RAPD markers utilization on the formation or maintenance of conservation nuclei of livestock species (Uso de marcadores RAPD en la formación o mantenimiento de núcleos de conservación de animales domésticos)

Egito A.A.

Description

Abstract
Genetic characterization is an essential issue in the conservation and breeding programs of any country. In these work we report the use of RAPD markers in population genetic study of three breeds of different species that are in Brazilian genetic conservation program. The objective was to analyze the genetic similarity of individuals of those populations breeds in order to contribute to ex situ and in situ conservation. The selection of animals with least genetic similarity can help to conserve the maximum variability within a population, and can even optimize the choice of breeders for ex situ conservation programs. These studies were carried out in the Animal Genetics Laboratory (AGL) at Embrapa"s Center for Genetic Resources and Biotechnology (CENARGEN). The native populations studied include: the Pantaneiro horse (in situ conservation nuclei), the bovine Crioulo Lageano (in situ conservation nuclei) and the Moxotó goat (five populations of these breed distributed in Northeast states). Using RAPD markers, obtained for each specie, we generated a Jaccard coefficient similarity matrix by NTSYS-pc v. 2.0 program. By the comparison between pairs of individuals we could chose those that were more similar between itself and those that were more distant. Using those matrix we suggested three kinds of procedure that could be used for helping the conservation of those breeds: the choice of the males to be semen donators - those less similar - avoiding duplication of samples (animals with high genetic similarity)
the indication of preferential crossings aiming at the maintenance of the maximum genetic variability and the indication of animals for discarding - those that had high similarity - the breeder chose one of them for the discard. This kind of analysis could be done between two populations of the same breed in order to contribute to the genetic sample exchange between different nuclei. We must remember that these recommendations are based exclusively on genetic data and must lead in account the phenotypic characteristics of each animal, not having however to be considered separately.
Resumen
La caracterización genética es una materia esencial en los programas de conservación y de cría de cualquier país. En este trabajo informamos del uso de marcadores RAPD en el estudio de genética de poblaciones de tres razas de diferentes especies incluidas en los programas de conservación en Brasil. El objetivo fue analizar la similitud genética individual de aquellas poblaciones raciales para contribuir a su conservación ex situ e in situ. La selección de animales con menor similitud genética puede ayudar a conservar el máximo de variabilidad dentro de poblaciones y puede optimizar el trabajo de los criadores para los programas de conservación ex situ. Estos trabajos fueron realizados en el Laboratorio de Genética Animal (AGL) del Centro para los Recursos Genéticos y la Biotecnología (CENARGEN) de EMBRAPA. Las poblaciones nativas incluidas fueron: caballo Pantaneiro (núcleo de conservación in situ), el bovino Criollo Lageano (núcleo de conservación in situ), y la cabra Moxotó (cinco poblaciones de esta raza distribuidas en los estados del Nordeste). Usando marcadores RAPD, obtenidos para cada especie, generamos una matriz de coeficientes de similitud de Jaccard, mediante un programa NTSYS-pc v.2.0. Mediante la comparación entre pares de individuos podríamos escoger aquellos que fueron más similares entre ellos y aquellos que fueron más distantes. Usando estas matrices sugerimos tres tipos de procedimientos que podrían ser usados para apoyar la conservación de estas razas: la elección de machos para donantes de semen (animales con alta similitud genética).

Sujets

• Genética de la conservación

Informations

• Publié par: erevistas
• Publié le: 01 janvier 2005
• Nombre de lectures: 5
• Langue: English

Extrait

RAPD MARKERS UTILIZATION ON THE FORMATION OR
MAINTENANCE OF CONSERVATION NUCLEI OF
LIVESTOCK SPECIES
USO DE MARCADORES RAPD EN LA FORMACIÓN O MANTENIMIENTO DE NÚCLEOS
DE CONSERVACIÓN DE ANIMALES DOMÉSTICOS
1 2 2 3 2 1Egito, A.A.* , B. Fuck , A.L. Spritze , R.R. Oliveira , C. McManus , A.S. Mariante ,
3 1 1 1 4M.N. Ribeiro , M.S.M. Albuquerque , S.R. Paiva , S.T.R. Castro and S.A. Santos
1Embrapa Recursos Genéticos e Biotecnologia. PqEB – Final W5 Norte. Brasília-DF. Brasil.
2Universidade de Brasília. Faculdade de Agronomia e Veterinária. Brasília-DF. Brasil.
3Universidade Rural de Pernambuco. Recife-PE. Brasil.
4Embrapa Pantanal. Caixa Postal 109. Corumbá-MS. Brasil.
*E-mail: [e-mail].
ADDITIONAL KEYWORDS PALABRAS CLAVE ADICIONALES
Native breeds. Populations structure. Conser- Razas autóctonas. Estructura de poblaciones.
vation genetics. Genética de la conservación.
SUMMARY
Genetic characterization is an essential issue Moxotó goat (five populations of these breed
distributed in Northeast states). Using RAPDin the conservation and breeding programs of
markers, obtained for each specie, we generatedany country. In these work we report the use of
RAPD markers in population genetic study of a Jaccard coefficient similarity matrix by NTSYS-
three breeds of different species that are in pc v. 2.0 program. By the comparison between
pairs of individuals we could chose those thatBrazilian genetic conservation program. The
objective was to analyze the genetic similarity of were more similar between itself and those that
were more distant. Using those matrix weindividuals of those populations breeds in order
suggested three kinds of procedure that could beto contribute to ex situ and in situ conservation.
The selection of animals with least genetic used for helping the conservation of those breeds:
similarity can help to conserve the maximum the choice of the males to be semen donators -
those less similar - avoiding duplication of samplesvariability within a population, and can even
optimize the choice of breeders for ex situ (animals with high genetic similarity); the indication
of preferential crossings aiming at the mainte-conservation programs. These studies were
nance of the maximum genetic variability and thecarried out in the Animal Genetics Laboratory
(AGL) at Embrapa's Center for Genetic Resources indication of animals for discarding - those that
and Biotechnology (CENARGEN). The native had high similarity - the breeder chose one of
them for the discard. This kind of analysis couldpopulations studied include: the Pantaneiro horse
(in situ conservation nuclei), the bovine Crioulo be done between two populations of the same
breed in order to contribute to the genetic sampleLageano (in situ conservation nuclei) and the
Arch. Zootec. 54: 277-281. 2005.
RAPDEgito.p65 277 21/12/2005, 9:46EGITO ET AL.
exchange between different nuclei. We must ma variabilidad genética y la indicación de anima-
remember that these recommendations are based les a descartar -aquellos que tienen la máxima
exclusively on genetic data and must lead in similitud- los criadores escogen uno de ellos para
account the phenotypic characteristics of each descartar. Este tipo de análisis podría realizarse
animal, not having however to be considered entre dos poblaciones de la misma raza para
separately. contribuir al intercambio de individuos entre dife-
rentes núcleos. Debemos recordar que estas
recomendaciones están basadas exclusivamen-
te en datos genéticos y debemos tener en cuentaRESUMEN
las características fenotípicas de cada animal,
La caracterización genética es una materia no teniendo, de cualquier manera que ser consi-
esencial en los programas de conservación y de deradas separadamente.
cría de cualquier país. En este trabajo informa-
mos del uso de marcadores RAPD en el estudio
de genética de poblaciones de tres razas de INTRODUCTION
diferentes especies incluidas en los programas
de conservación en Brasil. El objetivo fue anali- The proposal for conservation of
zar la similitud genética individual de aquellas endangered livestock populations is
poblaciones raciales para contribuir a su conser- being the cryopreservation of gametes
vación ex situ e in situ. La selección de animales and zygotes of several donators and in
con menor similitud genética puede ayudar a situ conservation nuclei (live animals
conservar el máximo de variabilidad dentro de
in reproducing herds). Taking into
poblaciones y puede optimizar el trabajo de los
account that the main objective is to
criadores para los programas de conservación
store a representative sample of the
ex situ. Estos trabajos fueron realizados en el
population variability, its fundamentalLaboratorio de Genética Animal (AGL) del Centro
to evaluate the genetic variation of thepara los Recursos Genéticos y la Biotecnología
stocked individuals and to maintain the(CENARGEN) de EMBRAPA. Las poblaciones
maximum variability as possible in thenativas incluidas fueron: caballo Pantaneiro (nú-
conservation herd.cleo de conservación in situ), el bovino Criollo
Lageano (núcleo de conservación in situ), y la Genetic characterization, contrary
cabra Moxotó (cinco poblaciones de esta raza to phenotypic characterization, is totally
distribuidas en los estados del Nordeste). Usan- free of environmental influences,
do marcadores RAPD, obtenidos para cada es- thereby making the data generated more
pecie, generamos una matriz de coeficientes de accurate. The use of molecular markers
similitud de Jaccard, mediante un programa can aid decisions relating to choice of
NTSYS-pc v.2.0. Mediante la comparación entre
breeds/populations to be conserved,
pares de individuos podríamos escoger aquellos
when there is a shortage of resources,
que fueron más similares entre ellos y aquellos
as well as estimating the genetic
que fueron más distantes. Usando estas matri-
variability of species, breeds andces sugerimos tres tipos de procedimientos que
populations (Egito et al., 1999). Thuspodrían ser usados para apoyar la conservación
being the techniques for the analysis ofde estas razas: la elección de machos para
the genetic variability are an essentialdonantes de semen (animales con alta similitud
ingredient for the programs of rationalgenética); la indicación de apareamientos prefe-
renciales buscando el mantenimiento de la máxi- conservation and improvement, once
Archivos de zootecnia vol. 54, núm. 206-207, p. 278.
RAPDEgito.p65 278 21/12/2005, 9:46RAPD MARKERS FOR MAINTENANCE OF CONSERVATION NUCLEI OF LIVESTOCK
they must be based on the combination populations of these breed distributed
of the phenotypic and genetic data in Pernambuco, Paraiba and Rio Gran-
(Hetzel and Drinkwater, 1992). de do Norte, Brazilian northeast States).
The calculation of pairwise genetic Genomic DNA extraction from
similarities indices between individuals blood cells of individuals was based on
may help to choose those animals that Miller et al. (1988) with slight modi-
possess a lesser genetic similarity and fications.
might be a value tool to select the In Pantaneiro horse a total of 13
future donators of germplasm for the primers were selected from 146
Brazilian Animal Germplasm Bank or decamer oligonucleotide primers and
to indicate the preferential mating of used to amplify DNA from 48 animals.
less similar animals with intention to These primers amplified a total of 44
keep the maximum variability on the polymorphic bands.
nuclei (Egito et al., 2001). In the Crioulo Lageano herd, from a
In these work we report the use of total of 210 animals studied, we
RAPD markers in population genetic selected the youngest animals (80
study of three breeds of different animals that were borne from 1996 to
species that are in the Brazilian Genetic 2000) to analyze the pairwise similarity
Conservation Program. Using Jaccard's or dissimilarity in order to propose a
coefficient we analyzed the genetic breeding scheme for the nuclei. They
similarity of individuals, in pairs, in were amplified with 43 primers selected
order to contribute to ex situ and in from a total of 120 oligonucleotides
situ conservation. that generated 77 RAPD markers.
Seven populations (N= 264 animals)
of Moxotó goat were analyzed
MATERIAL AND METHODS separately one from the other with the
objective to help in crossbreeding inside
SIMILARITY STUDIES IN BREEDS/SPECIES each population and for the formation
CONSERVATIONS of conservation's nuclei of these
The studies were carried out in the breeds. The DNA from these animals
Animal Genetics Laboratory (AGL) at was amplified with 16 primers that
Embrapa's Center for Genetic Resour- generated 56 polymorphic bands.
ces and Biotechnology (CENARGEN) RAPD-PCR reactions were carried
and had been part of a program of pos- out in a final volume of 13 ml, with 20
graduation that exist in partnership mM Tris-HCl (pH 8.4); 50 mM KCl;
between the Embrapa and some 3.5 mM MgCl ; 200 mM of each dNTP;2
Brazilian Universities. 8 percent of 2.5 mg/ml of BSA; 0.4 mM
The native populations studied of the arbitrary primer; 1