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| Author(s): |
Raquel Belini Ariede
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Jaboticabal. 2022-03-04. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal |
| Defense date: | 2021-12-20 |
| Advisor: | Diogo Teruo Hashimoto |
| Abstract | |
Tambaqui (Colossoma macropomum) is the most important neotropical fish in freshwater aquaculture in South America. Disease outbreaks caused by the bacteria Aeromonas hydrophila result in significant losses for tambaqui production. Furthermore, the increase in production of this species in aquaculture is limited by the lack of genetic improvement programs, especially for disease resistance traits and fillet yield. The objective of this study was to characterize the performance of tambaqui C. macropomum families for resistance to Aeromonas hydrophila and fillet growth/yield traits, through quantitative genetics and genomic association of SNPs (single nucleotide polymorphisms). First, the results of genetic parameters for resistance to A. hydrophila and the genetic correlation with daily weight gain in tambaqui juveniles demonstrated that it is possible to include these traits in selective breeding programs. Then, to proceed with genomic analyses, a dense SNP array for tambaqui was developed, with the characterization of 30,000 candidate SNPs for the Axiom/ThermoFischer genotyping platform (30K SerraSNP array). After this, the genetic architecture of resistance to A. hydrophila in tambaqui was investigated by a genome-wide association study (GWAS) to identify quantitative trait loci (QTLs) and putative genes associated with this trait in tambaqui. A dense linkage map was developed for tambaqui using genotype data; resulting in 17,374 SNPs distributed in 27 linkage groups. GWAS analysis identified several candidate QTLs associated with A. hydrophila resistance, distributed into six linkage groups. Several candidate genes related to the immune response were located close to the putative QTLs. Regarding growth/yield traits, quantitative genetic analysis revealed moderatehigh heritability, which demonstrates that they are under moderate genetic control and must respond to genetic selection. A deep learning approach and computer vision system (CVS) was also validated to obtain the morphometric measurements of tambaqui on a large scale and in an automated way. GWAS analyzes for these traits confirmed that they are under polygenic control, with the identification of only a few QTLs with statistical significance. In conclusion, both traits evaluated in this study, resistance to A. hydrophila and growth and body yield traits, demonstrate to be under genetic control and influenced by several genomic regions, and can be included in improvement programs for tambaqui. (AU) | |
| FAPESP's process: | 17/19717-3 - Genome analysis for SNPs association with resistance to Aeromonas hydrophila and fillet yield in tambaqui (Colossoma macropomum) |
| Grantee: | Raquel Belini Ariede |
| Support Opportunities: | Scholarships in Brazil - Doctorate |