Integrating Innovative Approaches for Competitive and Sustainable Performance across the Mediterranean Aquaculture Value Chain

PerformFISH Trains the New Generation of Aquaculture Researchers

Lisen Li a P10 (CCMAR) trainee with an MSc in Aquaculture from Shanghai Ocean University (SHOU, Shanghai, China) is advancing well with his PhD in the context of “juvenile quality and growth potential” (WP2). Lisen presented some of his work about lysozyme, an enzyme involved in immune protection, at Aquaculture Europe 2019 in Berlin, Germany.

This work has now come to fruition and he recently published it in the journal Developmental and Comparative Immunology (https://doi.org/10.1016/j.dci.2020.103772). In this article Lisen looked at the evolution of the lysozyme family in vertebrates and then focussed on the forms present in sea bream and sea bass.  This enzyme is present in many tissues at the surface of the body and has an important role in immune defence because it breaks down the bacterial cell wall and so provides protection against bacterial invasion. Lisen found that fish have both G- and C-lysozyme forms but also identified for the first time in fish a more recently identified family member lactalbumin, which was extremely high in sea bream eggs. As part of his work Lisen developed an evolutionary model to explain lysozyme gene family evolution from the invertebrates (like bivalves) through to the vertebrates. But why is this work relevant for aquaculture? Fish eggs contain lysozyme presumably to protect them from bacteria and Lisen found that the activity varied during development and when he looked at gene transcripts for the different forms of lysozyme in sea bream eggs and larvae he found their expression was significantly different between eggs and early larvae from different sea bream broodstock suggesting that the mother provides immune protection in sea bream, which is similar to what happens in humans.

(Picture: Lisen developing his outreach skills by manning the PeformFISH booth in Aquaculture Europe 2019 in Berlin!)