Eimeria sinaitae n. sp. (Apicomplexa: Eimeriidae) from the Rock Agama (Agama sinaita) in Saudi Arabia

Eimeria sinaitae n. sp. is described from the gall bladder of Agama sinaita from Wasie, Saudi Arabia. Sporulated oocysts are elongate-ellipsoid 34.4 times 22.0 (29.0–40.0 times 17.4–24.5) μm. Oocyst wall is smooth, greenish yellow, 1.2 (1.0–1.4) μm thick, and two-layered. Micropyle, polar granule, and oocyst residuum are absent. Sporocysts are ellipsoid 11.4 times 7.6 (9.8–15.0 times 6.7–9.0) μm. Sporocyst residuum is present. The sporocysts lack a Stieda body. Sporozoites are crescent-shaped, blunt at one end and tapered at the other. Eimeria species from Agamidae are compared.     

Understanding the function of nocturnal song in ovenbirds: males do not countersing at night

Many diurnal bird species vocalize at night, however the function of nocturnal song is, generally, still poorly understood. Previous research has suggested that nocturnal song may serve a social function and is influenced by environmental factors. To test whether males attend to the nocturnal song of conspecifics, we experimentally exposed ovenbirds Seiurus aurocapilla to nocturnal flight songs, and recorded their response both during the night and during the following dawn chorus. We compared latency to song and vocal output before and after playback exposure to determine if males altered their vocalizations in response to exposure to flight songs from an unknown male. We found no evidence of counter singing or change in nocturnal song output, nor a change in vocal output during the dawn chorus following playback exposure. Our results suggest that, in ovenbirds, nocturnal song does not serve as an intraspecific social function. Nocturnal song, through rare, may be significant in the mating systems of some diurnal bird species, and requires additional study.     

The Detection of Inhibitors of the Sclerotinia sclerotiorum (Lib.) de Bary Extracellular Proteinases in Sunflower

Abstract: Water-soluble protein fractions from leaves, seeds and heads of sunflower were shown to contain inhibitors of trypsin, chymotrypsin and extracellular proteinases from Sclerotinia sclerotiorum , a pathogen of sunflower, and Colletotrichum lindemuthianum. These included bifunctional inhibitors of trypsin and subtilisin. Comparison with the patterns of inhibition of standard proteinases indicated that the major extracellular proteinases of S. sclerotiorum are subtilisin-like. It is speculated that the sunflower inhibitors play a role in conferring resistance to fungal infection.     

Concentration and composition of free amino acids and osmolalities of porcine oviductal and uterine fluid and their effects on development of porcine IVF embryos

The concentration of free amino acids and the osmolalities in porcine oviductal (OF) and uterine fluids (UFs) on day 3 (D3) and day 5 (D5) were measured by HPLC and Vapor Pressure Osmometer, respectively. Based on these measurements we designed new media based on PZM3 by modifying the amino acid composition and osmolality. The effectiveness of the modified PZM3 on the development of porcine IVF embryos was then investigated. A total of 24 free amino acids were measured, including 20 protein and 4 nonprotein amino acids (beta-alanine, taurine, ornithine, and citrulline). There was no significant difference in the total concentration of amino acids among D3OF (13.06 +/- 3.63 mmol/L), D3UF (10.54 +/- 5.16 mmol/L), or D5UF (10.23 +/- 6.69 mmol/L). But the total concentration of amino acids in D5OF (5.89 +/- 1.47 mmol/L) was significantly lower than the three fluids above. Some individual amino acids varied significantly depending on where they were collected and from which day. The blastocyst rates of porcine IVF embryos were not improved when embryos were cultured in PZM3 with amino acids at D3OF (PZM3-D3OF, 20.3 +/- 7.9%) or D5UF (PZM3-D5UF, 14.3 +/- 10.7%) concentrations or in PZM3-D3OF for the first 48 (20.5 +/- 15.1), 72 (25.6 +/- 10.4), and 96 (18.7 +/- 10.0) hr and then transferred into PZM3-D5UF compared with PZM3 with Sigma amino acid solution (PZM3-SAA) (30.8 +/- 9.1%). However, when IVF embryos were cultured in PZM3-D5UF, the average nuclear number per blastocyst (57.6 +/- 8.3) was increased compared to PZM3-SAA (40.5 +/- 3.5). The osmolalities in D3OF, D3UF, D5OF, and D5UF were 318 +/- 8, 320 +/- 32, 321, and 293 +/- 8 mOsM, respectively. When the IVF embryos were cultured in PZM3-SAA and PZM3-D3OF at a variety of osmolalities (150-360 mOsM), higher blastocyst rates were obtained at 270-300 mOsM in the PZM3-SAA group (24.6-33.9%) and 270-290 mOsM in PZM3-D3OF group (22.4-24.2%). The blastocyst rate gradually decreased when the osmolality was increased or decreased in both groups. When the embryos were cultured in PZM3-SAA at 330 mOsM for the first 72 hr and then transferred to 250 mOsM (33.3 +/- 3.4%), the blastocyst rate was higher than original PZM3 (21.2 +/- 2.2%) (288 mOsM).     

Tree swallows (Tachycineta bicolor) nesting on wetlands impacted by oil sands mining are highly parasitized by the bird blow fly Protocalliphora spp

Oil sands mining is steadily expanding in Alberta, Canada. Major companies are planning reclamation strategies for mine tailings, in which wetlands will be used for the bioremediation of water and sediments contaminated with polycyclic aromatic hydrocarbons and naphthenic acids during the extraction process. A series of experimental wetlands were built on companies' leases to assess the feasibility of this approach, and tree swallows (Tachycineta bicolor) were designated as upper trophic biological sentinels. From May to July 2004, prevalence and intensity of infestation with bird blow flies Protocalliphora spp. (Diptera: Calliphoridae) were measured in nests on oil sands reclaimed wetlands and compared with those on a reference site. Nestling growth and survival also were monitored. Prevalence of infestation was surprisingly high for a small cavity nester; 100% of the 38 nests examined were infested. Nests on wetlands containing oil sands waste materials harbored on average from 60% to 72% more blow fly larvae than those on the reference site. Nestlings on reclaimed sites suffered mean parasitic burdens about twice that of those on the reference site; and for comparable parasitic load, they exhibited greater pathologic effects (e.g., decreased body mass) than control nestlings. The heavy blow fly infestation on oil sands-impacted wetlands suggests that oil sands mining disturbs several components of the local ecosystem, including habitat characteristics, blow fly predators, and host resistance to parasites.     

Re‐targeting of a plant defense protease by a cyst nematode effector

Plants mount defense responses during pathogen attacks, and robust host defense suppression by pathogen effector proteins is essential for infection success. 4E02 is an effector of the sugar beet cyst nematode Heterodera schachtii. Arabidopsis thaliana lines expressing the effector‐coding sequence showed altered expression levels of defense response genes, as well as higher susceptibility to both the biotroph H. schachtii and the necrotroph Botrytis cinerea, indicating a potential suppression of defenses by 4E02. Yeast two‐hybrid analyses showed that 4E02 targets A. thaliana vacuolar papain‐like cysteine protease (PLCP) ‘Responsive to Dehydration 21A’ (RD21A), which has been shown to function in the plant defense response. Activity‐based protein profiling analyses documented that the in planta presence of 4E02 does not impede enzymatic activity of RD21A. Instead, 4E02 mediates a re‐localization of this protease from the vacuole to the nucleus and cytoplasm, which is likely to prevent the protease from performing its defense function and at the same time, brings it in contact with novel substrates. Yeast two‐hybrid analyses showed that RD21A interacts with multiple host proteins including enzymes involved in defense responses as well as carbohydrate metabolism. In support of a role in carbohydrate metabolism of RD21A after its effector‐mediated re‐localization, we observed cell wall compositional changes in 4E02 expressing A. thaliana lines. Collectively, our study shows that 4E02 removes RD21A from its defense‐inducing pathway and repurposes this enzyme by targeting the active protease to different cell compartments.     

A genotypically unique Babesia gibsoni-like parasite recovered from a dog in Oklahoma

A small Babesia gibsoni-like parasite was identified and isolated as the cause of clinical babesiosis in a dog from Oklahoma. Because this was potentially the first documented case of B. gibsoni infection in Oklahoma, further characterization was warranted, and the 18S nuclear small subunit ribosomal RNA gene was sequenced. Sequence comparison with other piroplasms from dogs showed significant nucleotide sequence differences between this isolate and both B. canis and B. gibsoni. These findings demonstrate that in domestic dogs in North America there are at least 2 "small" B. gibsoni-like organisms with distinct nucleotide sequences and that the geographic distribution of the "small" canine Babesia species may be wider than previously recognized.     

Effects of Lithium on Inositol Phospholipid Hydrolysis and Inhibition of Dopamine D1 Receptor-Mediated Cyclic AMP Formation by Carbachol in Rat Brain Slices

The in vitro and ex vivo effects of lithium on muscarinic cholinergic inositol phospholipid hydrolysis and muscarinic cholinergic inhibition of dopamine D1-receptor-stimulated cyclic AMP formation were examined in rat brain slices. Following chronic lithium feeding, carbachol-stimulated inositol phosphate accumulation was reduced ex vivo in slices of cerebral cortex but not in striatal slices. Lithium (1 mM) in vitro had no direct effect on dopamine D1-receptor-stimulated cyclic AMP formation, but enhanced the inhibitory effect of carbachol on the D1 response, in striatal slices, and this was not significantly altered by prior lithium feeding. Lithium therefore has effects on two discrete muscarinic responses in rat brain which are apparently maintained after chronic exposure to the ion and might be relevant to its antimanic actions.     

Molecular phylogeny of Solms‐laubachia (Brassicaceae) s.l., based on multiple nuclear and plastid DNA sequences,and its biogeographic implications

Abstract The Hengduan Mountains region of south‐west China is a noted biodiversity hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky‐island species of Solms‐laubachia Muschl. (Brassicaceae), have been little studied. Previous molecular studies on the phylogeny of Solms‐laubachia showed it to be paraphyletic, leading to considerable expansion not only of its taxonomic limits, but also its geographic range, with the inclusion of taxa from outside the Hengduan region. However, these studies provided little resolution of interspecific relationships, preventing inferences about historical biogeography within the clade. In the present study, new sequence data from two nuclear genes (LEAFY and G3pdh) and two chloroplast intergenic spacers (petN–psbM and psbM–trnD) were combined with existing markers to increase phylogenetic signals. Phaeonychium villosum (Maxim.) Al‐Shehbaz was found to be nested within Solms‐laubachia s.l. In general, phylogenetic relationships appear to be a good predictor of geography, with the Hengduan Mountain endemics embedded in a paraphyletic grade of species from the western Himalayas and central Asia, but they also imply morphological homoplasy. Incongruence was detected between the nuclear and chloroplast gene trees, perhaps resulting from incomplete lineage sorting of ancestral polymorphisms. The crown age of Solms‐laubachia s.l. was estimated to be approximately 1.42–3.68 mya, using Bayesian relaxed molecular clock analysis. Historical biogeographic analysis using a parametric dispersal–extinction–cladogenesis model inferred central Asia and the western Himalayas as most probable ancestral range of Solms‐laubachia s.l., and estimated higher rates of eastward expansion than westward during the diversification of descendant lineages. In summary, our results suggest that Solms‐laubachia s.l. originated during the Pliocene in central Asia, and subsequently migrated eastward into the Hengduan Mountains, colonizing sky‐island, alpine scree‐slope habitats that may have provided novel ecological opportunity and accelerated speciation, ultimately establishing this region as the present center of diversity of the genus.     

Phosphate acquisition components of the Myxococcus xanthus Pho regulon are regulated by both phosphate availability and development

In many organisms, phosphatase expression and phosphate (P) uptake are coordinately regulated by the Pho regulon. In Myxococcus xanthus P limitation initiates multicellular development, a process associated with changes in phosphatase expression. We sought here to characterize the link between P acquisition and development in this bacterium, an organism capable of preying upon other microorganisms as a sole nutrient source. M. xanthus seems to possess no significant internal P stores, as reducing the P concentration to less than 10 μM retarded growth within one doubling time. Pyrophosphate, polyphosphate, and glyceraldehyde-3-phosphate could support growth as sole P sources, although many other P-containing biomolecules could not (including nucleic acids and phospholipids). Several Pho regulon promoters were found to be highly active during vegetative growth, and P limitation specifically induced pstSCAB, AcPA1, and pho3 promoter activity and repressed pit expression. Enhanced pstSCAB and pho3 promoter activities in a phoP4 mutant (in the presence of high and low concentrations of P) suggested that PhoP4 acts as a repressor of these genes. However, in a phoP4 background, the activities of pstSCAB remained P regulated, suggesting that there is additional regulation by a P-sensitive factor. Initiation of multicellular development caused immediate down-regulation of Pho regulon genes and caused pstSCAB and pho3 promoter activities to become P insensitive. Hence, P acquisition components of the M. xanthus Pho regulon are regulated by both P availability and development, with developmental down-regulation overriding up-regulation by P limitation. These observations suggest that when development is initiated, subsequent changes in P availability become irrelevant to the population, which presumably has sufficient intrinsic P to ensure completion of the developmental program.