A Whole Genome Radiation Hybrid Panel and The Framework Physical Map of Yellowtail (Seriola quinqueradiata)

Yellowtail (Seriola quinqueradiata) is one of the most important fisheries and aquaculture fish in Japan. However, its rearing depends on the capture of wild seeds, because artificial reproduction on a commercial basis is not fully developed yet. And, it is needed to develop the breeding of yellowtail having economically important traits using genomic information. In this study, we constructed a framework physical map of the yellowtail genome using radiation hybrid panel. Cultured yellowtail cells derived from the fin were transfected plasmids containing geneticin-resistant gene. These cultured cells were irradiated by 30, 40, 50, 60, 80, and 100 Gy X-ray exposure, and fused with mouse melanoma cells. We obtained 421 fused cells having yellowtail chromosome fragments survived in medium containing geneticin. Approximately 100 microsatellite markers used in yellowtail linkage map were genotyped using the 421 fused cells. This result of retention of markers in each cell led to the selection of 93 fused cells as a radiation hybrid (RH) panel. To genotype the markers using RH panel, we tried to use Dynamic Array (Fluidigm) for an expression assay platform allowing 9,216 real-time PCR reactions (96 primers × 96 samples) to be performed on a single chip. Now, EST (expressed sequence tag) and SNPs (single nucleotide polymorphisms) are being mapped using Dynamic Array. This work was supported by the Program for Promotion of Basic and Applied Research for Innovation in Bio-oriented Industry (BRAIN).