Early ontogenetic development, digestive enzymatic activity and gene expression in red sea bream (Pagrus major)

Ontogeny of Expression and Activity of Digestive Enzymes and Establishment of gh/igf1 Axis in the Omnivorous Fish Chelon labrosus

“…Correspondingly, in our study an increasing trend of pga2 and atp4a expression from 21 dph onward coincided with proliferation of gastric glands in this species at 23 dph (Figure 1), although maximum expression levels and therefore, expected fully stomach functionality, was not achieved until 50 dph. The decreasing trend measured beyond this point is not in agreement with findings in species with carnivorous habits, in which the mRNA levels of these genes increase toward advanced developmental stages [5,9,17,34].…”

“…While pepsinogen expression and pepsin specific activity patterns are usually reported to be in line during the ontogeny of fish species [5,9,35], our attempts to detect pepsin activity by using a highly sensitive fluorometric substrate, failed. Similarly, no acid protease activity was detected in the larvae of another mullet species (Mugil cephalus) until 79 dph, and the authors suggested a crucial role of alkaline proteases in this family [34].…”

“…Although the study of the ontogeny of digestive enzymes at transcriptional level can provide useful information due to its high accuracy and specificity even for different gene isoforms [7], it has been carried out in relatively few species [6]. Additionally, even fewer studies have assessed the ontogeny of digestive system using simultaneously molecular and biochemical techniques [5,8,9]. Such studies can provide a better insight into transcriptional/translational relations of the digestive machinery and can help to understand to what extent the enzymatic hydrolysis of macronutrients is programmed, activated, and/or modulated [6].…”

Comparative ontogeny of the digestive tract ofOncorhynchus mykiss♀ xSalmo trutta caspius♂ triploid hybrids to their parental species

“…The reduction in amylase activity in RT and CBT with age may be linked to carnivorous feeding as previously reported for other carnivorous fish species such as seabream and other marine species (Khoa et al, 2019;Yúfera et al, 2018). No progressive increase in amylase was observed in the triploid hybrids during early development, suggesting a difference in the carbohydrate metabolism pattern in this particular group compared with RT and CBT.…”

“…The gradual rise in the specific activity of amylase during development coincided with weaning to dry food in RT and CBT and corroborates observations in other fish larvae that the development of the digestive system is stimulated by food (Zouiten et al., 2008). The reduction in amylase activity in RT and CBT with age may be linked to carnivorous feeding as previously reported for other carnivorous fish species such as seabream and other marine species (Khoa et al., 2019; Yúfera et al., 2018). No progressive increase in amylase was observed in the triploid hybrids during early development, suggesting a difference in the carbohydrate metabolism pattern in this particular group compared with RT and CBT.…”