Development of a brain cell line from swordtail fish, Xiphophorus helleri, and the inducible expression for cytochrome P450 1A

Swordtail fish, Xiphophorus helleri, is an ideal experimental animal for Ecological toxicology studies, which is sensitive to environmental contaminants. The construction of related cell lines can provide foundation for its application. The aim of this study were to establish the swordtail fish brain cell line SFB (swordtail fish brain cell line) and to study its CYP1A mRNA inductive effect. Primary brain cell culture of Swordtail fish was initiated by trypsin digestion methods, and a stable brain cell line was obtained successfully after culture and proliferation. The optimal culture medium for SFB was Leibovitz-15 to blend DMEM/F12 medium with 1:1 supplemented with 15% fetal bovine serum, and the optimal culture conditions for SFB were 27℃ and 5% CO2. The SFB grew actively under the optimal medium and culture conditions, the doubling time is 43. 048 hours at 65th passage . And chromosome analysis showed that the SFB exhibited chromosomal a diploidy with a modal chromosome number of 48, the karyotype formula was 2n=2st 46t, NF=48, which consistent with the swordtail fish.The cells maintained their original shape and high viability after cryopreserved and resuscitated. The induction experimental results showed that, the expression of CYP1A mRNA in B(a)P-treated (10-8~10-5mol/L) SFB cells increased significantly, and increased along with the increasing dosage of B(a)P. A dose-dependent relationship between the levels of CYP1A mRNA expression and doses of B(a)P was observed. Thus, the establishment of this cell line will provide convenience for the toxicological evaluation and a basis for its application in Ecological toxicology.