This study aimed to investigate the function of the constitutively activating mutation D540G on eel FSHR activity by in vitro functional studies. Site-directed mutagenesis was carried out to generate the D-to-G mutation at position 540 of the pcDNA3-eel FSHR construct. Vectors expressing either wild type or mutant receptor were transfected into Chinese hamster ovary (CHO-K1) cells. The functional characteristics of both the wild type and mutant receptors were analyzed by a cAMP assay. cAMP accumulation was highly increased in cells transfected with the D540G mutant receptor in a dose-dependent manner. Of note, basal cAMP levels were remarkably increased (~13.1-fold) with expression of this mutant when compared to wild type receptor. These findings suggest that the D540G mutation in the eel FSHR may contribute to ovulation during eel sex maturation as well as play a pivotal role in inducing FSHR activity.

ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONFLICTS OF INTEREST
ACKNOWLEDGEMENTS
AUTHOR'S AFFILIATION, POSITION ANDORCID NO.
REFERENCES

• Jeong-Soo Kim(Animal Biotechnology, Graduate School of Future Convergence Technology, Hankyong National University, Anseong 17579, Korea)
• Munkhzaya Byambaragchaa(Animal Biotechnology, Graduate School of Future Convergence Technology, Hankyong National University, Anseong 17579, Korea)
• Kwan-Sik Min(Animal Biotechnology, Graduate School of Future Convergence Technology, Hankyong National University, Anseong 17579, Korea, Department of Animal Life Science, Institute of Genetic Engineering, Hankyong National University, Anseong 17579, Korea) Corresponding author