Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80302-0334, USA.
Smithsonian Tropical Research Institute, 9100 Panama City PL, Washington, DC 20521-9100, USA.
Mol Ecol. 2013 Aug;22(16):4141-4143. doi: 10.1111/mec.12431.
Microbial ecology of animals is taking on significance in the modern dialogue for the biology of species. Similar to a nuclear genome, the entire bacterial assemblage maintains an ancestral signal of the host's evolution leading to cophylogeny between the host and the microbes they harbour (Brucker & Bordenstein 2012b). The stability of such associations is of great interest as they provide a means for species to acquire new traits and genetic diversity that their own genomes lack (McFall-Ngai et al. 2013). The role of gut microbiota, for example, in host health and nutrition is widely recognized and a shared characteristic among animals. The role of bacteria colonizing the outside surfaces of animals is less well understood, but rather than random colonization, these microbes on skin, cuticles, scales and feathers in many cases provide benefits to the host. The symbiosis of leaf-cutter ants, their fungus gardens and their microbiota is a fascinating and complex system. Whether culture-independent bacterial diversity on the cuticle of leaf-cutter ants is high or highly constrained by subcuticular gland secretions is one prominent question. In this issue of Molecular Ecology, Andersen et al. (2013) show that leaf-cutting ants, Acromyrmex echinatior, maintain a dominant and colony-specific bacterium called Pseudonocardia on their cuticles (the laterocervical plates in particular). This bacterium is involved in protecting the ants and their fungal gardens from disease. Other fungus-gardening attine species as well as soil and vegetation can harbour Pseudonocardia. However, it was previously unknown how stable the bacterial strain-ant colony association was through the lifetime of the colony.
动物微生物生态学在物种生物学的现代对话中具有重要意义。类似于核基因组，整个细菌组合体保持着宿主进化的祖先信号，导致宿主与其所携带的微生物之间的共进化（Brucker 和 Bordenstein 2012b）。这些关联的稳定性非常重要，因为它们为物种提供了一种获得新特征和遗传多样性的手段，而这些特征和遗传多样性是它们自己的基因组所缺乏的（McFall-Ngai 等人，2013）。例如，肠道微生物群在宿主健康和营养中的作用已得到广泛认可，这是动物的共同特征。在动物体表定植的细菌的作用虽然还不太清楚，但这些细菌在皮肤、角质层、鳞片和羽毛上的定植并非随机的，在许多情况下它们会给宿主带来好处。切叶蚁及其真菌园和微生物群的共生关系是一个迷人而复杂的系统。切叶蚁体表的非培养细菌多样性是高还是受到皮下腺分泌物的高度限制，这是一个突出的问题。在本期《分子生态学》中，Andersen 等人（2013）表明，切叶蚁（Acromyrmex echinatior）在其体表（特别是侧颈板）上维持一种称为假诺卡氏菌的优势和特定于群体的细菌。这种细菌参与保护蚂蚁及其真菌园免受疾病侵害。其他菌圃蚁种以及土壤和植被也可能含有假诺卡氏菌。然而，以前并不知道这种细菌菌株与蚁群的关联在蚁群的整个生命周期中是多么稳定。
