Transcriptomic evidences of local thermal adaptation for the native fish Colossoma macropomum (Cuvier, 1818)

Abstract

Brazil has five climatically distinct regions, with an annual average temperature difference up to 14 ºC between the northern and southern extremes. Environmental variation of this magnitude can lead to new genetic patterns among farmed fish populations. Genetically differentiated populations of tambaqui (Colossoma macropomum Cuvier, 1818), an important freshwater fish for Brazilian continental aquaculture, may be associated with regional adaptation. In this study, we selected tambaquis raised in two thermally distinct regions, belonging to different latitudes, to test this hypothesis. De novo transcriptome analysis was performed to compare the significant differences of genes expressed in the liver of juvenile tambaqui from a northern population (Balbina) and a southeastern population (Brumado). In total, 2,410 genes were differentially expressed (1,196 in Balbina and 1,214 in Brumado). Many of the genes are involved in a multitude of biological functions such as biosynthetic processes, homeostasis, biorhythm, immunity, cell signaling, ribosome biogenesis, modification of proteins, intracellular transport, structure/cytoskeleton, and catalytic activity. Enrichment analysis based on biological networks showed a different protein interaction profile for each population, whose encoding genes may play potential functions in local thermal adaptation of fish to their respective farming environments.

Genome assembly and annotation of the tambaqui (Colossoma macropomum): an emblematic fish of the Amazon River basin

“…Transcriptomic characterization of tambaqui exposed to (i) distinct climate change scenarios and (ii) during gonadal differentiation have provided a helpful resource for the understanding of the molecular mechanisms underlying both the adaptation to a future new climate and the process of sex determination [7,8,9]. Other molecular mechanisms related to enzymatic capacity for long-chain polyunsaturated fatty acid biosynthesis have also been confirmed by a functional characterization of core genes in these processes [10,11].…”

Acute thermal stress elicits interactions between gene expression and alternative splicing in a fish of conservation concern

“…The gene rbm39 was associated with prpf38b by co-expression in the STRING v11 database (Szklarczyk et al, 2019), and showed differential exon usage in response to thermal stress in our experiment. Furthermore, rbm39 was differentially expressed in one of two thermally distinct populations of tambaqui ( Colossoma macropomum ) and is thought to play a role in local adaptation to thermal conditions (Fé-Gonçalves et al, 2020). In spotted seabass ( Lateolabrax maculatus ), rbm39 was identified as a differentially expressed transcript in salt water versus fresh water (Tian et al, 2019), consistent with the differential exon usage identified in the present study.…”

Capítulo 23: Impactos de la deforestación y el cambio climático sobre la biodiversidad, los procesos ecológicos y la adaptación ambiental

“…The exposure of some species, particularly the Tambaqui (a model species), to climate rooms built to mimic the future scenario forecast by IPCC for the year 2050 revealed many damages and some degree of mortality to fish subjected to warmer temperatures. The whole transcriptome gene expression showed that differentially expressed genes act to readjust or adapt protein expression and respond to changes in their metabolism (Fé-Gonçalves et al 2020). Either they adjust their metabolism or die.…”