Adult Goats (adult + goat)

Distribution by Scientific Domains

Selected Abstracts

Contrasting genetic structures of two parasitic nematodes, determined on the basis of neutral microsatellite markers and selected anthelmintic resistance markers

Abstract For the first time, the neutral genetic relatedness of natural populations of Trichostrongylid nematodes was investigated in relation to polymorphism of the ,-tubulin gene, which is selected for anthelminthic treatments. The aim of the study was to assess the contribution of several evolutionary processes: migration and genetic drift by neutral genetic markers and selection by anthelminthic treatments on the presence of resistance alleles at ,-tubulin. We studied two nematode species (Teladorsagia circumcincta and Haemonchus contortus) common in temperate climatic zones; these species are characterized by contrasting life history traits. We studied 10 isolated populations of goat nematode parasites: no infected adult goat had been exchanged after the herds were established. Beta-tubulin polymorphism was similar in these two species. One and two ,-tubulin alleles from T. circumcincta and H. contortus respectively were shared by several populations. Most of the ,-tubulin alleles were ,private' alleles. No recombination between alleles was detected in BZ-resistant alleles from T. circumcincta and H. contortus. The T. circumcincta populations have not diverged much since their isolation (FST <0.08), whereas H. contortus displayed marked local genetic differentiation (FST ranging from 0.08 to 0.18). These findings suggest that there are severe bottlenecks in the H. contortus populations, possibly because of their reduced abundance during unfavourable periods and their high reproductive rate, which allows the species to persist even after severe population reduction. Overall, the data reported contradict the hypothesis of the origin of ,-tubulin resistance alleles in these populations from a single mutational event, but two other hypotheses (recurrent mutation generating new alleles in isolated populations and the introduction of existing alleles) emerge as equally likely. [source]

Diversity in five goat populations of the Lombardy Alps: comparison of estimates obtained from morphometric traits and molecular markers

P. Crepaldi
Phenotypic and genetic variability were studied within and between the goat populations of Bionda dell'Adamello, Frisa, Orobica, Verzaschese and Val di Livo. These are populations reared for most of the year on pastures of the Lombardy Alps, numbering a minimum of 1000 and a maximum of 8000 individuals per breed. The first four are standardized breeds of recent formation; at present they are supported by the European Union measures for the conservation of rare breeds. On the basis of its visible genetic profile the Val di Livo goat may be classified as a primary population. Phenotypic variability was estimated on the basis of six somatic measurements on 60,140 adult goats per breed, whereas genetic variation was measured on the basis of 201 AFLP loci. The partition of the total molecular variation into the within and between breed components indicates that the majority of the molecular variability is conserved within populations, whereas only 8.8% can be attributed to between population variation. Morphometric and molecular marker data produced unrelated distance values and different topology of UPGMA clusters. It may be hypothesized that the morphometric originality of the Val di Livo goat is mostly determined by environmental factors and selection pressure rather than by different origin and genome evolution. Conversely Orobica seems to have diverged from the other breeds at the genome level, which may be explained by an undocumented Southern Italian origin. An objective evaluation of conservation priorities may in the near future be based on the integrated use of molecular markers and of information on quantitative traits and allelic variation with adaptive relevance. Diversité dans cinq populations de chèvres des Alpes lombardes: comparaisons entre estmations obtenues par des mesures somatiques et par des marqueurs moléculaires On a etudié la variabilité phénotypique et génétique entre et parmi les populations de chèvres Bionda dell'Adamello, Frisa, Orobica, Verzaschese et Val di Livo. Il s'agit de populations qui content entre 1000 et 8000 sujets, elevés pour la plus part de l'année sur les pâturages des Alpes de Lombardie. Les quatre premières, actuellement sauvegardées par des mesures communautaires, sont des races à standard recemment constituées. La chèvre de la Val di Livo peut être rangée parmi les races primaires. La diversité phénotypique a été montrée par un dendrogramme obtenus des distances euclidiennes calculées à partir de six mesures somatiques qui avaient été prises sur 60,140 chèvres adultes pour chaque race. La diversité génétique a été montrée par un dendrogramme bâti sur la matrice des distances de Nei obtenues des 201 marqueurs moléculaires AFLP, produits par 7 combinaisons de primers, sur 30 sujets pour chaque race. La décomposition de la variabilité génétique totale estimée par les données moléculaires a montré que la plus part de la variabilité est conservée parmi la population, tandis que seulement l,8,8% peut être imputé aux différences entre populations. Les données moléculaires et somatiques ont donné lieu à des distances qui ne sont pas corrélées et à des cluster avec une topologie nettement différente. La comparaison entre les deux approches permet d'avancer l'hypothèse que l'originalité somatique de la chèvre de la Val di Livo pourrait être due à des facteurs d'environnement et/ou à la pression de sélection plutôt qu'à des facteurs liés à l'évolution du genome. Au contraire ces derniers seraient responsables de l'originalité génétique de la race Orobica et confirmeraient des témoignages orals non documentés. Un choix objectif des ressources génétiques qui méritent d'être conservées pourra probablement se baser sur l'employ conjoint des marqueurs et de renseignements sur les caractères quantitatifs et sur les variantes alléliques des gènes qui ont une valeur adaptative. Diversität in fünf Ziegenpopulationen der lombardischen Alpen: Vergleich von Schätzungen auf der Basis morphologischer Eigenschaften und molekularer Marker Es wurden die phänotypische und genetische Variabilität innerhalb und zwischen Bionda dell'Adamello, Frisa, Orobica, Verzaschese und Val di Livo Ziegenpopulationen untersucht. Diese Populationen, mit Größen zwischen 1000 und 8000 Tieren, werden den größten Teil des Jahres auf Weiden der lombardischen Alpen gehalten. Die vier erstgenannten Populationen sind erst kürzlich standardisierte Rassen; gegenwärtig werden sie mit EU-Mitteln für die Erhaltung seltener Rassen, unterstützt. Auf der Basis des erkennbaren genetischen Profils muß die Rasse Val di Livo als eine Primärpopulation eingeordnet werden. Phänotypische Variabilität wurde auf der Basis von sechs Körpermaßen an 60,140 ausgewachsenen Ziegen je Rasse geschätzt, die genetische Variation wurde auf der Basis von 201 AFLP-Loci gemessen. Die Aufteilung der gesamten molekularen Varianz in Varianzkomponenten innerhalb und zwischen Populationen zeigt, daß der größte Teil der molekularen Variabilität innerhalb der Populationen auftritt, und nur 8,8% der Gesamtvarianz auf die Varianz zwischen den Populationen entfällt. Morphologische und molekulare Marker erzeugten unabhängige Distanzwerte und unterschiedliche upgma-Cluster. Es kann die Hypothese aufgestellt werden, daß die morphologische Einzigartigkeit der Val di Livo Ziege stärker auf Umwelteffekte und Selektionsdruck als auf eine unterschiedliche Herkunft oder genomische Evolution zurückzuführen ist. Dagegen scheint Orobica auf Genomebene von den anderen Rassen abzuweichen, was durch einen nicht dokumentierten süditalienischen Ursprung erklärt werden könnte. Eine objektive Bewertung von Prioritäten für Konservierungsmaßnahmen dürfte in Zukunft auf einen integrierten Gebrauch molekularer Marker, Informationen über quantitative Merkmale sowie der genetischen Variation bezüglich der Adaptationsfähigkeit basieren. [source]

Safety of, and biological and functional response to, a novel metallic implant for the management of focal full-thickness cartilage defects: Preliminary assessment in an animal model out to 1 year

Carl A. Kirker-Head
Abstract Focal full-thickness cartilage lesions of the human medial femoral condyle (MFC) can cause pain and functional impairment. Affected middle-aged patients respond unpredictably to existing treatments and knee arthroplasty may be required, prompting risk of revision. This study assesses the safety of, and biological and functional response to, a metallic resurfacing implant which may delay or obviate the need for traditional arthroplasty. The anatomic contour of the surgically exposed MFC of six adult goats was digitally mapped and an 11 mm diameter full-thickness osteochondral defect was created. An anchor-based Co,Cr resurfacing implant, matching the mapped articular contour, was implanted. Each goat's contralateral unoperated femorotibial joint was used as a control. Postoperative outcome was assessed by lameness examination, radiography, arthroscopy, synoviocentesis, necropsy, and histology up to 26 (n,=,3) or 52 (n,=,3) weeks. By postoperative week (POW) 4, goats demonstrated normal range of motion, no joint effusion, and only mild lameness in the operated limb. By POW 26 the animals were sound with only occasional very mild lameness. Arthroscopy at POW 14 revealed moderate synovial inflammation and a chondral membrane extending centrally across the implant surface. Radiographs at POWs 14 to 52 implied implant stability in the operated joints, as well as subchondral bone remodeling and mild exostosis formation in the operated and contralateral unoperated joints of some goats. By POW 26, histology revealed new trabecular bone abutting the implant. At POWs 26 and 52 MFC cartilage was metachromatic and intact in the operated and unoperated femorotibial joints. Proximal tibiae of some operated and unoperated limbs demonstrated limited subchondral bone remodeling and foci of articular cartilage fibrillation and thinning. The chondral membrane crossing the prosthesis possessed a metachromatic matrix containing singular and clustered chondrocytes. Our data imply the safety, biocompatibility, and functionality of the implant. Focal articular damage was documented in the operated joints at POWs 26 and 52, but lesions were much reduced over those previously reported in untreated defects. Expanded animal or preclinical human studies are justified. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source]

Neurophysiological and biomechanical characterization of goat cervical facet joint capsules

Ying Lu
Abstract Cervical facet joints have been implicated as a major source of pain after whiplash injury. We sought to identify facet joint capsule receptors in the cervical spine and quantify their responses to capsular deformation. The response of mechanosensitive afferents in C5,C6 facet joint capsules to craniocaudal stretch (0.5 mm/s) was examined in anaesthetized adult goats. Capsular afferents were characterized into Group III and IV based on their conduction velocity. Two-dimensional strains across the capsules during stretch were obtained by a stereoimaging technique and finite element modeling. 17 (53%) Group III and 14 (56%) Group IV afferents were identified with low strain thresholds of 0.107 ± 0.033 and 0.100 ± 0.046. A subpopulation of low-strain-threshold afferents had discharge rate saturation at the strains of 0.388 ± 0.121 (n = 9, Group III) and 0.341 ± 0.159 (n = 9, Group IV). Two (8%) Group IV units responded only to high strains (0.460 ± 0.170). 15 (47%) Group III and 9 (36%) Group IV units could not be excited even by noxious capsular stretch. Simple linear regressions were conducted with capsular load and principal strain as independent variables and neural response of low-strain-threshold afferents as the dependent variable. Correlation coefficients (R2) were 0.73 ± 0.11 with load, and 0.82 ± 0.12 with principal strain. The stiffness of the C5,C6 capsules was 16.8 ± 11.4 N/mm. Our results indicate that sensory receptors in cervical facet joint capsules are not only capable of signaling a graded physiological mechanical stimulus, but may also elieit pain sensation under excessive deformation. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]

Mitochondrial organization in prepubertal goat oocytes during in vitro maturation and fertilization

Esther Velilla
Abstract The aim of this study was to evaluate mitochondrial distribution during in vitro maturation (at 0, 15, 20, and 27 hr of IVM) and fertilization of prepubertal goat oocytes compared to mitochondrial distribution of ovulated and in vitro fertilized oocytes from adult goats. Oocytes from prepubertal goats were recovered from a slaughterhouse and were matured in M199 with hormones and serum for 27 hr. Ovulated oocytes were collected from gonadotrophin-treated Murciana goats. Frozen-thawed spermatozoa were selected by centrifugation in Percoll gradient and were capacitated in DMH with 20% steer serum for 1 hr. Ovulated and IVM-oocytes were inseminated in DMH medium with steer serum and calcium lactate for 20 hr. Oocytes and presumptive zygotes were stained with Mitotraker Green FM and observed under a confocal laser scanning microscope. Ultrastructural morphology of oocytes and presumptive zygotes were analyzed by transmission electron microscopy (TEM). Prepubertal goat oocytes at germinal vesicle stage (GV) presented mitochondria localized in the cortical and perinuclear region. IVM-oocytes at metaphase II presented mitochondria peripheral polarized to the region opposite were the metaphase spindle is positioned and within the polar body. Ovulated oocytes presented peripheral mitochondria distribution and mitochondrial aggregation around the MII spindle. At 20 hr post-insemination, mitochondria were distributed around the two synchronous pronuclei (2PN rpar; in zygotes ovulated oocytes whereas in prepubertal 2PN-zygotes mitochondria presented a peripheral polarized distribution. Images by TEM detected that immature prepubertal goat oocytes that are less electrodense and present fewer cristae than in vitro matured prepubertal goat oocytes; these are characterized by being associated to swollen vesicles. Mol. Reprod. Dev. 73: 617,626, 2006 © 2006 Wiley-Liss, Inc. [source]