De novo transcriptome assembly for the rose spotted snapperLutjanus guttatusand expression analysis of growth/atrophy-related genes

Abstract

The rose spotted snapper is an important fishery resource with potential for farming in several Latin American countries. Since transcriptomic information was not available for this species, we generated a reference transcriptome from eleven tissues (brain, heart, gonad, liver, gut, muscle, white skin, dark skin, and visceral fat) using Illumina HiSeq2000 platform. Transcriptome assembly and annotation were performed with Trinity and Trinotate respectively; 267,601 contigs were assembled, average contig length was 845 bp; 85,677 putative protein sequences were identified. Sixty‐six per cent of them showed a significant match to the SwissProt Database. From this assembly, we selected growth/atrophy‐related genes to investigate the effect of dietary protein source on gene expression. Pacap expression was measured in the brain; igf1, igf2 and ghr were measured in liver; and mtor, igf1, igf2, myod1, myod2, myogenin, foxo3a, foxo3b, murf1, mafbx, mstn1 and mstn2 were measured in muscle. A feeding trial with juveniles was performed, in which three diets were formulated, a fishmeal‐based diet (FM), a terrestrial animal protein diet (PPM) with porcine meat meal and poultry by‐products meal, and a vegetable diet (VEG) with a blend of soybean protein concentrate and corn gluten. A reduced expression of somatotropic and myogenic genes in fish fed the VEG diet was observed; however, expression of atrophy genes did not increase with this diet suggesting that atrophy mechanisms were not involved. These results indicate that protein from a vegetable source does not provide proper amino acid requirements to juvenile fish, decreasing expression of myogenic and other growth‐related genes.

A preliminary study of the effect of total fishmeal replacement with different dietary sources on the gut microbiota of spotted rose snapper juvenile ( Lutjanus guttatus Steindachner, 1869)

“…The growth performance of L. guttatus fed experimental diets has been reported in a previous study (Escalante‐Rojas, Peña, Hernández, Llera‐Herrera, & Garcia‐Gasca, 2018). Fish survival was greater than 87% and was not affected by dietary treatment (Table 2).…”

“…The growth performance of L. guttatus fed experimental diets has been reported in a previous study (Escalante-Rojas, Peña, Hernández, Llera-Herrera, & Garcia-Gasca, 2018). Fish survival was greater than 87% and was not affected by dietary treatment ( Furthermore, the feed conversion ratio of fish fed the FM diet was 1.46 ± 0.16, while in fish fed PPM and VEGM diets, the feed conversion ratios were 1.35 ± 0.10 and 1.89 ± 0.06 respectively.…”

“…In a previous study by Escalante‐Rojas et al. (2018), the effect of these diets on growth performance and feed efficiency were evaluated. It was reported that a plant‐based diet (a mix of soya bean concentrate and corn gluten meal) reduces the expression of somatotropic and myogenic genes in L. guttatus , when compared with fish fed protein from fishmeal or poultry by‐product and porcine meat meal.…”

Comparative Physiological and Transcriptomic Profiling Offers Insight into the Sexual Dimorphism of Hepatic Metabolism in Size-Dimorphic Spotted Scat (Scatophagus argus)

“…As a downstream component of the HPL axis, the liver possesses the greatest density of GH receptors [ 18 ] and in part mediates the growth-promoting effects of GH by secreting IGF-I in response to the stimulation of GH [ 19 , 20 , 21 , 22 ]. Given its central involvement in the regulation of growth, the liver has been widely used as a target organ to decipher the genetic and metabolic mechanisms that contribute to the significantly different growth rate of fish [ 18 , 23 , 24 , 25 , 26 , 27 , 28 ], and these findings help us to reach a better understanding of the regulation of growth. Accordingly, it is reasonable to suppose that the liver also participates in the formation process of SSD in fish species.…”