Microtubules with 15 subunits in cockroach epidermal cells

Since Ledbetter and Porter (1964) described the 13 subunits which are visible in cross sections of negatively stained plant microtubules, subsequent observations have generally confirmed this number. By using Mizuhira's fixative composed of tannic acid and glutaraldehyde, it is easyto demonstrate the subunits of microtublules without optical reinforcement Cytoplasmic microtubules and sperm axonemes, fixed with Mizuhira's fixtive, similarly show 13 subunits (Mizuhira's and Futaesaku, 1971, 1972; Futaesaky et al., 1972; Tilney et al., 1973). This paper will describe a particular type of microtubule in insect epidermal cells fixed with the above fixative. The number of the subunits is found to be 15 in tranverse sections.     

Giemsa banding patterns in chronic lymphocytic leukaemia.

The banding patterns of chromosomes from 20 patients with chronic lymphocytic leukaemia (C.L.L.) have been analyzed. 97 of 100 metaphases examined had a normal banding pattern. The 3 remaining metaphases, all from one patient had bands similar to those seen after aging. It is concluded that the chromosomes in C.L.L. have normal banding patterns. The majority of cytogenetic studies in chronic lymphocytic leukaemia have reported normal chromosomes (Fitzgerald and Adams 1965; Oppenheim et al., 1965; Lawler et al., 1968). An inherited abnormality of G group chromosome (No. 22) has been reported in a family, three members of whom developed C.L.L. (Fitzgerald and Hamer, 1969), but further investigations of cases of familial leukaemia failed to reveal a similar abnormality (Fitzgerald et. al., 1966). The development of new techniques which allow the positive identification of individual chromosomes (Caspersson et al., 1969; Dutrillaux and Lejeune, 1971; Sumner et al., 1971; Seabright, 1971), has revolutionised human cutogenetics and revealed additional information regarding chromosome abnormalities and leukaemia (Rowley, 1973; Lobb et al., 1972; Milligan and Garson, 1974). The purpose of this investigation was to determine whether the chromosomes in C.L.L. have normal banding patterns.     

A Field Outbreak Caused by Bovine Respiratory Syncytial Virus

Bovine respiratory syncytial virus (BRSV) caused a large epizootic of acute respiratory disease in Japan in 1968—69 (Inaba et al. 1970, Inaba et al. 1972). A much smaller outbreak occurred in Switzerland (Paccaud & Jacquier 1970). In Belgium the virus has been isolated from an outbreak of respiratory disease (Wellemans et al. 1970). BRSV has later been proved an important causal agent of respiratory disorders in the same country (Wellemans & Leiinen 1975). In England and USA the virus has caused and been isolated from outbreaks of acute respiratory disease in calves (Jacobs & Edington 1971, Rosenquist 1974, Smith et al. 1974). In Denmark BRSV has sporadically been isolated from pneumonic calf lungs (Bitsch et al. 1976).     

Heterogeneous distribution of enzymes among plasma-membrane fragments sedimenting with the microsomal fraction of rat liver

Plasma-membrane fragments recovered in the microsomal fraction of rat liver homogenates were shown to be heterogeneous in density. It was demonstrated that 5'-nucleotidase, the most commonly used plasma-membrane marker, is concentrated in the lightest subfraction. Two of the published procedures for the isolation of plasma-membrane fragments from the microsomal fraction (Touster et al., 1970; Hinton et al., 1971) are shown to give products which are not representative of all the plasma-membrane fragments of microsomal size, and it is argued that a third procedure (House & Weidemann, 1970) is likely to give a similar product.     

Bacteriophage P22 virion protein which performs an essential early function. I. Analysis of 16-ts mutants.

The product of gene 16 of phage P22, P16, is a head protein. P16 does not play an essential role in phage assembly since particles formed without this protein appear normal by electron microscopy examination (Botstein et al., 1973). P16 is essential when the particle infects a cell in the following cycle of infection (Botstein et al., 1973; King et al., 1973). We have characterized a mutant of P22 carrying a temperature-sensitive allele of gene 16. This mutant has previously been referred to as P22 25-ts (Levine et al., 1970, 1972) and P22 X-ts (Bezdek and Soska, 1970, 1973). P22 16-ts behaves as an early mutant at the nonpermissive temperature. Temperature shift experiments show that P16 of the infecting virion acts within the first 10 min at 25 C and that gene 16 product is required late in the latent period for incorporation into infectious phage. Induction does not require P16 for the production of particles. Particles produced either in a P22 16-ts thermal shift-up infection or after induction of 16-ts lysogens at 41 C are missing P16 and are, therefore, defective. P16 in P22 16-ts virions formed at the permissive temperature appears to be heat labile; it is inactivated after infection at 41 C. A simple assay for defective particles based on a complementation test is described.     

The preparation and properties of pyruvate kinase from yeast

A new method is described for the preparation of pyruvate kinase from yeast. This eliminates proteolysis during the preparation. The molecular weight of yeast pyruvate kinase is 215000, and it is composed of four subunits. Such properties of the enzyme as its extinction coefficient, cold-lability, thiol-group reactivity and binding of Mn(2+) ions are compared with those previously reported for yeast pyruvate kinase prepared by different methods. The specific activity is significantly higher than previously observed, but otherwise the enzyme is similar, apart from its molecular weight and Mn(2+)-binding characteristics, to preparations from Saccharomyces cerevisiae obtained in this laboratory (e.g. Fell et al., 1972, and references therein) and that of C. H. Suelter (e.g. Kuczenski & Suelter, 1971, and references therein), and is different from the enzyme isolated from Saccharomyces carlsbergensis by B. Hess and his co-workers (e.g. Wieker & Hess, 1972, and references therein).     

Chromosome differences in Peromyscus maniculatus populations at different altitudes in Colorado

Mice of the genus Peromyscus all have 48 chromosomes. Yet the appearance of the 48 chromosomes is highly variable from species to species (Hsu & Arrighi, 1966, 1968, 1971; Pathak et al., 1973) and even in different populations of the same species (Sparkes & Arakaki, 1966; Ohno et al., 1966; Hsu & Arrighi, 1968; Arakaki et al. 1970; Te & Dawson, 1971; Bradshaw & Hsu, 1972; Murray & Kitchin, 1976). The evolutionary significance of this variation and the mechanisms for its initiation and maintenance have been of interest for quite a few years. However, it was not until the sophisticated chromosome banding techniques became available that mammalian cytogeneticists were able to begin to study the chromosome variation of Peromyscus in some detail. The use of C-banding led Hsu & Arrighi (1971) to the finding that the short arms of chromosomes in three different species of Peromyscus contained constitutive heterochromatin. These results suggested that the variations in the number of acrocentric chromosomes in Peromyscus might be a result of different amounts of heterochromatin. Later studies (Duffey, 1972; Waterbury, 1972; and Pathak et al., 1973) were also consistent with this hypothesis.However, it was soon discovered that not all chromosomal differences among Peromyscus populations are due to heterochromatin changes. Studies by Arighi et al. (1976) and Murray & Kitchin (1976) showed that some chromosomal differences between species and subspecies of Peromyscus are due to pericentric inversions. Thus, it appears that both inversions and the addition of heterochromatin are involved in the evolution of the karyotype of Peromyscus.The purpose of our study was to investigate the chromosomes of Peromyscus maniculatus in different populations in Colorado (U.S.A.) and to test for relationships involving an altitudinal gradient. In the first part of this study, orcein stained chromosomes from three subspecies of mice sampled at nine different altitudes were examined for karyotype variability. In the second part of the study, karyotypes of two subspecies (P. m. rufinus and P. m. luteus), representing high and low altitude populations were examined with Q banding to determine the mechanisms responsible for chromosomal differences.     

Facilitated diffusion: The problem of boundary conditions

Summary The model equations suggested by Wyman (1966) to explain Wittenberg's (1966) experiments on oxygen diffusion facilitated by haemoglobin have been studied by various authors. Kreuzer and Hoofd (1970) use a semi-analytical and numerical approach; Kutchaiet al. (1970) use a purely numerical approach; and Murray (1971) solved the equations analytically. Although the results they obtain are in good agreement with experiment, Kreuzer and Hoofd (1970) and Kutchaiet al. (1970) on the one hand and Murray (1971) and Murray and Wyman (1971) on the other use fundamentally different boundary conditions. This paper reconsiders the problem and proves that these different boundary conditions are equivalent for practically all situations of biological interest. The conclusion is that the simple algebraic result of Murray (1971) suffices for most experimental situations. In the extreme situations where his procedure is not applicable, which are distinguished in the text, the numerical scheme of Kutchaiet al. (1970) is recommended.P. J. M. would like to thank the Science Research Council for their financial support.     

On the Fertility and Survival of Deep Frozen Boar Spermatozoa Thawed in Skim Milk

Satisfactory conception rates of deep frozen boar spermatozoa were obtained, with insemination by way of the cervix, after thawing the deep frozen spermatozoa in boar seminal plasma, both in preliminary trials (Crabo & Einarsson 1971, Crabo et al. 1972 b) and in a large field trial (Einarsson et al. 1972). Fertility with pellet frozen boar spermatozoa, thawed without dilution, was reported by Graham et al. (1971 a, b) and Pursel & Johnson (1971).     

Efficient algorithms for searching for exact repetition of nucleotide sequences

Summary There are several algorithms designed for searches for homologous sequences (Fitch 1966; Needleman and Wunsch 1970; Chva'tal and Sankoff 1975; Griggs 1977; Sannkoff 1972; Smith and Waterman 1981; Smith et al. 1981, Wagner and Fisher 1974; Waterman et al. 1976). This paper presents some very simple and useful high speed, text editing algorithms that search for exact nucleotide sequence repetition and genome duplication. The last algorithm suggested here is specifically adapted for the 4-letter alphabet of nucleotide sequences. Owing to the rapid accumulation of nucleotide sequences and the frequent need to search for sequence repetition or where a given set of nucleotides occurs in long sequences, efficient algorithms of this type are a necessity.     

Besprechungen

Book reviewed in this article: Kriston , Irmgard (1971): Zum Problem des Lernverhaltens von Apis mellifica L. gegenüber verschiedenen Duftstoffen. Z. vgl. Physiol. 74 , 169–189. Lauer , Josta, und Martin Lindauer (1971): Genetisch fixierte Lerndispositionen bei der Honigbiene Hölldobler , B. 1) (1971): Sex pheromone in the Ant Xenomyrmex floridanus Rosengren , Rainer (1971): Route fidelity, visual memory, and recruitment behaviour in foraging wood ants of the genus Formica Rüppell , Georg, und Elfriede Gösswein (1972): Die Schwärme von Leucaspius delineatus Gerlach , Richard (1971): Die Geheimnisse der Amphibien und Reptilien ed. Immelmann , Klaus, Jürgen Nicolai , Joachim Steinbacher und Hans E. Wolters Isenmann , P., und E. P. Jouvcntin (1970): Eco-éthologie du Manchot empereur (Aptenodytes forsteri) et comparaison avec le Manchot Adélie Brosset , A. (1971): Recherches sur la Biologie des Pycnonotidés du Gabon Isenmann , P. (1970): Contribution á l'étude de la zone de velage du Phoque de Weddell Zippelius , H.-M. (1971): Soziale Hautpflege als Beschwichtigungsgebärde bei Säugetieren Lorenz , Konrad (1971): Knowledge, beliefs, and freedom (Wissen, Glauben und Freiheit) Charles-Dominique , P., und R. D. Martin (1972): Behaviour and Ecology of nocturnal Prosimians/Comportement et Ecologie des Prosimiens nocturnes Dijk , D. E. van (1971): Anuran ecology in relation particularly to oviposition and development out of water     

The messaoudensis-trifidum acritarch assemblage (Ordovician: late Tremadoc-early Arenig) of the Barriga Shale Formation, Sierra Morena (SW-Spain)

The "messaoudensis-trifidum acritarch assemblage" is currently considered to be characteristic of latest Tremadoc-earliest Arenig cold-water environments on the periphery of Gondwana, at high latitudes in the southern hemisphere. An integrated biostratigraphical study on both acritarchs and graptolites was until now only available for localities in northwest England. Reinvestigation of the "messaoudensis-trifidum acritarch assemblage" from the Barriga Formation (Sierra Morena, southwestern Spain), which contains some graptolite horizons that can be attributed to the latest Tremadoc (pre-phyllograptoides and pre-approximatus graptolite biozones), strengthens the biostratigraphical potential of the "messaoudensis-trifidum assemblage", and the importance of some of the acritarch taxa recovered from these levels. It is concluded that the acritarch genera Coryphidium Vavrdová, 1972, Peteinosphaeridium Staplin et al., 1965 emend. Playford et al., 1995, Striatotheca, Burmann, 1970, and the Veryhachium lairdii group (rectangular veryhachiids) appear in the latest Tremadoc, and should not be considered as indicators of the base of the Arenig, as previously suggested.     

Inverted terminal repetition in adeno-associated virus DNA: independence of the orientation at either end of the genome

Complementary strands of adeno-associated virus DNA labeled with 32P at the 5' ends were separated and then self-annealed to form single-stranded circles stabilized by hydrogen bonds between the complementary sequences in the inverted terminal repetitions. We have previously shown that there are two distinct sequences in the terminal repetition which represent an inversion of the first 125 nucleotides (E. Lusby et al., J. Virol. 34:402-409, 1980; I. S. Spear et al., Virology 24:627-634, 1977). Base pairing between terminal sequences of the same orientation leads to a normal double helical structure. If sequences of the opposite orientation pair, an aberrant secondary structure is formed. HpaII digestion of the self-annealed, single-stranded circles led to labeled terminal fragments that corresponded both to those generated from termini of a normal double helical structure and those generated from an aberrant terminal secondary structure. Thus, the orientation of the terminal repetition at one end of the genome is not influenced by the orientation at the other end.     

5' LTR complete nucleotide sequence of Chinese hamster intracisternal A-particle.

Retrovirus like sequences homologous to mouse IAP are present in Chinese hamster genome (Lueders K.K. and Kuff, E.L., 1981, 1983, Servenay et al., 1990). Murine IAP long terminal repeats (LTRs) can function as effective promoters in different cell types (Horowitz M. et al., 1984, Howe, C.C. et al., 1986). Thus CHO IAP sequences could act as retrotransposons in the cellular genome, and in this way affect the expression of other genes at the target sites. We had sequenced previously a Chinese hamster IAP genomic region corresponding mainly to the gag gene and including 57 nucleotides of U5 5' LTR (Servenay et al., 1988). In this paper, we present the 5' LTR complete nucleotide sequence of the Chinese hamster IAP element and its comparison with those of mouse and Syrian hamster.     

The autocatalytic processing of the subtilisin Carlsberg pro-region is independent of the primary structure of the cleavage site

Subtilisins are extracellular seryl-proteases produced by bacilli (Markland and Emil, 1971). In addition to signal sequences, these proteases have N-terminal extensions (pro-regions) which have also been identified in several other proteases (Silen et al., 1988; Vasantha et al., 1984; Polhner et al., 1987; Henderson et al., 1987; Yanagida et al., 1986; Takagi et al., 1985). The pro-region holds the pro-protease associated with the membrane and release of the protease takes place as a result of pro-region removal by autocatalytic processing (Egnell and Flock, 1991). In this report we describe the construction of four deletion-mutations in the gene encoding subtilisin Carlsberg at the junction between the pro-region and mature subtilisin Carlsberg. We found that the introduction of different deletions abolished the ability of subtilisin to undergo autocatalytic cleavage of the pro-region in cis, whereas cleavage by exogenous subtilisin could still occur in trans. Point mutations were also introduced in positions -5 to +4 around the pro-region and native subtilisin cleavage site. Processing of pro-subtilisin with the point mutations showed that the autocatalytic cleavage and recognition of this junction of the subtilisin Carlsberg pro-region is independent of the amino acid sequence around the cleavage site.     

Prediction of the energy value of commercial pig feeds,according to the various energy systems used in the European Community that are based on simple analytical parameters of the feed

An attempt was made to predict the energy value of mixed pig feeds from chemical composition alone, using multiple linear regression analysis. A total of 24 commercial mixed pig feeds were collected on the Belgian market and analysed for various chemical parameters. The digestibility of the Weende nutrients was also determined.For several energy systems used in the European Community (EC), the most reliable regression is given for one to seven independent variables. It was finally found that Nettoenergie Fett (Schiemann et al., 1971), net energy growth (A. Just, 1975, personal communication), digestible energy (Schiemann et al., 1971), metabolizable energy (Just, 1975), Gesamtnährstoffe and total digestible nutrients were most accurately predicted when the following five variables were entered in the regression equation: crude protein, crude fat and the three nitrogen-free extractives (NFE) fractions: starch, invert sugars and “other NFE” (= NFE — starch — invert sugars).     

Sequences of cDNAs for human salivary and pancreatic α-amylases

The nucleotide sequences of the cloned human salivary and pancreatic α-amylase cDNAs correspond to the continuous mRNA sequences of 1768 and 1566 nucleotides, respectively. These include all of the amino acid coding regions. Salivary cDNA contains 200 bp in the 5′-noncoding region and 32 in the 3′-noncoding region. Pancreatic cDNA contains 3 and 27 bp of 5′- and 3′-noncoding regions, respectively. The nucleotide sequence humology of the two cDNAs is 96% in the coding region, and the predicted amino acid sequences are 94% homologous.Comparison of the sequences of human α-amylase cDNAs with those previously obtained for mouse α-amylase genes (Hagenbuchle et al., 1980; Schibler et al., 1982) showed the possibility of gene conversion between the two genes of human α-amylase.