DNA from non-viable bacteria biases diversity estimates in the corals Acropora loripes and Pocillopora acuta.

Background: Nucleic acid-based analytical methods have greatly expanded our understanding of global prokaryotic diversity, yet standard metabarcoding methods provide no information on the most fundamental physiological state of bacteria, viability. Scleractinian corals harbour a complex microbiome in which bacterial symbionts play critical roles in maintaining health and functioning of the holobiont. However, the coral holobiont contains both dead and living bacteria.

Heat stress reduces the contribution of diazotrophs to coral holobiont nitrogen cycling.

Efficient nutrient cycling in the coral-algal symbiosis requires constant but limited nitrogen availability. Coral-associated diazotrophs, i.e.

Microbes support enhanced nitrogen requirements of coral holobionts in a high CO environment.

Ocean acidification is posing a threat to calcifying organisms due to the increased energy requirements of calcification under high CO conditions. The ability of scleractinian corals to cope with future ocean conditions will thus depend on their ability to fulfil their carbon requirement. However, the primary productivity of coral holobionts is limited by low nitrogen (N) availability in coral reef waters.

Molecular Evolution of the Neural Crest Regulatory Network in Ray-Finned Fish.

Gene regulatory networks (GRN) are central to developmental processes. They are composed of transcription factors and signaling molecules orchestrating gene expression modules that tightly regulate the development of organisms. The neural crest (NC) is a multipotent cell population that is considered a key innovation of vertebrates.