Exploration of appetite regulation in Yangtze sturgeon (Acipenser dabryanus) during dietary transition

Abstract

Background The Yangtze sturgeon is an endangered fish species, and artificial breeding is an effective means of restoring its population. However, after transitioning to an artificial diet, several Yangtze sturgeons are reluctant to eat. Therefore, the objectivity of the current study was to investigate the response of appetite regulatory factors and analyze their expression throughout various stages of dietary transition. Results The body length and body weight of Yangtze sturgeons failed transiting diet were significantly lower than those succeed transiting diet sturgeons. Since the brain is the center of appetite regulation, RNA-seq of the brain was employed to analyze the differentially expressed genes and their biological functions in successfully and unsuccessfully transit diet fry. After that, 82,151 unigenes and 3222 DEGs were obtained. Based on the results of RNA-seq, appetite factors, including pomc, cart, npy and agrp, were cloned, and then a diet transiting experiment was designed to explore the changes in appetite after feeding a microcapsule diet (dietary transition group). The results showed that during the dietary transition period, the expression of cart was increased on the 1st and 3rd days but decreased on the 5th, 6th, 8th and 10th days. The expression of agrp was downregulated on the 1st and 3rd days but upregulated on the 5th, 6th, 8th and 10th days. Conclusions The results of this study can provide information for a better understanding of the appetite change during the dietary transition of Yangtze sturgeon and improve their survival rate after the dietary transition.