Mise en évidence de la présence d'acide ribonucléique dans le noyau des spermatides âgées d'Acanthodactylus erythrurus lineomaculatus Dum. & Bibr. (Lacertidae)

Résumé Nous avons abservé au moyen de méthodes cytochimiques, l'élimination progressive de l'ARN nucléaire dans les spermatides âgées d'un Lézard. Il ressort de cette étude que l'ARN lié à la chromatine s'observe pendant toute la spermiogenèse et n'est éliminé qu'au terme ultime de cette spermiogenèse c'est à dire au moment de la transformation de la spermatide en spermatozoïde.Ces résultats diffèrent de ceux obtenus chez un Insecte où l'ARN nucléaire disparaît aux tous premiers stades de la spermiogenèse, en même temps que les nucléoles.

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Demonstration of nuclear RNA in the mature spermatids of Acanthodactylus erythrurus lineomaculatus Dum. & Bibr. (Lacertidae)

Summary Cytochemical methods have shown a progressive elimination of nuclear RNA from mature spermatids in the lizard Acanthodactylus erythrurus. The RNA bound to chromatin has been observed throughout spermiogenesis and is eliminated only at the final stage, i. e., the stage of transformation from the spermatid to the spermatozoon.These results differ from those obtained in insects where the nuclear as well as the nucleolar RNA disappears during the early stages of spermiogenesis.

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Zusammenfassung Mit cytochemischen Untersuchungsmethoden haben wir bei der Eidechse Acanthodactylus erythrurus festgestellt, daß die Kern-RNS aus den älteren Spermatiden eliminiert wird. So wird die chromatingebundene-RNS, die während der gesamten Spermiogenese beobachtet werden kann, erst im letzten Stadium der Spermiogenese ausgestoßen, das heißt im Stadium der Umwandlung der Spermatiden in Spermien.Diese Ergebnisse stehen nicht im Einklang mit denen, die bei Insekten gewonnen wurden. Bei den letzteren verschwindet die RNS des Zellkerns und der Nukleolen in den Anfangsstadien der Spermiogenese.

     

Immunocytochemical identification of an LHRH-producing system originating in the preoptic nucleus of the duck

Summary A fluorescent technique applying specific LHRH and vasotocin antisera was used for the immunocytochemical localization of the respective neurosecretory systems in the hypothalamus of gonadectomized, testosteronetreated and/or serotonin injected male domestic ducks. An immunoreactive (IR) LHRH-producing system, with perikarya located in the preoptic nucleus, could be traced through the ventral hypothalamus down to the external layer of the rostral and caudal ME, in close vicinity to the hypophysial portal system. An IR-vasotocin system originating in the paraventricular and supraoptic nuclei ran through the ventral hypothalamus, but terminated in (i) the external layer of the rostral ME, and (ii) in the posterior lobe of the hypophysis.Dr. B. Kerdelhué, Laboratoire des Hormones polypeptidiques du CNRS, F-91190 Gif-sur-Yvette, France     

No evidence that polymorphisms of brain regulator genes Microcephalin and ASPM are associated with general mental ability, head circumference or altruism

We test the hypothesis that polymorphisms of the brain regulator genes MCPH1 and ASPM contribute to variations in human brain size and its correlates. We measured general mental ability, head circumference and social intelligence in 644 Canadian adults (496 Caucasians, 36 Orientals, 84 Mixed Race/Other and 28 Blacks; 257 men and 387 women). The gene polymorphisms were assessed from buccal DNA; mental ability by Wonderlic Personnel Test and Multidimensional Aptitude Battery; head circumference by stretchless tape; and social intelligence by prosocial attitude questionnaires. Although all measures were construct valid and the allele frequencies showed expected population differences, no relationship was found between the genes and any of the criteria. Among Caucasian 18-25 year olds, for example, the two mental ability tests correlated with each other (r=0.78, N=476, p<0.001), with head circumference (r=0.17, N=182, p<0.05) and with prosocial attitudes (r=0.23, N=182, p<0.001).     

Linking microarray reporters with protein functions

Background  

The analysis of microarray experiments requires accurate and up-to-date functional annotation of the microarray reporters to optimize the interpretation of the biological processes involved. Pathway visualization tools are used to connect gene expression data with existing biological pathways by using specific database identifiers that link reporters with elements in the pathways.     

Supramolecular structures of peptide assemblies in membranes by neutron off-plane scattering: method of analysis

In a previous paper (Yang et al., Biophys. J. 75:641-645, 1998), we showed a simple, efficient method of recording the diffraction patterns of supramolecular peptide assemblies in membranes where the samples were prepared in the form of oriented multilayers. Here we develop a method of analysis based on the diffraction theory of two-dimensional liquids. Gramicidin was used as a prototype model because its pore structure in membrane in known. At full hydration, the diffraction patterns of alamethicin and magainin are similar to gramicidin except in the scale of q (the momentum transfer of scattering), clearly indicating that both alamethicin and magainin form pores in membranes but of different sizes. When the hydration of the multilayer samples was decreased while the bilayers were still fluid, the in-plane positions of the membrane pores became correlated from one bilayer to the next. We believe that this is a new manifestation of the hydration force. The effect is most prominent in magainin patterns, which are used to demonstrate the method of analysis. When magainin samples were further dehydrated or cooled, the liquid-like diffraction turned into crystal-like patterns. This discovery points to the possibility of investigating the supramolecular structures with high-order diffraction.     

铅锌镉联合染毒及营养干预对大鼠血液系统的影响研究

目的：了解铅锌镉联合染毒对大鼠血液系统的影响及营养干预对其损伤的修复作用。方法：选择SPF级初断乳Wistar大鼠72只,随机分为对照组、染毒组和干预组,分别采用生理盐水、铅锌镉联合染毒液及染毒后以营养干预液灌胃28天和56天之后,检测其血液系统中五元素和血细胞的指标。结果：染毒组较对照组大鼠血铜、血锌含量高,血钙含量低于对照组,差异均有统计学意义（P〈0．05）;染毒组血铜含量高于干预组,血钙含量低于干预组,差异均有统计学意义（P〈0．05）;干预组红细胞（RBC）计数、血红蛋白（Hb）、血细胞比容（HCT）均高于染毒组,差异均有统计学意义（P〈0．05）;对照组白细胞（WBC）计数高于染毒组、干预组,差异均有统计学意义（P〈0．05）。结论：铅镉对大鼠血铜、血钙、血锌水平有影响;综合营养干预对重金属元素造成的血液系统损伤有明显的拮抗作用,对血液系统有一定的保护及修复作用。