Fig. 2

Characterization of five Acipenser baerii gonad-derived cell lines. a Morphologies of each cell line were observed at early and late passages. Early and late passages indicate the cells at passages 15 to 16 and passages 54 to 55, respectively. Two cell types were observed in culture: wide-spread cells that occupy a wide surface area and small polygonal cells that grow densely. A different ratio of two cell types in culture was observed depending on cell lines and passage number. Scale bar = 100 μm. b Flow cytometry was performed to analyze DNA contents of the cell lines at the late passage. A diploid A. baerii heart-derived cell line was used as a control (red lines). All cell lines maintained normal diploid state in spite of long-term culture. c RT-PCR analysis was performed to identify the expression of several genes including ar, cyp17a1, lh, sox9, and star in the cell lines at both early and late passages. All cell lines regardless of passage number expressed ar, lh, and sox9 but not expressed cyp17a1. Expression of star gene was very weak or not detected depending on cell lines. E, early passage; L, late passage