Molecular genetic differentiation in earthworms inhabiting a heterogeneous Pb-polluted landscape.
A Pb-mine site situated on acidic soil, but comprising of Ca-enriched islands around derelict buildings was used to study the spatial pattern of genetic diversity in Lumbricus rubellus. Two distinct genetic lineages ('A' and 'B'), differentiated at both the mitochondrial (mtDNA COII) and nuclear level (AFLPs) were revealed with a mean inter-lineage mtDNA sequence divergence of approximately 13%, indicative of a cryptic species complex. AFLP analysis indicates that lineage A individuals within one central 'ecological island' site are uniquely clustered, with little genetic overlap with lineage A individuals at the two peripheral sites. FTIR microspectroscopy of Pb-sequestering chloragocytes revealed different phosphate profiles in residents of adjacent acidic and calcareous islands. Bioinformatics found over-representation of Ca pathway genes in EST(Pb) libraries. Subsequent sequencing of a Ca-transport gene, SERCA, revealed mutations in the protein's cytosolic domain. We recommend the mandatory genotyping of all individuals prior to field-based ecotoxicological assays, particularly those using discriminating genomic technologies.
Andre
J
J
Cardiff School of Biosciences, Cardiff University, BIOSI 1, Museum Avenue, Cardiff CF10 3TL, UK. Andrej@cardiff.ac.uk
King
R A
RA
Stürzenbaum
S R
SR
Kille
P
P
Hodson
M E
ME
Morgan
A J
AJ
D054458:Amplified Fragment Length Polymorphism Analysis; D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D003576:Electron Transport Complex IV / Q000235:genetics; D014644:Genetic Variation; D007854:Lead / Q000032:analysis* / Q000378:metabolism; D009835:Oligochaeta / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000235:genetics; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism
D004272:DNA, Mitochondrial; D012989:Soil Pollutants; D007854:Lead; D003576:Electron Transport Complex IV; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases