Chromosome localization and polymorphism of an oestrogen-inducible gene specifically expressed in some breast cancers

Summary The BCEI gene codes for a small secreted protein and is expressed in the human mammary tumour cell line MCF7 under oestrogen control and in some breast cancers. We have mapped the gene to chromosome 21 using a panel of somatic hybrid lines, and in situ hybridization has allowed a precise assignment to band 21q223. Two restriction fragment length polymorphisms (RFLP) are described that should be of use in linkage or population studies to test a possible involvement of the BCEI gene in genetic predisposition to breast cancer. This gene should also be a useful marker for the genetic and physical mapping of chromosome 21, and for a better definition of the region involved in the clinical phenotype of Downs syndrome.     

Enhancement of shoot regeneration potential by liquid medium culture from mature cotyledons of sunflower (Helianthus annuus L.)

We describe here a liquid culture system for the regeneration of shoots at high frequencies from mature cotyledon tissues of three genotypes of sunflower (Helianthus annuus L.) one of which had previously been found to be recalcitrant to regeneration when cotyledons were cultured on solid medium. Cotyledons were excised from 2-day-old seedlings and incubated in liquid Murashige and Skoog's modified medium supplemented with 5.4 M naphthaleneacetic acid (NAA) and 4.4 M benzylaminopurine (BAP). After two weeks in culture, the whole upper surface of regenerating explants was covered with green shootlets. The percentages of regenerating explants of three genotypes varied between 60 and 70%, and the number of shoots per regenerating explant was highly increased. The shootlets were transferred to solid Murashige and Skoog's medium allowing shoot development, then to rooting medium. Rooted plantlets were successfully acclimatized and gave fertile plants. The role of liquid medium culture in the induction of sunflower regeneration is discussed.Abbreviations BAP 6-benzylaminopurine - NAA 1-naphthaleneacetic acid - IAA indole-3-acetic acid - IBA indole-3-butyric acid     

Callus formation and induction of a cell suspension culture from Acacia senegal

Cell proliferation has been induced from the cambial zone of a branch of Acacia senegal, kept on the basal Knop and Ball medium in the presence of auxin. Transferred on the more complete nutrient medium of Schenk and Hildebrandt, the colonies gave rise to several cell lines. One of the friable lines, consisting of aggregates of parenchymatous cells, gave a cell suspension culture in an agitated liquid medium which is maintained as a strain of illimited growth. The heterogeneous suspension did not undergo noticeable changes after eight transfers. Aggregates collected on a 1000-m nylon seive were able to grow on a solid medium and gave back a friable callus similar to the initial colonies.     

HIBERNATION CHEZ TROIS ESPÈCES DE MÉTOPIINES: HYMENOPTERA,ICHNEUMONIDAE

Résumé Les conditions de l'hibernation sont étudiées chez les trois espèces de Métopiines Chorinaeus funebris Gravenhorst, Triclistus podagricus Gravenhorst et Triclistus pygmaeus Cresson. Ces espèces hibernent à des stades de développement compris entre l'éonymphe et l'adulte non émergé (Tableau I). La durée de l'incubation complémentaire après réactivation par le froid à 2^o varie entre 10 et 30 jours en moyenne (Tableaux II, IV et V). Chez T. podagricus et T. pygmaeus, on a observé également des émergences d'adultes avant l'hiver (Tableau III). I1 semble que T. podagricus ne parvienne au stade d'imago hibernant qu'après une baisse de la température d'élevage. Aucune souche dépourvue de diapause n'a pu être créée, mais pour les trois espèces, deux générations annuelles seraient possibles sous conditions contrôlées. Enfin, l'utilisation éventuelle de T. pygmaeus pour une lutte biologique contre Zeiraphera diniana Guénée est évoquée.

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Summary The conditions of hibernation have been investigated in the three metopiine species Chorinaeus funebris, Triclistus podagricus and Triclistus pygmaeus, all entomophagous on Zeiraphera diniana Guénée (Lepidoptera, Tortricidae) in the Engadine Valley (Switzerland). The hibernating stages are eonymph, pronymph or unemerged adult inside the host pupae (Table I). The length of the complementary incubation after reactivation at 2^o varies between 10–30 days (Tables II, IV and V). A small number of T. podagricus and of T. pygmaeus regularly appear as adults before winter, in rearings of both laboratory and field populations (Table III). It seems that T. podagricus larvae need a reduction in the initial rearing temperature before full development is achieved and the hibernating stage is reached (imago). No strain without diapause could be obtained for any of the three species, but the rearing of two annual generations under controlled conditions is possible in the laboratory. The eventual use of T. pygmaeus as a control agent against Z. diniana is discussed.

     

Index of new names of syntaxa published in 1992

The present work collects the new names of syntaxa (in the sense of the Code of Phytosociological Nomenclature,Barkman et al. 1986) above subassociation, rank found in the literature received by the Library of the Conservatoire et Jardin botaniques in Geneva. For the year 1992, 658 names have been listed. For each one of them, an appreciation about its validity is given relating to the Code of Phytosociological Nomenclature. Fifteen names are given in addition to the Indexes 1987, 1990 and 1991 (Theurillat & Moravec 1990, 1993, 1994).     

An acoustic telemetry study of seabream (Sparus aurata L.): first results on activity rhythm,effects of environmental variables and space utilization

The movements of seabream (Sparus aurata L) were recorded in two earthen ponds (250 m² and 400 m²) by tracking fish tagged with miniature acoustic transmitters. Five seabreams, 500 g in weight, were tracked for periods of four or five days. Fish positions were recorded continuously using an acoustic telemetry system. Each of the five tagged seabreams were tracked individually. Two fishes were released schooled with numerous other individuals, two others were released in isolation and one was grouped with three other individuals.The schooled seabreams were more active in general and, in the large school they were diurnal; isolated fishes however, were more active at night. Temperature influences significantly and progressively the fish activity. Activity decreases at night and increases during daylight. Oxygen saturation also influences swimming activity with a general positive relationship.The horizontal distribution of this species was not uniform. Its resting area was generally located around some particular landmarks such as inlet or outlet pipes in the ponds. No feverish feeding competition was observed between individuals of the same school. The feeding area was cleaned rapidly, in less than 10 minutes, without subsequent returns from the resting area to the feeding area.

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Résumé Les déplacements de la daurade (Sparus aurata L.) ont été enregistrés dans deux bassins en terre (250 m² et 400 m²) en suivant des poissons marqués avec des émetteurs acoustiques miniaturisés. Cinq daurades d'un poids individuel de 500 g furent suivies durant des périodes de 4 ou 5 jours. Les positions des poissons ont été enregistrées en continu avec un systéme de télémétrie acoustique. Chacun des cinq poissons marqués fut suivi individuellement. Deux poissons furent regroupés avec de nombreux autres individus, deux autres furent laissés seuls et le dernier fut mis avec trois autres individus.Les daurades groupées étaient en général plus actives et, en grand banc, étaient diurnes; les poissons isolés étaient toutefois plus actifs durant la nuit. La température influence significativement et progressivement l'activité des poissons. L'activité décroît durant la nuit et augmente pendant le jour. Le pourcentage de saturation en oxygéne agit aussi, de façon positive, sur l'activité de nage.La distribution horizontale de cette espéce n'est pas uniforme. Son aire de repos est généralement localisée dans quelques zones particuliéres comme les arrivées et les sorties d'eau. Aucune compétition alimentaire fébrile n'a été observée entre les individus d'un même banc. L'aire de nourrissage est rapidement nettoyée, en moins de 10 minutes, sans retours ultérieurs depuis la zone de repos jusqu' à la zone de nourrissage.