Morphogenic potential of mechanically isolated single cells from Digitalis obscura L. callus

Calli from hypocotyl and root explants of Digitalis obscura L. showed regeneration of adventitious shoots, roots and embryos when transferred to Murashige & Skoog medium supplemented with cytokinins alone or in combination with auxins. Optimum shoot-bud formation was achieved in the presence of IAA and BA, while roots mainly appeared either in absence of growth regulators or with IAA and Kn. Embryo formation took place only in those combinations that included Kn. Embryo development was influenced by the type of auxin, and precocious germination occurred in media with NAA. Mechanically isolated cells from hypocotyl- and root-derived calli were plated in MS medium supplemented with several IAA and BA combinations. Single cells were able to proliferate forming callus within 20–30 days in culture. In order to induce organogenesis, calli were transferred to various regeneration media. Shoot-bud differentiation efficiency depended on both callus origin and medium initially used for cell culture, best results being obtained in calli grown from hypocotyl-derived cells cultured in the presence of casein hydrolysate. A further subculture to medium containing coconut milk and lower concentrations of NH₄NO₃ and sucrose promoted shoot development. Rooting was readily achieved upon transferring shoots onto half-strength MS medium. Plantlets were ultimately established in soil.Abbreviations BA benzyladenine - BM basal medium - CH casein hydrolysate - CM coconut milk - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indoleacetic acid - Kn kinetin - MS Murashige & Skoog - NAA naphthaleneacetic acid     

Z-linked inheritance of male olfactory response to sex pheromone components in two species of tortricid moths, Ctenopseustis obliquana and Ctenopseustis sp.

The olfactory response from male pheromone sensitive sensilla was investigated in the endemic New Zealand brownheaded leafrollers Ctenopseustis obliquana (Walker) and C. sp. ropeana (Lepidoptera, Tortricidae). The responses from 281 sensilla from the parental strains and from both the reciprocal crosses, including F₁, F₂ and maternal and paternal backcrosses were recorded, and statistically analysed using a multivariate analysis.In males of both the parental strains, a large amplitude cell responded to the main pheromone component of the conspecific female, in C. obliquana (Z)-8-tetradecenyl acetate (Z8-14:OAc) and in C. sp ropeana (Z)-5-tetradecenyl acetate (Z5-14:OAc). Both male types also possessed a small amplitude cell, which in C. obliquana responded weakly to Z5-14:OAc and tetradecyl acetate (14:OAc), and in C. sp ropeana responded to Z8-14:OAc. The responses from the different types of hybrid males were more variable than the responses from parental males. A main pattern could, however be seen, corresponding with the expected pattern in a sex-linked inheritance on the Z-chromosome of a C. sp ropeana type dominant genetic factor. The more pronounced variation in the hybrids could not be explained by this model, and might be due to the involvement of additional genes.

---

Résumé Les réactions olfactives des sensilles mâles sensibles aux phéromones ont été examinées par enregistrement de l'extrémité de la sensille chez les tordeuses C. obliquana Walker et C. sp. ropeana. Les enregistrements ont porté sur 281 sensilles des lignées parentales et des croisements réciproques de F₁, F₂ et de croisements en retour maternel et paternel. Les résultats des enregistrements d'une sensille ont été soumis à une analyse en composantes principales.Chez les mâles de chaque lignée parentale un seul type physiologique de sensille a été découvert; une cellule répond par un pic grand au principal constituant de la phéromone femelle conspécifique. (Z)-8-acétate tétradécényl (Z8-14:OAc) pour C. obliquana, et (Z)-5-acétate tétradécényl (Z5-14:OAc) pour C. sp. ropeana. Une seconde type de cellule dans les sensilles des deux espèces de mâles présente un pic petit pour Z5-14:OAc et pour l'acétate tétradécyl (14:OAc) chez C. obliquana, et pour C. sp. ropeana au Z8-14:OAc. Les réponses des sensilles des différents types de mâles hybrides sont plus hétérogènes que celles des sensilles de leurs pères. Un schéma général pourrait cependant être décelé, correspondant au schéma prévu avec une hérédité d'un facteur dominant liée au sexe sur le chromosome Z de C. sp. ropeana. La variation plus accentuée chez les hybrides ne peut être expliquée par ce modèle, et pourrait impliquer des gènes additionnels.

     

Effect of short-and long-term exposure to low environmental temperature on brain regional GABA metabolism

Single exposure of adult male rats to low environmental temperature (LET, 12 ± 0.5°C) for 2 h significantly increased the hypothalamic and striatal GABA levels without affecting those in other regions of brain. The activity of glutamate decarboxylase (GAD) was elevated in hypothalamus (H) and corpus striatum (CS) under these conditions. GABA accumulation rate (measured with ethanolamine-O-sulfate, an inhibitor of GABA-transaminase) was also increased in both H and CS of rats exposed to LET for 2 h. Unlike after a single exposure, the repeated exposure (2 h/day) for 7, 15, and 30 onsecutive days did not change the hypothalamic GABA metabolism. No change in GABA metabolism was observed in CS when rats were repeatedly exposed to LET for 7 consecutive days. Prolongation of repeated exposure to LET (2 h/day) for 15 and 30 consecutive days decreased the striatal GABA level and increased the activity of GABA-transaminase, although GAD activity was not altered under these conditions. These results suggest that single exposure to LET accelerates GABA synthesis and may reduce the GABAergic activity in both H and CS; whereas repeated exposure to LET for 15 or 30 consecutive days enhances GABAergic activity with the stimulation of GABA utilization only in CS without affecting its synthesizing process. Thus, it may be suggested that the hypothalamic and striatal GABA system may play a characteristic role in response to short-and long-term exposure to LET.     

植物单盐毒害和离子拮抗机理研究Ⅰ.单盐和混合盐对植物原生质体膜某些特性、超氧物歧化酶和过氧化氢酶活性的影响

单盐(KCl, CaCl_2或MgCl_2)和混合盐(KC_1+CaCl_2或KCl+MgCl_2)对植物原生质体完整率、存活率和膜透性等均有明显影响。K~+、Ca~(2+)或Mg~(2+)等单种阳离子明显降低原生质体膜完整率和存活率而增加其物质渗漏量,其中以单价阳离子K~+的影响为甚。上述单种阳离子还明显降低小麦幼叶超氧物歧化酶(SOD)和过氧化氢酶活性。只有由单价和二价阳离子组成的平衡混合盐才能使原生质体维持较高的完整率、存活率和较正常的膜透性.并能使细胞维持较高的SOD和过氧化氢酶活性。 认为单盐毒害机理可能是首先引起细胞膜发生不正常的膜相变或细胞累积较多的有害氧自由基,引起膜脂发生过氧化或脱酯化而破坏膜结构。在离子平衡混合盐作用下,膜系才能维持正常液晶相,具有较高活性的SOD和过氧化氢酶等生物保护性酶系是离子拮抗作用之原因。     

Effect of chloramphenicol and lincomycin on chloroplast DNA amplification in greening pea leaves

The light-induced increase in chloroplast DNA was not inhibited by two inhibitors of protein synthesis on 70S polysomes, chloramphenicol and lincomycin, in greening pea leaves. The changes in chloroplast DNA were observed by fluorescence microscopy and measured by hybridization to specific cloned probes. The results suggest that the light-induced increase in chloroplast DNA proceeds without de novo protein synthesis in the chloroplast, in agreement with those with mutants and cultured leaf tissue.     

Nematode Mitochondrial DNA: Anomalies and Applications

The mitochondrial genome of animal cells is currently under intense investigation by molecular, evolutionary, and population biologists. This review summarizes the available information on the molecular biology of nematode mitochondrial DNA and explains how the fundamental knowledge obtained from these basic studies may be applied to nematode systematics, evolution, and diagnostics.     

New techniques in rapid viral diagnosis

Abstract The development of new diagnostic techniques in immunology and molecular biology during the last two decades has opened up new possibilities for rapid viral diagnosis. Solid phase immunoassays for antigen and antibody detection are now widely used in diagnostic settings. Several novel techniques have been introduced and have led to commercially available tests. Diagnostic methods using nucleic acid amplification procedures are already applied in research laboratories and will be commercialized soon. Biosensor-based diagnostic techniques have the potential of generating a result nearly instantaneously and it has become possible to monitor kinetic processes. Automatization and simplified procedures are needed to allow diagnostic tests to be performed soon after the sample has been obtained from the patient. In order to evaluate the new procedures and avoid false results, rigorous quality control in diagnostic virology will have to be instituted.     

Universal primers for amplification of three non-coding regions of chloroplast DNA

Six primers for the amplification of three non-coding regions of chloroplast DNA via the polymerase chain reaction (PCR) have been designed. In order to find out whether these primers were universal, we used them in an attempt to amplify DNA from various plant species. The primers worked for most species tested including algae, bryophytes, pteridophytes, gymnosperms and angiosperms. The fact that they amplify chloroplast DNA non-coding regions over a wide taxonomic range means that these primers may be used to study the population biology (in supplying markers) and evolution (inter- and probably intraspecific phylogenies) of plants.