Selection for growth is associated in gilthead sea bream (Sparus aurata) with diet flexibility, changes in growth patterns and higher intestine plasticity

Genetic selection for growth drives differences in intestinal microbiota composition and parasite disease resistance in gilthead sea bream

“…they had shorter intestines when fed standard diets, but they exhibited longer intestines when fed plant-based diets. This intestinal plasticity was genetically regulated and correlated with changes in liver and adipose tissue and fast growth rates both in favorable (summer) and non-favorable (winter) seasons [31]. The intestinal plasticity of this protandrous hermaphrodite sh has also been reported previously, with increased villi length and larger number of goblet cells in sh fed plant-based diets [32,33].…”

“…Five different gilthead sea bream families selected by growth derived from the PROGENSA (Spanish selection program of gilthead sea bream) broodstock were used in this study (F3 generation) [27,28,31]. The ve families were then grouped in three sets, named suprafamilies, by their different growth trajectories as previously described [31]: fast (families e5e2 and e6e2, constituting suprafamily e5e6), intermediate (family c2c7) and slow (families c4c2 and e4e1, constituting suprafamily c4e4). It is important to bear in mind that these families are not of clonal origin, they have substantial genomic heterogeneity, and were grouped considering phenotypic characters.…”

“…For instance, genetic correlations between growth rate and disease resistance or survival have been described [67,68]. In gilthead sea bream in particular, productive traits linked to growth selection, such as mortality rates, disease resistance, tissue biometrics, intestinal plasticity, skeletal deformities, llet yield, and esh and carcass quality, have been evaluated [26][27][28][29][30][31]69]. However, the relation between intestinal microbiota and growth selection has never been studied in this species.…”

“…A similar result was described when growth trajectories and tissue and intestinal plasticity were studied in the same gilthead sea bream families. Unlike intermediate and slow-growth families, fastgrowth families demonstrated the capacity to reshape their intestines to adapt to plant-based diets, with no impact on their growth parameters [31]. In animal husbandry, the presence of certain groups of bacteria has been related with improvements in feed e ciency and growth performance.…”

“…Despite the genomic heterogeneity, gilthead sea bream families selected for heritable growth are more robust. They adapt better to dietary changes, reshaping their intestines and organosomatic indexes, with no signi cant effects on their growth and health parameters [31], and can cope more e ciently with pathogens. These animals also harbor a plastic microbiota which effectively adapts to the metabolic challenges induced by dietary changes, with clear bene ts on health, growth and, possibly, disease resilience.…”