News, Publications

Publication: Identifying biochemical phenotypic differences between cryptic species

There is a new publication today in the Royal Society Journal Biology Letters co-authored by Professors Kille & Morgan, with other colleagues.

It’s great to see such massive results recognised by the Royal Society. See for the full text

Identifying biochemical phenotypic differences between cryptic species

Manuel LiebekeMichael W. BrufordRobert K. Donnelly,Timothy M. D. EbbelsJie HaoPeter KilleElma LahiveRachael M. MadisonA. John MorganGabriela A. Pinto-Juma, David J. SpurgeonClaus Svendsen and Jacob G. Bundy


Molecular genetic methods can distinguish divergent evolutionary lineages in what previously appeared to be single species, but it is not always clear what functional differences exist between such cryptic species. We used a metabolomic approach to profile biochemical phenotype (metabotype) differences between two putative cryptic species of the earthworm Lumbricus rubellus. There were no straightforward metabolite biomarkers of lineage, i.e. no metabolites that were always at higher concentration in one lineage. Multivariate methods, however, identified a small number of metabolites that together helped distinguish the lineages, including uncommon metabolites such as Nε-trimethyllysine, which is not usually found at high concentrations. This approach could be useful for characterizing functional trait differences, especially as it is applicable to essentially any species group, irrespective of its genome sequencing status.



Figure 1.
The two earthworm lineages have robust metabolic differences. (a) Cross-validated scores for OPLS-DA analysis of lineages A and B; individual data points are shown on top of boxplots with distribution shape. (b) OPLS-DA loadings; points also identified as significant by univariate analysis (table 2) marked in red. Laminine and unassigned aromatic compound labelled on plot. (c) Set 1 worms and (d) set 2 worms: laminine versus aromatic compound, both shown as log10-transformed intensities. Lineage A, black; lineage B, red. Points are connected to the group centroids.