Seleção de marcadores moleculares em associação a características de interesse produtivo no tambaqui (Colossoma macropomum)
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Data
2017-02-23
Autores
Ariede, Raquel Belini [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O Tambaqui (Colossoma macropomum), natural das bacias do rio Amazonas e do rio Orinoco, possui características favoráveis ao sistema de cultivo e boa aceitação de mercado. Contudo, há poucos estudos genéticos realizados com esta espécie, especialmente de melhoramento genético. Para a construção de um mapa genético desta espécie, é necessário o desenvolvimento de um elevado número de marcadores moleculares. Desta forma, este estudo teve como objetivo caracterizar microssatélites gene-associados e neutros (não gênicos), obtidos por Next Generation Sequencing (RNA-seq e Whole Genome Shotgun - WGS, respectivamente), para serem disponibilizados em estudos de associação com QTLs (Quantitative Trait Loci) e construção de um mapa genético. De modo geral, a avaliação de 200 marcadores (100 de cada conjunto) resultou em 45 loci polimórficos. Do conjunto de marcadores RNA-seq, as heterozigosidades observada e esperada (HO e HE) variaram de 0,09 a 0,73, e 0,09 a 0,85, respectivamente. Do conjunto WGS, HO e HE variaram de 0,33 a 0,95, e 0,28 a 0,92, respectivamente. Posteriormente, alguns microssatélites foram testados em três famílias de C. macropomum para buscar associações com características de resistência à bactéria e crescimento. Para o estudo de resistência, três famílias (n = 120), foram submetidas ao desafio bacteriano com Aeromonas hydrophila. Os dados do desafio apresentaram diferenças significativas nos tempos de morte e taxa de mortalidade entre as famílias. O crescimento foi avaliado por medidas morfométricas e peso, sendo que todas as características estavam correlacionadas significativamente (p < 0,01). Análises de associação microssatélite/fenótipo sugeriram que o marcador gene-associado c3842 (tncrc6b) está associado ao comprimento padrão (CP) e um marcador neutro (r912) com a altura 2 (A2). O presente estudo possibilitou prospectar marcadores moleculares associados com crescimento que poderão ser utilizados na validação de seleção assistida por marcadores em famílias de tambaqui. Em conclusão, estes dados servirão como subsídios biotecnológicos para acelerar o melhoramento genético do tambaqui, que é a principal espécie nativa produzida na América do Sul.
Tambaqui (Colossoma macropomum), is a fish species of the Amazon and Orinoco rivers, with favorable traits to the production system and market acceptance. However, there are few genetic studies with this species, especially genetic improvement. For the construction of a genetic map of this species, the development of a high number of molecular markers is necessary. Thus, this study aimed to characterize gene-associated and neutral (non-gene) microsatellites obtained by Next Generation Sequencing (RNA-seq and Whole Genome Shotgun - WGS, respectively), to be available in association studies with Quantitative Trait Loci (QTLs) and construction of a genetic map. Overall, the evaluation of 200 markers (100 of each set) resulted in 45 polymorphic loci. In the RNA-seq data, the observed and expected heterozygosity (Ho and He) ranged from 0.09 to 0.73, and 0.09 to 0.85, respectively. In the WGS data, Ho and He ranged from 0.33 to 0.95, and 0.28 to 0.92, respectively. Subsequently, some microsatellites were tested in three families of C. macropomum to seek associations with bacterial resistance and growth characteristics. For the resistance study, three families (n = 120) were submitted to the bacterial challenge with Aeromonas hydrophila. The challenge data presented significant differences in time of death and mortality rate among the families. Growth was evaluated by morphometric measures and weight, and all the characteristics were significantly correlated (p < 0.01). Microsatellite/phenotype association analyzes have suggested that the gene-associated marker (tncrc6b) is associated with the standard length (CP) and a neutral marker (r912) with height 2 (A2). The present study made it possible to prospect for molecular markers associated with growth that could be used in the validation of marker - assisted selection in tambaqui families. In conclusion, these data will serve as biotechnology subsidies to accelerate the genetic improvement of tambaqui, which is the main native species produced in South America.
Tambaqui (Colossoma macropomum), is a fish species of the Amazon and Orinoco rivers, with favorable traits to the production system and market acceptance. However, there are few genetic studies with this species, especially genetic improvement. For the construction of a genetic map of this species, the development of a high number of molecular markers is necessary. Thus, this study aimed to characterize gene-associated and neutral (non-gene) microsatellites obtained by Next Generation Sequencing (RNA-seq and Whole Genome Shotgun - WGS, respectively), to be available in association studies with Quantitative Trait Loci (QTLs) and construction of a genetic map. Overall, the evaluation of 200 markers (100 of each set) resulted in 45 polymorphic loci. In the RNA-seq data, the observed and expected heterozygosity (Ho and He) ranged from 0.09 to 0.73, and 0.09 to 0.85, respectively. In the WGS data, Ho and He ranged from 0.33 to 0.95, and 0.28 to 0.92, respectively. Subsequently, some microsatellites were tested in three families of C. macropomum to seek associations with bacterial resistance and growth characteristics. For the resistance study, three families (n = 120) were submitted to the bacterial challenge with Aeromonas hydrophila. The challenge data presented significant differences in time of death and mortality rate among the families. Growth was evaluated by morphometric measures and weight, and all the characteristics were significantly correlated (p < 0.01). Microsatellite/phenotype association analyzes have suggested that the gene-associated marker (tncrc6b) is associated with the standard length (CP) and a neutral marker (r912) with height 2 (A2). The present study made it possible to prospect for molecular markers associated with growth that could be used in the validation of marker - assisted selection in tambaqui families. In conclusion, these data will serve as biotechnology subsidies to accelerate the genetic improvement of tambaqui, which is the main native species produced in South America.
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Palavras-chave
NGS, Tambaqui, Desafio bacteriano, Microssatélites gene-associados