Abstract
In this study, the effects of different feeding frequencies on the growth and the expression of genes in the GH/IGF axis were assessed in juvenile Chinese sturgeon. The newly hatched Chinese sturgeons were bred for 38 days at three different feeding frequencies groups (feeding frequency of two times a day, TWD; three times a day, THD; and four times a day, FOD), and the expression levels of the GH/IGF axis responses to feeding frequency were determined by quantitative real-time PCR. In addition, the full-length of the Coding Sequences of IGF I and IGF II genes (489-bp and 660-bp, respectively), were cloned and analyzed from Chinese sturgeon the first time. Multiple sequence alignments of IGFs revealed that Chinese sturgeon are high sequence identity to IGFs from other species. The phylogenetic relationships based on the IGF I and IGF II amino acid sequences were consistent with the traditional classification. After 38 days of growth, the three different feeding frequencies groups of Chinese sturgeon had no significant difference of body length, body weight, specific growth rate, the survival rate, the rate of weight gain and the condition factor. However, the relative expression of Chinese sturgeon GH in the pituitary decreased with increasing feeding frequency. The relative expression of Chinese sturgeon GHR in liver and skeletal muscle was deceased with increasing feeding frequency, while the relative expression of GHR in stomach and intestines at THD group was significantly higher than that of at TWD group and FOD group (p < 0.05). The relative expression of Chinese sturgeon IGF I in liver increased significantly with increasing feeding frequency (p < 0.05). The relative expression of IGF I in stomach and skeletal muscle was similar at the three groups. The relative expression of IGF I in intestines was significantly higher at FOD group than at TWD group and THD group (p < 0.05). The relative expression of Chinese sturgeon IGF II in liver at TWD group was significantly higher than that at THD group and FOD group (p < 0.05). However, the relative expression of IGF II in stomach, intestines and skeletal muscle at THD group was higher than that at TWD group and FOD group. Based on these previous studies that liver IGF I is regarded as a biomarker of growth performance, this result suggested that the juvenile Chinese sturgeon is better for growth when feeding four times daily compared to twice and thrice daily.
Highlights
Chinese sturgeon Acipenser sinensis is an anadromous species that only spawns in Yangtze River of C hina[1]
The growth hormone (GH)-insulin-like growth factors (IGFs) axis that is involved in many metabolic pathways and physiological processes related to somatic growth, development, metabolism, and reproduction plays an important role in the regulation of the growth-promoting actions in fish[13,14,15]
After 38 days of growth, the three different feeding frequencies groups of Chinese sturgeon had no significant difference of body length, body weight, specific growth rate, the survival rate, the rate of weight gain and the condition factor
Summary
Chinese sturgeon Acipenser sinensis is an anadromous species that only spawns in Yangtze River of C hina[1]. It is urgently to increase the efforts of research and conservation and to protect the spawning environment of Chinese sturgeon In this situation, artificial propagation is one of the effective strategies to enhance the wild population. It is important to study Chinese sturgeon to speed up the rate of growth of this species. Feeding frequency plays important role in the growth of fish, especially in the early s tages[6]. Investigation of the appropriate feeding frequency for individual growth is important for successful culture of Chinese sturgeon. The GH-IGF axis that is involved in many metabolic pathways and physiological processes related to somatic growth, development, metabolism, and reproduction plays an important role in the regulation of the growth-promoting actions in fish[13,14,15]. GHR play essential role in the production and release of IGF I in the liver and other tissues[18]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
