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1.
An. acad. bras. ciênc ; 90(1): 343-356, Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-886893

ABSTRACT

ABSTRACT An experiment was conducted to examine the influencing characters on rice by using 64 rice genotypes, including four local landraces, four released cultivars and 56 mutant lines (M5) derived from these genotypes, with application of the genotype by trait (GT) biplot methodology. The first two principal components (PC1 and PC2) accounted for 46.6% of total variation in 64 genotypes. The polygon view of GT biplot suggested seven sections for 64 genotypes. The vertex G38 had good amounts of grain yield, panicle length, hundred grain weight, internodes length, plant height and fertility percentage. Generally based on vector view it was demonstrated that the selection of high grain yield would be performed via thousand grain weight, panicle weight and number of filled grain per panicle. These traits should be considered simultaneously as effective selection criteria evolving high yielding rice genotypes because of their large contribution to grain yield. The genotypes G2, G4 and G7 could be considered for the developing of desirable progenies in the selection strategy of rice improvement programs. This study revealed GT biplot can graphically display the interrelationships among traits. In conclusion, it is recommended the use of GGE biplot to identify superior genotypes for simultaneous improvement of several traits.


Subject(s)
Oryza/genetics , Crops, Agricultural/genetics , Quantitative Trait, Heritable , Oryza/growth & development , Genetic Variation/genetics , Crops, Agricultural/growth & development , Gene-Environment Interaction , Iran
2.
An. acad. bras. ciênc ; 89(4): 2931-2943, Oct.-Dec. 2017. tab
Article in English | LILACS | ID: biblio-886870

ABSTRACT

ABSTRACT In this paper, the existence of a genotype x environment interaction for the average daily weight in GIFT Nile tilapia (Oreochromis niloticus) in different regions in the state of Paraná (Brazil) was analyzed. The heritability results were high in the uni-characteristic analysis: 0.71, 0.72 and 0.67 for the cities of Palotina (PL), Floriano (FL) and Diamond North (DN), respectively. Genetic correlations estimated in bivariate analyzes were weak with values between 0.12 for PL-FL, 0.06 for PL and 0.23 for DN-FL-DN. The Spearman correlation values were low, which indicated a change in ranking in the selection of animals in different environments in the study. There was heterogeneity in the phenotypic variance among the three regions and heterogeneity in the residual variance between PL and DN. The direct genetic gain was greater for the region with a DN value gain of 198.24 g/generation, followed by FL (98.73 g/generation) and finally PL (98.73 g/generation). The indirect genetic gains were lower than 0.37 and greater than 0.02 g/generation. The evidence of the genotype x environment interaction was verified, which indicated the phenotypic heterogeneity of the variances among the three regions, weak genetic correlation and modified rankings in the different environments.


Subject(s)
Animals , Male , Female , Body Weight/genetics , Quantitative Trait, Heritable , Cichlids/genetics , Gene-Environment Interaction , Brazil , Bayes Theorem , Cichlids/anatomy & histology , Genotype
3.
Rev. méd. Chile ; 145(3): 368-372, Mar. 2017.
Article in Spanish | LILACS | ID: biblio-845549

ABSTRACT

This review aims to summarize information about the genetic etiology of attention deficit disorder with hyperactivity (ADHD), with particular reference to the contributions of our research group. We also discuss the genetic comorbidity estimated from genome-wide single nucleotide polymorphisms (SNP´s) between ADHD and major psychiatric disorders such as schizophrenia (E), major depressive disorder (MDD), bipolar disorder (BD) and autism spectrum disorders (ASD). A high genetic comorbidity was found between E and BD (46%), a moderate comorbidity between MDD and E, MDD and BD and MDD and ADHD (18%, 22% and 10% respectively) and a low comorbidity between E and ASD (2.5%). Furthermore, we show evidence concerning the genetic determination of psychiatric diseases, which is significantly lower when it is estimated from genome-wide SNP´s rather than using traditional quantitative genetic methodology (ADHD = E = 23%, BD = 25%, MDD = 21% and ASD = 17%). From an evolutionary perspective, we suggest that behavioral traits such as hyperactivity, inattention and impulsivity, which play a role in ADHD and perhaps also other hereditary traits which are part of major psychiatric disorders, could have had a high adaptive value during the early stages of the evolution of Homo sapiens. However, they became progressively less adaptive and definitively disadvantageous, to the extreme that they are involved in frequently diagnosed major psychiatric disorders.


Subject(s)
Humans , Attention Deficit Disorder with Hyperactivity/genetics , Quantitative Trait, Heritable , Genetic Predisposition to Disease/genetics , Schizophrenia/genetics , Bipolar Disorder/genetics , Comorbidity , Depressive Disorder, Major/genetics , Autism Spectrum Disorder/genetics
4.
An. acad. bras. ciênc ; 89(3,supl): 2515-2523, 2017. tab
Article in English | LILACS | ID: biblio-886806

ABSTRACT

ABSTRACT Genetic parameters for reproductive traits in female Nile tilapia were estimated in this study using Bayesian inference method. The data set presented information from 451 Nile tilapia females that were evaluated at two different places in Maringá - Paraná - Brazil (hapas of 1 and 10 m³) and at one location in Alfenas - Minas Gerais - Brazil. A spawning examination was conducted once a week from October 2012 to March 2013 for a total of 23 weeks of evaluation. Single-trait analyses for spawning success, multiple spawning, spawning frequency, and volume of eggs/female were performed by using the software MTGSAM Threshold. The heritability estimates were 0.14, 0.16, 0.53, and 0.08 for spawning success, multiple spawning, spawning frequency and volume of eggs/female, respectively, indicating it is possible to achieve a substantial genetic gain using these reproductive traits as selection criteria.


Subject(s)
Animals , Female , Oviposition/genetics , Reproduction/genetics , Quantitative Trait, Heritable , Cichlids/genetics , Genitalia, Female , Oviposition/physiology , Phenotype , Reproduction/physiology , Bayes Theorem , Cichlids/anatomy & histology , Cichlids/physiology
5.
Arq. bras. med. vet. zootec ; 67(5): 1287-1294, tab, graf
Article in Portuguese | LILACS | ID: lil-764441

ABSTRACT

Diversos fatores predisponentes são descritos para as afecções mamárias ou distúrbios secundários que comprometem a qualidade e produtividade de leite de fêmeas nas diferentes espécies. As características fenotípicas do úbere são consideradas na avaliação econômica de uma fêmea caprina, tanto pelo potencial de produção como pelo registro genealógico dessa fêmea. A limitação de estudos correlacionando essas características com a saúde do úbere gera a dúvida a respeito do significado da conformação do mesmo à saúde e produtividade da glândula mamária. Sendo assim, este estudo teve como objetivo relacionar os parâmetros da conformação do úbere com a celularidade da glândula mamária aferida pelo teste California Mastitis Test (CMT) e contagem de células somáticas (CCS) em 80 cabras da raça Saanen sem alterações no exame clínico da glândula mamária nem no teste de Tamis. Observou-se que a maioria dos parâmetros fenotípicos de úbere não influenciou a CCS, sendo considerados puramente estéticos. A circunferência e profundidade de úbere demonstraram correlação negativa com a celularidade e, por serem características de herdabilidade moderada a alta, podem ser parâmetros considerados para seleção genética de caprinos.


Several predisposing factors are described for mammary diseases or secondary disorders that compromise the quality and productivity of milk from females in different species. The phenotypic characteristics of the udder are considered in the economic evaluation of a female goat, whether for production potential, or as the genealogical record for these females. The limitation of studies correlating these features with the udder health raises doubt about the meaning of the conformation to the health and productivity of the mammary gland. Therefore, this study aimed to list the parameters of the udder conformation with the cellularity of the mammary gland checked by California Mastitis Test (CMT) and somatic cell count (SCC) in 80 Saanen goats without alterations in the clinical examination of the mammary gland or the Tamis test. It was observed that most of the phenotypic parameters of the udder did not influence the CCS, being considered purely esthetic. The circumference and udder depth showed negative correlation with the cellularity and moderate to high heritability traits can be considered parameters for genetic selection of goats.


Subject(s)
Animals , Goats , Mammary Glands, Animal , Milk , Mastitis/veterinary , Ruminants , Cell Count/veterinary , Food Production , Phenotype , Quantitative Trait, Heritable
6.
Arch. endocrinol. metab. (Online) ; 59(3): 265-269, 06/2015. graf
Article in English | LILACS | ID: lil-751313

ABSTRACT

The concomitant occurrence of primary hyperparathyroidism (PHPT) due to parathyroid adenoma and papillary thyroid carcinoma (PTC) is not common. The co-occurrence of parathyroid tumors and thyroid diseases can lead to misdiagnosis owing to mutual interference of imaging in the early period of disease. The most commonly used imaging techniques for the preoperative localization of parathyroid and thyroid adenomas are technetium-99m sestamibi (99mTc-MIBI) scintigraphy and ultrasonography of the neck. Recently, 99mTc-MIBI single-photon emission computed tomography associated with computed tomography scintigraphy (SPECT/CT) has been used to detect PHPT, and its diagnostic value is being evaluated. Herein, we report a patient with an unusual co-occurrence of parathyroid adenoma and multiple thyroid diseases, including papillary thyroid carcinoma, thyroid adenoma and lymphocytic thyroiditis, which were localized with 99mTc-MIBI SPECT/CT and confirmed surgically. We suggest that 99mTc-MIBI SPECT/CT can play an important role in the diagnosis of parathyroid and thyroid lesions. Arch Endocrinol Metab. 2015;59(3):265-9.


Subject(s)
Humans , Data Interpretation, Statistical , Gene-Environment Interaction , Models, Genetic , Quantitative Trait, Heritable , Family , Genotype , Phenotype
7.
Article in English | IMSEAR | ID: sea-162032

ABSTRACT

Introduction: Th e pelvis is most sexually dimorphic and is the fi rst bone assessed in sex determination because it is the skeletal element most aff ected by reproduction and parturition.1 Th e assessment of the pelvis is made through metric measurements as well as through the visual analysis of non-metric traits; both important aspects of the analysis. Th e best methods for determining sex from adult skeletal remains involve measurement and inspection of the hip bone that presents a number of gender-related anatomical diff erences.2 Most osteologists visually (stereoscopic) evaluate these diff erences and integrate this subjective assessment ofhip bonemorphology into their sex determinations. Th e aim of thepresent study is to visually evaluate sexual diff erences in hip bone and comparing its effi cacy with metric assessment. Methods: Th is study is done on 46 hip bones of adult individuals of known sex from museum of department of anatomy of SGRRIM&HS Dehradun and TMMC&RC Moradabad, India. All these hip bones were visually examined and under mentioned fi ve characters of the hip bone were used, (A) aspects of the preauricular surface, (B) aspects of the greater sciatic notch, (C) the form of the composite arch, (D) the morphology of the inferior pelvis, and (E) ischiopubic proportions. Results: In this study traits of the group (A) were most sexually dimorphic while traits of the group (E) were least sexually dimorphic. Conclusion: Diagnostic accuracy is excellent when the complete hip bone is available. Hip bone features used for sex determination by visual assessment seem to be fairly stable.


Subject(s)
Adult , Endoscopy/methods , Female , Humans , Male , Pelvic Bones/anatomy & histology , Pelvic Bones/analysis , Quantitative Trait, Heritable , Sex Characteristics/etiology
8.
Braz. j. med. biol. res ; 45(12): 1269-1275, Dec. 2012. tab
Article in English | LILACS | ID: lil-659641

ABSTRACT

Blood pressure (BP) and physical activity (PA) levels are inversely associated. Since genetic factors account for the observed variation in each of these traits, it is possible that part of their association may be related to common genetic and/or environmental influences. Thus, this study was designed to estimate the genetic and environmental correlations of BP and PA phenotypes in nuclear families from Muzambinho, Brazil. Families including 236 offspring (6 to 24 years) and their 82 fathers and 122 mothers (24 to 65 years) were evaluated. BP was measured, and total PA (TPA) was assessed by an interview (commuting, occupational, leisure time, and school time PA). Quantitative genetic modeling was used to estimate maximal heritability (h²), and genetic and environmental correlations. Heritability was significant for all phenotypes (systolic BP: h² = 0.37 ± 0.10, P < 0.05; diastolic BP: h² = 0.39 ± 0.09, P < 0.05; TPA: h² = 0.24 ± 0.09, P < 0.05). Significant genetic (r g) and environmental (r e) correlations were detected between systolic and diastolic BP (r g = 0.67 ± 0.12 and r e = 0.48 ± 0.08, P < 0.05). Genetic correlations between BP and TPA were not significant, while a tendency to an environmental cross-trait correlation was found between diastolic BP and TPA (r e = -0.18 ± 0.09, P = 0.057). In conclusion, BP and PA are under genetic influences. Systolic and diastolic BP share common genes and environmental influences. Diastolic BP and TPA are probably under similar environmental influences.


Subject(s)
Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Young Adult , Blood Pressure/genetics , Gene-Environment Interaction , Genetic Predisposition to Disease/genetics , Hypertension/genetics , Motor Activity/genetics , Brazil , Quantitative Trait, Heritable
9.
Arch. latinoam. nutr ; 61(4): 389-395, dic. 2011. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-702747

ABSTRACT

Estudio descriptivo correlacional. Los objetivos fueron: 1) evaluar la percepción materna del peso del hijo mediante dos pruebas percepción por palabras (PP) e índice de masa corporal del hijo percibido por la madre (IMCP), 2) Evaluar sensibilidad y especificidad de las pruebas y 3) Cuantificar la heredabilidad (h2) del índice de masa corporal (IMC) en 173 diadas (madre-hijo). La PP fue valorada por la pregunta ¿cómo cree que su hijo esta? Para valorar el IMCP, la madre refirió peso y talla del hijo y se calculó el IMC del hijo percibido por la madre. Se midió peso y talla a madres e hijos. Se encontró que 10.3% de madres de hijos con sobrepeso (SP) y 1.8% de madres de hijos con obesidad (OB) los percibieron de forma adecuada por la prueba (PP) y por la prueba IMCP el 38.5% y 67.3% de madres de hijos con SP y OB respectivamente. La sensibilidad de PP fue 5.3% y especificidad 29.1%. La sensibilidad de IMCP fue 55.3% y especificidad 54.4%. La h2 del IMC fue de 15%. Se concluye que las madres no perciben el SP-OB de sus hijos y que el cuestionar a la madre peso y talla del hijo (IMCP) podría ayudar a percibir el SP-OB del hijo. La h2 del IMC indica que los factores del estilo de vida en esta población contribuyen al SP-OB. Dada la amplia diversidad socio-económica y cultural, estos resultados de Campeche deberán de ser validados con diseños similares de estudio.


Descriptive correlational study. The objectives were the following: 1) evaluate maternal perception of her child’s weight through two test, Word-perception (WP) test and the Body mass index (BMI) of the child as perceived by the mother (Body weight index perception [BWIP]); 2) evaluate the sensitivity and specificity of the tests, and 3) quantify BMI heritability (h2) in 173 mother-child dyads. WP was assessed by asking the question, How do you think your child is? For assessing BWIP, the mother referred the child’s weight and height, and we calculated the child’s BMI as perceived by the mother. The weight and height of the mothers and their children were measured. We found that 10.3% of mothers of children with Overweight (OW) and 1.8% of mothers of children with Obesity (OB) perceived their children adequately by means of WP; by means of the BWIP test, 38.5 and 67.3% of mothers of children with OW and OB, respectively, exhibited adequate perception. BWIP sensitivity was 55.3% and specificity was 54.4%. BWI h2 was 15%. We was concluded that mothers did not perceive the OW-OB of their children, and that asking the mother for the weight and height of the child (BMIP) will aids her to perceive the OW-OB of her child. The BWI h2 indicate that the lifestyle factors of this population contribute to OW-OB. Given the broad socioeconomic and cultural diversity, these results of the southeastern Mexican state of Campeche should be evaluated with similar study designs.


Subject(s)
Child , Female , Humans , Male , Mothers , Obesity/genetics , Quantitative Trait, Heritable , Weight Perception , Body Mass Index , Mexico , Obesity/psychology , Sensitivity and Specificity
11.
China Journal of Chinese Materia Medica ; (24): 2457-2461, 2011.
Article in Chinese | WPRIM | ID: wpr-293225

ABSTRACT

<p><b>OBJECTIVE</b>The main aim of the research was to evaluate genetic variability and interrelationships of mainly quantitative traits in 2-year population, and provide a basis for high-yield breeding of Glycyrrhiza uralensis.</p><p><b>METHOD</b>Four genotype G. uralensis population were transplanting in four different environment using complete randomized block design with three replication, and the 10 quantitative traits, including plant height (PH), stem diameter (SD), tiller number (TN), taproot length (TRL), root length (RL), root diameter (RD), diameter of 20 cm below the root head (D20), taperingness (TR), lateral root number (LRN) and root fresh weight (RFW) were measured in field.</p><p><b>RESULT</b>The difference among population for all evaluated traits were significant (P<0.05) through Duncan's multiple range tests, and the coefficient of variation of RFW and LRN were above 25%. The analysis of variance was used to evaluate the traits of four populations across to four different environment Genotype, environment and their interaction effect were significant (P<0.05) or highly significant (P<0.01) for mainly evaluated traits. Simple correlation between traits showed that PH, SD, LRN, RL, RD and D20 had highly significant (P<0.01) and positive correlation with RFW. Results of the path coefficient analyses showed that D20 had the greatest positive direct effect on RFW, followed by the traits of PH and RL.</p><p><b>CONCLUSION</b>Selection for increased D20, RL and PH would be the best indirect selection traits for increasing root yield. Meanwhile, ample genetic variability exists in the G. uralensis 2-year population, it could be used for breeding improvement of root yield.</p>


Subject(s)
Breeding , Methods , Environment , Genes, Modifier , Glycyrrhiza uralensis , Genetics , Metabolism , Phenotype , Plant Roots , Genetics , Metabolism , Plant Stems , Genetics , Metabolism , Plants, Medicinal , Chemistry , Quantitative Trait Loci , Genetics , Quantitative Trait, Heritable
12.
An. acad. bras. ciênc ; 81(4): 707-714, Dec. 2009. graf
Article in English | LILACS | ID: lil-529932

ABSTRACT

An agent-based computer simulation of death by inheritable mutations in a changing environment shows a maximal population, or avoids extinction, at some intermediate mutation rate of the individuals. Our results indicate that death seems needed to allow for evolution of the fittest, as required by a changing environment.


Simulação computacional de agentes individuais que se reproduzem e morrem por acúmulo de mutações herdadas mostra um máximo da população ou evita extinção, para taxas de mutação intermediárias. Assim, as mortes parecem necessárias para a evolução dos mais adaptados a um ambiente mutante.


Subject(s)
Female , Humans , Male , Computer Simulation , Models, Genetic , Mutation/genetics , Population Dynamics , Selection, Genetic/genetics , Genetics, Population , Monte Carlo Method , Phenotype , Population Density , Quantitative Trait, Heritable
13.
J Genet ; 2008 Dec; 87(3): 241-55
Article in English | IMSEAR | ID: sea-114453

ABSTRACT

Genetic variability in 10 natural Tunisian populations of Medicago laciniata were analysed using 19 quantitative traits and 12 polymorphic microsatellite loci. A large degree of genetic variability within-populations and among-populations was detected for both quantitative characters and molecular markers. High genetic differentiation among populations for quantitative traits was seen, with Q(ST) = 0.47, and F(ST) = 0.47 for microsatellite markers. Several quantitative traits displayed no statistical difference in the levels of Q(ST) and F(ST). Further, significant correlations between quantitative traits and eco-geographical factors suggest that divergence in the traits among populations may track environmental differences. There was no significant correlation between genetic variability at quantitative traits and microsatellite markers within populations. The site-of-origin of eco-geographical factors explain between 18.13% and 23.40% of genetic variance among populations at quantitative traits and microsatellite markers, respectively. The environmental factors that most influence variation in measured traits among populations are assimilated phosphorus (P(2)0(5)) and mean annual rainfall, followed by climate and soil texture, altitude and organic matter. Significant associations between eco-geographical factors and gene diversity, He, were established in five microsatellite loci suggesting that these simple sequence repeats (SSRs) are not necessarily biologically neutral.


Subject(s)
Ecological and Environmental Phenomena , Genetic Markers , Genetic Variation , Geography , Inheritance Patterns/genetics , Genetic Linkage , Medicago/anatomy & histology , Microsatellite Repeats/genetics , Minisatellite Repeats/genetics , Phylogeny , Population Dynamics , Quantitative Trait, Heritable , Statistics, Nonparametric , Tunisia
15.
J Genet ; 2008 Dec; 87(3): 201-7
Article in English | IMSEAR | ID: sea-114242

ABSTRACT

In the analysis of inheritance of quantitative traits with low heritability, an F(2:3) design that genotypes plants in F(2) and phenotypes plants in F(2:3) progeny is often used in plant genetics. Although statistical approaches for mapping quantitative trait loci (QTL) in the F(2:3) design have been well developed, those for binary traits of biological interest and economic importance are seldom addressed. In this study, an attempt was made to map binary trait loci (BTL) in the F(2:3) design. The fundamental idea was: the F(2) plants were genotyped, all phenotypic values of each F(2:3) progeny were measured for binary trait, and these binary trait values and the marker genotype informations were used to detect BTL under the penetrance and liability models. The proposed method was verified by a series of Monte-Carlo simulation experiments. These results showed that maximum likelihood approaches under the penetrance and liability models provide accurate estimates for the effects and the locations of BTL with high statistical power, even under of low heritability. Moreover, the penetrance model is as efficient as the liability model, and the F(2:3) design is more efficient than classical F(2) design, even though only a single progeny is collected from each F(2:3) family. With the maximum likelihood approaches under the penetrance and the liability models developed in this study, we can map binary traits as we can do for quantitative trait in the F(2:3) design.


Subject(s)
Chromosome Mapping , Computer Simulation , Crosses, Genetic , Genotype , Likelihood Functions , Models, Genetic , Phenotype , Quantitative Trait Loci/genetics , Quantitative Trait, Heritable
16.
Genet. mol. res. (Online) ; 7(1): 234-242, Jan. 2008. ilus, tab
Article in English | LILACS | ID: lil-553790

ABSTRACT

With the aim of estimating the coefficient of heritability of average annual productivity of Nellore cows (COWPROD), a data set from 24,855 animals with known pedigree was analyzed. COWPROD is defined as the amount (in kilograms) of weaned calves produced yearly by one cow during her remaining time in herd ignoring a fixed period of 365 days. COWPROD was calculated regarding three standards: a) based on the post-weaning weight from the calves ignoring any kind of adjustment (COWPROD_NAJ), b) adjusted weight for the fixed effects (COWPROD_AJFIX) and c) adjusted weight for the fixed effects and for the genetic merit of the sire (COWPROD_AJFIN). The obtained heritabilities were 0.15, 0.15 and 0.16 for COWPROD_NAJ, COWPROD_AJFIX and COWPROD_AJFIN, respectively. A complete set composed of 105,158 COWPROD records on 130,740 animals in pedigree was also analyzed for predicting the genetic merit of all animals in the data set and for the calculation of the genetic, phenotypic and residual trends. Ranking correlation was high for the adjusted and non-adjusted data, yet, for some of the animals, the difference among the genetic values was large. This would be an indication that it would be better to work always with the adjusted weaning weights. The genetic trend was positive, but was of small magnitude (0.26% of the trait average) and the residual trend was negative as a consequence of the large intensification of the production system, which has been occurring in the last years in the farms studied. The phenotypic trend was also negative and intermediate between the genetic and the residual ones.


Subject(s)
Animals , Female , Cattle/genetics , Crosses, Genetic , Quantitative Trait, Heritable , Reproduction/genetics , Body Weight , Phenotype
17.
J Genet ; 2007 Aug; 86(2): 149-58
Article in English | IMSEAR | ID: sea-114280

ABSTRACT

Mesosternal (MS) bristles in Drosophila are a pair of machrochaetae found at the sternal end of the sternopleural (STP) microchaetae, and are thought to be invariable. In a closely related drosophilid genus, Zaprionus, their number is four and, in contrast to Drosophila, they show interspecific and intraspecific variability. The genetic basis of MS bristle number variability was studied in Z. indianus, the only cosmopolitan species of the genus. The trait responded rapidly to selection and two lines were obtained, one lacking any bristles (0-0) and the other bearing the normal phenotype (2-2). Other symmetrical phenotypes, (1-1) and (3-3), could also be selected for, but with lesser success. By contrast, STP bristle number did not vary significantly between the two lines (0-0) and (2-2), revealing its genetic independence from MS bristle number. Reciprocal crosses between these two lines showed that MS bristle number is mainly influenced by a major gene on the X chromosome (i.e. F(1) males always resembled their mothers) with codominant expression (i.e. heterozygous F(1) females harboured an average phenotype of 2 bristles). However, trait penetrance was incomplete and backcrosses revealed that this variability was partly due to genetic modifiers, most likely autosomal. The canalization of MS bristle number was investigated under different temperatures, and the increased appearance of abnormal phenotypes mainly occurred at extreme temperatures. There was a bias, however, towards bristle loss, as shown by a liability (developmental map) analysis. Finally, when ancestral and introduced populations were compared, the latter were far less stable, suggesting that genetic bottlenecks may perturb the MS bristle number canalization system. MS bristle number, thus, appears to be an excellent model for investigating developmental canalization at both the quantitative and the molecular level.


Subject(s)
Animals , Cell Count , Cilia/genetics , Crosses, Genetic , Drosophilidae/anatomy & histology , Female , Genes, X-Linked , Genetic Variation , Geography , Phylogeny , Quantitative Trait, Heritable , Selection, Genetic , Species Specificity , Sternum
18.
Genet. mol. res. (Online) ; 6(1): 67-78, 2007. tab
Article in English | LILACS | ID: lil-456752

ABSTRACT

Records of Holstein cows from the Dairy Records Processing Center at Raleigh, NC were edited to obtain three data sets: 65,720 first, 50,694 second, and 65,445 later lactations. Correlations among yield traits and somatic cell score were estimated with three different models: 1) bovine somatotropin (bST) administration ignored, 2) bST administration as a fixed effect and 3) administration of bST as part of the contemporary group (herd-year-month-bST). Heritability estimates ranged from 0.13 to 0.17 for milk, 0.12 to 0.20 for fat, 0.14 to 0.16 for protein yields, and 0.08 to 0.09 for somatic cell score. Estimates were less for later than first lactations. Estimates of genetic correlations among yields ranged from 0.35 to 0.85 with no important differences between estimates with the 3 models. Estimates for lactation 2 agreed with estimates for lactation 1. Estimates of genetic correlations for later lactations were generally greater than for lactations 1 and 2 except between milk and protein yields. Estimates of genetic correlations between yields and somatic cell score were mostly negative or small (-0.45 to 0.11). Estimates of environmental correlations among yield traits were similar with all models (0.77 to 0.97). Estimates of environmental correlations between yields and somatic cell score were negative (-0.22 to -0.14). Estimates of phenotypic correlations among yield traits ranged from 0.70 to 0.95. Estimates of phenotypic correlations between yields and somatic cell score were small and negative. For all three data sets and all traits, no important differences in estimates of genetic parameters were found for the two models that adjusted for bST and the model that did not


Subject(s)
Animals , Female , Cattle , Cattle/genetics , Growth Hormone/pharmacology , Lactation/genetics , Quantitative Trait, Heritable , Genetic Variation , Dairying , Environment , Fats/analysis , Lactation/drug effects , Lactation/physiology , Linear Models , Milk/chemistry , Regression Analysis , Seasons
19.
Genet. mol. res. (Online) ; 6(1): 79-93, 2007. tab, graf, ilus
Article in English | LILACS | ID: lil-456753

ABSTRACT

Records of Holstein cows were used to examine how different models account for the effect of bovine somatotropin (bST) treatment on genetic evaluation of dairy sires for yield traits and somatic cell score. Data set 1 included 65,720 first-lactation records. Set 2 included 50,644 second-lactation records. Set 3 included 45,505 records for lactations three, four and five. Estimated breeding values (EBV) of sires were with three different animal models. With Model 1, bST administration was ignored. With Model 2, bST administration was used as a fixed effect. With Model 3, administration of bST was used to define the contemporary group (herd-year-month of calving-bST). Correlations for EBV of 1,366 sires with treated daughters between pairs of the three models were calculated for milk, fat and protein yields and somatic cell score for the three data sets. Correlations for EBV of sires between pairs of models for all traits ranged from 0.971 to 0.999. Fractions of sires with bST-treated progeny selected in common (top 10 to 15%) were 0.94 and usually greater for all pairs of models for all traits and parities. For this study, the method of statistical adjustment for bST treatment resulted in a negligible effect on genetic evaluations of sires when some daughters were treated with bST and suggests that selection of sires to produce the next generation of sires and cows might not be significantly affected by how the effect of bST is modeled for prediction of breeding values for milk, fat and protein yields and somatic cell score


Subject(s)
Animals , Female , Cattle , Cattle/genetics , Growth Hormone/pharmacology , Lactation/genetics , Quantitative Trait, Heritable , Genetic Variation , Dairying , Environment , Fats/analysis , Lactation/drug effects , Lactation/physiology , Linear Models , Milk/chemistry , Regression Analysis
20.
Genet. mol. res. (Online) ; 6(1): 188-196, 2007.
Article in English | LILACS | ID: lil-456764

ABSTRACT

The present study was carried out to estimate both (co)variance components and genetic parameters for frame scores obtained using two methods (FRAME_GMA and FRAME_BIF) as well as phenotypic and genetic correlations with traits such as weaning weight, weight gain from weaning to yearling, scrotal circumference, muscle score, and an empiric index for animal classification for the Special Certificate of Identification and Production (CEIP). Data on 12,728 animals, raised in Southeastern Brazil, with ages from 490 to 610 days were analyzed. Estimates of heritability for FRAME_GMA and FRAME_BIF in multi-trait analysis were 0.28 and 0.24, respectively. Genetic correlation coefficients between frame scores and the growth trait were of medium magnitude, which indicates that genetic selection for weight resulted in undesirable responses, increasing the animals’ frames. Small changes should be expected in the frame of animals that have been submitted to a genetic selection regarding muscle score and scrotal circumference. The low magnitude of phenotypic and genetic correlation between frame scores and the empirical selection index that classifies animals for CEIP, a Brazilian official certificate that recognizes the value of seedstock that is not registered at breeders associations, but is genetically evaluated, does not indicate important responses in giving a CEIP to animals that have been directly or indirectly selected for frame. Other studies must be performed to determine estimates of the genetic parameters for frame scores in other beef cattle populations


Subject(s)
Animals , Male , Female , Cattle , Selection, Genetic , Body Size/genetics , Cattle/genetics , Quantitative Trait, Heritable , Cattle/anatomy & histology , Models, Genetic , Phenotype
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