Genetic parameters for resistance to Aeromonas hydrophila in the Neotropical fish pacu (Piaractus mesopotamicus)

Mastrochirico-Filho, Vito A.; Ariede, Raquel B.; Freitas, Milena V.; Lira, Lieschen V.G.; Agudelo, John F.G.; Pilarski, Fabiana; Neto, Rafael Vilhena Reis; Yáñez, José M.; Hashimoto, Diogo Teruo

doi:10.1016/j.aquaculture.2019.734442

Cited by 16 publications

(26 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results of genetic parameters revealed signi cant genetic variation for A. hydrophila resistance with moderate heritability values (0.20 ± 0.09 for TS and 0.35 ± 0.15 for TD) ( Table 1). The present estimates showed higher levels of genetic variation than previous heritability estimates carried out in a different population of pacu (h 2 = 0.15 for TS and h 2 = 0.12 for TD) [6]. In general, our results were within the range to those previously reported for A. hydrophila resistance in others species, such as Clarias macrocephalus, Megalobrama amblycephala, and Labeo rohita, ranging from 0.12 to 0.39 [32][33][34].…”

Section: Genetic Parameterssupporting

confidence: 72%

“…Bacterial challenge was performed in 2016 at LaGeAC using a strain of A. hydrophila isolated from an outbreak of pacu aeromoniosis in a commercial facility from the São Paulo State, by the Laboratory of Microbiology and Parasitology of Aquatic Organisms, at UNESP, Jaboticabal city (São Paulo State, Brazil). The strain of A. hydrophila was the same of that used by Mastrochirico-Filho et al (2019) [6]. The strain was cultured in Agar Trypticase Soy (ATS), Vegitone (Sigma-Aldrich) for 24 h (28°C).…”

Section: Aeromonas Hydrophila Challengementioning

confidence: 99%

“…The challenge test performed in this study was carried out by intraperitoneal inoculation, according to protocols of Mastrochirico-Filho et al (2019) [6]. The LD 50 (lethal dose in 50 % of individuals) was previously tested in 60 randomly chosen juvenile individuals from the same pacu families using concentrations adjusted by optical density of the solution at 0.400, 0.600 and 0.800 at 625 nm in spectrophotometer (2100 Unico, Japan).…”

Section: Aeromonas Hydrophila Challengementioning

confidence: 99%

“…The incidence of sanitary problems linked to intensi cation of sh production have resulted in large mortalities due to A. hydrophila infection in important cultivated sh species in South America, such as pacu (Piaractus mesopotamicus) [4,5]. Although there is no o cial statistics about losses in pacu farming related to A. hydrophila outbreaks, non-o cial communications of Brazilian farmers have reported that A. hydrophila infection is responsible for total losses ranging between 20 to 30 % of annual production [6].…”

Section: Introductionmentioning

confidence: 99%

“…Experimental challenges for A. hydrophila in pacu families have shown signi cant genetic variation in for resistance against this bacteria when using binary survival status and time of death as trait de nitions, which demonstrate the potential for the genetic improvement of Aeromonas resistance in this species [6]. However, a GWAS to understand the genomic basis of resistance to A. hydrophila has not yet been performed in pacu.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Development of a SNP linkage map and genome-wide association study for resistance to Aeromonas hydrophila in pacu (Piaractus mesopotamicus)

Mastrochirico-Filho

Borges

Freitas

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Background Pacu ( Piaractus mesopotamicus ) is one of the most important neotropical aquaculture species in South America. Disease outbreaks triggered by the bacterium Aeromonas hydrophila have resulted in significant losses to pacu production. Selective breeding using genomic information is a powerful strategy to improve disease resistance in fish species. This study aimed to investigate the genetic architecture of resistance to A. hydrophila in pacu via a Genome-Wide Association Study (GWAS) to identify Quantitative Trait Loci (QTLs) and putative genes associated with this trait in 14 pacu full-sib families. An experimental challenge was performed in order to assess the levels of genetic variation for resistance against the bacteria using the following trait definition: binary test survival (TS) and time of death (TD). Results The analysis of genetic parameters identified moderate heritability values for both resistance traits: h 2 = 0.20 (± 0.09) for TS and h 2 = 0.35 (± 0.15) for TD. To enable the GWAS, a pacu linkage map was developed using genotype data derived from Restriction Site Associated DNA Sequencing (RAD-Seq), resulting in 27 linkage groups consisting of 17,453 Single Nucleotide Polymorphisms (SNPs). The length of linkage groups varied from 79.95 (LG14) to 137.01 (LG1) cM, with a total integrated map length of 2,755.60 cM. GWAS analysis identified 22 putative QTLs associated to A. hydrophila resistance (defined as genomic regions explaining > 1% of the additive genetic variance for the trait), distributed in 17 linkage groups. Several candidate genes related to immune response were located close to the putative QTLs, such as tbk1 , trim16 , Il12rb2 and lyz2 . Conclusion The outputs of this study include the first medium density linkage map for pacu, which can be used as a framework to study different traits relevant to the production of this species. In addition, resistance to A. hydrophila was found to be moderately heritable but with a polygenic architecture suggesting that genomic selection, instead of marker assisted selection, might be tested for efficiently improving resistance to one of the most problematic diseases that affects the South American aquaculture.

show abstract