FISHing for ciliates: Catalyzed reporter deposition fluorescence in situ hybridization for the detection of planktonic freshwater ciliates.

0569062 - BC 2023 RIV CH eng J - Journal Article
Dirren-Pitsch, G. - Buhler, D. - Salcher, Michaela M. - Bassin, B. - Le Moigne, A. - Schuler, M. - Pernthaler, J. - Posch, T.
FISHing for ciliates: Catalyzed reporter deposition fluorescence in situ hybridization for the detection of planktonic freshwater ciliates.
Frontiers in Microbiology. Roč. 13, Dec (2022), č. článku 1070232. ISSN 1664-302X. E-ISSN 1664-302X
R&D Projects: GA ČR(CZ) GX20-12496X
Institutional support: RVO:60077344
Keywords : planktonic ciliates * card-fish * fluorescence in situ hybridization * lake water samples * quantitative protargol staining * ciliate quantification
OECD category: Microbiology
Impact factor: 5.2, year: 2022
Method of publishing: Open access
https://doi.org/10.3389/fmicb.2022.1070232

Planktonic ciliate species form multiple trophic guilds and are central components of freshwater food webs. Progress in molecular analytical tools has opened new insight into ciliate assemblages. However, high and variable 18S rDNA copy numbers, typical for ciliates, make reliable quantification by amplicon sequencing extremely difficult. For an exact determination of abundances, the classical morphology-based quantitative protargol staining is still the method of choice. Morphotype analyses, however, are time consuming and need specific taxonomic expertise. Catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) may represent a promising tool for the analysis of planktonic ciliates by combining molecular identification with microscopic quantification. We tested the applicability of CARD-FISH using nine cultured ciliate species. Eight species- and three genus-specific oligonucleotide probes were designed based on their 18S rRNA genes. The CARD-FISH protocol was adapted and the specificity of probes was established. We subsequently examined the precision of quantitation by CARD-FISH on single cultures and mock assemblages. Successful tests on lake water samples proved that planktonic ciliates could be identified and quantified in field samples by CARD-FISH. Double hybridizations allowed studying interspecific predator prey interactions between two ciliate species. In summary, we demonstrate that CARD-FISH with species-specific probes can facilitate studies on the population dynamics of closely related, small sized or cryptic species at high sampling frequencies.
Permanent Link: https://hdl.handle.net/11104/0340362