Molecular characterization and expression profiling of FOXL2 gene in goose (Anser cygnoides)

Forkhead box L2 (FOXL2) is a forkhead transcription factor essential for proper reproductive function in females and plays a crucial role in ovarian development in many species of vertebrates. However, little research on goose FOXL2 gene has been conducted. In this study, the cDNA and genomic DNA sequences of goose FOXL2 gene were cloned and characterized. The goose FOXL2 is a single exon gene and contains one open reading frame of 918 bp encoding a protein of 305 amino acids. Bioinformatics analysis displays that the deduced FOXL2 amino acid sequence contains the highly conserved forkhead box domain, which shares greatest similarity to avian species, especially to that of ducks and chicken. RT-qPCR analysis indicates that the FOXL2 mRNA is widely expressed in all examined tissues of fertilized female eggs (28 days), and differentially expressed in female adult (70 days) and laying Zhedong White geese (270 days). Meanwhile, FOXL2 is highly expressed in the hypothalamic-pituitary-ovarian axis, especially in the ovary tissues of the adult and laying geese. Furthermore, one microsatellite (TGTC1415-1418----) and five single nucleotide polymorphisms (A1290G, G1495A, T1554C, T1692A, C1695G and T1697G) were identified in the 3'-untranslated regions. All the information derived from this study could be valuable and facilitate further researches on the function of FOXL2 gene in geese.