Inner mitochondrial membrane anion channel is present in brown adipocytes but is not identical with the uncoupling protein

Summary Vesicles of inner mitochondrial membrane, mitoplasts, from rat brown adipose tissue were prepared by osmotic swelling and studied using the patch-clamp technique. Current events of a 107.8±8.7 pS (n=16, 21°C) channel were recorded in the mitoplast-attached mode. This channel was selective for anions and its kinetics resembled those of channels previously found in liver and heart mitochondria of mouse and ox. In whole-mitoplast mode each of five purine nucleotides (20 m) blocked the channel. This is the first demonstration of pharmacological blockade of this type of channel. Although a similar anion channel in mouse and ox mitochondria was suggested to be the uncoupling protein (UCP) associated with nonshivering thermogenesis, we present several arguments against this possibility. Thus we describe a high-conductance, purine-nucleotide-binding, anion selective mitochondrial channel, that is not the UCP.     

Allozyme variation among biotypes of the brown planthopperNilaparvata lugens in the Philippines

Allozyme variation was studied in threeNilaparvata lugens biotypes infesting specific rice varieties and a biotype infesting a weed grass,Leersia hexandra. Of the 20 enzymes inN. lugens for which activity was noted, 9 were polymorphic. Eleven enzyme loci were monomorphic for the same allele in all biotype populations; the rest were polymorphic for two or more alleles. The mean number of alleles per polymorphic locus was 2.3, while the mean number of alleles per locus was 1.5; heterozygosity ranged from 0.02 to 0.06 (biotype 1 > biotype 3 >Leersia-infesting biotype > biotype 2). Allelic frequency differences were observed in five loci among the four biotypes. However, the coefficient of genetic identity (I) of 0.99+ showed that the four biotype populations were genetically close relatives or merely populations ofN. lugens undergoing genetic differentiation. This work was partly supported by a financial grant received from the Directorate for Technical Cooperation and Humanitarian Aid, Switzerland.     

Sugar constituents of fucose-containing polysaccharides from various Japanese brown algae

Sugar constituents of the fucose-containing polysaccharides (FCPs) from 21 species of brown algae were analyzed. FCPs were extracted with hot water (100 °C, 4 h), separated by precipitation with 20% (v:v) ethanol in the presence of 0.05 M MgCl₂ to remove contaminating soluble alginate, and purified by DEAE-Sephadex column chromatography. The samples were hydrolyzed with HCI, and neutral sugar and uronic acid were separated by anion exchange chromatography. Their amounts were determined by gas-liquid chromatography. The neutral sugars in the FCPs from Ishige okamurae, Laminaria ochotensis, Myelophycus simplex, Padina arborescens and Sargassum thunbergii all contained arabinose, fucose, galactose, glucose, mannose, rhamnose and xylose residues. The FCPs from Ishige okamurae, Padina arborescens, Sargassum hemiphyllum, S. patents and S. sagamianum contained the four uronic acids, galacturonic acid, glucuronic acid, guluronic acid and mannuronic acid.     

Age-related flight and reproductive performance of the light brown apple moth, Epiphyas postvittana

The relationship between flight activity, reproduction and age of Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae) was studied using tethered flight assays. Flights began on the day of emergence, peaking on days four and five in females and on day five in males, and lasted for nine to ten days. The development of flight capacity was well synchronised with the build-up and decline of reproductive behaviours (calling, mating and oviposition). Flights of E. postvittana are thus inter-reproductive, and there is no obvious pre-oviposition period. Males were more active than females as 45–50% of male moths in comparison to 15–18% of female moths were capable of prolonged flights during the peak activity period. The results suggest that flights of E. postvittana are appetitive flights to a large extent, but it is suggested that some individuals may migrate, as there is no diapause in this species. The sexual dimorphism of flight capacity is discussed in relation to those of other tortricids and Lepidoptera in general.

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Zusammenfassung Die Beziehungen zwischen Flugaktivität, Fortpflanzung und Alter von Epiphyas postvittana (Walker) (Tortricidae) wurden untersucht mit Hilfe von angebudenen Flugapparaten. Flüge begannen am Tage des Schlüpfens, mit einen Maximum am vierten und fünften Tag bei Weibchen und am fünten Tag bei Männchen, und dauerten neun bis zehn Tage. Die Entwicklung des Flugvermögens war gut mit der Zu- und Abnahme des Fortpflanzungsverhaltens (Rufen, Kopulieren und Eiablage) korreliert. Flüge von E. postivittana finden also während der Fortpflanzungsperiode statt, und es gibt keine deutliche Periode vor der Eiablage. Männchen waren aktiver als Weibchen: 45–50% der Männchen verglichen mit 15–18% der Weibchen waren zu langen Flügen während der maximalen Aktivitätsperiode fähig. Das Ergebnis deutet an, das Flüge von E. postvittana im grossen Masse Appetenzflüge sind, doch es wird auf die Möglichkeit hingewiesen, dass einige Individuen wandern können, da die Art keine Diapause hat. Der Geschlechtsdimorphismus in der Flugaktivität wird diskutiert und verglichen mit dem anderer Tortriciden und der Lepidoptera allgemein.

     

The role of availability of food and water to the adult Epiphyas postvittana, the light brown apple moth, in its reproductive performance

Female Epiphyas postvittana (Lepidoptera, Tortricidae) moths were able to lay fertile eggs without feeding, but they require water to achieve their full reproductive potential. Fecundity of moths given water from emergence was not different from that of moths fed with 30% honey solution. Deprivation of feeding during the early stage (up to three days after emergence) showed no significant decrease in fecundity provided that honey solution was available from the age of four days after emergence. Starved moths laid less than 30% of the number of eggs laid by those fed with honey solution or water. Fecundity was correlated with moth weight at emergence when moths were fed with water or honey solution, but not when no food or water was provided. Moths of both sexes fed on honey solution copulated less frequently, lost body weight at a lower rate and had a greater longevity, compared with those fed with water or nothing. These results are discussed in relation to the reproductive strategy of this species.

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Zusammenfassung Weibliche Motten der Art Epiphyas postvittana (Lepidoptera, Tortricidae) legten fruchtbare Eier ohne Nahrung aufzunehmen, brauchten jedoch Wasser, um ihr volles Fortpflanzung — Potential zu erreichen. Fruchtbarkeit von Motten, denen Wasser von der Zeit des Schlüpfens an gegeben wurde, unterschied sich nicht von der Fruchtbarkeit der Motten, die mit einer 30 prozentigen Honiglösung gefüttert wurden. Nahrungsentzug während der frühen Entwicklung (bis zu drei Tagen nach Schlüpfen) führte nicht zu einer Reduktion der Fruchtbarkit, vorausgesetzt dass Honiglösung von einem Alter von vier Tagen nach Schlüpfen angeboten wurde. Hungernde Motten legten weniger als 30% der Eier als mit Honiglösung oder Wasser gefütterte Motten. Fruchtbarkeit war korreliert mit dem Gewicht der Motten zur Zeit des Schlüpfeus, wenn die Motten mit Wasser oder Honiglösung gefüttert wurden, jedoch nicht, wenn weder Nahrung noch Wasser angeboten wurde. Mit Honiglösung gefütterte Motten beiderlei Geschlechts kopulierten weniger häufig, verloren Gewicht langsamer und lebten langer als mit Wasser oder nicht gefütterte Motten. Die Ergebnisse werden diskutiert in Bezug auf die Fortpflanzungsstrategie der Art.

     

Application of noninvasive techniques to monitor reproductive function in a brown hyena(Hyena brunnea)

Estrus in a 10-yr-old brown hyena was described by monitoring urinary steroid metabolites. These studies were repeated the succeeding year and combined with ultrasonography, vaginal cytology, and laparoscopy to further aid in identifying natural and induced estrus. Collection of semen from a 14-yr-old male brown hyena was accomplished by electroejaculation. Use of frozen semen once during natural estrus and again during estrus induced with follicle stimulating hormone (FSH) did not result in pregnancy. Further studies with this animal indicate that stimulation with gonadotropin releasing hormone (GNRH), rather than FSH, may be the more appropriate treatment for stimulating ovulation in canids or related species. While this study did not result in conception, a significant step toward that end was realized by utilizing urinary estrogen to monitor the estrus cycle.     

ULTRASTRUCTURE OF SWARMERS IN THE LAMINARIALES (PHAEOPHYCEAE). I. ZOOSPORES1

Zoospores of 17 species in 14 genera of Laminariales, collected in the northeast Pacific Ocean, were studied by electron microscopy. These zoospores are unique in the brown algae in lacking both an eyespot in the single chloroplast and any associated swelling at the base of the shorter, posterior flagellum. Spores of all species examined possess a distal whiplash portion on the longer, mastigoneme-bearing anterior flagellum. This appendage may sometimes be as long as the mastigoneme-bearing portion of the flagellum, but it is only seldom preserved in the preparations for electron microscopy. A microtubular cytoskeleton is probably responsible for maintaining the shape of the spore. It consists of a short band of about 10 microtubules between the two basal bodies, scattered tubules converging at the anterior of the spore, a band of 7–9 tubules directed anteriorly from the anterior basal body, and a band directed posteriorly from the posterior basal body. These anterior and posterior bands may form one continuous band looping around the periphery of the spore. Variation with possible taxonomic significance was found in the ultrastructure of vesicles which apparently contain adhesive material, and which are extruded through the plasmalemma when the zoospores settle.     

ULTRASTRUCTURE OF SWARMERS IN THE LAMINARIALES (PHAEOPHYCEAE). II. SPERM1

The ultrastructure of sperm from 13 species in 11 genera of Laminariales collected in the northeast Pacific Ocean is unique in the brown algae. The sperm are elongate, and possess a nucleus, several mitochondria and two or three chloroplasts, but no eyespot. The anterior flagellum bears mastigonemes on the proximal half of its length; a distal “whiplash” portion lacks mastigonemes and is an extension of only the two central singlet microtubules of the axoneme. A peculiar feature of these sperm is the posterior flagellum, which is longer than the anterior flagellum and tapers distally as the doublet microtubules become singlets and decrease in number. This feature contrasts with the laminarialean zoospore, which possesses a short posterior flagellum with the usual “9 + 2” axoneme. The structure of these sperm differs from that reported for Chorda, the sperm of which resembles a primitive brown algal zoospore. The facts support the concept that Chorda is the most primitive member of the Laminariales.     

The relation between spruce monoculture and incipient podzolisation in ochreous brown earths of the Belgian Ardennes

Summary The effects of coniferous monoculture on the distribution of C, Fe and Al in the upper horizons of brown ochreous earths of the Belgian Ardennes were investigated by comparing 5 soil profiles developed under an 80 year old spruce stand with another 5 profiles developed under a climactic broad-leaved forest (beechwood).Organic carbon, Fe and Al were extracted with 0.1N NaOH/Na-tetraborate solution buffered at pH 9.7: recent studies have shown that this extraction is particularly appropriate for the detection of incipient podzolisation in brown earths-brown podzolic soils intergrades.Even if most of the classic podzolisation indexes fail to illustrate differences, nevertheless our results show that fulvic acids and organo-ferric complexes are present in significantly greater amounts in the upper part of the cambic (B)₁ horizon of the soils developed under conifers. Moreover, this podzolic tendancy is confirmed by the weathering patterns of the clay minerals in the A₁(B) horizons developed under spruces, i.e. a more pronouced weathering of chloritic layers than those observed in the beechwood soil, with a correlative genesis of more abundant smectite-like minerals. One may therefore conclude that the change in the humus type (moder to mor) after the planting of spruce trees, has been sufficient, within the local climatic and edaphic context, to promote incipient podzolisation.     

Sulphated heteropolysaccharides from Padina pavonia

Extraction with hydrochloric acid (pH 2.5) of the brown alga Padina pavonia afforded water-soluble and water-insoluble polysaccharides comprising D-glucuronic acid, L-fucose, D-xylose, D-mannose, D-glucose and D- galactose residues. The water-soluble polysaccharide was fractionated by using ethanol, and cetylpyridinium chloride and by chromatography on DEAE-cellulose. A neutral laminaran-like glucan, a sulphated heteropolysaccharide composed of the aforementioned sugars and a protein moiety were obtained. The isolated heteropolysaccharide showed high anticoagulation activity.