Characterisation of microsatellite loci in the habitat-forming kelp, Ecklonia radiata (Phaeophyceae, Laminariales)

The original publication can be found at www.springerlink.comHabitat forming algae play an important role in the ecology of temperate reefs worldwide. Despite this, our understanding of levels of gene flow within and among populations of algae is largely limited to studies on intertidal species; we know comparatively little about important habitat-forming subtidal algae. Here, we develop eight polymorphic microsatellite markers for the characterisation of population genetic diversity and structure in the subtidal kelp, Ecklonia radiata. This large macroalga is the most abundant habitat-forming kelp on the subtidal rocky reefs of temperate Australia and New Zealand where it forms extensive forests that support an astounding diversity of associated taxa.G. Dolman and M. A. Colema

Coding of group odor in the subcaudal gland secreation of the European badger Meles meles: chemical composition and pouch microbiota

The fermentation hypothesis predicts that odor profiles of mammals depend partly on the primary gland products excreted by the animal and partly on the composition of the bacterial flora converting these into secondary metabolites. Some mammalian odors, such as shared group odors, however, need to be consistent yet flexible (e.g., to allow for changes in social-group affiliation), and are thus predisposed for microbial mediation. Using terminal restriction fragment (TRF) length polymorphism analyses we analyzed the microbial community in subcaudal-gland secretions of European badgers (Meles meles) in relation to the chemical scent profiles as determined by gas chromatography-mass spectrometry analyses (GCMS) of 66 adults belonging to six different social groups. We found a total of 50 TRFs and 125 different chemical compounds with a subset of four TRFs best explaining the structure in the chemical matrix. Nevertheless, although semiochemical profiles were group specific, microbial profiles were not. In our approach, however, the number of operational taxonomic units exceeded the numbers of TRFs, and thus our analyses were likely limited by the afforded resolution. As it is likely that the variation in metabolic activity is found at the species-, subspecies-, or even strain-level, future high-throughput sequencing can be expected to reveal more subtle differences in the microbial communities between social groups

Ecophysiology of photosynthesis in macroalgae

Macroalgae occur in the marine benthos from the upper intertidal to depths of more than 200 m, contributing up to 1 Pg C per year to global primary productivity. Freshwater macroalgae are mainly green (Chlorophyta) with some red (Rhodophyta) and a small contribution of brown (Phaeophyceae) algae, while in the ocean all three higher taxa are important. Attempts to relate the depth distribution of three higher taxa of marine macroalgae to their photosynthetic light use through their pigmentation in relation to variations in spectral quality of photosynthetically active radiation (PAR) with depth (complementary chromatic adaptation) and optical thickness (package effect) have been relatively unsuccessful. The presence (Chlorophyta, Phaeophyceae) or absence (Rhodophyta) of a xanthophyll cycle is also not well correlated with depth distribution of marine algae. The relative absence of freshwater brown algae does not seem to be related to their photosynthetic light use. Photosynthetic inorganic carbon acquisition in some red and a few green macroalgae involves entry of CO2 by diffusion. Other red and green macroalgae, and brown macroalgae, have CO2 concentrating mechanisms; these frequently involve acid and alkaline zones on the surface of the alga with CO2 (produced from HCO3-) entering in the acid zones, while some macroalgae have CCMs based on active influx of HCO3-. These various mechanisms of carbon acquisition have different responses to the thickness of the diffusion boundary layer, which is determined by macroalgal morphology and water velocity. Energetic predictions that macroalgae growing at or near the lower limit of PAR for growth should rely on diffusive CO2 entry without acid and alkaline zones, and on NH 4+ rather than NO3- as nitrogen source, are only partially borne out by observation. The impact of global environmental change on marine macroalgae mainly relates to ocean acidification and warming with shoaling of the thermocline and decreased nutrient flux to the upper mixed layer. Predictions of the impact on macroalgae requires further experiments on interactions among increased inorganic carbon, increased temperature and decreased nitrogen and phosphorus supply, and, when possible, studies of genetic adaptation to environmental change. © 2012 Springer Science+Business Media B.V