Temperature Affects Musculoskeletal Development and Muscle Lipid Metabolism of Gilthead Sea Bream (Sparus aurata)

Abstract

World population is expected to increase to approximately 9 thousand million people by 2050 with a consequent food security decline. Besides, climate change is a major challenge that humanity is facing, with a predicted rise in mean sea surface temperature of more than 2°C during this century. This study aims to determine whether a rearing temperature of 19, 24, or 28°C may influence musculoskeletal development and muscle lipid metabolism in gilthead sea bream juveniles. The expression of growth hormone (GH)/insulin-like growth factors (IGFs) system-, osteogenic-, myogenic-, and lipid metabolism-related genes in bone and/or white muscle of treated fish, and the in vitro viability, mineralization, and osteogenic genes expression in primary cultured cells derived from bone of the same fish were analyzed. The highest temperature significantly down-regulated igf-1, igf-2 , the receptor igf-1ra , and the binding proteins igfbp-4 and igfbp-5b in bone, and in muscle, igf-1 and igf-1ra , suggesting impaired musculoskeletal development. Concerning myogenic factors expression, contrary responses were observed, since the increase to 24°C significantly down-regulated myod1 and mrf4 , while at 28°C myod2 and myogenin were significantly up-regulated. Moreover, in the muscle tissue, the expression of the fatty acid transporters cd36 and fabp11 , and the lipases lipa and lpl-lk resulted significantly increased at elevated temperatures, whereas β-oxidation markers cpt1a and cpt1b were significantly reduced. Regarding the primary cultured bone-derived cells, a significant up-regulation of the extracellular matrix proteins on, op , and ocn expression was found with increased temperatures, together with a gradual decrease in mineralization along with fish rearing temperature. Overall, these results suggest that increasing water temperature in this species appears to induce unfavorable growth and development of bone and muscle, through modulating the expression of different members of the GH/IGFs axis, myogenic and osteogenic genes, while accelerating the utilization of lipids as an energy source, although less efficiently than at optimal temperatures.

Musculoskeletal Growth Modulation in Gilthead Sea Bream Juveniles Reared at High Water Temperature and Fed with Palm and Rapeseed Oils-Based Diets

“…On the other hand, igf-2 and gh receptors (ghr-1 and ghr-2) remained unaltered or increased in the case of ghr-2 in bone, supporting the recognized major involvement of IGF-1, compared to the other components of the hormonal axis such as GH, directly controlling musculoskeletal growth in fish [29][30][31]. This GH-IGFs axis gene expression pattern is in agreement with that previously described in a shorter trial (i.e., 3 days) with the same species reared as well at 28 • C temperature [26]. In addition, the up-regulating effect of high temperature on ghr-2 observed in this study in bone was also reported in the liver of rainbow trout (Oncorhynchus mykiss) juveniles [32] and embryos of the same species [33].…”

“…In fact, it is known that the two isoforms of the GH receptor are differentially regulated depending on the tissue, in response to a temperature change [32], which agrees with the results observed in the present work. Furthermore, an increase (not significant) of igfbp-1a, an important growth and development inhibitor [34], was also observed in both tissues in agreement with Balbuena-Pecino et al [26]. All in all, the transcriptional modulation of GH-IGFs axis members in gilthead sea bream caused by the elevation of water rearing temperature to 28 • C appears to be contributing to a critical turnover regulation of the musculoskeletal system to find growth homeostasis.…”

“…All the analyses were performed in triplicate wells using 384-well plates with 2.5 µL of iTaq Universal SYBR Green Supermix (Bio-Rad, El Prat de Llobregat, Spain), 250 nM of forward and reverse primers and 1 µL of diluted cDNA for each sample, in a final volume of 5 µL. All reactions were performed in the conditions previously described [26]. Moreover, three negative controls were also included and run in duplicate: no template control (NTC), no reverse transcriptase control (RTC), and PCR control (PCR, MilliQ water).…”

3D Ensemble Simulation of Seawater Temperature – An Application for Aquaculture Operations

“…While analyzing the probabilities we focused on two thermal limits. Based on literature the upper and lower limits of SWT were considered as 26 • C and 15 • C (Mayer et al, 2008;Ibarz et al, 2010;Llorente and Luna, 2013;Balbuena-Pecino et al, 2019). Various studies specify varying thresholds for seabream.…”

“…For operational decision making in aquaculture farms, temperature is an important environmental property (Hurst, 2007;Ibarz et al, 2010;Besson et al, 2016;Masroor et al, 2018). Fish species have tolerance levels of temperature and beyond these tolerance levels, fish growth and health are adversely impacted (Berlinsky et al, 2007;Llorente and Luna, 2013;Balbuena-Pecino et al, 2019). At such scenarios, to run the farm business profitably, appropriate measure needs to be taken related to operations (Besson et al, 2016;Hobday et al, 2016).…”