Genome-wide analysis clarifies the population genetic structure of wild gilthead sea bream (Sparus aurata)

Gilthead sea bream is an important target for both recreational and commercial fishing in Europe, where it is also one of the most important cultured fish. Its distribution ranges from the Mediterranean to the African and European coasts of the North-East Atlantic. Until now, the population genetic structure of this species in the wild has largely been studied using microsatellite DNA markers, with minimal genetic differentiation being detected. In this geographically widespread study, 958 wild gilthead sea bream from 23 locations within the Mediterranean Sea and Atlantic Ocean were genotyped at 1159 genome-wide SNP markers by RAD sequencing. Outlier analyses identified 18 loci potentially under selection. Neutral marker analyses identified weak subdivision into three genetic clusters: Atlantic, West, and East Mediterranean. The latter group could be further subdivided into an Ionian/Adriatic and an Aegean group using the outlier markers alone. Seascape analysis suggested that this differentiation was mainly due to difference in salinity, this being also supported by preliminary genomic functional analysis. These results are of fundamental importance for the development of proper management of this species in the wild and are a first step toward the study of the potential genetic impact of the sea bream aquaculture industry.

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Genome-wide analysis clarifies the population genetic structure of wild Gilthead Sea Bream (Sparus aurata)

10.1101/2020.07.06.189241 ◽

2020 ◽

Author(s):

Francesco Maroso ◽

Konstantinos Gkagkavouzis ◽

Sabina De Innocentiis ◽

Jasmien Hillen ◽

Fernanda do Prado ◽

...

Keyword(s):

Genetic Structure ◽

Sparus Aurata ◽

Snp Markers ◽

Gilthead Sea Bream ◽

Sea Bream ◽

Commercial Fishing ◽

North East ◽

The North ◽

In The Wild ◽

The Mediterranean

AbstractGilthead sea bream is an important target for both recreational and commercial fishing in Europe, where it is also one of the most important cultured fish. Its distribution range goes from the Mediterranean to the African and European coasts of the North-East Atlantic. So far, the genetic structure of this species in the wild has been studied with microsatellite DNA, but the pattern of differentiation could not be fully clarified. In this study, almost 1000 wild sea bream from 23 locations in the Mediterranean Sea and Atlantic ocean where genotyped at 1159 SNP markers, of which 18 potentially under selection. Neutral markers suggested the presence of a weak subdivision into three genetic clusters: Atlantic, West and East Mediterranean. This last group could be further subdivided into an Ionian/Adriatic and an Aegean group using outlier markers. Seascape analysis suggested that this differentiation was mainly due to difference in salinity, and this was also supported by preliminary genomic functional analysis. These results are of fundamental importance for the development of proper management of this species in the wild and are a first step toward the study of the potential genetic impact of the sea bream aquaculture industry.

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Low levels of population genetic structure in the gilthead sea bream, Sparus aurata, along the coast of Italy

ICES Journal of Marine Science ◽

10.1093/icesjms/fsr175 ◽

2011 ◽

Vol 69 (1) ◽

pp. 41-50 ◽

Cited By ~ 18

Author(s):

Paolo Franchini ◽

Luciana Sola ◽

Donatella Crosetti ◽

Valentina Milana ◽

Anna Rita Rossi

Keyword(s):

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

Sparus Aurata ◽

Isolation By Distance ◽

Gilthead Sea Bream ◽

Sea Bream ◽

Population Subdivision ◽

Distributional Pattern ◽

Low Levels

Abstract Franchini, P., Sola, L., Crosetti, D., Milana, V., and Rossi, A. R. 2012. Low levels of population genetic structure in the gilthead sea bream, Sparus aurata, along the coast of Italy. – ICES Journal of Marine Science, 69: 41–50. The gilthead sea bream, Sparus aurata, is a coastal, commercially important fish. Contrasting results concerning the genetic structure of the species at different geographic scales have been reported. Here, an investigation is made into the population genetic structure of S. aurata along the coast of Italy, using samples analysed previously and material from new sampling sites (12) and using different microsatellite loci (10). One sample from the eastern Atlantic and three temporal replicates from one site were also included. The presence of a weak (overall FST = 0.0072), but significant, genetic population subdivision was detected by F-statistics. Temporal replicates indicate genetic data consistency over time. Isolation by distance between the Atlantic and the coast of Italy is suggested by a Mantel test. The distributional pattern of genetic variance obtained by analysis of molecular variation reflects the geographic sampling areas, but is only partially congruent with the results obtained with fewer sites and loci. The dispersal of passive eggs/larvae by the main currents appears to contribute to shaping the gene flow. Given the intensity of sea bream aquaculture activities in Italy, the possibility that aquaculture may have partially contributed to the population genetic pattern detected cannot be excluded.

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