A frameshift mutation in SLC2A2 induces cryptic splice sites. Schematic representation of exon-intron boundaries of bovine SLC2A2
(A). RT-PCR primers (P1, P2) were designed to hybridize to exons 6 and 8 (E6, E8). The green arrow indicates the position of rs379675307 at the beginning of exon 7 (E7). Examination of SLC2A2 mRNA with RT-PCR (B). A 370 bp product was amplified in a liver sample of a homozygous wild type (wt/wt) animal. In liver and kidney samples of the mutant homozygous animal (mt/mt), two RT-PCR products of 370 bp (red asterisk) and 400 bp (yellow asterisk) were observed. The 370 bp RT-PCR fragment corresponds to the c.771_778delTTGAAAAGinsCATC (mt1) variant (C). The 400 bp RT-PCR fragment represents three aberrant nucleotide sequences at the 5′-end of exon 7 with 412 bp (mt2) and 405 bp (mt3, mt4). The red vertical line delineates the last nucleotide of exon 6, blue letters indicate concordant nucleotides and underscores the c.771_778delTTGAAAAGinsCATC variant in four aberrant sequences. Wild type (wt) and mutant (mt1 – mt4) sequence of bovine GLUT2 (D). Blue letters indicate concordant amino acids, red color highlights the premature termination codons in mt1, mt3 and mt4.