SEQUENCE CHARACTERIZATION OF INSULIN-LIKE GROWTH FACTOR II (IGF2) PROMOTER 2 IN PHILIPPINE NATIVE PIGS (Sus scrofa Lin.)

Abstract

Insulin-like Growth Factor 2 (IGF2) is known to be one of the critical drivers of animal growth. Part of the IGF2 was sequenced to determine if there are DNA variants that differ between the two largest and two smallest Philippine native pig breeds. Samples (n=30) were taken from native pigs reared in Institutional herds from Quezon, Marinduque, Kalinga, and Eastern Samar.  The promoter 2 (P2) region was amplified via PCR and sent for sequencing. Seven distinct single-nucleotide polymorphisms were detected. Allelic and genotypic frequencies were computed per genetic and body size groupings. Using Fisher’s Exact Test of Independence, the proportion of alleles in SNP g.652 C>G was seen to be significantly different among the four Philippine native pig genetic groups (p-value = 0.0134), and between large and small-sized pig groups (p-value = 0.0168). P2 sequence motif characterization was performed using JASPAR, revealing fourteen (14) transcription factor (TF) binding sites which interact with seven (7) distinct TFs found in pigs, suggesting that base mutations within the proximity of these TF binding sites may influence P2-mediated IGF2 expression in Philippine native pigs.