A guide for banding North Island robin (Petroica longipes) nestlings

Measures of population productivity and individual survival are essential for effective conservation management and scientific investigations. In studies of birds, individuals are often marked with unique colour band combinations to enable estimates of population vital rates. If birds are banded in the nest this must be done at the correct stage in nestling development. If nestlings are banded too early it can lead to leg damage. If they are banded too late it can cause early fledging and reduced survival. Here, we use photographs to guide estimation of the best stage to band North Island robin (Petroica longipes), or toutouwai, nestlings, which is typically at 9–12 days of age.     

Mitochondrial dynamics: cell-type and hippocampal region specific changes following global cerebral ischemia

Journal of Bioenergetics and Biomembranes - Mitochondria are organelles that undergo continuous cycles of fission and fusion. This dynamic nature of mitochondria is important for cell physiology....     

Chemical genetic identification of glutamine phosphoribosylpyrophosphate amidotransferase as the target for a novel bleaching herbicide in Arabidopsis

A novel phenyltriazole acetic acid compound (DAS734) produced bleaching of new growth on a variety of dicotyledonous weeds and was a potent inhibitor of Arabidopsis (Arabidopsis thaliana) seedling growth. The phytotoxic effects of DAS734 on Arabidopsis were completely alleviated by addition of adenine to the growth media. A screen of ethylmethanesulfonate-mutagenized Arabidopsis seedlings recovered seven lines with resistance levels to DAS734 ranging from 5- to 125-fold. Genetic tests determined that all the resistance mutations were dominant and allelic. One mutation was mapped to an interval on chromosome 4 containing At4g34740, which encodes an isoform of glutamine phosphoribosylamidotransferase (AtGPRAT2), the first enzyme of the purine biosynthetic pathway. Sequencing of At4g34740 from the resistant lines showed that all seven contained mutations producing changes in the encoded polypeptide sequence. Two lines with the highest level of resistance (125-fold) contained the mutation R264K. The wild-type and mutant AtGPRAT2 enzymes were cloned and functionally overexpressed in Escherichia coli. Assays of the recombinant enzyme showed that DAS734 was a potent, slow-binding inhibitor of the wild-type enzyme (I(50) approximately 0.2 microm), whereas the mutant enzyme R264K was not significantly inhibited by 200 microm DAS734. Another GPRAT isoform in Arabidopsis, AtGPRAT3, was also inhibited by DAS734. This combination of chemical, genetic, and biochemical evidence indicates that the phytotoxicity of DAS734 arises from direct inhibition of GPRAT and establishes its utility as a new and specific chemical genetic probe of plant purine biosynthesis. The effects of this novel GPRAT inhibitor are compared to the phenotypes of known AtGPRAT genetic mutants.     

Palynostratigraphy and palaeogeography of the Padeha, Khoshyeilagh, and Mobarak formations in the eastern Alborz Range (Kopet-Dagh region), northeastern Iran

A total of 113 surface samples collected from the Padeha, Khoshyeilagh, and Mobarak formations of Kuh-e-Ozum, northeast of Jajarm town were processed for palynomorphs, in order to determine age relationships. Well-preserved and abundant palynomorphs dominated by organic-walled-marine microphytoplankton (acritarchs and prasinophyte phycomata), miospores and subordinate chitinozoans, and scolecodonts were recovered. Seven species of prasinophyte phycomata (four genera), 19 acritarch species (14 genera), one species of chitinozoa, and 26 miospore species (19 genera) were recorded and assigned to eight local Assemblage Zones. Assemblage Zones I-IV occur in the Padeha Formation and suggest an Early Late Devonian (Frasnian) age whilst assemblages zones V-VII are present in the Khoshyeilagh Formation and indicate Late Devonian (Famennian) ages. Assemblage zone VIII, which occurs in the basal part of Mobarak Formation, suggests a Lower Mississippian (Tournaisian) age for this formation. Many of the palynomorph groups encountered are closely comparable with coeval assemblages recorded from Western Australia, southwest Ireland, England, Turkey, Saudi Arabia, North Africa, and South America, indicating the close relationship of the Iranian Platform to other parts of the northern Gondwana Domain during the time interval represented by these strata. The presence of marine palynomorphs (acritarchs/prasinophyte phycomata, chitinozoans, and scolecodonts), and shelly macrofauna (brachiopods, gastropods, and corals) in Member c of the Padeha Formation (as well as the Khoshyeilagh and Mobarak formations), together with associated miospores, indicate an open marine (moderately nearshore) depositional environment for the Upper Devonian and Lower Carboniferous deposits in northeastern Alborz Range (Kopet-Dagh region) of Iran.     

Elevated temperatures alter an ant‐aphid mutualism

Ant‐hemipteran mutualisms are keystone interactions that can be variously affected by warming: these mutualisms can be strengthened or weakened, or the species can transition to new mutualist partners. We examined the effects of elevated temperatures on an ant‐aphid mutualism in the subalpine zone of the Rocky Mountains in Colorado, USA. In this system, inflorescences of the host plant, Ligusticum porteri Coult. & Rose (Apiaceae), are colonized by the ant‐tended aphid Aphis asclepiadis Fitch or less frequently by the non‐ant tended aphid Cavariella aegopodii (Scopoli) (both Hemiptera: Aphididae). Using an 8‐year observational study, we tested for two key mechanisms by which ant‐hemipteran mutualisms may be altered by climate change: shifts in species identity and phenological mismatch. Whereas the aphid species colonizing the host plant is not changing in response to year‐to‐year variation in temperature, we found evidence that a phenological mismatch between ants and aphids could occur. In warmer years, colonization of host plant inflorescences by ants is decreased, whereas for A. asclepiadis aphids, host plant colonization is mostly responsive to date of snowmelt. We also experimentally established A. asclepiadis colonies on replicate host plants at ambient and elevated temperatures. Ant abundance did not differ between aphid colonies at ambient vs. elevated temperatures, but ants were less likely to engage in tending behaviors on aphid colonies at elevated temperatures. Sugar composition of aphid honeydew was also altered by experimental warming. Despite reduced tending by ants, aphid colonies at elevated temperatures had fewer intraguild predators. Altogether, our results suggest that higher temperatures may disrupt this ant‐aphid mutualism through both phenological mismatch and by altering benefits exchanged in the interaction.     

Chemical genetics define the roles of p38alpha and p38beta in acute and chronic inflammation

The p38 MAP kinase signal transduction pathway is an important regulator of proinflammatory cytokine production and inflammation. Defining the roles of the various p38 family members, specifically p38alpha and p38beta, in these processes has been difficult. Here we use a chemical genetics approach using knock-in mice in which either p38alpha or p38beta kinase has been rendered resistant to the effects of specific inhibitors along with p38beta knock-out mice to dissect the biological function of these specific kinase isoforms. Mice harboring a T106M mutation in p38alpha are resistant to pharmacological inhibition of LPS-induced TNF production and collagen antibody-induced arthritis, indicating that p38beta activity is not required for acute or chronic inflammatory responses. LPS-induced TNF production, however, is still completely sensitive to p38 inhibitors in mice with a T106M point mutation in p38beta. Similarly, p38beta knock-out mice respond normally to inflammatory stimuli. These results demonstrate conclusively that specific inhibition of the p38alpha isoform is necessary and sufficient for anti-inflammatory efficacy in vivo.     

Molecular characterization of the Rocky Mountain elk (Cervus elaphus nelsoni) PRNP putative promoter

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) affecting deer (Odocoileus spp.), moose (Alces alces), and Rocky Mountain elk (Cervus elaphus nelsoni). Leucine homozygosity at elk PRNP codon 132 has been associated with reduced CWD susceptibility. However, naturally acquired CWD has been detected in elk possessing the 132 Leu/Leu genotype. Recent human and bovine studies indicate that PRNP regulatory polymorphisms may also influence TSE occurrence. Therefore, we generated sequences for the elk PRNP putative promoter (2.2 kb), exon 1 (predicted; 54 bp), intron 1 (predicted; 193 bp), and exon 3 (771 bp). Promoter prediction analysis using CpGProD yielded a single elk PRNP promoter that was homologous to regions of known promoter activity in cow and sheep. Molecular interrogation of the elk PRNP putative promoter revealed 32 diallelic single-nucleotide polymorphisms (SNPs). No variation was detected within the predicted exon 1 or intron 1 sequences. Evaluation of elk PRNP exon 3 revealed 3 SNPs (63Y, 312R, 394W-->Met/Leu). Bayesian haplotype reconstruction resulted in 3 elk PRNP haplotypes, with complete linkage disequilibrium observed between all PRNP putative promoter SNPs and codon 132. The results of this study provide the initial genomic foundation for future comparative and haplotype-based elk PRNP studies.