Expression Patterns of Growth Related Genes in Juvenile Red Spotted Grouper (Epinephelus akaara) with Different Growth Performance after Size Grading

Abstract

Fish shows great difference in growth rate between individuals during larval development and early growth. This difference seriously reduces the production efficiency in fish culture. Growth hormone (GH)/Insulin-like growth factor 1 (IGF1) system is said to play some pivotal roles in fish growth. In this study, we investigated differences of GH, IGF1 and GHR gene expressions in juvenile red spotted grouper ( Epinephelus akaara ) with different growth performance. Red spotted groupers were reared under the same environmental condition (water temperature 24±1℃, natural light) for 96 days after hatching. They were divided into 3 groups by size (fast growing, middle growing and slow growing groups: FGG, MGG, and SGG, respectively). RNA was extracted from the brain, liver and muscle tissues from each group, and target gene expression was examined by real-time PCR. In the brain with pituitary gland, expression of GH gene in FGG was significantly higher than the expression in SGG, but the expression of IGF1 and GHR genes in the muscle was highest in SGG. Difference of GHR and IGF1 mRNA in the liver between groups with different growth performance was less clear than that in other tissues, although level of IGF1 mRNA was higher in SGG than in MGG. These results suggest that hormonal governing of growth is not the same in fast growing and slow growing fish, and size grading could cause a shift of hormonal state and growth pattern in this species.

Grading frequency affect the growth performance and intra−cohort cannibalism in African catfish (Clarias gariepinus, burchell, 1822) culture

“…Growth rate was improved by 15% and 12% in the grading every two weeks and grading every four weeks over the control group. This is in agreement with previous studies that have established that size grading affect the growth performance of several species of fish (Barki et al, 2000;Kamstra, 1993;Lambert & Dutil, 2001;Mgaya & Mercer, 1995;Mun et al, 2019;Nightingale et al, 2018). In restricted spaces such as ponds, aquaria and concrete tanks, the African catfish tends to exhibit changes in behavioural patterns when there are size variations in the cohorts leading to reduced feed intake, aggression, death and cannibalism (Martins et al, 2005b).…”

Transcriptome analysis of the muscle of fast‐ and slow‐growing phoenix barb (Spinibarbus denticulatus denticulatus)

“…indicated that the growth hormone (GH)/insulin‐like growth factor 1 (IGF1) was highly expressed in the fast‐growing (FG) juvenile of red spotted grouper ( Epinephelus akaara ), especially in the muscle tissue, compared with the slow‐growing (SG) breed (Mun et al ., 2019). Nonetheless, these growth‐related genes are widely distributed in both FG and SG fish, with only limited genetic variations, making the selection of genetic markers difficult (Mun et al ., 2019; Reis Neto et al ., 2019). Recent transcriptomic studies have shown that there are considerable differences in the expression patterns of these genes between FG and SG breeds, especially those associated with hormone and lipid metabolism (Cleveland et al ., 2020; Lu, Chen, et al ., 2020; Mun et al ., 2019).…”

“…Nonetheless, these growth‐related genes are widely distributed in both FG and SG fish, with only limited genetic variations, making the selection of genetic markers difficult (Mun et al ., 2019; Reis Neto et al ., 2019). Recent transcriptomic studies have shown that there are considerable differences in the expression patterns of these genes between FG and SG breeds, especially those associated with hormone and lipid metabolism (Cleveland et al ., 2020; Lu, Chen, et al ., 2020; Mun et al ., 2019). Overall, these findings improve the understanding of the molecular mechanisms of growth, providing target genes and markers to increase the efficiency of selective breeding (Yang et al ., 2020).…”

GROWTH AND EXPRESSION PATTERN OF GROWTH-RELATED GENES IN THE FAST-GROWING GIANT GOURAMI Osphronemus goramy

“…In fish, AMPK is reported to maintain cellular energy and promotes catabolic pathways to provide energy (Causey et al, 2019;Sanchez-Gurmaches et al, 2012). The expression of these genes has been reported to be related to the better growth rate in several fish species (Gilannejad et al, 2020;Mun et al, 2019). Aside from its expression levels, the polymorphisms of growth-related genes such as GH and IGF-1 gene were also reported to be related to the better growth in fish such as in common carp (Berenjkar et al, 2018), Atlantic salmon (Tsai et al, 2014), and Chinese perch (Tian et al, 2014).…”