FN Archimer Export Format PT J TI Unveiling protist diversity associated with the Pacific oyster Crassostrea gigas using blocking and excluding primers BT AF Clerissi, Camille Guillou, Laure Escoubas, Jean Michel Toulza, Eve AS 1:1,2;2:3;3:4;4:5; FF 1:PDG-RBE-IHPE;2:;3:;4:; C1 IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Perpignan, France PSL Université Paris: EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, 52 Avenue Paul Alduy, 66860, Perpignan Cedex, France Sorbonne Université, CNRS, UMR7144 Adaptation et Diversité en Milieu Marin, Ecology of Marine Plankton (ECOMAP), Station Biologique de Roscoff SBR, Roscoff, France IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Montpellier, France IHPE, Univ. Montpellier, CNRS, Ifremer, Univ. Perpignan Via Domitia, Perpignan, France C2 IFREMER, FRANCE EPHE, FRANCE UNIV SORBONNE, FRANCE CNRS, FRANCE UNIV PERPIGNAN, FRANCE SI MONTPELLIER SE PDG-RBE-IHPE UM IHPE IN WOS Ifremer UMR WOS Cotutelle UMR DOAJ copubli-france copubli-univ-france IF 3.605 TC 5 UR https://archimer.ifremer.fr/doc/00636/74799/75165.pdf https://archimer.ifremer.fr/doc/00636/74799/75166.xls https://archimer.ifremer.fr/doc/00636/74799/75167.tiff https://archimer.ifremer.fr/doc/00636/74799/75168.xls https://archimer.ifremer.fr/doc/00636/74799/75169.tiff https://archimer.ifremer.fr/doc/00636/74799/75170.xls https://archimer.ifremer.fr/doc/00636/74799/75171.xls https://archimer.ifremer.fr/doc/00636/74799/75172.tiff https://archimer.ifremer.fr/doc/00636/74799/75173.xls LA English DT Article DE ;Holobiont;Metabarcoding;Microbiome;Ostreoida;Crassostrea AB Background Microbiome of macroorganisms might directly or indirectly influence host development and homeostasis. Many studies focused on the diversity and distribution of prokaryotes within these assemblages, but the eukaryotic microbial compartment remains underexplored so far. Results To tackle this issue, we compared blocking and excluding primers to analyze microeukaryotic communities associated with Crassostrea gigas oysters. High-throughput sequencing of 18S rRNA genes variable loops revealed that excluding primers performed better by not amplifying oyster DNA, whereas the blocking primer did not totally prevent host contaminations. However, blocking and excluding primers showed similar pattern of alpha and beta diversities when protist communities were sequenced using metabarcoding. Alveolata, Stramenopiles and Archaeplastida were the main protist phyla associated with oysters. In particular, Codonellopsis, Cyclotella, Gymnodinium, Polarella, Trichodina, and Woloszynskia were the dominant genera. The potential pathogen Alexandrium was also found in high abundances within some samples. Conclusions Our study revealed the main protist taxa within oysters as well as the occurrence of potential oyster pathogens. These new primer sets are promising tools to better understand oyster homeostasis and disease development, such as the Pacific Oyster Mortality Syndrome (POMS) targeting juveniles. PY 2020 PD JUN SO Bmc Microbiology SN 1471-2180 PU Springer Science and Business Media LLC VL 20 IS 1 UT 000548771400002 DI 10.1186/s12866-020-01860-1 ID 74799 ER EF