Abstract:

In the present study, the specific primers were designed for the screening of the fatty acid desaturase gene
in Isochrysis galbana 3011 under low-temperature induction and for the determination of fatty acid desaturase by real
time-qPCR. Results showed that of 14 primers designed using prime5, 7 provided specific amplification. Based on
amplification efficiency, the largest relative expression amounts of Des4, Des5, Des6, Des8, Des9 and Des12 were 7.71,
11.33, 42.58, 22.02, 73.91 and 16.01, respectively, all of which dropped after an initial rise with decreasing temperature.
Statistical analysis performed using SPSS19.0 software indicated that there was highly significant difference between the
relative expression amounts of 6 genes at 18 ℃ and those obtained at three other temperatures 12, 15, 21 ℃ (P < 0.01). The
induction at 18 ℃ for 24 h could effectively increase the expression of Des9 in Isochrysis galbana 3011. This study has
demonstrated a feasible method to manipulate the content of polyunsaturated fatty acids in microalgae.

Key words: low temperature, fatty acids desaturase, Isochrysis galbana 3011, real time fluorescence quantitative polymerase chain reaction(real time-qPCR), gene expression