Genetic diversity of Microcystis blooms (Cyanobacteria) in recently constructed reservoirs in Tigray (Northern Ethiopia) assessed by rDNA ITS

TY - JOUR

T1 - Genetic diversity of Microcystis blooms (Cyanobacteria) in recently constructed reservoirs in Tigray (Northern Ethiopia) assessed by rDNA ITS

AU - van Gremberghe, I.

AU - van der Gucht, K.

AU - Vanormelingen, P.

AU - Asmelash, T.

AU - Dejenie, T.

AU - D'Hondt, S.

AU - Declerck, S.

AU - De Meester, Luc

AU - Vyverman, W.

N1 - WOS:000289300200012 ISI Document Delivery No.: 747DJ Times Cited: 6 Cited Reference Count: 65 van Gremberghe, Ineke Van der Gucht, Katleen Vanormelingen, Pieter Asmelash, Tsehaye Dejenie, Tadesse D'hondt, Sofie Declerck, Steven De Meester, Luc Vyverman, Wim Declerck, Steven/E-4338-2010; De Meester, Luc/F-3832-2015 Declerck, Steven/0000-0001-6179-667X; De Meester, Luc/0000-0001-5433-6843 Aquatic Ecology project in the VLIR Inter University Cooperation programme; MEKELLE University; BELSPO (Belgian Science Policy) This research was financially supported by the Aquatic Ecology project in the VLIR Inter University Cooperation programme with MEKELLE University. We thank the local university authorities, the programme research managers Jan Nyssen and Hans Bauer, and programme director Seppe Deckers for their support. We thank Ann-Eline Debeer for helping with DGGE analyses. The comparison of local ITS diversity to data from Flanders was possible thanks to samples obtained in the framework of the project "B-Blooms" (Algal blooms: emerging problem for health and sustainable use of surface waters), nationally supported by BELSPO (Belgian Science Policy). 6 1 25 Springer Dordrecht 1573-5125 80

PY - 2011

Y1 - 2011

N2 - The cyanobacterium Microcystis is notorious for forming extensive and potentially toxic blooms in nutrient-rich freshwater bodies worldwide. However, little is known about the factors underlying the genetic diversity and structure of natural Microcystis populations, despite the fact that this knowledge is essential to understand the build-up of blooms. Microcystis blooms are common and occur year-round in Africa, but are underinvestigated in this continent. We studied the genetic diversity and structure of Microcystis populations in 30 man-made reservoirs in Tigray (Northern Ethiopia) using Denaturing Gradient Gel Electrophoresis of the 16S-23S rDNA internal transcribed spacer (ITS) region and assessed the importance of local environmental conditions and geographic position of the reservoirs for the observed patterns. The analyses showed that both regional and local Microcystis ITS diversity in these recently constructed reservoirs was relatively low, with several dense blooms containing only a single ITS type. Especially one non-toxic ITS type dominated a considerable fraction of Microcystis blooms, but appeared restricted in its geographic distribution. The relationship between Microcystis ITS population structure and abiotic variables (water clarity, pH) and with zooplankton (Daphnia biomass) indicates a (limited) influence of environmental conditions on Microcystis population structure in the reservoirs of Tigray.

AB - The cyanobacterium Microcystis is notorious for forming extensive and potentially toxic blooms in nutrient-rich freshwater bodies worldwide. However, little is known about the factors underlying the genetic diversity and structure of natural Microcystis populations, despite the fact that this knowledge is essential to understand the build-up of blooms. Microcystis blooms are common and occur year-round in Africa, but are underinvestigated in this continent. We studied the genetic diversity and structure of Microcystis populations in 30 man-made reservoirs in Tigray (Northern Ethiopia) using Denaturing Gradient Gel Electrophoresis of the 16S-23S rDNA internal transcribed spacer (ITS) region and assessed the importance of local environmental conditions and geographic position of the reservoirs for the observed patterns. The analyses showed that both regional and local Microcystis ITS diversity in these recently constructed reservoirs was relatively low, with several dense blooms containing only a single ITS type. Especially one non-toxic ITS type dominated a considerable fraction of Microcystis blooms, but appeared restricted in its geographic distribution. The relationship between Microcystis ITS population structure and abiotic variables (water clarity, pH) and with zooplankton (Daphnia biomass) indicates a (limited) influence of environmental conditions on Microcystis population structure in the reservoirs of Tigray.

KW - Microcystis Blooms 16S-23S rDNA ITS Population structure Diversity Africa gradient gel-electrophoresis fresh-water lakes ribosomal-rna spatiotemporal changes toxic cyanobacterium natural-populations intergenic spacer nontoxic strains aeruginosa communitie

U2 - 10.1007/s10452-011-9354-z

DO - 10.1007/s10452-011-9354-z

M3 - Article

SN - 1386-2588

VL - 45

SP - 289

EP - 306

JO - Aquatic Ecology

JF - Aquatic Ecology

IS - 2

ER -