Defensive symbioses of animals with prokaryotic and eukaryotic microorganisms

Abstract

Many organisms team up with microbes for defense against predators, parasites, parasitoids, or pathogens. Here we review the described protective symbioses between animals (including marine invertebrates, nematodes, insects, and vertebrates) and bacteria, fungi, and dinoflagellates. We focus on associations where the microbial natural products mediating the protective activity have been elucidated or at least strong evidence for the role of symbiotic microbes in defense is available. In addition to providing an overview of the known defensive animal-microbe symbioses, we aim to derive general patterns on the chemistry, ecology, and evolution of such associations.

Engineering Microbiomes to Improve Plant and Animal Health

“…Microbiomes of animals and plants are often dominated by eubacteria, but fungi, protozoa, archaea, and viruses also can play important roles in these communities [1][2][3][4][5]. Microbiomes are not passive players [6,7]; rather, microbes can alter host development, physiology, and systemic defenses [2,8,9], enable toxin production and disease resistance [10,11], increase host tolerance to stress and drought [12][13][14], modulate niche breadth [15], and change fitness outcomes in host interactions with competitors, predators, and pathogens [6]. Because microbiomes can encompass a hundred-fold more genes than host genomes [16], and because this 'hologenome' of a hostmicrobiome association can vary over space and time [17,18], microbiomes can function as a phenotypically plastic buffer between the host-genotype's effects and the environmental effects that interact to shape host phenotypes.…”

Latitudinal variation in the microbiome of the sponge Ircinia campana correlates with host haplotype but not anti-predatory chemical defense

“…More recently, the potential and realized contributions of symbiotic microorganisms to host defensive chemistry has suggested a link between the microbial ecology and chemical ecology of marine sponges. Investigations of secondary metabolite production in sponges have found evidence that symbiotic microbes are involved in the production of specific bioactive compounds originally attributed to host sponges, including chemical analyses of host and symbiont cell partitions and the characterization and localization of biosynthetic gene clusters (Bewley & Faulkner 1998, Piel 2009, Hentschel et al 2012, Flórez et al 2015, Freeman et al 2016. Other studies have targeted broader linkages between symbiont community composition and sponge chemistry, for example, documenting co-variation between microbial communities and metabolite profiles of the sponge Mycale hentscheli (Anderson et al 2010).…”

Antifungal Bacteria on Woodland Salamander Skin Exhibit High Taxonomic Diversity and Geographic Variability

“…KEYWORDS Batrachochytrium dendrobatidis, pathogen inhibition, salamanders, skin bacteria, symbionts T he skin microbiome of vertebrates serves as a barrier against pathogens (1-3) and can mediate disease risk (4,5). Lower disease risk in vertebrates has been associated with different characteristics of the microbiome, such as high bacterial species richness (6)(7)(8), specific microbial community assemblages (2,7,9,10), and the presence of microbes that produce metabolites that inhibit growth of pathogens (1,11,12).…”