POPULATION STRUCTURE IN AN INSHORE CETACEAN REVEALED BY MICROSATELLITE AND mtDNA ANALYSIS: BOTTLENOSE DOLPHINS (TURSIOPS SP.) IN SHARK BAY, WESTERN AUSTRALIA

We examined population substructure of bottlenose dolphins ( Tursiops sp). in Shark Bay, Western Australia, using 10 highly polymorphic microsatellite loci, and mitochondrial DNA (mtDNA). For microsatellite analysis, 302 different animals were sampled from seven localities throughout the bay. Analysis of genetic differentiation between sampling localities showed a significant correlation between the number of migrants ( Nm ) calculated from F _ST, R _ST and private alleles, and distance between localities–a pattern of isolation-by-distance. For mtDNA, 220 individuals from all seven localities were sequenced for a 351 base pair fragment of the control region, resulting in eight haplotypes, with two distinct clusters of haplotypes. Values of F _ST and (φ)_ST for mtDNA yielded statistically significant differences, mostly between localities that were not adjacent to each other, suggesting female gene flow over a scale larger than the sampled localities. We also observed a significant correlation between the number of female migrants calculated from F _ST and φ_ST and the distance of sampling localities. Our results indicate that dispersal in female dolphins in Shark Bay is more restricted than that of males.     

Wood anatomy ofTrimeniaceae

Four collections of three species ofTrimenia and one collection ofPiptocalyx were studied; early-formed and later-formed wood was analyzed for oneTrimenia. Liquid-preserved material permitted analysis of mucilage and starch storage in wood ofT. neocaledonica andP. moorei. BecausePiptocalyx is scandent whereasTrimenia is arborescent, wood differences relative to evolution of a climbing habit could be examined.Piptocalyx contrasts withTrimenia in having wider vessels, more numerous per mm², resulting in a conductive area five times greater per unit area than that of theTrimenia woods averaged.Piptocalyx has appreciably fewer bars per perforation plate and thus much greater conductive area per perforation plate than have the species ofTrimenia. Rays inPiptocalyx are much taller and wider than those ofTrimenia. Wood ofTrimeniaceae is highly primitive in its scalariform perforation plates, scalariform lateral wall pitting on vessels, relatively long vessels elements, and heterocellular rays. Imperforate tracheary elements are septate nucleate fibertracheids (or even libriform fibers) rather than tracheids, but loss of borders on pits (and thus lowered conductive function of the imperforate tracheary elements) can be explained by the development of these elements into starchstoring cells. Some fiber-tracheids inT. neocaledonica are enlarged mucilagecontaining cells. Details of vessel structure inTrimeniaceae are similar to those ofMonimiaceae (s. s.), but similarity to some other lauralean (annonalean) families may be found: in mucilage presence,Trimeniaceae resembleLauraceae rather thanMonimiaceae. Wood ofTrimeniaceae may be regarded as highly mesomorphic, corresponding to the moist habitats in which all of the species occur.     

Influence of 0.5 ppm nitrogen dioxide exposure of mice on macrophage congregation in the lungs

Summary The lungs of 12 mice, half of which were exposed to continuous 0.5 ppm nitrogen dioxide for 3 weeks, were explanted in culture, and the instances of macrophage congregation were quantitated according to numbers of target cells involved, categories of congregation from three to 11 or more, numbers of macrophages participating in each category for the total cultures, and the influence of delaying explantation for 24 and 96 hr. A total of 9042 macrophages and 2140 epithelial and spindle target cells were counted in the outgrowths from 306 explants. The incidence of macrophage congregation (or numbers of target cells) was greater for the cultures from the NO₂-exposed animals, both with respect to total incidences between groups (p→0), and the 0-hr (p<0.001) and 24-hr (p<0.01) culture subgroups. In addition, the values for T₃ to T₆ macrophage congregation were individually and consistently greater for the exposed animal group. Postmortem interval stress at 96 hr appeared to result in large colonies, but they were reduced greatly in number. Also the incidence of macrophage congregation fell by 28% as compared to 0-hr and 24-hr subgroups. Supported by Grants NHLI No. HL 17412 and EPA No. R. 800881.     

PURIFICATION AND PROPERTIES OF A PROLYL ENDOPEPTIDASE FROM RABBIT BRAIN

Abstract— An enzyme with the specificity of a prolyl endopeptidase was purified about 880-fold from rabbit brain. The enzyme hydrolyzes peptidylprolyl-peptide and peptidylprolyl-amino acid bonds. Several biologically active peptides such as angiotensin, bradykinin, neurotensin. substance P and thyrotropin releasing hormone are degraded by hydrolysis of the bond between the carboxyl group of proline and the adjacent amino acid or ammonia respectively. The enzyme is activated by dithiothreitol and inhibited by heavy metals and thiol blocking agents. The serine protease inhibitor phenylmethanesulfonylfluoride has no effect on activity; however, inhibition was obtained with diisopropylfluorophosphate. Prolyl endopeptidase has a molecular weight of about 66,000 and a pH optimum of about 8.3. A new chromogenic substrate, N -benzyloxycarbonylglycyl-L-prolylsulfamethoxazole, was used for determination of enzyme activity. The substrate is hydrolyzed to N -benzyloxycarbonylglycyl-L-proline and free sulfamethoxazole which can be conveniently determined by a colorimetric procedure.     

Subcellular Distribution of Prolyl Endopeptidase and Cation-Sensitive Neutral Endopeptidase in Rabbit Brain

Abstract: The subcellular distribution of prolyl endopeptidase, and of cationsensitive neutral endopeptidase, two enzymes actively metabolizing many neuropeptides, was determined in homogenates of rabbit brain. The subcellular distribution of both enzymes was more similar to lactate dehydrogenase, a cytoplasmic enzyme marker, than to choline acetyltransferase, a synaptosomal marker. Only 35% of the activity of these two neutral endopeptidases was found in the crude mitochondrial fraction (P₂), the bulk of the remaining activity being associated with the high-speed supernatant. Prolyl endopeptidase and cation-sensitive neutral endopeptidase thus can be regarded as mainly cytoplasmic enzymes in the rabbit brain.