The breeding biology of the WheatearOenanthe oenanthe in South Sweden during three contrasting years

Summary The breeding phenology, territory size, egg dimensions, clutch size, nestling growth and reproductive success of a dense population of WheatearsOenanthe oenanthe was studied on the island of Öland, S. Sweden during the years 1985–1987. The 1987 season was exceptionally cold and rainy, 1986 had the warmest and driest conditions, while 1985 was intermediate with respect to weather. Cold, windy and rainy weather was associated to prolonged incubation, greater intervals between first and replacement clutches, prolonged nestling growth, lower fledging condition, increased starvation and increased predation. Large clutches were laid earlier in the season and contained relatively larger eggs than small clutches. Incubation periods decreased with clutch size. Female size was positively correlated with egg size and with clutch size. The last egg laid in a clutch had a tendency to be heavier than eggs laid previously, especially in large clutches. Nestling starvation increased with brood size in 2 years.

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Zusammenfassung 1985–1987 wurden Phänologie, Siedlungsdichte, Eimaße, Gelegegröße, Jungenwachstum und Bruterfolg einer Population des Steinschmätzers auf der südschwedischen Insel Öland untersucht. 1987 waren die Lufttemperaturen besonders niedrig und die Niederschläge sehr hoch. Der Sommer 1986 wies dagegen die höchsten Temperaturen und niedrigsten Niederschläge der 3 Jahre auf. Kaltes, windiges und regnerisches Wetter war mit längerer Brütezeit, längeren Intervallen zwischen Erst- und Ersatzbruten, langsamerem Jungenwachstum, schlechterer Kondition der ausfliegenden Jungen und höheren Verlusten durch Verhungern und Beutefeinde korreliert. Die Gelegegröße nahm mit dem Legedatum ab; die größten Gelege hatten im Mittel größere Eier. Die Bebrütungszeit nahm mit der Gelegegröße ab. Größere Weibchen legten größere Eier und zeigten Tendenz, größere Gelege zu produzieren. Die zuletzt gelegten Eier waren meist die schwersten, besonders in großen Gelegen. Ausfälle durch Verhungern stiegen in 2 Jahren mit der Brutgröße.

     

Dicarboxylic acid anhydrides as dissociating agents of protein-containing structures

Dissociation of protein-containing structures by modification of protein amino groups with dicarboxylic acid anhydrides is a mild procedure which, in some cases, offers advantages over treatment with alternative dissociating agents, such as urea, guanidine hydrochloride, detergents, high ionic strength, and extremes of pH: In addition to dissociating multimeric proteins and protein aggregates, dicarboxylic acid anhydrides are effective dissociating agents for membrane-bound proteins and nucleoprotein particles. With most dicarboxylic acid anhydrides reviewed, the introduced reagent residues can be eliminated under moderate acid conditions, which allows the purification of unmodified individual components, and the use of disassembly-reconstitution systems valuable for investigating the structural and functional roles played by the individual components of complex particles:Each reagent can be suitable for a particular purpose, depending on the required specificity of the modification and stability of the modified groups: The stability of the acylated amino groups ranges from the very stable succinylated amino groups to the very labile acylation obtained with dimethylmaleic anhydride: Between these extremes, the stability of the modified amino groups decreases stepwise in the following order: maleic, exo-cis-3,6-endoxo-⁴-tetrahydrophthalic, citraconic, and 3,4,5,6-tetrahydrophthalic anhydride. With respect to the selectivity of the produced modification, little or no modification of hydroxyamino acid and cysteine residues has been observed with dimethylmaleic, exo-cis-3,6-endoxo-⁴-tetrahydrophthalic, and 3,4,5,6-tetrahydrophthalic anhydrides: With the other reagents, the extent of modification of hydroxyamino acid residues increases in the order citraconic, maleic and succinic anhydride: Citraconic and maleic anhydrides can produce irreversible modification of cysteine residues, the reactivity of sulfhydryl groups being higher with maleic anhydride:     

Subunit structure and higher order assembly of the hemocyanins of five members of the Naticidae family of marine gastropods: Calinaticina oldroydii (Dall), Euspira heros (Say), Neverita duplicata (Say), Polinices draconis (Dall), and Polinices lewisii (Gould)

1. The hemocyanins of the Naticidae family, E. heros, N. duplicata, P. draconis, P. lewisii and C. oldroydii were investigated by sedimentation velocity and scanning transmission electron microscopy. 2. At pH 8.0, 0.05 M Mg2+ E. heros hemocyanin is found to be predominantly in the tri-decameric state with a sedimentation coefficient (So20,w) of 131.3 (+/- 0.6) S. While the hemocyanin of N. duplicata is also mainly in the 130 S form, the hemocyanin of C. oldroydii is largely in the di-decameric form with a sedimentation coefficient close to 100 S. Other Naticidae hemocyanins, those of P. lewisii and P. draconis, have mixtures of the 100 S and 130 S di- and tri-decamers, and minor amounts of 150 S and faster sedimenting components. 3. The average particle masses based on STEM measurements are 8.85 x 10(6), 1303 x 10(6), and 17.1 x 10(6) da for the di-, tri-, and tetra-decameric assemblies of hemocyanin. 4. The subunit mol. wts of C. oldroydii hemocyanin and the published values for E. heros hemocyanin at alkaline pHs and in the presence of 8.0 M urea range from 4.2 x 10(5) to 4.8 x 10(5), suggesting the same decameric organization of the sub-assemblies of the Naticidae hemocyanins as for other molluscan hemocyanins. 5. The appearance of the larger hemocyanin particles in the electron micrographs support the hypothesis for their assembly that was based on similar studies of the hemocyanins of the Melongenidae family. According to this scheme the formation of higher aggregates is accomplished by the tail-to-head addition of each decameric unit to a central di-decamer which itself has the tail-to-tail Mellema and Klug arrangement of decamers. In this model all the higher aggregates terminate from either end with the same "collar" ends.     

Analysis of polyadenylated RNA from brain synaptosomes and mitochondria

We have isolated RNA from sheep brain synaptosomes and mitochondria separated by an aqueous two-phase system composed of dextran and poly(ethylene glycol). RNA was fractionated through oligo(dT)-cellulose columns and analyzed by electrophoresis through agarose slab gels containing methylmercuric hydroxide and stained with ethidium bromide. The electrophoretic patterns of the poly(A)-containing RNA fraction from synaptosomes and mitochondria are very similar although some high molecular weight RNA species, clearly visible in the synaptosomal fraction, are scarcely detected in the mitochondrial preparations. The electrophoretic analysis of a cleaner RNA preparation from digitonin-treated free mitochondria (mitoplasts) showed that all the poly (A)-RNA species of the synaptosomal preparation are also present in mitoplast. These results strongly suggest that all the discrete poly(A)-RNA species identified in brain synaptosomes are of mitochondrial origin.     

Yeast myosin heavy chain mutant: maintenance of the cell type specific budding pattern and the normal deposition of chitin and cell wall components requires an intact myosin heavy chain gene

Recent studies with myosin heavy chain mutants in the slime mold Dictyostelium discoideum and the yeast Saccharomyces cerevisiae indicate that the myosin heavy chain gene is not essential for cell survival under laboratory growth conditions. However, cells lacking a normal myosin heavy chain gene demonstrate substantial alterations in growth and cell division. In this study, we report that a disruption mutant in the rod portion of the yeast myosin heavy chain gene, MYO1, produces abnormal chitin distribution and cell wall organization at the mother-bud neck in a high proportion of dividing cells. It is suggested that this phenotype is the cause of the cell division defect and the osmotic sensitivity of yeast MYO1 mutants. In the absence of a normal MYO1 polypeptide, yeast cells alter their cell type specific budding pattern. It is concluded that an intact myosin heavy chain gene is required to maintain the cell type specific budding pattern and the correct localization and deposition of chitin and cell wall components during cell growth and division.     

Quantitative autoradiographic localization of neuropeptide Y (NPY) binding sites in rat posterior pituitary lobe

1. We have localized and quantified neuropeptide Y (NPY) binding sites in the rat pituitary gland after incubation of tissue sections in the presence of 125I-Bolton-Hunter NPY followed by autoradiography, computerized microdensitometry, and comparison to 125I-standards. 2. In the rat, NPY binding sites are localized exclusively to the part of the posterior pituitary lobe closer to the pituitary stalk. No NPY binding sites could be found in the intermediate or the anterior pituitary lobes. 3. Our results suggest a role for NPY in the regulation of pituitary function and, in particular, that of the neural lobe.     

Developmental expression of 44-kDa bone phosphoprotein (osteopontin) and bone γ-carboxyglutamic acid (Gla)-containing protein (osteocalcin) in calcifying tissues of rat

New aspects of the distribution and developmental appearance of the 44-kDa bone phosphoprotein (44K BPP, also called sialoprotein I or osteopontin) and bone gamma-carboxyglutamic acid (Gla)-containing protein (BGP, also called osteocalcin) during osteogenesis and dentinogenesis were investigated with immunocytochemical techniques using monospecific, affinity-purified polyclonal antibodies. Sections from newborn rat incisors and from various bone anlagen of newborn animals and fetuses were processed for detection of 44K BPP or BGP antigenicity. In addition, histochemical reactions for detection of alkaline phosphatase or calcium salts were performed on a number of the sections. The 44K BPP appears to be synthesized and secreted by chondrocytes only in the areas of cartilage-to-bone transition; these cells could participate indirectly in the process of bone formation by providing a suitable scaffold onto which primary marrow osteoblasts attach and spread. During osteogenesis, 44K BPP is found in bone-forming cells almost concomitantly with the appearance of alkaline phosphatase and before osteoid deposition, whereas BGP is still absent during early stages of mineralization. We hypothesize that this dramatic difference between the developmental appearance of 44K BPP and BGP reflects the delayed expression of the BGP gene relative to that of 44K BPP. In long-term cultures of bone marrow from adult mice, some fibroblastic cells expressed the 44K BPP phenotype; these cells could represent early osteogenic progenitor cells. Some experiments also suggested that, as with BGP, 44K BPP or an immunologically related protein is synthesized by some odontoblasts and secreted into predentin, prior to the onset of mineralization.