Chromosomal rearrangements in cattle and pigs revealed by chromosome microdissection and chromosome painting

A pericentric inversion of chromosome 4 in a boar, as well as a case of (2q-;5p+) translocation mosaicism in a bull were analysed by chromosome painting using probes generated by conventional microdissection. For the porcine inversion, probes specific for p arms and q arms were produced and hybridised simultaneously on metaphases of a heterozygote carrier. In the case of the bovine translocation, two whole chromosome probes (chromosome 5, and derived chromosome 5) were elaborated and hybridised independently on chromosomal preparations of the bull who was a carrier of the mosaic translocation. The impossibility of differentiating chromosomes 2 and der(2) from other chromosomes of the metaphases did not allow the production of painting probes for these chromosomes. For all experiments, the quality of painting was comparable to that usually observed with probes obtained from flow-sorted chromosomes. The results obtained allowed confirmation of the interpretations proposed with G-banding karyotype analyses. In the bovine case, however, the reciprocity of the translocation could not be proven. The results presented in this paper show the usefulness of the microdissection technique for characterising chromosomal rearrangements in species for which commercial probes are not available. They also confirmed that the main limiting factor of the technique is the quality of the chromosomal preparations, which does not allow the identification of target chromosomes or chromosome fragments in all cases

Estimation of the proportion of genetically unbalanced spermatozoa in the semen of boars carrying chromosomal rearrangements using FISH on sperm nuclei

Many chromosomal rearrangements are detected each year in France on young boars candidates for reproduction. The possible use of these animals requires a good knowledge of the potential effect of the rearrangements on the prolificacy of their mates. This effect can be estimated by an accurate determination of the rate of unbalanced spermatozoa in the semen of boars which carry the rearrangements. Indeed, these spermatozoa exhibiting normal fertilizing ability are responsible for an early embryonic mortality, and then, for a decrease of the litter sizes. The "spermFISH" technique, i.e. fluorescent in situ hybridization on decondensed sperm heads, has been used on several occasions in Man, in this perspective. In livestock species, this method was formerly used mainly for semen sexing purposes. We used it, for the first time, to estimate the rates of imbalance in the semen of four boars carrying chromosomal rearrangements: two reciprocal translocations, rcp(3;15)(q27;q13) and rcp(12;14)(q13;q21), as well as two independent cases of trisomy 18 mosaicism. The rates of unbalanced gametes were relatively high for the two reciprocal translocations (47.83% and 24.33%, respectively). These values differed from the apparent effects of the rearrangements estimated using a limited number of litters: a decrease in prolificacy of 23% (estimation obtained using the results of 6 litters) and 39% (57 litters), respectively for the 3/15 and 12/14 translocations. The imbalance rates were much lower for the trisomy mosaics (0.58% and 1.13%), suggesting a very moderate effect of this special kind of chromosomal rearrangement

Chromosomal control of pig populations in France: 2002-2006 survey

The chromosomal control of pig populations has been widely developed in France over the last ten years. By December 31st, 2006, 13 765 individuals had been karyotyped in our laboratory, 62% of these since 2002. Ninety percent were young purebred boars controlled before service in artificial insemination centres, and 3% were hypoprolific boars. So far, 102 constitutional structural chromosomal rearrangements (67 since 2002) have been described. Fifty-six were reciprocal translocations and 8 peri- or paracentric inversions. For the first time since the beginning of the programme and after more than 11 000 pigs had been karyotyped, one Robertsonian translocation was identified in 2005 and two others in 2006. The estimated prevalence of balanced structural chromosomal rearrangements in a sample of more than 7700 young boars controlled before service was 0.47%. Twenty-one of the 67 rearrangements described since 2002 were identified in hypoprolific boars. All were reciprocal translocations. Twelve mosaics (XX/XY in 11 individuals, XY/XXY in one individual) were also diagnosed. Two corresponded to hypoprolific boars, and three to intersexed animals. The results presented in this communication would justify an intensification of the chromosomal control of French and, on a broader scale, European and North-American pig populations

A new reciprocal translocation in a subfertile bull

Three bulls of the Montbéliarde breed that exhibited fertility rates lower than 30% following more than 400 artificial inseminations were examined. Semen quality (sperm motility and morphology) from these bulls was normal. Fertilizing ability estimated from in vitro embryo production results was studied for two of them. In vitro production rate was very low for one bull (A) and normal for the other (B). Cytogenetic analyses were carried out on the three bulls using chromosome banding techniques. These analyses revealed a reciprocal translocation (12;17)(q22;q14) in bull B. Based on family analyses, the hypothesis of a de novo origin of this rearrangement is proposed

Porcine neurofibromatosis : a new syndrome

A genetically dominant neoplasic disease similar to human neurofibromatosis has just been discovered in pigs. Two of the three clinical forms known in man have been identified in several pig farms: one with large subcutaneous tumours, the other exclusively intradermal. Clinical and pathology studies have been performed on these lesions. Tumour cells are being cultured and the sequencing of their genome is underway. This research is especially important because no animal model of this very common disease in man was available until now.Une affection tumorale similaire à la neurofibromatose de l'Homme vient d'être découverte chez le porc. Cette maladie, de caractère génétique dominant, a été retrouvée dans plusieurs élevages sous deux des trois formes rencontrées chez l'Homme, l'une à grosses tumeurs sous-cutanées et l'autre, strictement intradermique. Ces lésions ont été étudiées aux plans clinique et anatomopathologique. Les cellules tumorales ont été mises en culture et le séquençage de leur génome entrepris. Ce travail revêt une importance toute particulière car il n'existait jusqu'alors aucun modèle animal de cette maladie très fréquente chez l'Homme

Comparison of Serum HBsAg Quantitation by Four Immunoassays, and Relationships of HBsAg Level with HBV Replication and HBV Genotypes

BACKGROUND: The decline in hepatitis B virus surface antigen (HBsAg) may be an early predictor of the viral efficacy of Hepatitis B virus (HBV) therapy. The HBsAg levels obtained by different immunoassays now need comparing and the relationships between levels of HBsAg and HBV DNA alongside HBsAg and genotype must be evaluated. METHODOLOGY/PRINCIPAL FINDINGS: HBsAg levels were compared among 80 patients using the Abbott Architect assay, a commercial immunoassay approved for HBsAg detection and quantitation, and three other assays derived from immunoassays approved for HBsAg detection (manufactured by Diasorin, Bio-Rad and Roche). Good correlation was found between the Abbot vs. Diasorin, Bio-Rad and Roche assays with narrow 95% limits of agreement and small mean differences: -0.06 to 0.11, -0.09 log(10) IU/mL; -0.57 to 0.64, -0.04 log(10) IU/mL; -0.09 to 0.45, -0.27 log(10) IU/mL, respectively. These agreements were not affected by genotypes A or D. HBsAg was weakly correlated with HBV DNA, whatever the HBsAg assay used: Abbott, ρ = 0.36 p = 0.001, Diasorin ρ = 0.34, p = 0.002; Bio-Rad ρ = 0.37, p<0.001; or Roche ρ = 0.41, p<0.001. This relationship between levels of HBsAg and HBV DNA seemed to depend on genotypes. Whereas HBsAg (Abbott assay) tended to correlate with HBV DNA for genotype A (ρ = 0.44, p = 0.02), no such correlation was significant for genotypes D (ρ = 0.29, p = 0.15). CONCLUSION/SIGNIFICANCE: The quantitation of HBsAg in routine clinical samples is comparable between the reference assay and the adapted assays with acceptable accuracy limits, low levels of variability and minimum discrepancy. While HBsAg quantitation is not affected by HBV genotype, the observed association between levels of HBsAg and HBV DNA seems genotype dependent

Les étapes de la prévision économique. Deuxième partie. Les cycles et la prévision

Many economists have for a long time searched regularities in the movements of the economic activity. They tried to describe, to explain, to forecast and also to find some basis for economic policies. In a first-part, the major types of business cycles are presented altogether with exogen causes. Then, the article describes how the economist have integrated the causes of business cycles in a general framework of economic activity.Les économistes ont longtemps cherché une relative régularité dans les mouvements plus ou moins récurrents de l'activité économique. Ils visaient à la fois à décrire, expliquer, prévoir et aussi proposer des mesures de politique économique. Dans une première partie, les principaux types de cycles économiques sont présentés ainsi que quelques exemples de causes exogènes. Les grandes étapes de l'endogénéisation des cycles sont ensuite retracées dans une seconde partie.Alcouffe Alain, Ducos Gilbert. Les étapes de la prévision économique. Deuxième partie. Les cycles et la prévision. In: Sciences de la société, n°27, 1992. La ressource humaine (1) pp. 163-178

Les grandes étapes de la prévision économique 3 e Partie : La modélisation et la prévision macroéconomiques

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Les grandes étapes de la prévision économique 1° Partie : des indices à la météorologie économique

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