October 2013 archive

Postdoctoral position in Toxoplasma

POSTDOCTORAL POSITION Biochemistry, Microbiology, Drug development   Indiana University School of Medicine POSTDOCTORAL POSITION available to investigate the efficacy and mechanism of experimental drugs to treat infection caused by the protozoan parasite Toxoplasma gondii. Related to the malaria parasite, Toxoplasma causes birth defects and life-threatening infection in immunocompromised AIDS or heart transplant patients. The successful candidate will continue the …

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The flagellar apparatus of Breviata anathema, a eukaryote without a clear supergroup affinity.

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The flagellar apparatus of Breviata anathema, a eukaryote without a clear supergroup affinity.

Eur J Protistol. 2013 Aug;49(3):354-72

Authors: Heiss AA, Walker G, Simpson AG

Abstract
Breviata anathema is an anaerobic amoeboid flagellate that does not branch within any established ‘supergroup’. Molecular phylogenies suggest affinities to Amoebozoa, Opisthokonta, or apusomonads. Here we describe its flagellar apparatus ultrastructure. Breviata has two basal bodies. The flagellated anterior basal body (AB) is associated with a fan of ∼18 microtubules and a short singlet microtubular root. Three microtubular roots associate with the posterior basal body. One, the right root (RR), is initially a triplet that splits into two parts. The other two are singlets: the left root (LR), and the middle root (MR), which arises on the posterior side of the basal body. The MR, LR and smaller part of RR support the left ventral side of the cell, while the larger part of RR runs down the right. Outer dynein arms were not observed on the flagellar axoneme. The mitochondrion-like organelle sometimes contains some tubular cristae. The posterior flagellar apparatus resembles that of several eukaryotic lineages, particularly apusomonads, ancyromonads, excavates, and myxogastrid amoebozoans. This comparison suggests that the complex flagellar apparatus of myxogastrids is actually plesiomorphic within Amoebozoa. The widely distributed splitting right root and posterior singlet (MR in Breviata) may be plesiomorphies in many eukaryotic lineages, and thus could be features of the last eukaryotic common ancestor.

PMID: 23523042 [PubMed – indexed for MEDLINE]

Whole-genome sequencing of Theileria parva strains provides insight into parasite migration and diversification in the African continent.

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Whole-genome sequencing of Theileria parva strains provides insight into parasite migration and diversification in the African continent.
DNA Res. 2013 Jun;20(3):209-20
Authors: Hayashida K, Abe T, Weir W, N…

A journey into the wild of the cnidarian model system Aiptasia and its symbionts.

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A journey into the wild of the cnidarian model system Aiptasia and its symbionts.

Mol Ecol. 2013 Sep;22(17):4366-8

Authors: Voolstra CR

Abstract
The existence of coral reef ecosystems relies critically on the mutualistic relationship between calcifying cnidarians and photosynthetic, dinoflagellate endosymbionts in the genus Symbiodinium. Reef-corals have declined globally due to anthropogenic stressors, for example, rising sea-surface temperatures and pollution that often disrupt these symbiotic relationships (known as coral bleaching), exacerbating mass mortality and the spread of disease. This threatens one of the most biodiverse marine ecosystems providing habitats to millions of species and supporting an estimated 500 million people globally (Hoegh-Guldberg et al. 2007). Our understanding of cnidarian–dinoflagellate symbioses has improved notably with the recent application of genomic and transcriptomic tools (e.g. Voolstra et al. 2009; Bayer et al. 2012; Davy et al. 2012), but a model system that allows for easy manipulation in a laboratory environment is needed to decipher underlying cellular mechanisms important to the functioning of these symbioses. To this end, the sea anemone Aiptasia, otherwise known as a ‘pest’ to aquarium hobbyists, is emerging as such a model system (Schoenberg & Trench 1980; Sunagawa et al. 2009; Lehnert et al. 2012). Aiptasia is easy to grow in culture and, in contrast to its stony relatives, can be maintained aposymbiotically (i.e. dinoflagellate free) with regular feeding. However, we lack basic information on the natural distribution and genetic diversity of these anemones and their endosymbiotic dinoflagellates. These data are essential for placing the significance of this model system into an ecological context. In this issue of Molecular Ecology, Thornhill et al. (2013) are the first to present genetic evidence on the global distribution, diversity and population structure of Aiptasia and its associated Symbiodinium spp. By integrating analyses of the host and symbiont, this research concludes that the current Aitpasia taxonomy probably needs revision and that two distinct Aiptasia lineages are prevalent that have probably been spread through human activity. One lineage engages in a specific symbiosis with Symbiodinium minutum throughout the tropics, whereas a second, local Aiptasia sp. population in Florida appears more flexible in partnering with more than one symbiont. The existence of symbiont-specific and symbiont-flexible Aiptasia lineages can greatly complement laboratory-based experiments looking into mechanisms of symbiont selectivity. In a broader context, the study by Thornhill et al. (2013) should inspire more studies to target the natural environment of model systems in a global context targeting all participating member species when establishing ecological and genetic baselines.

PMID: 24137737 [PubMed – in process]

Postdoctoral opportunity in the CGEB

Postdoctoral position Aging, frailty and the microbiome Location: Beiko lab, Faculty of Computer Science, Dalhousie University Halifax, Nova Scotia, Canada Description: We are seeking a postdoctoral fellow to carry out analysis of microbial data as part of a series of studies on aging, frailty and the microbiome. The project is a large collaboration that includes clinical …

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Diversity of Babesia in Ixodes ricinus ticks in Poland.

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Diversity of Babesia in Ixodes ricinus ticks in Poland.

Adv Med Sci. 2012;57(2):364-9

Authors: Welc-Falęciak R, Bajer A, Paziewska-Harris A, Baumann-Popczyk A, Siński E

Abstract
PURPOSE: The aims of this study were: (1) to estimate Babesia prevalence in the most common species of tick in Poland, Ixodes ricinus, in two recreational areas (Urwitałt in the Mazury Lake District and Bielański Forest in Warsaw), and (2) to evaluate the molecular diversity of Babesia isolates in questing I. ricinus in Poland.
MATERIAL AND METHODS: Questing ticks were collected from vegetation in forest areas in Urwitałt near Mikołajki and in Bielański Forest (Warsaw). Purified genomic DNA was used with specific primers to amplify a fragment of the Babesia spp. 18S rRNA gene.
RESULTS: Tick-drag indices for I. ricinus were high in both study areas, reaching somewhat higher values in Urwitałt than in Bielański Forest. The overall prevalence of Babesia spp. in examined ticks was 1.6%. In Urwitałt, two strains of B. microti were identified using rRNA sequences: the enzootic Munich strain and an isolate close to the zoonotic Jena strain. The proportion of infections due to these two strains in questing ticks reversed over a six-year period. During 3 years of study in Bielański Forest, all Babesia isolates obtained from I. ricinus were identical to Babesia sp. EU1 (B. venatorum), previously recognized as an agent of human babesiosis.
CONCLUSIONS: This study has confirmed the presence of enzoonotic and zoonotic Babesia species/strains in the abundant human-biting tick I. ricinus in recreational areas in Poland. It has also shown that the distribution of different genotypes has changed over time, however the reasons for these fluctuations still remain to be investigated.

PMID: 22968337 [PubMed – indexed for MEDLINE]

Integrating microRNA and mRNA expression profiling in Symbiodinium microadriaticum, a dinoflagellate symbiont of reef-building corals.

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Integrating microRNA and mRNA expression profiling in Symbiodinium microadriaticum, a dinoflagellate symbiont of reef-building corals.
BMC Genomics. 2013 Oct 12;14(1):704
Authors: Baumgarten S, Bayer T, Aran…

Post-Doctoral Fellowship, Canadian Food Inspection Agency

Post-Doctoral Fellowship, Canadian Food Inspection Agency Posted: Monday, September 16, 2013 Apply By: Wednesday, October 30, 2013 Position: Post-Doctoral Fellowship Department: Ontario Laboratory Network facility City: Ottawa Province: Ontario Website: click here Type: Full-time, Contract Job Description: Applications are solicited for a post doctoral fellowship position in a Genomics Research and Development Initiative (GRDI)-funded project to be carried out at the CFIA’s Ontario …

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12-week paid research internships for science undergrads

The Mitacs Globalink 2014 student application is closingOctober 11! Students from Brazil, China, India, Mexico, Turkey and Vietnam are eligible. Are you an excellent student interested in developing your research expertise with top professors? Are you an undergraduate student from Brazil, China, India, Mexico, Turkey or Vietnam interested in exploring your field of study in Canada? Would you want …

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Comparative Genomic Analysis of Multi-Subunit Tethering Complexes Demonstrates an Ancient Pan-Eukaryotic Complement and Sculpting in Apicomplexa.

Comparative Genomic Analysis of Multi-Subunit Tethering Complexes Demonstrates an Ancient Pan-Eukaryotic Complement and Sculpting in Apicomplexa.
PLoS One. 2013;8(9):e76278
Authors: Klinger CM, Klute MJ, Dacks JB
Abs…