, 2013). In contrast, the most comprehensive efforts to describe the global distributions of marine heterotrophic microbes have relied on only a few hundreds of samples (e.g. Brown et al., 2012 and Ladau et al., 2013). Second, of the many factors invoked to explain the existence of spatial biogeography, the nutritional aspect is often overlooked. This is because it is easier to correlate readily available physical parameters such as temperature or salinity with the structure and function of microbial communities, rather than spatially co-varying levels of nutrients that are not always part of the metadata collected in microbial studies. HSP signaling pathway This is particularly true for some

macro-,

and micro-nutrients, such as NH4, Fe, Zn, Ni and Cu that are present in vanishingly small amounts and require specialist techniques for measurement. Resource-based selective pressure is not limited to resource availability but is the result of a tradeoff between metabolic cost for uptake and the resulting growth benefit. Moreover a conceptual framework for microbial biogeography has to take into account the role that underlying micropatchiness exerts on community structure (for example particle vs. free-living) leading to microscale resource partitioning and the evolution of very defined and contrasting trophic strategies (Lauro et al., 2009). Finally, most marine microbial ecology is still framed this website in terms of “bottom-up” considerations, examining how communities assemble in relation to resource availability and abiotic

factors (Strom, 2008). Yet the selective pressure community interactions exert on the structure and function of microbial communities is evident in the continual reshaping of communities by mortality, allelopathy and symbiosis. A better understanding of these processes is emerging based on new sampling methods and analysis tools, including nano-SIMS (e.g. Thompson et al., 2012), in-situ sample collection (Shade et al., 2009 and Ottesen et al., 2013) and better quantitative measures of the relationships between gene expression at the transcriptional Acetophenone (transcriptomics) and translational levels (proteomics) (Waldbauer et al., 2012). However, even with these significant knowledge gaps, there is much to be learned from the study of marine microbial biogeography and the development of new sampling and analysis techniques will constantly be refining our view of this field. The authors thank the crew of the S/Y Indigo V for insightful discussions. MVB and FML are supported by fellowships from the Australian Research Council (DP0988002 and DE120102610). “
“Species-specific patterns of gene expression are predicted to correlate with their ecological niches and can now be compared and analyzed using global transcription analysis via RNA-seq.