Association of polymorphisms of the ß-defensin 1 gene with nematode and protozoan infection traits in goat.

This study's purpose was to identify polymorphisms (SNP) in the goat ß-defensin 1 gene and to associate these SNPs with traits related to nematodean and protozoan infections in Anglo-Nubian goats from semiarid region of Brazil. A total of 184 animals were used for DNA extraction, PCR and DNA automatic sequencing. The association analyses included the fixed effects of animal age, bloodline and genotype of the SNP marker in the statistical model. The means of genotypes were compared by the Fisher test (P < 0.05). Twelve polymorphism genotypes were found: two in intron 1, seven in exon 2 and three in 3' untranslated region. The SNPs of exon 2 were responsible for amino acid substitutions in six genetic codes, and the changes in the 25th and 33rd codes affected the protein function. The SNP 1937 was significantly associated with number of protozoan oocysts, whereas SNP 2001 was associated with degree of anaemia (Famacha©). Polymorphism 2046, in turn, showed a significant association with Famacha© degree and number of protozoan oocysts. SNP 2140 associated with maximum EPG of the animal. Results from this study suggest that the ß-defensin 1 gene can be used as a molecular marker for selection of goats regarding the susceptibility to endoparasites infections.

B-spline polynomials models for analyzing growth patterns of Guzerat young bulls in field performance tests.

OBJECTIVE: The aim of this study was to identify suitable polynomial regression for modeling the average growth trajectory and to estimate the relative development of the rib eye area, scrotal circumference, and morphometric measurements of Guzerat young bulls. METHODS: A total of 45 recently weaned males, aged 325.8±28.0 days and weighing 219.9±38.05 kg, were evaluated. The animals were kept on Brachiaria brizantha pastures, received multiple supplementations, and were managed under uniform conditions for 294 days, with evaluations conducted every 56 days. The average growth trajectory was adjusted using ordinary polynomials, Legendre polynomials, and quadratic B-splines. The coefficient of determination, mean absolute deviation, mean square error, the value of the restricted likelihood function, Akaike information criteria, and consistent Akaike information criteria were applied to assess the quality of the fits. For the study of allometric growth, the power model was applied. RESULTS: Ordinary polynomial and Legendre polynomial models of the fifth order provided the best fits. B-splines yielded the best fits in comparing models with the same number of parameters. Based on the restricted likelihood function, Akaike's information criterion, and consistent Akaike's information criterion, the B-splines model with six intervals described the growth trajectory of evaluated animals more smoothly and consistently. In the study of allometric growth, the evaluated traits exhibited negative heterogeneity (b<1) relative to the animals' weight (p<0.01), indicating the precocity of Guzerat cattle for weight gain on pasture. CONCLUSION: Complementary studies of growth trajectory and allometry can help identify when an animal's weight changes and thus assist in decision-making regarding management practices, nutritional requirements, and genetic selection strategies to optimize growth and animal performance.

Polymorphism of the leptin gene in buffalo breed groups from eastern Amazon.

The objective of this work was to characterize genetically some buffalo herds raised in Varzea (VA) and Terra-Firme (upland) (TF) ecosystems through polymorphism of the intron 2 of the leptin gene ( LEP-1620). Two hundred seventy-nine animals from four distinct populations were evaluated using the PCR-RFLP method for LEP-1620 polymorphism (SNP) of the leptin gene with restriction enzyme BsaAI. The animal samples were sorted into 4 groups, according to their breed and environmental origin: Mediterranean TF, Murrah TF, Mediterranean VA and Crossbreed VA. Two alleles (A and G) were detected and their frequencies were analyzed. Allele A frequency ranged from 0.395 (Mediterranean TF) to 0.850 (Murrah TF), with AA genotype ranged from 0.114 (Murrah TF) to 0.700 (Mediterranean TF). The observed and expected heterozygosities ranged from 0.268 (Mediterranean TF) to 0.562 (Murrah TF), and 0.255 (Mediterranean TF) to 0.478 (Murrah TF), respectively. The Hardy-Weinberg probabilities were greater than 0.05. The Crossbred herd in Varzea was the only population with significant inbreeding and the Shannon index ranged between 0.423 (Mediterranean TF) and 0.671 (Murrah TF).

Aspectos bioecológicos e genético-comportamentais envolvidos na conservação da abelha Jandaíra, Melipona subnitida Ducke (Apidae, Meliponini), e o uso de ferramentas moleculares nos estudos de diversidade / Bioecological and behavioral genetic aspects involved in the conservation of the stingless bee Melipona subnitida Ducke (Apidae, Meliponini) and the use of molecular tools in studies of diversity

A abelha sem ferrão Melipona subnitida atualmente está presente em quase toda a região nordeste, em função da boa adaptabilidade ao semiárido nordestino e do potencial econômico-ecológico proporcionado pela produção de mel e pela polinização de cultivos em condições de confinamento. Apesar disso, é uma espécie ameaçada devido a processos de degradação ambiental, dentre os quais estão o desmatamento, o uso indiscriminado de agrotóxicos e o extrativismo. Tais interferências tendem a isolar as populações de Jandaíra, provocando uma queda na variabilidade genética e, consequentemente, uma redução na capacidade adaptativa da espécie. Porém, técnicas de biologia molecular estão sendo implementadas, possibilitando que populações desse tipo sejam avaliadas quanto ao seu grau de variabilidade genética. Marcadores moleculares do tipo microssatélites de DNA vêm sendo bastante usados, porém, em função do alto custo exigido para seu desenvolvimento, diversos estudos vêm empregando microssatélites transferidos de táxons próximos com amplo sucesso em estudos voltados à caracterização e à diversidade genética. Dessa forma, a presente revisão objetivou avaliar os mais relevantes aspectos bioecológicos e genético-comportamentais envolvidos na conservação da abelha Jandaíra, a fim de auxiliar na avaliação do grau de diversidade genética da espécie, bem como da sua distribuição entre indivíduos e populações da abelha sem ferrão M. subnitida.(AU)

The stingless bee Melipona subnitida is now present almost everywhere in the Brazilian Northeastern, as a consequence of its good adaptability to the semiarid and economic and ecological potential offered by the honey production and pollination of commercial crops under confined conditions. Nevertheless, it is an endangered species due to environmental degradation processes, among which are: deforestation, indiscriminate use of pesticides and honey extraction. Such interference tends to isolate populations of Jandaíra causing a decrease in genetic variability, and therefore a reduction in the adaptive capacity of the species. However, advanced Molecular Biology techniques have been used allowing such populations to be assessed for their degree of genetic variability. Molecular markers such as microsatellite DNA are widely applied to genetic diversity studies. However, due to the high costs required for their development, several studies have been focused on the use of microsatellites transferred from closely related taxa with much success in studies on the genetic characterization of species and their populations. Therefore, this review aimed to evaluate the most relevant ecological and behavioral aspects in order to assist the population genetic studies of the stingless bee M. subnitida.(AU)

Repetibilidade e correlações entre caracteres morfo-agronômicos de cajazeira / Repeatability and correlations among yellow mombim morphoagronomical traits

Objetivou-se estimar os coeficientes de repetibilidade em quatorze cajazeiras (Spondias mombin L.), no município de Teresina, PI, utilizando-se o método de análise de variância; determinar o número de medições necessárias para predição do valor real dos indivíduos e os coeficientes de correlação fenotípica entre os caracteres: comprimento e largura da folha, número de folíolos por folha, peso da panícula, número de frutos por panícula, comprimento, diâmetro e peso do fruto, peso da semente, rendimento de polpa, teor de sólidos solúveis, acidez titulável, relação sólidos solúveis/acidez. Os genótipos diferiram com relação a todos os caracteres avaliados, indicando a presença de variabilidade genética. As estimativas dos coeficientes de repetibilidade expressaram maior estabilidade para peso do fruto, diâmetro do fruto, peso da semente, acidez titulável e relação sólidos solúveis/acidez titulável, indicando maior precisão na predição do valor real desses caracteres, nas cajazeiras. A avaliação de onze frutos é suficiente para predizer o valor real de todos os caracteres, com 90% de confiabilidade. A seleção para maior produtividade de frutos pode ser alcançada através da seleção indireta para caracteres relacionados à folha. Panícula mais pesada pode ser obtida pela seleção indireta de genótipos com sementes de menor peso.

The objective of this work was to estimate the coefficient of repeatability in fourteen yellow mombim (Spondias mombin L.), in Teresina, Piauí State, through the variance analysis method, in order to determine the number of measures necessary for an accurate prediction of the real genotype value and the correlation coefficients among the leaf length, leaf width, number of leaflets for leaf, panicles weight, number of fruits for panicles, fruit length, fruit diameter, fruit weight, seed weight, pulp revenue, soluble solid (SS), titrable acidity (AT) and SS/AT ratio. The genotypes had significant differences in all traits, indicating the existence of genetic variability. The estimates of the coefficients of repeatability expressed a greater stability for fruit weight, fruit diameter, seed weight, titrable acidity and soluble solid/titrable acidity ratio, indicating more accuracy to the real value pediction of these yellow mombim traits. The evaluation of eleven fruits is enough to predict the real value of all characters with an accuracy of 90%. The selection for characters related to the leaf could lead to an indirect selection for high fruit yield. The high panicle weight could be selected through the indirect selection for low seed weight.

Maternal effects on the genetic evaluation of Tabapuã beef cattle

The aim of this investigation was to study the influence of maternal effects on the genetic evaluation of sire production in Tabapuã beef cattle. Single and multiple trait analyses were done with adjusted animal weights at 120, 240 and 420 days of age. Antagonism was observed between additive direct and maternal genetic effects, with the maternal effect being higher until weaning. The inclusion of maternal effects in the models removed part of the additive variance only in single trait analyses and resulted in smaller means and standard deviations for the sire breeding values. The use of maternal effect associated with single or multiple traits may affect sire ranking. The contradictory results of the single and multiple trait analyses for additive direct and maternal effects indicate that caution is needed when considering recommendations about the importance of maternal effects in Tabapuã beef cattle.