biodiversity of prokaryotic communities associated with the ectoderm of ectopleura crocea (cnidaria, hydrozoa)的原核生物多样性社区相关的外胚层ectopleura稚鱼(刺细胞动物水螅纲).pdfVIP

Biodiversity of Prokaryotic Communities Associated with the Ectoderm of Ectopleura crocea (Cnidaria, Hydrozoa) 1 2 3 1 1 Cristina Gioia Di Camillo *, Gian Marco Luna , Marzia Bo , Giuseppe Giordano , Cinzia Corinaldesi , Giorgio Bavestrello3 1 Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy, 2 Institute of Marine Sciences–National Research Council (CNR), Venice, Italy, 3 Department for the Study of the Land and its Resources, University of Genoa, Genoa, Italy Abstract The surface of many marine organisms is colonized by complex communities of microbes, yet our understanding of the diversity and role of host-associated microbes is still limited. We investigated the association between Ectopleura crocea (a colonial hydroid distributed worldwide in temperate waters) and prokaryotic assemblages colonizing the hydranth surface. We used, for the first time on a marine hydroid, a combination of electron and epifluorescence microscopy and 16S rDNA tag pyrosequencing to investigate the associated prokaryotic diversity. Dense assemblages of prokaryotes were associated with the hydrant surface. Two microbial morphotypes were observed: one horseshoe-shaped and one fusiform, worm-like. These prokaryotes were observed on the hydrozoan epidermis, but not in the portions covered by the perisarcal exoskeleton, and their abundance was higher in March while decreased in late spring. Molecular analyses showed that assemblages were dominated by Bacteria rather than Archaea. Bacterial assemblages were highly diversified, with up to 113 genera and 570 Operational Taxonomic Units (OTUs), many of which were rare and contributed to ,0.4%. The two most abu