We recently identified large glucagon-expressing neurons that densely ramify neurites in the peripheral edge of the retina and regulate the proliferation of progenitors in the circumferential marginal zone (CMZ) of the postnatal chicken eye (Fischer et al. [2005] J Neurosci 25:10157-10166). However, nothing is known about the transmitters and proteins that are expressed by the glucagon-expressing neurons in the avian retina. We used antibodies to cell-distinguishing markers to better characterize the different types of glucagon-expressing neurons. We found that the large glucagon-expressing neurons were immunoreactive for substance P, neurofilament, Pax6, AP2alpha, HuD, calretinin, trkB, and trkC. Colocalization of glucagon and substance P in the large glucagon-expressing neurons indicates that these cells are the "bullwhip cells" that have been briefly described by Ehrlich et al. ([1987] J Comp Neurol 266:220-233). Similar to the bullwhip cells, the conventional glucagon-expressing amacrine cells were immunoreactive for calretinin, HuD, Pax6, and AP2alpha. Unlike bullwhip cells, the conventional glucagon-expressing amacrine cells were immunoreactive for GABA. While glucagon-immunoreactive amacrine cells were negative for substance P in central regions of the retina, a subset of this type of amacrine cell was immunoreactive for substance P in far peripheral regions of the retina. An additional type of glucagon/substance P-expressing neuron, resembling the bullwhip cells, was found in far peripheral and dorsal regions of the retina. Based on morphology, distribution within the retina, and histological markers, we conclude that there may be four different types of glucagon-expressing neurons in the avian retina.

Significance and Impact of the Study: The Cyanidiales are an order of unicellular eukaryotic algae that thrive in acidic geothermal environments. In this study, we report several novel observations relative to Cyanidiales ecology in Yellowstone National Park, including the following: (i) the identification of two phylogenetic lineages of Cyanidiales: Cyanidioschyzon and Galdieria; (ii) the absence of Galdieria in aquatic environments; (iii) the absence of Cyanidium and Galdieria phlegrea in prime Cyanidiales habitats; (iv) the cohabitation of Cyanidioschyzon and Galdieria in nonaqueous environments; and (v) the first in situ evidence regarding the relationship between soil moisture and Cyanidiales habitat preference and viability. AbstractThe Cyanidiales are unicellular red algae that are unique among phototrophs.

NASA has made great strides in the past five years to develop a suite of instruments for the International Space Station in order to perform molecular biology in space. However, a key piece of equipment that has been lacking is an instrument that can extract nucleic acids from an array of complex human and environmental samples. The Omics in Space team has developed the µTitan (simulated micro(µ) gravity tested instrument for automated nucleic acid) system capable of automated, streamlined, nucleic acid extraction that is adapted for use under microgravity. The µTitan system was validated using a whole cell microbial reference (WCMR) standard comprised of a suspension of nine bacterial strains, titrated to concentrations that would challenge the performance of the instrument, as well as to determine the detection limits for isolating DNA. Quantitative assessment of system performance was measured by comparing instrument input challenge dose vs recovery by Qubit spectrofluorometry, qPCR, Bioanalyzer, and Next Generation Sequencing. Overall, results indicate that the µTitan system performs equal to or greater than a similar commercially available, earth-based, automated nucleic acid extraction device. The µTitan system was also tested in Yellowstone National Park (YNP) with the WCMR, to mimic a remote setting, with limited resources. The performance of the device at YNP was comparable to that in a laboratory setting. Such a portable, fielddeployable, nucleic extraction system will be valuable for environmental microbiology, as well as in health care diagnostics.

The described diversity within the domain Archaea has recently expanded due to advances in sequencing technologies, but many habitats that likely harbor novel lineages of archaea remain understudied. Knowledge of archaea within natural and engineered hydrothermal systems, such as hot springs and engineered subsurface habitats, has been steadily increasing, but the majority of the work has focused on archaea living in acidic or circumneutral environments. The environmental pressures exerted by the combination of high temperatures and high pH likely select for divergent communities and distinct metabolic pathways from those observed in acidic or circumneutral systems. In this review, we examine what is currently known about the archaea found in thermoalkaline environments, focusing on the detection of novel lineages and knowledge of the ecology, metabolic pathways and functions of these populations and communities. We also discuss the potential of emerging multi–omics approaches, including proteomics and metabolomics, to enhance our understanding of archaea within extreme thermoalkaline systems.

Aims: Development of biomineralization technologies has largely focused on microbially induced carbonate precipitation (MICP) via Sporosarcina pasteurii ureolysis; however, as an obligate aerobe, the general utility of this organism is limited. Here, facultative and anaerobic haloalkaliphiles capable of ureolysis were enriched, identified and then compared to S. pasteurii regarding biomineralization activities. Methods and Results: Anaerobic and facultative enrichments for haloalkaliphilic and ureolytic micro-organisms were established from sediment slurries collected at Soap Lake (WA). Optimal pH, temperature and salinity were determined for highly ureolytic enrichments, with dominant populations identified via a combination of high-throughput SSU rRNA gene sequencing, clone libraries and Sanger sequencing of isolates. The enrichment cultures consisted primarily of Sporosarcina-and Clostridium-like organisms. Ureolysis rates and direct cell counts in the enrichment cultures were comparable to the S. pasteurii (strain ATCC 11859) type strain. Conclusions: Ureolysis rates from both facultatively and anaerobically enriched haloalkaliphiles were either not statistically significantly different to, or statistically significantly higher than, the S. pasteurii (strain ATCC 11859) rates. Work here concludes that extreme environments can harbour highly ureolytic active bacteria with potential advantages for large scale applications, such as environments devoid of oxygen. Significance and Impact of the Study: The bacterial consortia and isolates obtained add to the possible suite of organisms available for MICP implementation, therefore potentially improving the economics and efficiency of commercial biomineralization.Journal of Applied Microbiology ISSN 1364-5072 À , Br À , PO 4 3À and dissolved Fe.