We evaluated the suitability of high-throughput proteomic methods to monitor terrestrial ecosystems. Free-living Mus spretus from three sites along the "Domingo Rubio" (DR) stream were compared with mice from Doñana Biological Reserve ("Santa Olalla" lagoon (SOL) negative control), using specimens from an industrial settlement (phosphogypsum stacks (PS)) and rice fields ("Matochal" rice fields (ARZ)) as positive controls. Our 2-DE analysis showed 36 spots with significantly altered expression. Sixteen were identified by MALDI-TOF-PMF and peptide matching with Mus musculus databases. Identified proteins play different roles: cytoskeletal dynamics, proteolysis, biotransformation, oxidative-stress adaptation, and metabolism. Animals from different polluted environments showed contrasting differences in their proteomes, with specific increases and decreases in selected groups of proteins that seem to be co-ordinately regulated. Proteomic data were consistent with metal biomonitoring and conventional biomarker responses, indicating that DR (and PS/ARZ) animals sustained a heavier pollutant burden than SOL specimens and suffered a chronic oxidative stress. Whereas some protein expression differences may protect mice from pollutant toxicity, others should make them more susceptible. Transcript expression signatures agree with the documented lack of correlation between mRNA and protein levels. Nonetheless, a positive significant correlation was found between the gpx1 mRNA molecules and the intensity of one of the two identified GPX1 isospots.

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Organic producers, traders, and consumers must address 2 issues related to milk: authentication of the production system and nutritional differentiation. The presence of hippuric acid (HA) in goat milk samples has been proposed as a possible marker to differentiate the feeding regimen of goats. The objective of this work is to check the hypothesis that HA could be a marker for the type of feeding regimen of goats by studying the influence of production system (conventional or organic) and feeding regimen (with or without grazing fodder). With this purpose, commercial cow and goat milk samples (n=27) and raw goat milk samples (n=185; collected from different breeds, localizations, and dates) were analyzed. Samples were grouped according to breed, feeding regimen, production system, and origin to compare HA content by ANOVA and honestly significant difference Tukey test at a confidence level of ≥95%. Hippuric acid content was obtained by analyzing milk samples with capillary electrophoresis. This method was validated by analyzing part of the samples with HPLC as a reference technique. Sixty-nine raw goat milk samples (of the total 158 samples analyzed in this work) were quantified by capillary electrophoresis. In these samples, the lowest average content for HA was 7±3 mg/L. This value corresponds to a group of conventional raw milk samples from goats fed with compound feed. The highest value of this group was 28±10 mg/L, corresponding to goats fed compound feed plus grass. Conversely, for organic raw goat milk samples, the highest concentration was 67±14 mg/L, which corresponds to goats fed grass. By contrast, the lowest value of this organic group was 26±10 mg/L, which belongs to goats fed organic compounds. Notice that the highest HA average content was found in samples from grazing animals corresponding to the organic group. This result suggests that HA is a good marker to determine the type of goats feeding regimen; a high content of HA represents a diet based mainly or exclusively on eating green grass (grazing), independently of the production system. Hence, this marker would not be useful for the actual organic policies to distinguish organic milk under the current regulations, because organic dairy ruminants can be fed organic compound feed and conserved fodder without grazing at all.

Mus musculus mice have been investigated for the total elements content in different organs (lung, liver, spleen, kidney, brain, testicle, heart and muscle) and molecular mass distribution patterns of Mn, Ni, Cu, Zn, As, Pb, Cr, Fe, Co, Se and Cd. Some differences have been found in the organs studied, with especially relevant being the Cu-containing fraction present only in the brain and the As-containing one in the liver. Other differences related to the abundance of the metallospecies have also been found. The present paper is the first step in the study of the "metallome" of this inbred laboratory species from which the genome is completely known. This organism could be used as a model in future studies focused on wild mice and the analytical approach developed could be applied to wild mice to find markers of environmental pollution. [figure: see text] The present paper is the first step in the study of the "metallome" of the inbred laboratory specie Mus musculus from which the genome is completely known. Some interesting differences have been found in the extracts from the organs that are discussed along the text.