Transcriptomic assessment of dietary fishmeal partial replacement by soybean meal and prebiotics inclusion in the liver of juvenile Pacific yellowtail (Seriola lalandi).

BACKGROUND: Seriola lalandi is an important species for aquaculture, due to its rapid growth, adaptation to captivity and formulated diets, and high commercial value. Due to the rise in fishmeal (FM) price, efforts have been and still are made to replace it partially or entirely with vegetable meals in diets for carnivorous fish. The use of prebiotics when feeding vegetable meals has improved fish health. METHODS: Four experimental diets were assessed in juveniles, the control diet consisted of FM as the main protein source, the second diet included 2% of GroBiotic®-A (FM-P), in the third diet FM was partially replaced (25%) by soybean meal (SM25), and the fourth consisted of SM25 with 2% of GroBiotic®-A (SM25-P). Growth was evaluated and RNA-seq of the liver tissue was performed, including differential expression analysis and functional annotation to identify genes affected by the diets. RESULTS: Growth was not affected by this level of FM replacement, but it was improved by prebiotics. Annotation was achieved for 59,027 transcripts. Gene expression was affected by the factors: 225 transcripts due to FM replacement, 242 due to prebiotics inclusion, and 62 due to the interaction of factors. The SM25-P diet showed the least amount of differentially expressed genes against the control diet. CONCLUSION: The replacement of FM (25%) by soybean meal combined with prebiotics (2%) represents a good cost-benefit balance for S. lalandi juveniles since the fish growth increased and important metabolic and immune system genes in the liver were upregulated with this diet.

The complete mitochondrial DNA of the tropical gar (Atractosteus tropicus).

The mitogenome of the tropical gar, Atractosteus tropicus, (GeneBank accession number KJ531198) has a total length of 16,280 bp, and the arrangement consist of 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes and 22 transfer RNA similar to other Lepisosteidae family mitogenomes.

Genetic variability between complete mitochondrion genomes of the sablefish, Anoplopoma fimbria (Pallas, 1814).

The complete mitochondrial genome of the sablefish, Anoplopoma fimbria (Genbank accession KP777542) is 16,507 bp in size and contains the typical 37 genes (13 protein-coding, 2 ribosomal RNA, and 22 transfer RNA) found in teleosts mitogenomes. The genome varies in 118 positions with respect to another mitogenome sablefish specimen.