Liver mitochondria, confirmed as intact by complete suppression of succinate uptake and oxidation, possess a carnitine palmitoyltransferase I that is totally inhibited by malonyl CoA.

Succinate dehydrogenase activity in mitochondria, which were isolated by centrifuging partially purified mitochondria through 1. 315 M sucrose, was completely suppressed when [14C]succinate uptake was abolished by prior incubation of the mitochondria with carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) and valinomycin. The conclusion that these mitochondria were intact was confirmed by the fact that, when these mitochondria were broken by a freeze-thaw cycle followed by sonication, such inhibition was totally abolished. The yield of mitochondria, microsomes, and peroxisomes from the initial homogenate was 17.8, <0.1, and 0%, respectively, indicating that the mitochondria were not only intact but also essentially free of contamination from microsomes and peroxisomes. The overt form of carnitine palmitoyltransferase (CPT I) in these intact and pure mitochondria was totally inhibited by malonyl CoA, indicating that previous reports of incomplete inhibition in mitochondrial preparations resulted from interference from CPT activity in the inner mitochondrial membrane (CPT II), microsomes, or peroxisomes.     

Seed transmission of turnip yellow mosaic virus in winter turnip and winter oilseed rapes

This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYMV in a naturally infected winter turnip rape (Brassica napus var. silvestris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8.3% seed transmission of the virus was found in seed of plants from three localities. The proportion of infected seeds produced by artificially infected plants of winter oilseed rape (Brassica napus ssp. oleifera) and winter turnip rape cultivars was determined. The virus transmission rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and for the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in direct tests on bulk seed lots to estimate proportion of infected seed, but must be used on germinated seedlings.     

Aspects of hadrosaurian cranial anatomy

Supraorbital bones in Saurolophus angustirostris are described, and their presence in all hadrosaurs is suggested. Frontal-nasal and premaxillar-nasal fontanellae are distinguished in hadrosaurs; their presence is explained as connected with growth and considered to he responsible for the variability of crest structures. New data indicating the presence of a cartilaginous diverticulum nasi within the circumnarial depression in Saurobphus ongustirostris are presented. A physiological (respiratory and/or thermoregulatory) function of the nasal diverticulum is proposed.     

European checkerspots (Melitaeini: Lepidoptera,Nymphalidae) are not aposematic – the point of view of great tits (Parus major)

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Multiplex panels of polymorphic microsatellite loci for two cryptic bat species of the genus Pipistrellus,developed by cross‐species amplification within the family Vespertilionidae

The paper presents multiplex panels of polymorphic microsatellites for two closely related cryptic species Pipistrellus pipistrellus and Pipistrellus pygmaeus. We tested the cross‐species amplification of 34 microsatellite loci, originally developed for five vespertilionid bat species. Ten and nine polymorphic loci in P. pipistrellus (mean number of alleles per locus = 10.5) and P. pygmaeus (8.1), respectively, in three multiplex polymerase chain reactions per species were amplified. All loci can be analysed in a single fragment analysis and can be used as markers to the study of evolution and the ecology of structured populations of socially living bats.     

Evidence for triacylglycerol synthesis in the lumen of microsomes via a lipolysis-esterification pathway involving carnitine acyltransferases

In this study a pathway for the synthesis of triacylglycerol (TAG) within the lumen of the endoplasmic reticulum has been identified, using microsomes that had been preconditioned by depleting their endogenous substrates and then fusing them with biotinylated phosphatidylserine liposomes containing CoASH and Mg(2+). Incubating these fused microsomes with tri[(3)H] oleoylglycerol and [(14)C]oleoyl-CoA yielded microsome-associated triacylglycerol, which resisted extensive washing and had a [(3)H]:[(14)C] ratio close to 2:1. The data suggest that the precursor tri[(3)H]oleoylglycerol was hydrolyzed by microsomal lipase to membrane-bound di[(3)H]oleoylglycerol and subsequently re-esterified with luminal [(14)C]oleoyl-CoA. The accumulation of TAG within the microsomes, even when overt diacylglycerol acyltransferase (DGAT I) was inactive, is consistent with the existence of a latent diacylglycerol acyltransferase (DGAT II) within the microsomal lumen. Moreover, because luminal synthesis of TAG was carnitine-dependent and markedly reduced by glybenclamide, a potent carnitine acyltransferase inhibitor, microsomal carnitine acyltransferase appears to be essential for trafficking the [(14)C]oleoyl-CoA into the microsomal lumen for subsequent incorporation into newly synthesized TAG. This study thus provides the first direct demonstration of an enzymatic process leading to the synthesis of luminal triacylglycerol, which is a major component of very low density lipoproteins.     

The "Goldilocks Effect" in Cystic Fibrosis: identification of a lung phenotype in the <Emphasis Type="Italic">cftr</Emphasis> knockout and heterozygous mouse

Background  

Cystic Fibrosis is a pleiotropic disease in humans with primary morbidity and mortality associated with a lung disease phenotype. However, knockout in the mouse of cftr, the gene whose mutant alleles are responsible for cystic fibrosis, has previously failed to produce a readily, quantifiable lung phenotype.