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Molecular characterization of two common Chadian cattle breeds

Published online by Cambridge University Press:  01 August 2011

C. Flury
Affiliation:
Institue of Animal Science, Swiss Federal Institute of Technology (ETH), Universitätsstrasse 65, 8092 Zürich, Switzerland
B.N.R. Ngandolo
Affiliation:
Laboratoire de Recherches Vétérinaires et Zootechniques de Farcha, P.O. Box 433, N'Djaména, Chad
B. Müller
Affiliation:
Swiss Tropical Institute, P.O. Box, 4002 Basel, Switzerland
J. Zinsstag
Affiliation:
Swiss Tropical Institute, P.O. Box, 4002 Basel, Switzerland
H.N. Kadarmideen
Affiliation:
CSIRO Livestock Industries, JM Rendel Laboratory, P.O. Box 5545, Rockhampton, QLD 4702, Australia
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Summary

In previous studies, significant differences in Mycobacterium bovis infection prevalence was reported between two Chadian cattle breeds. Those findings and the established differentiation due to phenotypic characteristics suggest that the two breeds (Arab and Mbororo) are genetically different. To evaluate the genetic structure and the differences between these breeds, the genetic diversity within and between breeds was evaluated based on a total of 205 multilocus genotypes (21 microsatellite loci).

All of the loci under investigation were polymorphic and the number of alleles ranged from 4 to14 within the two populations. The analysis of population fixation resulted in a FST value of 0.006. Further the population assignment of the individual genotypes and the exact test of population differentiation did not support the hypothesis that the samples drawn from the two populations are genetically different. Population admixture and sample collection are discussed as possible reasons for the rejection of the hypothesis. Finally, recommendations for sample collection in extensive systems are given.

Resumé

Dans des études précédentes on avait observé des différences significatives dans les infections par Mycobacterium bovis chez les races bovines de Chadian. Ces observations et la différence due aux caractéristiques phénotipiques suggèrent que les deux races (Arabe et Mbororo) sont génétiquement différentes. Pour évaluer la structure génétique et les différences entre ces races on a évalué la diversité génétique dans et entre races sur un total de 205 génotypes multiloci (21 loci microsatélites). Tous les loci étudiés étaient polymorphiques et le nombre d'allèles allaient de 4 á 14 dans les populations. L'analyse de la fixation de la population a donné un Fst de valeur 0,006. Après l'asségnation des génotypes individuels á la population et le test exact de différence de la population, l'hypothèse des échantillons sortis de deux populations génétiquement différentes n'était pas correcte. Le mélange des populations et la saisie des échantillons sont étudiés comme possible cause du rejet de l'hypothèse. Pour finir, on présente une série de recomandations pour la saisie des échantillons dans des systèmes extensifs.

Resumen

En estudios anteriores se observaron diferencias significativas en infecciones prevalentemente por Mycobacterium bovis en dos razas bovinas de Chadian. Estos hallazgos y la diferenciación establecida debida a las características fenotípicas sugieren que las dos razas (Arabe y Mbororo) son genéticamente distintas. Para evaluar la estructura genética y las diferencias entre estas razas, se evaluaron la diversidad genética dentro y entre razas en un total de 205 genotipos multiloci (21 loci microsatélites). Todos los loci estudiados eran polimórficos y el número de alelos iba de 4 a 14 dentro de las dos poblaciones. El análisis de fijación de la población resultó en F con valor 0,006. Tras la asignación de genotipos individuales a la población y el test exacto de diferenciación de la población quedó eliminada la hipótesis de que las muestras sacadas de las dos poblaciones eran genéticamente diferentes. La mezcla de poblaciones y la recogida de muestras se discuten como posibles motivos que hicieron rechazar la hipótesis. Por fin, se presentan una serie de recomendaciones para la recogida de muestras en sistemas extensivos.

Type
Research Articles
Copyright
Copyright © Food and Agriculture Organization of the United Nations 2009

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References

List of References

Ayele, W.Y., Neill, S.D., Zinsstag, J., Weiss, M.G. & Pavlik, I. 2004. Bovine tuberculosis: an old disease but a new threat to Africa. Int. J. Tuberc. Lung Dis. 8, 924937.Google ScholarPubMed
Cosivi, O., Grange, J.M., Daborn, C.J., Raviglione, M.C., Fujikura, T., Cousins, D., Robinson, R.A., Huchzermeyer, H.F., de, K.I. & Meslin, F.X. 1998. Zoonotic tuberculosis due to Mycobacterium bovis in developing countries. Emerg. Infect. Dis. 4, 5970.CrossRefGoogle ScholarPubMed
DAGRIS. 2007. Domestic Animal Genetic Resources Information System (DAGRIS). Rege, J.E.O., Hanotte, O., Mamo, Y., Asrat, B. and Dessie, T. (Eds), <http://dagris.ilri.cgiar.org/>, International Livestock Research Institute, Addis Ababa, Ethiopia.Google Scholar
Eding, H. & Meuwissen, T.H.E. 2001. Marker-based estimates of between and within population kinships for the conservation of genetic diversity. Journal of Animal Breeding and Genetics 118: 141159.CrossRefGoogle Scholar
Excoffier, L., Laval, G. & Schneider, S. 2005. Arlequin (version 3.0): An integrated software package for population genetics data analysis Evolutionary Bioinformatics Online.CrossRefGoogle Scholar
FAO. 2007a. The state of the world's animal genetic resources for food and agriculture, Rischkowsky, B. and Pilling, D. (Eds), Rome, Italy, pp. 511.Google Scholar
FAO. 2007b. The state of the world's animal genetic resources for food and agriculture - annex: Country report Chad. Rischkowsky, B. and Pilling, D. (Eds), Rome, Italy, pp. 511.Google Scholar
FAO. 2007c. Domestic animal diversity information system (DAD-IS). <http://dad.fao.org/>, FAO, Rome, Italy.,+FAO,+Rome,+Italy.>Google Scholar
FAO. 2004. Secondary guidelines for development of national farm animal genetic resources management plans, Rome, Italy, pp. 55.Google Scholar
Goudet, J. 1995. Fstat (version 1.2): A computer program to calculate f-statistics. Journal of Heredity 86: 485486.CrossRefGoogle Scholar
Hanotte, O. & Jianlin, H.. 2005. Genetic characterization of livestock populations and its use in conservation decision-making. In: The role of biotechnology for the characterization and conservation of crop, forestry, animal and fishery genetic resources. FAO Workshop, Turin, Italy.Google Scholar
Hilty, M. 2006. Molecular epidemiology of mycobacteria: Development and refinement of innovative molecular typing tools to study mycobacterial infections, Universität Basel, Basel, Switzerland, pp. 157.Google Scholar
Ibeagha-Awemu, E.M., Jann, O.C., Weimann, C., & Erhardt, G.. 2004. Genetic diversity, introgression and relationships among West/Central African cattle breeds. Genetics Selection Evolution 36: 673690.CrossRefGoogle ScholarPubMed
Peter, C. 2005. Molekulargenetische Charakterisierung von Schafrassen Europas und des Nahen Ostens auf der Basis von Mikrosatelliten, Justus-Liebig-Universität, Giessen, Germany, pp. 160.Google Scholar
Pritchard, J.K., Stephens, M. & Donnelly, P. 2000. Inference of population structure using multilocus genotype data. Genetics 155: 945959.CrossRefGoogle ScholarPubMed
Qiagen. 2007. Qiagen: sample and assay technologies. <wwwl.qiagen.com/literature/handbooks/literature.aspx?id=1000190>..>Google Scholar
Rosenberg, N. A., Burke, T., Elo, K., Feldman, M.W., Freidlin, P.J., Groenen, M.A.M., Hillel, J., Mäki-Tanila, A., Tixier-Boichard, M., Vignal, A., Wimmers, K. & Weigend, S. 2001. Empirical evaluation of genetic clustering methods using multilocus genotypes from 20 chicken breeds. Genetics 159: 699713.CrossRefGoogle ScholarPubMed
Ruane, J. 1999. A critical review of the value of genetic distance studies in conservation of animal genetic resources. Journal of Animal Breeding and Genetics 116: 317323.CrossRefGoogle Scholar
Toro, M. & Caballero, . 2004. Characterisation and conservation of genetic diversity between breeds. In: Proceedings 55th EAAP Annual Meeting, Bled, Slovenia.Google Scholar
Weir, B. & Cockerham, C.. 1984. Estimating f-statistics for the analysis of population structure. Evolution 38: 12.Google ScholarPubMed
Woolliams, J. & Toro, M. 2007. Chapter 3. What is genetic diversity? In: Utilisation and conservation of farm animal genetic resources. Wageningen Academic Publishers, Netherlands, 5574.CrossRefGoogle Scholar
Zibrowski, D. 1997. Atlas d'élevage du bassin du lac tschad/livestock atlas of the lake chad bassin. CIRAD-EMVT, Wageningen, Netherlands, 7980.Google Scholar