TY - JOUR
T1 - Identification of pathways, gene networks, and paralogous gene families in Daphnia pulex responding to exposure to the toxic cyanobacterium Microcystis aeruginosa
AU - Asselman, Jana
AU - De Coninck, Dieter I M
AU - Glaholt, Stephen
AU - Colbourne, John K
AU - Janssen, Colin R
AU - Shaw, Joseph R
AU - De Schamphelaere, Karel A C
PY - 2012/8/7
Y1 - 2012/8/7
N2 - Although cyanobacteria produce a wide range of natural toxins that impact aquatic organisms, food webs, and water quality, the mechanisms of toxicity are still insufficiently understood. Here, we implemented a whole-genome expression microarray to identify pathways, gene networks, and paralogous gene families responsive to Microcystis stress in Daphnia pulex . Therefore, neonates of a sensitive isolate were given a diet contaminated with Microcystis to contrast with those given a control diet for 16 days. The microarray revealed 2247 differentially expressed (DE) genes (7.6% of the array) in response to Microcystis , of which 17% are lineage-specific (i.e., these genes have no detectable homology to any other gene in currently available databases) and 49% are gene duplicates (paralogues). We identified four pathways/gene networks and eight paralogous gene families affected by Microcystis . Differential regulation of the ribosome, including three paralogous gene families encoding 40S, 60S, and mitochondrial ribosomal proteins, suggests an impact of Microcystis on protein synthesis of D. pulex . In addition, differential regulation of the oxidative phosphorylation pathway (including the NADH:ubquinone oxidoreductase gene family) and the trypsin paralogous gene family (a major component of the digestive system in D. pulex ) could explain why fitness is reduced based on energy budget considerations.
AB - Although cyanobacteria produce a wide range of natural toxins that impact aquatic organisms, food webs, and water quality, the mechanisms of toxicity are still insufficiently understood. Here, we implemented a whole-genome expression microarray to identify pathways, gene networks, and paralogous gene families responsive to Microcystis stress in Daphnia pulex . Therefore, neonates of a sensitive isolate were given a diet contaminated with Microcystis to contrast with those given a control diet for 16 days. The microarray revealed 2247 differentially expressed (DE) genes (7.6% of the array) in response to Microcystis , of which 17% are lineage-specific (i.e., these genes have no detectable homology to any other gene in currently available databases) and 49% are gene duplicates (paralogues). We identified four pathways/gene networks and eight paralogous gene families affected by Microcystis . Differential regulation of the ribosome, including three paralogous gene families encoding 40S, 60S, and mitochondrial ribosomal proteins, suggests an impact of Microcystis on protein synthesis of D. pulex . In addition, differential regulation of the oxidative phosphorylation pathway (including the NADH:ubquinone oxidoreductase gene family) and the trypsin paralogous gene family (a major component of the digestive system in D. pulex ) could explain why fitness is reduced based on energy budget considerations.
KW - Animals
KW - Daphnia
KW - Gene Regulatory Networks
KW - Microcystis
KW - Multigene Family
KW - Real-Time Polymerase Chain Reaction
U2 - 10.1021/es301100j
DO - 10.1021/es301100j
M3 - Article
C2 - 22799445
SN - 0013-936X
VL - 46
SP - 8448
EP - 8457
JO - Environmental Science & Technology
JF - Environmental Science & Technology
IS - 15
ER -