Adenosine triphosphatase of bean plastids: its properties and site of formation

Extracts of bean (Phaseolus vulgaris L.) etioplasts and chloroplasts contain a dithiothreitol-activated Ca²⁺-dependent adenosine triphosphatase which is inhibited by Dio-9. The chloroplast and etioplast enzymes have identical R_F values upon disc gel electrophoresis. Optimum extraction of the enzyme from either plastid preparation is accomplished with 1 mm ethylenediamine tetraacetic acid. Photophosphorylation capacity can be partially restored to depleted chloroplast preparations by addition of either the chloroplast or etioplast extract. These results suggest that the adenosine triphosphatase from etioplasts and chloroplasts represents a modified coupling factor for photophosphorylation.     

The metal site of Pseudomonas aeruginosa azurin,revealed by a crystal structure determination of the co(II) derivative and co-EPR spectroscopy

The crystal structure of cobalt-substituted azurin from Pseudomonas aeruginosa has been determined to final crystallographic R value of 0.175 at 1.9 Å resolution. There are four molecules in the asymmetric unit in the structure, and these four molecules are packed as a dimer of dimers. The dimer packing is very similar to that of the wild-type Pseudomonas aeruginosa azurin dimer. Replacement of the native copper by the cobalt ion has only small effects on the metal binding site presumably because of the existence of an extensive network of hydrogen bonds in its immediate neighborhood. Some differences are obvious, however. In wild-type azurin the copper atom occupies a distorted trigonal bipyramidal site, while cobalt similar to zinc and nickel occupy a distorted tetrahedral site, in which the distance to the Met121,S^δ atom is increased to 3.3–3.5 Å and the distance to the carbonyl oxygen of Gly45 has decreased to 2.1–2.4 Å. The X-band EPR spectrum of the high-spin Co(II) in azurin is well resolved (apparent g values g_x′ = 5.23; g_y′ = 3.83; g_z′ = 1.995, and hyperfine splittings A_x′ = 31; A_y′ = 20–30; A_z′ = 53 G) and indicates that the ligand field is close to axial. Proteins 27:385–394, 1997. © 1997 Wiley-Liss, Inc.     

Diversification shifts in leafroller moths linked to continental colonization and the rise of angiosperms

Tectonic dynamics and niche availability play intertwined roles in determining patterns of diversification. Such drivers explain the current distribution of many clades, whereas events such as the rise of angiosperms can have more specific impacts, such as on the diversification rates of herbivores. The Tortricidae, a diverse group of phytophagous moths, are ideal for testing the effects of these determinants on the diversification of herbivorous clades. To estimate ancestral areas and diversification patterns in Tortricidae, a complete tribal‐level dated tree was inferred using molecular markers (one mitochondrial and five nuclear) and calibrated using fossil constraints. We found that Tortricidae diverged from their sister group c. 120 Myr ago (Ma) and diversified c. 97 Ma, a timeframe synchronous with the rise of angiosperms in the Early–mid Cretaceous. Ancestral areas analysis, based on updated Wallace's biogeographical regions, supports the hypothesis of a Gondwanan origin of Tortricidae in the South American plate. We also detected an increase in speciation rate that coincided with the peak of angiosperm diversification in the Cretaceous. This in turn probably was further heightened by continental colonization of the Palaeotropics when angiosperms became dominant by the end of the Late Cretaceous.     

Comments on controversial tick (Acari: Ixodida) species names and species described or resurrected from 2003 to 2008

There are numerous discrepancies in recent published lists of the ticks of the world. Here we review the controversial names, presenting evidence for or against their validity and excluding some altogether. We also address spelling errors and present a list of 17 species described or resurrected during the years 2003–2008. We consider the following 35 tick species names to be invalid: Argas fischeri Audouin, 1826, Ornithodoros boliviensis Kohls and Clifford, 1964, Ornithodoros steini (Schulze, 1935), Amblyomma acutangulatum Neumann, 1899, Amblyomma arianae Keirans and Garris, 1986, Amblyomma bibroni (Gervais, 1842), Amblyomma colasbelcouri (Santos Dias, 1958), Amblyomma concolor Neumann, 1899, Amblyomma cooperi Nuttall and Warburton, 1908, Amblyomma curruca Schulze, 1936, Amblyomma cyprium Neumann, 1899, Amblyomma decorosum (Koch, 1867), Amblyomma nocens Robinson, 1912, Amblyomma perpunctatum (Packard, 1869), Amblyomma striatum Koch, 1844, Amblyomma superbum Santos Dias, 1953, Amblyomma testudinis (Conil, 1877), Amblyomma trinitatis Turk, 1948, Dermacentor confractus (Schulze 1933), Dermacentor daghestanicus Olenev, 1928, Haemaphysalis himalaya Hoogstraal, 1966, Haemaphysalis vietnamensis Hoogstraal and Wilson, 1966, Hyalomma detritum Schulze, 1919, Ixodes apteridis Maskell, 1897, Ixodes donarthuri Santos Dias, 1980, Ixodes kempi Nuttall, 1913, Ixodes neotomae Cooley, 1944, Ixodes rangtangensis Teng, 1973, Ixodes robertsi Camicas, Hervy, Adam and Morel, 1998, Ixodes serrafreirei Amorim, Gazetta, Bossi and Linhares, 2003, Ixodes tertiarius Scudder, 1885, Ixodes uruguayensis Kohls and Clifford, 1967, Ixodes zealandicus Dumbleton, 1961, Ixodes zumpti Arthur, 1960 and Rhipicephalus camelopardalis Walker and Wiley, 1959. We consider the following 40 names valid: Argas delicatus Neumann, 1910, Argas vulgaris Filippova, 1961, Ornithodoros aragaoi Fonseca, 1960, Ornithodoros dugesi Mazzoti, 1943, Ornithodoros knoxjonesi Jones and Clifford, 1972, Ornithodoros marocanus Velu, 1919, Ornithodoros nattereri Warburton, 1927, Amblyomma beaurepairei Vogelsang and Santos Dias, 1953, Amblyomma crassipes (Neumann, 1901), Amblyomma echidnae Roberts, 1953, Amblyomma fuscum Neumann, 1907, Amblyomma orlovi (Kolonin, 1995), Amblyomma parkeri Fonseca and Arag?o, 1952, Amblyomma pseudoconcolor Arag?o, 1908, Bothriocroton oudemansi (Neumann, 1910), Bothriocroton tachyglossi (Roberts, 1953), Dermacentor abaensis Teng, 1963, Dermacentor confragus (Schulze 1933), Dermacentor ushakovae Filippova and Panova, 1987, Haemaphysalis anomaloceraea Teng, 1984, Haemaphysalis filippovae Bolotin, 1979, Haemaphysalis pavlovskyi Pospelova-Shtrom, 1935, Hyalomma excavatum Koch, 1844, Hyalomma isaaci Sharif, 1928, Hyalomma rufipes Koch, 1844, Hyalomma turanicum Pomerantzev, 1946, Ixodes arabukiensis Arthur, 1959, Ixodes boliviensis Neumann, 1904, Ixodes columnae Takada and Fujita, 1992, Ixodes maslovi Emel′yanova and Kozlovskaya, 1967, Ixodes sachalinensis Filippova, 1971, Ixodes siamensis Kitaoka and Suzuki, 1983, Ixodes sigelos Keirans, Clifford and Corwin, 1976, Ixodes succineus Weidner, 1964, Rhipicephalus aurantiacus Neumann, 1907, Rhipicephalus cliffordi Morel, 1965, Rhipicephalus pilans Schulze, 1935, Rhipicephalus pseudolongus Santos Dias, 1953, Rhipicephalus serranoi Santos Dias, 1950 and Rhipicephalus tetracornus Kitaoka and Suzuki, 1983.     

An examination of the infracommunities and component communities from impala (Aepyceros melampus) in the Kruger National Park, South Africa

The intestinal helminth parasites of the impala from the Kruger National Park, South Africa, were examined to describe the parasite community structure. Demographic variation and the associated differences in behavior were used to further investigate the patterns of community composition. Monte Carlo simulations were performed to test for differences in species richness and mean abundance between the various demographic groups, and nonmetric multidimensional scaling ordination was used to compare community composition. Seventeen species of nematodes, totaling more than 1.3 million worms, were recovered. Males harbored a greater number of nematode species than did females, but adult females were more heavily infected than their male counterparts. Lambs acquired infections early in life, and their parasite community composition rapidly approached that of the older animals. The parasite community in the juvenile and adult males was significantly different from the community of the adult females. These data suggest that social and feeding behavior of the different age-sex classes structure the parasite component community of impala. Additionally, the distinction between common and rare parasites, and their classification in other herbivores, implies complex transmission dynamics that includes extensive species sharing within the Kruger National Park.     

Detection of Anaplasma bovis in an undescribed tick species collected from the eastern rock sengi Elephantulus myurus

Ticks are important vectors of numerous pathogens causing illness, fatalities, and economic loss worldwide. Infectious disease episodes are increasing, and novel tick-borne pathogens are described frequently. Identification of novel reservoir hosts and vectors of tick-borne pathogens is essential if control measures are to be successful. In South Africa, the eastern rock sengi, Elephantulus myurus , hosts a number of tick species of veterinary importance. Despite this, there remains a paucity of information regarding the tick fauna of this species, the pathogen associations of ticks that it hosts, and its role as a reservoir host of tick-borne pathogens. The current study documents the tick fauna of E. myurus and sympatric small mammal species in Limpopo Province, South Africa. The pathogen associations of ticks hosted by elephant shrews were also investigated by PCR screening of engorged nymphs for a broad range of bacterial and protozoan tick-borne infections, including Borrelia burgdorferi sensu lato and members of Apicomplexa and the order Rickettsiales. There were marked differences in tick species and abundance among host species. Elephantulus myurus was heavily, and predominantly, parasitized by an as-yet undescribed tick species that we identify as Rhipicephalus sp. near warburtoni. PCR and sequence analysis revealed the presence of Anaplasma bovis in this tick species, which may have consequences for livestock production and conservation efforts in the area where this tick species occurs.     

Association of p60fyn with middle tumor antigen in murine polyomavirus-transformed rat cells.

Rabbit antisera raised against human FYN-specific peptides were used to evaluate the expression of the fyn gene product in normal and murine polyomavirus middle tumor antigen (MTAg)-transformed rat cells. The antisera were capable of detecting p60fyn in both normal and MTAg-transformed cells. Two different antisera directed against unique p60fyn sequences were found to detect p60fyn-MTAg complexes in cell lysates from the MTAg-transformed cells. The MTAg molecules immunoprecipitated by FYN antisera were phosphorylated on tyrosine during immune-complex kinase reactions at sites similar to those found on MTAg in complexes with pp60c-src. Whereas the abundance of p60fyn was estimated to be less in the MTAg-transformed cells than in their normal counterparts, the specific activities of p60fyn molecules in the normal and transformed cells were similar.