Detection of oestrus in the african elephant (Loxodonta africana).

Swabs of mucus and cells from the reproductive tract of a 15 year old female African elephant in captivity were examined. Daily samples were obtained over a 1-year period by means of a probe designed to penetrate the urogenital sinus to a depth of 90cm. Dried smears of mucous material showed ferning patterns at intervals of approximately 16 days. Dried spots of supernatant from washings of the swabs also showed intense ferning at 16-day intervals, but with greater regularity. Smears were stained and examined for the presence of squamous cells over a 4-month period. Results indicate a regular occurrence of Keratinisation at approximately 15-day intervals. These observations indicate that the oestrous cycle of this elephant has a duration of approximately 16 days.This is the first detailed study of the oestrous cycle in the African elephant, knowledge of which is essential for artificial breeding.     

Studies on the altered electrophoretic type of the factor VIII related antigen

Summary A distinct sub-group of von Willebrand's disease is characterized by an electrophoretically faster mobility of the factor VIII related antigen. Some of the physico-chemical properties of this variant antigen were investigated in this communication. The effect of temperature was tested by heating aliquots (0.5 ml) for 20 minutes at 45°C, 56°C and 65°C. The variant was found to be denatured at 56°C while the control was denatured at 65°C. The effect of pH was tested by assessing the quantity (Laurell technique) and electrophoretic mobility (two dimensional immunoelectrophoresis) of the antigen in a variety of buffers ranging in pH from 7.0 to 9.5. The quantity of antigen was variable both among variants and controls and the electrophoretic mobility of the variant antigen was faster at all pH's. Molecular weight differences between the variant and controls were not detected since the chromatographic profile of the variant was similar to that of the controls in Sepharose 6 B using a 0.02 M Tris-NaCl buffer at pH 7.0. The affinity of the antigen for human antibody was geterogeneous although the variant exhibited less affinity for one of the human antibodies but not the other. The inhibitory effect was more pronounced in serum than in plasma. Purified IgG, however, did not show any inhibition, as the residual antigen assayed by the Laurell technique, was similar to the expected values. This would imply that non-IgG plasmatic factors could also play a part in the observed inhibition.     

Labeling of succinate-cytochrome c reductase with 125I. Accessibility of the peptides to the aqueous phases on the cytosolic and matrix sides of the mitochondrial membrane

Lactoperoxidase-catalyzed radioiodination was used to study the arrangement of the component peptides of succinate-cytochrome c reductase with respect to the aqueous phases on each side of the mitochondrial inner membrane. Mitochondria depleted of their outer membrane and inside-out vesicles purified from submitochondrial particles by the lectin-affinity procedure (D'Souza, M. P., and Lindsay, J. G. (1981) Biochim. Biophys. Acta 640, 463-472) were iodinated using immobilized preparations of lactoperoxidase. The labeled membranes were solubilized in detergent and the succinate-cytochrome c reductase was purified by immunoprecipitation with specific IgG. Analysis of the radioiodine distribution after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and comparison with peptide stain patterns show that bands 2 (64 kilodaltons), 6 (30 kilodaltons), 9 (15 kilodaltons), and 11 (less than 10 kilodaltons) are labeled from the cytoplasmic surface of the membrane. Bands 1 (72 kilodaltons), 4 (48 kilodaltons), and 8 (20 kilodaltons) appear to be labeled on the matrix side of the membrane, while bands 3 (52 kilodaltons), 5 (35 kilodaltons), 7 (25 kilodaltons), and 10 (11 kilodaltons) are labeled from both sides of the membrane. Tentative identification of the labeled bands suggests that band 1 is the large subunit of succinate dehydrogenase. Bands 3 and 4 represent proteins which have been referred to as core proteins I and II. Bands 5 and 6 are the proteins associated with cytochromes b and c1, respectively; band 7 is the Rieske iron-sulfur protein.     

The Ultrastructure of the Fungus Trichoderma viride and Investigation of its Growth on Cellulose

Changes in the ultrastructure of Trichoderma viride during growth in shake cultures on cellobiose and cellulose fibres were examined. Electron micrographs of thin sections of germinating conidia, septate hyphae with ascomycete pores and other cell organelles are presented. Extensive autolysis of hyphae was observed after growth for 20 h on cellobiose. The fungus grew in the lumina and within the walls of cellulose fibres. The hyphae followed the directions of the laminar structure but did not grow across them. The observations indicated that the hyphae penetrated the fibres by causing cracks and by dissolving enzymatically the cellulose.     

Population structure in an isolated Arctic fox, Vulpes lagopus, population: the impact of geographical barriers

The genetic composition of a population reflects several aspects of the organism and its environment. The Icelandic Arctic fox population exceeds 8000 individuals and is comprised of both coastal and inland foxes. Several factors may affect within-population movement and subsequent genetic population structure. A narrow isthmus and sheep-proof fences may prevent movement between the north-western and central part and glacial rivers may reduce movement between the eastern and central part of Iceland. Moreover, population density and habitat characteristics can influence movement behaviour further. Here, we investigate the genetic structure in the Icelandic Arctic fox population ( n  = 108) using 10 microsatellite loci. Despite large glacial rivers, we found low divergence between the central and eastern part, suggesting extensive movement between these areas. However, both model- and frequency-based analyses suggest that the north-western part is genetically differentiated from the rest of Iceland (F_ST = 0.04, D_S = 0.094), corresponding to 100–200 generations of complete isolation. This suggests that the fences cannot be the sole cause of divergence. Rather, the isthmus causes limited movement between the regions, implying that protection in the Hornstrandir Nature Reserve has a minimal impact on Arctic fox population size in the rest of Iceland.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 18–26.     

Phylogeographic analyses reveal distinct lineages of the liverworts Metzgeria furcata (L.) Dumort. and Metzgeria conjugata Lindb. (Metzgeriaceae) in Europe and North America

Seed plant genera often exhibit intercontinental disjunctions where different species are found on different continents. Many morphologically circumscribed bryophyte species exhibit similar disjunctions. We used nucleotide sequences from the plastid and nuclear genomes to test hypotheses of phylogeography within representatives of the genus Metzgeria: Metzgeria furcata, Metzgeria conjugata, and Metzgeria myriopoda. The first two species have sexual and asexual populations, exhibit disjunctions between North America and Europe, and have been split into separate species, numerous subspecies or varieties. The third species occurs in eastern North America but is not reported from Europe. Phylogenetic analyses resolved three distinct lineages within the morphologically defined species, M. furcata: one in North America, and two in Europe. Similarly, three morphologically cryptic clades of M. conjugata were resolved by the molecular data: northern North America, Europe, and south‐eastern North America. For both species, molecular divergence among taxa occurred in the absence of morphological change. In the case of M. myriopoda, all plants from eastern North America were both morphologically uniform and genetically homogeneous (although not identical). The present study provides significant insight into a plant group with complex taxonomy, and indicates that these liverwort taxa with wide distributions, extreme sex ratios, and continental disjunctions harbor cryptic lineages. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 745–756.