Transcriptome profiling of developmental and xenobiotic responses in a keystone soil animal, the oligochaete annelid Lumbricus rubellus.
BACKGROUND
Natural contamination and anthropogenic pollution of soils are likely to be major determinants of functioning and survival of keystone invertebrate taxa. Soil animals will have both evolutionary adaptation and genetically programmed responses to these toxic chemicals, but mechanistic understanding of such is sparse. The clitellate annelid Lumbricus rubellus is a model organism for soil health testing, but genetic data have been lacking.


RESULTS
We generated a 17,000 sequence expressed sequence tag dataset, defining ~8,100 different putative genes, and built an 8,000-element transcriptome microarray for L. rubellus. Strikingly, less than half the putative genes (43%) were assigned annotations from the gene ontology (GO) system; this reflects the phylogenetic uniqueness of earthworms compared to the well-annotated model animals. The microarray was used to identify adult- and juvenile-specific transcript profiles in untreated animals and to determine dose-response transcription profiles following exposure to three xenobiotics from different chemical classes: inorganic (the metal cadmium), organic (the polycyclic aromatic hydrocarbon fluoranthene), and agrochemical (the herbicide atrazine). Analysis of these profiles revealed compound-specific fingerprints which identify the molecular responses of this annelid to each contaminant. The data and analyses are available in an integrated database, LumbriBASE.


CONCLUSIONS
L. rubellus has a complex response to contaminant exposure, but this can be efficiently analysed using molecular methods, revealing unique response profiles for different classes of effector. These profiles may assist in the development of novel monitoring or bioremediation protocols, as well as in understanding the ecosystem effects of exposure.
Owen
Jennifer
J
Institute of Evolutionary Biology, University of Edinburgh, King's Buildings, Edinburgh, EH9 3JT, UK. jennifer.owen@qiagen.com
Hedley
B Ann
BA
Svendsen
Claus
C
Wren
Jodie
J
Jonker
Martijs J
MJ
Hankard
Peter K
PK
Lister
Linsey J
LJ
Stürzenbaum
Stephen R
SR
Morgan
A John
AJ
Spurgeon
David J
DJ
Blaxter
Mark L
ML
Kille
Peter
P
D000818:Animals; D001280:Atrazine / Q000633:toxicity; D002104:Cadmium / Q000633:toxicity; D004781:Environmental Exposure; D020224:Expressed Sequence Tags; D005449:Fluorenes / Q000633:toxicity; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D015723:Gene Library; D006540:Herbicides / Q000633:toxicity; D009835:Oligochaeta / Q000187:drug effects* / Q000235:genetics* / Q000254:growth & development; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results; D012987:Soil; D012989:Soil Pollutants / Q000737:chemistry / Q000633:toxicity*; D015262:Xenobiotics / Q000737:chemistry / Q000633:toxicity*
D005449:Fluorenes; D006540:Herbicides; D012987:Soil; D012989:Soil Pollutants; D015262:Xenobiotics; D002104:Cadmium; C007738:fluoranthene; D001280:Atrazine