Physiological and proteomic evidences that domestication process differentially modulates the immune status of juvenile Eurasian perch (Perca fluviatilis) under chronic confinement stress.

The current study aimed to evaluate the influence of domestication process on the stress response and subsequent immune modulation in Eurasian perch juveniles (Perca fluviatilis) submitted to chronic confinement. Briefly, F1 and F4 generations were confined into small-size tanks and sampled 7 and 55 days after stocking. Cortisol and glucose levels as well as lysozyme activity and immunoglobulin level were evaluated in the serum. Spleen Somatic Index and spleen ROS production were also measured. A proteomic analysis was performed on serum sampled on day 7. Finally, both generations were genetically characterized using a microsatellite approach. Globally, results revealed that chronic confinement did not elicit a typical stress response but resulted in a prolonged immune stimulation. Proteomic results suggested that domestication process influenced the immune status of perch submitted to chronic confinement as the F1 confined fish displayed lower abundance of C3 complement component, transferrin and Apolipoprotein E. Microsatellite data showed a strong genetic drift as well as reduced genetic diversity, allelic number and heterozygosity along with domestication process. The present work is the first to report that fish under domestication can develop an immune response, assessed by a combined approach, following recurrent challenges imposed by captive environment despite a reduced genetic variation.

Development of novel microsatellite markers to identify the different invasive lineages in the Corbicula complex and to assess androgenesis.

Reliable markers are needed to identify the lineages in the invasive clam genus Corbicula. Previous studies have demonstrated that mitochondrial (mt) DNA poorly resolves Corbicula phylogeny, owing to its androgenetic reproductive mode. Moreover, hybridization and mitochondrial/nuclear mismatches occur. We developed the first eleven polymorphic markers to detect these phenomena and to investigate the nuclear identity of Corbicula populations. These microsatellite loci revealed three main lineages in Western Europe. One locus allowed rapid discrimination of these three lineages on agarose gel, saving time and money. Moreover, the eleven markers were successfully cross-amplified in the invasive Corbicula lineages found in North America.