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Arid regions represent nearly 30 % of the Earth's terrestrial surface, but their microbial biodiversity is not yet well characterized. The surface sands of deserts, a subset of arid regions, are generally subjected to large temperature fluctuations plus high UV light exposure and are low in organic matter. We examined surface sand samples from the Taklamaken (China, three samples) and Gobi (Mongolia, two samples) deserts, using pyrosequencing of PCR-amplified 16S V1/V2 rDNA sequences from total extracted DNA in order to gain an assessment of the bacterial population diversity. In total, 4,088 OTUs (using ≥97 % sequence similarity levels), with Chao1 estimates varying from 1,172 to 2,425 OTUs per sample, were discernable. These could be grouped into 102 families belonging to 15 phyla, with OTUs belonging to the Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria phyla being the most abundant. The bacterial population composition was statistically different among the samples, though members from 30 genera were found to be common among the five samples. An increase in phylotype numbers with increasing C/N ratio was noted, suggesting a possible role in the bacterial richness of these desert sand environments. Our results imply an unexpectedly large bacterial diversity residing in the harsh environment of these two Asian deserts, worthy of further investigation.

The asymmetrical positioning of neural structures on the left or right side of the brain in vertebrates and in invertebrates may be correlated with brain laterality, which is associated with cognitive skills. But until now this has not been illustrated experimentally. Here we describe an asymmetrically positioned brain structure in the fruitfly Drosophila and find that the small proportion of wild-type flies that have symmetrical brains with two such structures lack a normal long-term memory, although their short-term memory is intact. Our results indicate that brain asymmetry may be required for generating or retrieving long-term memory.