Existence of an ejaculatory-like reaction in ewes ovariectomized and treated with androgens in adulthood

The complete behavioral repertoire of male sexual activity can be observed during daily androgen treatment (testosterone propionate, 15 mg/day) of normal ewes ovariectomized as adults. This includes the ejaculatory pattern (deep thrust accompanied by a rapid backwards movement of the head) which is followed by a dramatic decrease in the frequency of sexual interactions, similar to the male's postejaculatory reduction of activity. However, the sexual performances of the genetic females remain lower than those of normal males in ejaculation latency, postejaculation latency, and mount/ejaculation ratio.     

Detection by DGGE of a new polymorphism closely linked to the adenomatous polyposis coli region

Summary The EF5.44 locus is in close proximity to the chromosome 5 region to which the genetic defect responsible for familial adenomatous polyposis has been mapped. We have devised two oligonucleotides that promote the specific polymerase chain reaction (PCR) amplificiation of a 365-bp sequence in this region. Analysis by denaturing gradient gel electrophoresis of the resulting fragment has unravelled individual differences that could be identified as a single base pair change in aMnlI restriction site. This PCR assayable polymorphism increases the informativeness at this locus, and should be useful in the presymptomatic diagnosis of familial adenomatous polyposis.     

Introduction dans le Sud-Est de la france d'un parasite:Pauesia cedrobii [Hym.: Aphidiidae] du puceron:Cedrobium laportei [Hom.: Lachnidae] du cèdre de l'atlas:Cedrus atlantica

Résumé Le parasitePauesia cedrobii Stary et Leclant, spécifique du puceron du CèdreCedrobium laportei Remaudière, a été récolté dans le Moyen-Atlas, (Maroc) puis introduit dans un peuplement de cèdre (Cedrus atlantica Manetti) du sud-est de la France au printemps 1981. La méthode utilisée a consisté en une introduction directe des parasites, préalablement isolés sur le lieu de récolte (momies) puis mis à éclore en chambre climatisée de fa?on à éliminer les hyperparasites. Après accouplement, 225 adultes ont été introduits dans des manchons installés sur des rameaux abritant des colonies deC. laportei. L'évolution des populations de l'h?te et du parasite a été suivie au niveau des points de lacher d'une part, et dans la parcelle d'autre part. L'installation définitive du parasite dans la parcelle s'est produite, 1 an après le lacher, grace à un automne et à un hiver particulièrement doux, qui ont favorisé la multiplication de l'h?te. Le parasite est définitivement implanté: il est encore présent 4 années après le lacher. Entre temps, il a été étendu à d'autres forêts de cèdre du sud-est de la France. Huit espèces d'hyperparasites autochtones se sont portés surP. cedrobii, mais ceci ne remet pas en cause la réussite de l'introduction de l'aphidiide. Avec la collaboration technique deE. Robert, A. Chalon, J. Chizky.     

A UV-supersensitive mutant in the yeast Schizosaccharomyces pombe

Summary A high UV-sensitive mutant was obtained from a UV-sensitive strain of the yeast Schizosaccharomyces pombe after a mutagenic treatment. By genetic analysis, it was possible to distinguish two independent loci. The double mutant is supersensitive, that is more UV-sensitive than either of the two single mutants. This suggests that the mutations involved interfere with two repair pathways that are, at least partially, independent of each other.Some properties of the two single mutants were studied. These mutants differ notably in their response to caffeine, to liquid-holding, to exposure to visible light after UV irradiation, and in their UV-sensitive during the logarithmic growth phase.Comparison of the properties of the wild-type strain and of the different UV sensitive mutants leads to the conclusion that one repair pathway is used preferentially in the wild-type strain.Abbreviations DRF dose reduction factor - LH liquid holding     

Xrs2, a DNA Repair Gene of Saccharomyces Cerevisiae, Is Needed for Meiotic Recombination

The XRS2 gene of Saccharomyces cerevisiae has been previously identified as a DNA repair gene. In this communication, we show that XRS2 also encodes an essential meiotic function. Spore inviability of xrs2 strains is rescued by a spo13 mutation, but meiotic recombination (both gene conversion and crossing over) is highly depressed in spo13 xrs2 diploids. The xrs2 mutation suppresses spore inviability of a spo13 rad52 strain suggesting that XRS2 acts prior to RAD52 in the meiotic recombination pathway. In agreement with the genetic data, meiosis-specific double-strand breaks at the ARG4 meiotic recombination hotspot are not detected in xrs2 strains. Despite its effects on meiotic recombination, the xrs2 mutation does not prevent mitotic recombination events, including homologous integration of linear DNA, mating-type switching and radiation-induced gene conversion. Moreover, xrs2 strains display a mitotic hyper-rec phenotype. Haploid xrs2 cells fail to carry out G2-repair of gamma-induced lesions, whereas xrs2 diploids are able to perform some diploid-specific repair of these lesions. Meiotic and mitotic phenotypes of xrs2 cells are very similar to those of rad50 cells suggesting that XRS2 is involved in homologous recombination in a way analogous to that of RAD50.     

Identification with a Monoclonal Antibody of a Phylogenetically Conserved Brain-Specific Determinant on a 130,000 Molecular Weight Glycoprotein of Human Brain

Human brain glycoproteins depleted of Thy-1 antigen were used to immunise Balb/c mice for monoclonal antibody production. The F3-87-8 antibody described in this paper interacts with a determinant present in large amounts on all human brain subregions studied (cerebral cortical grey matter, white matter, caudate, thalamus, dentate nucleus, putamen, cerebellar cortex) but absent from all other tissues examined (liver, heart, kidney, spleen, thymus, lymph node, erythrocyte, adrenal gland, and peripheral nerve). The determinant is conserved in mammalian evolution, as the brains of the rat and dog have amounts equal to that found in human brain. Balb/c mouse brain has approximately one-third as much antigen activity as these other mammalian brains, whereas brains of the frog and chicken have no detectable antigenic activity. Developmental studies showed that 16-week human foetal brain and neonatal dog brain had little or no antigen activity, indicating a dramatic increase in the amount of the determinant with brain maturation. Biochemical studies showed that the F3-87-8-bearing molecule was a major sialoglycoprotein of human brain with an apparent molecular weight of 130,000. It was shown by immunofluorescence to be particularly localised in what appeared to be fibre tracts in the thalamus and basal ganglia, and in the dentate nucleus, although all regions including grey matter were stained.