de etapas associados a pesquisa de Genética Quantitativa. A amostra foi constituída por 366 pares de irmãos dos 10 aos 18 anos de idade residentes no nordeste de Portugal Continental. As componentes do somatótipo foram estimadas com base no protocolo descrito por Carter & Heath (1990), a partir de 10 medidas somáticas. A análise exploratória dos dados foi efetuada nos "softwares" SPSS e PEDSTATS. As estimativas dos fatores genéticos foram obtidas no "software" SAGE. Os resultados salientaram uma elevada qualidade da informação (erro técnico de medida ≈1%). A componente mesomorfa é a mais elevada qualquer que seja a estrutura das irmandades: irmão-irmão, irmã-irmã, ou irmão-irmã. Mesmo depois de ajustadas para diferentes covariáveis as estimativas dos fatores genéticos são elevadas: 0,49 para a endomorfia, 0,55 para a mesomorfia, e 0,71 para e ectomorfia. Estes resultados sugerem a presença de fatores genéticos substanciais a governar a variação no somatótipo no seio da população.; The aims of this study were to determine the influence of genetic and environmental factors in siblings variation in somatotype components...