3 resultados para heritability

em Universidade Federal do Rio Grande do Norte(UFRN)


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This work has contributed to knowledge of the order Testudines from cytogenetic and morphological point of view. With regard to the aspects proposed cytogenetic characterization of the species Mesoclemmys tuberculata (n = 5), endemic to the Caatinga biomes, through conventional techniques of cytogenetics and molecular levels. This species presented 2n = 58, NF = 64, the first submetacentric pair, the second metacentric and third subtelocentric, and the other microchromosome telocentric. This species showed a nucleolar bearing pair, coincident with the 18S ribosomal rDNA and that proved to be heterochromatic. Small heterochromatic blocks were also found in the centromeres of the largest chromosomes, as well as terminal regions in most other chromosomes of the complement, that were GC +. Telomeric sequences showed variable patterns of signal intensity, with some repeats more intense in microchromosomes and subtly in the larger ones. When compared with other species of the genus, the G-banding patterns showed a marked similarity between them. The first karyotypic description of the species will aid in future studies and the understanding of evolutionary aspects of this family. From the morphological point of view, we carried out studies of fluctuating asymmetry in sea turtle Eretmochelys imbricata, using methods of benchmarking between hatchlings and adults and their implications for natural selection. Data were collected at two different times: first during the spawning female and the second during the outbreak and birth of the nest. The analyzed characteristics consisted of measurements of length and width of front and rear flippers (CANT, LANT, CPOS and LPOS) also collected data on the number of hull plates, side plates (NPL), the surrounding plates (NPCIRC), and plastron; plates power plants (NPP), inframarginais plates (NPIM). With the values of asymmetry we calculated the value of strict heritability for these traits, the calculation was based on only one parent. A nonparametric analysis Mann-Whitneywas performed to compare the groups (females X hatchlings, newborn hatchlings X dead hatchlings). Adult females showed no bilateral fluctuating asymmetry (FA = 0) on the number plates of the hull and plastron, while offspring, living and dead, showed a greater level of variation in these meristic parameters. In the analysis of females x hatchlings we found a significant difference between the levels of asymmetry in hoof plates (p=0.006) an the width of hindlimbs (p=0.001). Levels of FA suggest an accurate indicator as to the viability or maintenance of the individual to the reproductive phase. The coefficient of heritability (h2) of FA , obtained from the regression analysis, showed that both have low and not statistically significant values(p> 0.1). In the case of exclusion of the effective role of genetics in the generation of FA, reproductive strategies based on high number of subsidiaries products, such as those observed in E. imbricata seems to implicate the production of individuals with high level of developmental instability

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genetic and environmental factors contribute to the development of cardiovascular risk and that influence can be differentiated by factors characteristic of each population, age and sex. Aim: To investigate the heritability of anthropometric and biochemical markers as predictors of cardiovascular risk in men and women of different age groups, using the method of twins. Methods: A sample of 88 subjects and of these 52 children and adolescents (08-17 years old) 32 monozygotic (20 female and 12 male) and 20 dizygotic (12 female and 08 male) and 36 adults (18-28 years age) 24 monozygotic (08 female and 16 male) and 12 dizygotic (06 female and 06 male), living in the metropolitan region of Natal / RN, Brazil. Anthropometric measures were taken as the height, body mass, waist circumference (WC), sum of skinfolds (ΣDC), fat percentage CUN-BAE, BMI and conicity. Biochemical markers analyzed were: fasting glucose (GLU), total cholesterol (COL), HDL-C, LDL-C and triglycerides (TG). After processing the data the index of heritability (h2) = (S ² MZ) / S ² DZ (DZ S ²) X100 was applied disaggregated by sex and age. Results: The variables showed differential heritability of behavior for men and women, depending on age. The variables with the highest heritability values were ΣDC, GLU, HDL, TG, in men and BMI, WC, ΣDC, GLU, HDL-C and TG in women. And more influenced by the environment variables were: body mass, BMI, Chol, LDL-C in men; body mass and LDL-C in women. Conclusion: Differences index of heritability by gender for cardiovascular risk predictors may assist in planning specific intervention strategies according to gender and stage of life of that individual. It is from the level of environmental influence that can run interventions for changes of components related to cardiovascular risk

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The main specie of marine shrimp raised at Brazil and in the world is Litopenaeus vannamei, which had arrived in Brazil in the `80s. However, the entry of infectious myonecrosis virus (IMNV), causing the infectious myonecrosis disease in marine shrimps, brought economic losses to the national shrimp farming, with up to 70% of mortality in the shrimp production. In this way, the objective was to evaluate the survival of shrimps Litopenaeus vannamei infected with IMNV using the non parametric estimator of Kaplan-Meier and a model of frailty for grouped data. It were conducted three tests of viral challenges lasting 20 days each, at different periods of the year, keeping the parameters of pH, temperature, oxygen and ammonia monitored daily. It was evaluated 60 full-sib families of L. vannamei infected by IMNV in each viral challenge. The confirmation of the infection by IMNV was performed using the technique of PCR in real time through Sybr Green dye. Using the Kaplan-Meier estimator it was possible to detect significant differences (p <0.0001) between the survival curves of families and tanks and also in the joint analysis between viral challenges. It were estimated in each challenge, genetic parameters such as genetic value of family, it`s respective rate risk (frailty), and heritability in the logarithmic scale through the frailty model for grouped data. The heritability estimates were respectively 0.59; 0.36; and 0.59 in the viral challenges 1; 2; and 3, and it was also possible to identify families that have lower and higher rates of risk for the disease. These results can be used for selecting families more resistant to the IMNV infection and to include characteristic of disease resistance in L. vannamei into the genetic improvement programs