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La môle hydatiforme partielle (MHP) fait partie des maladies trophoblastiques gestationnelles. Appelée également môle embryonnée, il s´agit d´un œuf humain pathologique comportant des villosités en transformation vésiculaire, mais conservant une forme placentaire reconnaissable et une cavité amniotique avec un fœtus. La circonstance diagnostic la plus commune étant le tableau d´avortement spontané au premier trimestre. Rarement les môles partielles persistent au-delà du premier trimestre et sont alors source de complications maternelles et fœtales et de confusion diagnostique. L´origine génétique des MHP correspond à une conception triploïde avec un lot chromosomique supplémentaire d´origine paternelle. La coexistence d´un fœtus de caryotype normal avec une MHP est une situation exceptionnelle. Nous rapportons un cas rare de grossesse molaire partielle avec fœtus vivant diploïde à 27 semaines d´aménorrhée (SA) chez une femme âgée de 36 ans dont le diagnostic est portée à l´occasion d´une menace d´accouchement prématurée associée à un placenta prævia.

Nous illustrons à travers ce cas l'utilité du dépistage précoce des malformations fétales au sein d'une unité de diagnostic anténatal, à travers les images d'une omphalocèle diagnostiquée au premier trimestre de la grossesse. Il s'agit d'une patiente âgée de 42 ans, G2P1, ayant fait une première échographie à 12SA+4 jrs montrant une omphalocèle (A,B,C,D). Les informations sur les différentes investigations ont été expliquées à la patiente, qui a décidé de poursuivre la grossesse. Une amniocentèse a été réalisée à 16 SA en vue d'un caryotype. La patiente reconsulte à 19 SA pour réévaluation échographique et interprétation des résultats du caryotype. L'échographie a montré une omphalocèle mesurant 4cm de diamètre, avec un collet à 14,3 mm, contenant le foie et l'estomac (E,F). Le résultat du caryotype révélait une trisomie 18. Une interruption médicalisée de la grossesse a été demandée par la patiente.

Les sujets 47XYY ont souvent un fonctionnement gonadotrope normal, l´association à un déficit en 5alpha réductase chez ces sujets est rare ; la présentation clinique classique des déficits en 5 alpha réductase est un pseudohermaphrodisme masculin, rarement un micropénis comme mode de révélation. Le traitement par énanthate de testostérone du micropénis ne donne pas de bons résultats dans les déficits en 5alpha réductase, la dihydrotestostérone(DHT) à une efficacité prouvée dans ce cas. Nous rapportons l´observation d´un patient de 17 ans, référé dans notre formation pour la prise en charge d´un micropénis ne répondant pas aux 2 cures à base d´énanthate de testostérone. Le bilan notait une testostérone normale, des gonadotrophines à la limite supérieure de la normale, une DHT basse, avec augmentation du rapport testostérone/DHT > 20.caryotype 47XYY. Le déficit en 5 alpha réductase chez ces sujets pose la problématique d´une simple coïncidence, ou d´un lien effectif.

THE UPDATED NEW EDITION OF THE POPULAR COLLECTION OF HIGH-RESOLUTION CHROMOSOME PHOTOGRAPHS—FOR GENETICISTS, MAMMOLOGISTS, AND BIOLOGISTS INTERESTED IN COMPARATIVE GENOMICS, SYSTEMATICS, AND CHROMOSOME STRUCTURE Filled with a visually exquisite collection of the banded metaphase chromosome karyotypes from some 1, 000 species of mammals, the Atlas of Mammalian Chromosomes offers an unabridged compendium of the state of this genomic art form. The Atlas??contains the best karyotype produced, the common and Latin name of the species, the published citation, and identifies the contributing authors. Nearly all karyotypes are G-banded, revealing the chromosomal bar codes of homologous segments among related species. The Atlas brings together information from a range of cytogenetic literature and features high-quality karyotype images for nearly every mammal studied to date. When the Atlas was first published, only three mammals were sequenced. Today, that number is over 300. Now in its second edition, this book contains extensive revisions and major additions such as new karyotypes that employ G- and C- banding to represent euchromatin and heterochromatin genome composition, new phylogenetic trees for each order, homology segment chromosome information on published aligned chromosome painting. Summaries of the painting data for some species indicate conserved homology segments among compared species. An invaluable resource for today's comparative genomics era, this comprehensive collection of high-resolution chromosome photographs: * Assembles information previously scattered throughout the cytogenetics literature in one comprehensive volume * Provides chromosome information and illustrations for the karyotypes of 300 new species * Addresses the mandate of the Human Genome Project to annotate the genomes of other organisms * Serves as a basis for chromosome-level genome assemblies * Offers a detailed summation of three decades of ZooFish (chromosome painting) * Presents high-resolution photos of karyotypes that represent more than 1, 000 mammal species Written for geneticists, mammalogists, and biologists, the Atlas of Mammalian Chromosomes offers a step forward for an understanding of species formation, of genome organization, and of DNA script for natural selection.

Image en médecine Nous illustrons à travers ce cas l'utilité du dépistage précoce des malformations fœtales au sein d'une unité de diagnostic anténatal, à travers les images d'une omphalocèle diagnostiquée au premier trimestre de la grossesse. Figure 1 A, C) coupe LCC montrant l’omphalocèle; B) coupe transversale mettant en évidence le sac tout autour du défect; D) échographie en mode 3D montrant l’omphalocèle; E) contenu hépatique de l’omphalocèle; F) axe mésentérique 1 Service de Gynécologie et Obstétrique, CHU Bougatfa, Bizerte Université Tunis El Manar, Tunisie

L´érythrophagocytose blastique correspond à une hyperactivation des blastes. L´érythrophagocytose est retrouvée dans les hémopathies myéloïdes surtout avec la t (8;16). Dans ce travail nous présentons un cas exceptionnel d´érythrophagocytose blastique au cours d´une leucémie aigue lymphoblastique T sans anomalies cytogénétiques. A.Z âgée de 19 ans, l´examen à l´admission a trouvé un syndrome fébrile avec des vertiges et phosphènes, un syndrome tumoral avec une hypertrophie amygdalienne et gingivale. L´hémogramme a objectivé une hyperleucocytose (399.5 G/L), avec une anémie arégénérative (Hb: 9,3 g/dl) et thrombopénie (plaquettes: 40 G/L). Le myélogramme a montré 90% des blastes (MPO négative) avec des images d´érythrophagocytose blastique. L´immunophénotypage a confirmé une LAL T. L´analyse cytogénétique était normale. L´érythrophagocytose blastique dans une LAL T semblerait être une entité distincte nécessite la précision de l´impact de ces images sur le diagnostic, le pronostic voir même le traitement des LAL T.

Sturgeons (Chondrostei: Acipenseriformes) display markedly disjunction distributions with a wide distribution in the northern hemisphere. Their unique benthic specializations and conserved morphology, evolutionary age, the variation in their basic diadromous life history, and the large public interest due to their near extinction or critically endangered status make sturgeons and paddlefishes interesting groups for molecular and cytogenetic studies. From altogether 27 acipenseriform species, seventeen species are supposed to be critically endangered, two species are classified as endangered, four species are vulnerable and other species are near threatened or in low-risk (IUCN Red list 2010). Sturgeons are characteristic by a relatively high number of chromosomes in cell nuclei and differences in ploidy levels. Sturgeons displayed a strong tendency for interspecific and inter-generic hybridization under altered environmental conditions as well as under conditions of artificial propagation. Almost 20 inter-specific sturgeon hybrids were described. The decrease of natural populations and tendencies leading to restocking may result in uncontrolled restocking, production of hybrid specimens (even with non-native species) and decrease of natural genetic diversity of species in their original distribution area. Identification of parental species of natural hybrids by modern methods of molecular biology is still not easy. Here, we attempt to briefly summarize the major aspects of sturgeon genetics and cytogenetics related to ploidy levels and interspecific hybridization.

Resolving the persistence of sexual reproduction despite its overwhelming costs (known as the paradox of sex) is one of the most persistent challenges of evolutionary biology. In thinking about this paradox, the focus has traditionally been on the evolutionary benefits of genetic recombination in generating offspring diversity and purging deleterious mutations. The similarity of pattern between evolution of organisms and evolution among cancer cells suggests that the asexual process generates more diverse genomes owing to less controlled reproduction systems, while sexual reproduction generates more stable genomes because the sexual process can serve as a mechanism to \"filter out\" aberrations at the chromosome level. Our reinterpretation of data from the literature strongly supports this hypothesis. Thus, the principal consequence of sexual reproduction is the reduction of drastic genetic diversity at the genome or chromosome level, resulting in the preservation of species identity rather than the provision of evolutionary diversity for future environmental challenges. Genetic recombination does contribute to genetic diversity, but it does so secondarily and within the framework of the chromosomally defined genome.

Nuclear restriction fragment length polymorphism (RFLP) analysis was used to determine the wild diploid Arachis species that hybridized to form tetraploid domesticated peanut. Results using 20 previously mapped cDNA clones strongly indicated A. duranensis as the progenitor of the A genome of domesticated peanut and A. ipaensis as the B genome parent. A large amount of RFLP variability was found among the various accessions of A. duranensis, and accessions most similar to the A genome of cultivated peanut were identified. Chloroplast DNA RFLP analysis determined that A. duranensis was the female parent of the original hybridization event. Domesticated peanut is known to have one genome with a distinctly smaller pair of chromosomes (\"A\"), and one genome that lacks this pair. Cytogenetic analysis demonstrated that A. duranensis has a pair of \"A\" chromosomes, and A. ipaensis does not. The cytogenetic evidence is thus consistent with the RFLP evidence concerning the identity of the progenitors, RFLP and cytogenetic evidence indicate a single origin for domesticated peanut in Northern Argentina or Southern Bolivia, followed by diversification under the influence of cultivation

Chromosomal forms of Anopheles gambiae, given the informal designations Bamako, Mopti, and Savannah, have been recognized by the presence or absence of four paracentric inversions on chromosome 2. Studies of karyotype frequencies at sites where the forms occur in sympatry have led to the suggestion that these forms represent species. We conducted a study of the genetic structure of populations of An. gambiae from two villages in Mali, west Africa. Populations at each site were composed of the Bamako and Mopti forms and the sibling species, Anopheles arabiensis. Karyotypes were determined for each individual mosquito and genotypes at 21 microsatellite loci determined. A number of the microsatellites have been physically mapped to polytene chromosomes, making it possible to select loci based on their position relative to the inversions used to define forms. We found that the chromosomal forms differ at all loci on chromosome 2, but there were few differences for loci on other chromosomes. Geographic variation was small. Gene flow appears to vary among different regions within the genome, being lowest on chromosome 2, probably due to hitchhiking with the inversions. We conclude that the majority of observed genetic divergence between chromosomal forms can be explained by forces that need not involve reproductive isolation, although reproductive isolation is not ruled out. We found low levels of gene flow between the sibling species Anopheles gambiae and Anopheles arabiensis, similar to estimates based on observed frequencies of hybrid karyotypes in natural populations