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Marker Technology (marker + technology)

Distribution by Scientific Domains

Life Sciences	60%

Selected Abstracts

Integrating molecular genetic technology with traditional approaches for genetic improvement in aquaculture species

AQUACULTURE RESEARCH, Issue 1 2000
G P. Davis
Genetic improvement of aquaculture species offers a substantial opportunity for increased production efficiency, health, product quality and, ultimately, profitability in aquacultural enterprises. Technolo-gies exist that can be implemented immediately to improve multiple traits that have economic value, while simultaneously accounting for inbreeding effects. Genetic improvement techniques for delivering genetic gain include formal definition of the breeding objective, estimation of genetic parameters that describe populations and their differences, evaluation of additive and non-additive genetic merit of individuals or families and defining the structure of a breeding programme in terms of mating plans. Novel genetic technologies involving the use of DNA-based tools are also under development for a range of aquaculture species. These gene marker technologies can be used for identification and monitoring of lines, families and individuals, monitoring and control of inbreeding, diagnosis of simply inherited traits and genetic improvement through selection for favourable genes and gene combinations. The identification of quantitative trait loci (QTL), and direct or linked markers for them, will facilitate marker-assisted selection in aquaculture species, enabling improvement in economically important traits, particularly those that are difficult to breed for, such as food conversion efficiency and disease resistance. [source]

Identification of monozygous twins and microsatellite mutation rate in pigs from QTL linkage analysis data

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 5 2001
L. Grapes
In previous work, microsatellite markers have primarily been tools for genome studies. However, the use of marker data can be extended beyond its original intent to maximize the amount of information obtained. There have been few studies to determine the occurrence of monozygous (MZ) twins in pigs. The advent of DNA marker technology, and microsatellites in particular, allows MZ twins to be identified based on their genotype data. To determine if MZ twin births occur in pigs, genotypes for F2 individuals, n=525, from 65 Berkshire × Yorkshire families were examined. One pair of female twins was found to have matching genotype data (95% CI: 0,2.94 twins). This is a unique result since there have been no published reports to date of twin pigs that survived until birth. Additionally, three dinucleotide microsatellite mutations were found after screening 134 565 meioses of 125 loci spanning the entire genome and the X chromosome. The average mutation rate for the population, n=570, was 2.23 × 10,5 (95% CI: 6.17 × 10,6,6.51 × 10,5). A mutation rate similar to this was published earlier for dinucleotide repeat microsatellite mutations in swine. Identification de jumeaux monozygotes et taux de mutation des microsatellites à partir de données d, analyse de liaison avec des caractères quantitatifs Jusqu'à présent, les marqueurs microsatelittes ont été principalement utilisés comme outils pour étudier le génome. Cependant, l'utilisation des données de marquage peut être étendue au delà de ce but initial et permet d'obtenir d'autres types d'informations. Au cours des dernières années, il n'y a eu que peu d'études visant à determiner l'existence de jumeaux monozygotes (MZ) chez le porc. L'avènement des techniques de marquage de l'ADN, et plus particulièrement des microsatelittes, permet l'identification de jumeaux MZ sur la base de leur génotype aux marqueurs. Afin de déterminer s'il existe des jumeaux MZ chez le porc, nous avons examiné les génotypes d'individus F2 (n=525) issus de 65 familles Berkshire × Yorkshire. La recherche d'individus ayant un genotype identique a permis d'identifer un couple de jumeaux femelles (95% CI: 0,2.94). Il s'agit d'un résultat unique car jusqu'à ce jour, il n'y avait aucun cas publié de jumeaux ayant survécus après la naissance chez le porc. Par ailleurs, après analyse de 134 565 méioses pour 125 loci répartis sur l'ensemble du génome et sur le chromosome X, 3 mutations ont été trouvées au niveau de microsatelittes dinucleotidiques. Le taux moyen de mutation dans la population (n=570) a été estiméà 2.23 × 10,5 (95% IC: 6.17 × 10,6à 6.51 × 10,5). Un taux de mutation similaire à celui-ci a été publié précédemment pour des marqueurs microsatelittes dinucleotidiques chez le porc. [source]

Utility of AFLP markers for the assessment of genetic diversity within Brassica nigra germplasm

PLANT BREEDING, Issue 1 2004
M. S. Negi
Abstract Genetic diversity of 18 Brassica nigra accessions was estimated using amplified fragment length polymorphism (AFLP) marker technology. Two B. rapa and two B. juncea accessions were selected as outliers in the study. Eight AFLP primer combinations generated a total of 426 bands, of which 79% were polymorphic. The UPGMA method was employed to construct a dendrogram based on the Jaccard's similarity coefficient. The accessions of B. rapa separated from those of B. nigra at a genetic similarity coefficient of 0.27 while those of B. juncea did so at 0.5. The genetic similarity coefficients within the B. nigra accessions ranged from 0.58 to 0.86. Based on these coefficients it was concluded that the B. nigra accessions show high levels of genetic variation. These results have significant implications in the crop improvement programmes for the agronomically important crop B. juncea, an amphidiploid of B. nigra and B. rapa. Two incorrectly labelled B. nigra accessions were also identified. These accessions were found to cluster with those of B. juncea accessions. This result demonstrates the great value of AFLP markers in the management of genebanks. [source]

Development of a vaccine marker technology: Display of B cell epitopes on the surface of recombinant polyomavirus-like pentamers and capsoids induces peptide-specific antibodies in piglets after vaccination

BIOTECHNOLOGY JOURNAL, Issue 12 2006
Markus Neugebauer
Abstract Highly immunogenic capsomers (pentamers) and virus-like particles (VLPs) were generated through insertion of foreign B cell epitopes into the surface-exposed loops of the VP1 protein of murine polyomavirus and via heterologous expression of the recombinant fusion proteins in E. coli. Usually, complex proteins like the keyhole limpet hemocyanin (KLH) act as standard carrier devices for the display of such immunogenic peptides after chemical linkage. Here, a comparative analysis revealed that antibody responses raised against the carrier entities, KLH or VP1 pentamers, did not significantly differ up to 18 weeks, demonstrating the highly immunogenic nature of VP1-based particulate structures. The carrier-specific antibody response was reproducibly detected in the meat juice after processing. More importantly, chimeric VP1 pentamers and VLPs carrying peptides of 12 and 14 amino acids in length, inserted into the BC2 loop, induced a strong and long-lasting humoral immune response against VP1 and the inserted foreign epitope. Remarkably, the epitope-specific antibody response was only moderately decreased when VP1 pentamers were used instead of VLPs. In conclusion, we identified polyomavirus VP1-based structures displaying surface-exposed immunodominant B cell epitopes as being an efficient carrier system for the induction of potent peptide-specific antibodies. The application of this approach in vaccine marker technology in livestock holding and the meat production chain is discussed. [source]