S. Dunner
Complutense University of Madrid
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Publication
Featured researches published by S. Dunner.
Mammalian Genome | 1998
Luc Grobet; Dominique Poncelet; Luis José Royo; Benoît Brouwers; Dimitri Pirottin; Charles Michaux; François Ménissier; Marta Zanotti; S. Dunner; Michel Georges
We have determined the entire myostatin coding sequence for 32 double-muscled cattle sampled from ten European cattle breeds. Seven DNA sequence polymorphisms were identified, of which five would be predicted to disrupt the function of the protein, one is a conservative amino acid substitution, and one a silent DNA sequence variant. Four additional DNA sequence polymorphisms were identified in myostatin intronic sequences. In all but two breeds, all double-muscled animals were either homozygous or compound heterozygotes for one of the five loss-offunction mutations. The absence of obvious loss-of-function mutations in the coding sequence of the two remaining breeds points either towards additional mutations in unexplored segments of the gene, or towards locus heterogeneity of double-muscling.
Genetics Selection Evolution | 2001
Javier Cañón; Paolo Alexandrino; Isabel Bessa; Carlos Carleos; Yolanda Carretero; S. Dunner; Nuno Ferran; David García; J. Jordana; Denis Laloë; Albano Pereira; Armand Sánchez; Katayoun Moazami-Goudarzi
This study was undertaken to determine the genetic structure, evolutionary relationships, and the genetic diversity among 18 local cattle breeds from Spain, Portugal, and France using 16 microsatellites. Heterozygosities, estimates of Fst, genetic distances, multivariate and diversity analyses, and assignment tests were performed. Heterozygosities ranged from 0.54 in the Pirenaica breed to 0.72 in the Barrosã breed. Seven percent of the total genetic variability can be attributed to differences among breeds (mean Fst = 0.07; P < 0.01). Five different genetic distances were computed and compared with no correlation found to be significantly different from 0 between distances based on the effective size of the population and those which use the size of the alleles. The Weitzman recursive approach and a multivariate analysis were used to measure the contribution of the breeds diversity. The Weitzman approach suggests that the most important breeds to be preserved are those grouped into two clusters: the cluster formed by the Mirandesa and Alistana breeds and that of the Sayaguesa and Tudanca breeds. The hypothetical extinction of one of those clusters represents a 17% loss of diversity. A correspondence analysis not only distinguished four breed groups but also confirmed results of previous studies classifying the important breeds contributing to diversity. In addition, the variation between breeds was sufficiently high so as to allow individuals to be assigned to their breed of origin with a probability of 99% for simulated samples.
Genetics Selection Evolution | 2003
S. Dunner; M. Eugenia Miranda; Yves Amigues; Javier Cañón; Michel Georges; R Hanset; John L. Williams; François Ménissier
A total of 678 individuals from 28 European bovine breeds were both phenotyped and analysed at the myostatin locus by the Single Strand Conformation Polymorphism (SSCP) method. Seven new mutations were identified which contribute to the high polymorphism (1 SNP every 100 bp) present in this small gene; twenty haplotypes were described and a genotyping method was set up using the Oligonucleotide Ligation Assay (OLA) method. Some haplotypes appeared to be exclusive to a particular breed; this was the case for 5 in the Charolaise (involving mutation Q204X) and 7 in the Maine-Anjou (involving mutation E226X). The relationships between the different haplotypes were studied, thus allowing to test the earlier hypothesis on the origin of muscular hypertrophy in Europe: muscular hypertrophy (namely nt821(del11)) was mainly spread in different waves from northern Europe milk purpose populations in most breeds; however, other mutations (mostly disruptive) arose in a single breed, were highly selected and have since scarcely evolved to other populations.
Steroids | 2006
Juan Carlos Illera; M.D. Pérez-Alenza; Ana Nieto; María Ángeles Jiménez; Gema Silván; S. Dunner; L. Peña
The aims of this study were to investigate the serum and tissue content of androgens and estrogens in canine inflammatory mammary carcinomas (IMC) as well as in non-inflammatory malignant mammary tumors (MMT), and assessed the immunoexpression of estrogen and androgen receptors using immunohistochemistry. Profiles for the androgens dehydroepiandrosterone (DHEA), androstenedione (A4), and testosterone (T), and for the estrogens 17beta estradiol (E2) and estrone-sulphate (SO4E1) were measured both in tissue homogenates and in serum of MMT and IMC by EIA techniques in 42 non-inflammatory malignant mammary tumors (MMT) and in 14 inflammatory mammary carcinomas (IMC), prospectively collected from 56 female dogs. Androgen receptor (AR) and estrogen receptor alpha (ERalpha) and beta (ERbeta) expression was studied using immunohistochemistry (strepavidin-biotin-peroxidase method) in samples of 32 MMT and 14 IMC, and counted by a computer image analyzer. IMC serum and tissue levels of androgens were significantly higher than MMT levels. Tissue content of estrogens was also significantly higher in IMC than in MMT. Serum values of SO4E1 were significantly higher in IMC, but serum levels of E2 were significantly lower in IMC compared to MMT cases. Medium-high androgen receptor intensity was observed in 64.28% of IMC and 40.62% of MMT. No important differences were found between ERalpha expression in IMC (100% negative) and MMT (90% negative). ERbeta and AR were intensely expressed in highly malignant inflammatory mammary carcinoma cells. To our knowledge, this is the first report relative to AR immunohistochemistry in canine mammary cancer and to estrogens or androgens in serum of dogs with benign or malignant mammary tumors.
Mammalian Genome | 1997
S. Dunner; Carole Charlier; Frédéric Farnir; Benoît Brouwers; J. Canon; Michel Georges
The Spanish “Asturiana” cattle breed is characterized by the segregation of a genetically determined muscular hypertrophy referred to as double-muscling or “culones”. We demonstrate by linkage analysis that this muscular hypertrophy involves the mh locus previously shown to cause double-muscling in the Belgian Blue cattle breed, pointing towards locus homogeneity of this trait across both breeds. Moreover, using a twopoint and multipoint maximum likelihood approach, we show that flanking microsatellite markers are in linkage disequilibrium with the mh locus in both breeds albeit with different alleles. Finally, we discuss how allelic homogeneity across breeds might be exploited to achieve efficient genetic fine-mapping of the mh locus.
Animal Genetics | 2009
Riccardo Negrini; Letizia Nicoloso; P. Crepaldi; Elisabetta Milanesi; Licia Colli; F. Chegdani; Lorraine Pariset; S. Dunner; Hubert Levéziel; John L. Williams; P. Ajmone Marsan
The effectiveness of single nucleotide polymorphisms (SNPs) for the assignment of cattle to their source breeds was investigated by analysing a panel of 90 SNPs assayed on 24 European breeds. Breed assignment was performed by comparing the Bayesian and frequentist methods implemented in the STRUCTURE 2.2 and GENECLASS 2 software programs. The use of SNPs for the reallocation of known individuals to their breeds of origin and the assignment of unknown individuals was tested. In the reallocation tests, the methods implemented in STRUCTURE 2.2 performed better than those in GENECLASS 2, with 96% vs. 85% correct assignments respectively. In contrast, the methods implemented in GENECLASS 2 showed a greater correct assignment rate in allocating animals treated as unknowns to a reference dataset (62% vs. 51% and 80% vs. 65% in field tests 1 and 2 respectively). These results demonstrate that SNPs are suitable for the assignment of individuals to reference breeds. The results also indicate that STRUCTURE 2.2 and GENECLASS 2 can be complementary tools to assess breed integrity and assignment. Our findings also stress the importance of a high-quality reference dataset in allocation studies.
Animal Genetics | 2014
M. Promerová; Leif Andersson; R. Juras; M. C. T. Penedo; Monika Reissmann; T. Tozaki; Rebecca R. Bellone; S. Dunner; P. Hořín; Freyja Imsland; P. Imsland; Sofia Mikko; D. Modrý; Knut H. Røed; Doreen Schwochow; J. L. Vega-Pla; H. Mehrabani-Yeganeh; N. Yousefi-Mashouf; E.G. Cothran; Gabriella Lindgren
For centuries, domestic horses have represented an important means of transport and served as working and companion animals. Although their role in transportation is less important today, many horse breeds are still subject to intense selection based on their pattern of locomotion. A striking example of such a selected trait is the ability of a horse to perform additional gaits other than the common walk, trot and gallop. Those could be four-beat ambling gaits, which are particularly smooth and comfortable for the rider, or pace, used mainly in racing. Gaited horse breeds occur around the globe, suggesting that gaitedness is an old trait, selected for in many breeds. A recent study discovered that a nonsense mutation in DMRT3 has a major impact on gaitedness in horses and is present at a high frequency in gaited breeds and in horses bred for harness racing. Here, we report a study of the worldwide distribution of this mutation. We genotyped 4396 horses representing 141 horse breeds for the DMRT3 stop mutation. More than half (2749) of these horses also were genotyped for a SNP situated 32 kb upstream of the DMRT3 nonsense mutation because these two SNPs are in very strong linkage disequilibrium. We show that the DMRT3 mutation is present in 68 of the 141 genotyped horse breeds at a frequency ranging from 1% to 100%. We also show that the mutation is not limited to a geographical area, but is found worldwide. The breeds with a high frequency of the stop mutation (>50%) are either classified as gaited or bred for harness racing.
Genetics Selection Evolution | 1998
S. Dunner; María Luisa Checa; J.P. Gutiérrez; Juan P Martin; Javier Cañón
Geneticists are faced with various problems when managing small natural populations (e.g. high inbreeding, loss of economic value). We propose here the man- agement of a small population through the example of the Asturcon (a Celtic pony population) by examining two sources of information: a studbook created in 1981 and the polymorphism of ten microsatellite markers chosen according to the recommenda- tions of ISAG (International Society of Animal Genetics). This information allows us to estimate several genetic parameters useful in assessing the genetic situation of the population in order to propose conservation strategies. Results show the reliability of molecular information in populations where no studbook exists. Overall inbreeding value (F) and fixation index (FIT) are moderate (F = 0.027; FIT = 0.056), effective number of founders is small (n = 22), and the population is divided into three dis- tinct groups (F = 0.078; P < 0.001). The molecular heterozygosity (H = 71.2 %) computed in a random sample gives an accurate vision of the real inbreeding. These parameters and the application of the concept of average relatedness allow us to rec- ommend to the breeders the choice of the best matings to control the inbreeding level while maintaining a low paternity error rate.
Animal Genetics | 2012
J. V. Delgado; Atzel Acosta; E. Armstrong; E. Camacho; S. Dunner; V. Landi; José Ribamar Felipe Marques; L. Melucci; M. C. T. Penedo; A. Postiglioni; C. Rodellar; P. Sponenberg; Odalys Uffo; R. Ulloa-Arvizu; J. L. Vega-Pla; A. Villalobos; Delsito Zambrano; Pilar Zaragoza; L. T. Gama; Catarina Ginja
Genetic diversity in and relationships among 26 Creole cattle breeds from 10 American countries were assessed using 19 microsatellites. Heterozygosities, F-statistics estimates, genetic distances, multivariate analyses and assignment tests were performed. The levels of within-breed diversity detected in Creole cattle were considerable and higher than those previously reported for European breeds, but similar to those found in other Latin American breeds. Differences among breeds accounted for 8.4% of the total genetic variability. Most breeds clustered separately when the number of pre-defined populations was 21 (the most probable K value), with the exception of some closely related breeds that shared the same cluster and others that were admixed. Despite the high genetic diversity detected, significant inbreeding was also observed within some breeds, and heterozygote excess was detected in others. These results indicate that Creoles represent important reservoirs of cattle genetic diversity and that appropriate conservation measures should be implemented for these native breeds in order to minimize inbreeding and uncontrolled crossbreeding.
PLOS ONE | 2012
Amparo Martínez Martínez; L. T. Gama; Javier Cañón; Catarina Ginja; Juan Vicente Delgado; S. Dunner; V. Landi; Inmaculada Martín-Burriel; M. Cecilia T. Penedo; C. Rodellar; J. L. Vega-Pla; Atzel Acosta; Luz A Álvarez; Esperanza Camacho; O. Cortés; José Ribamar Felipe Marques; Roberto Martı́nez; Rubén Martínez; Lilia Melucci; Guillermo Martı́nez-Velázquez; Jaime Eduardo Muñoz; Alicia Postiglioni; J. Quiroz; Philip Sponenberg; Odalys Uffo; Axel Villalobos; Delsito Zambrano; Pilar Zaragoza
Background American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, and may have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources. Methodology/Principal Findings We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu. Conclusions/Significance Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental conditions.