The SA defect is caused by an insertion within exon 27 of Tex14. A. A genomic insertion of 51 bp originating from Tex14 intron 27 (grey bar) has been duplicated into exon 27. This duplication carries an additional splicing site (AG) 18 bp from the duplication start site. In the mRNA of SA affected testis the Tex14 exon 27 has been replaced by 33 nt of the direct duplication and 30 nt of the 3' end of the exon 27. Thus, the 67 bp of the 5' end of the exon 27 is absent in the Tex14 mRNA of SA affected boars. The aberrant splicing in the mRNA creates a premature translation stop codon (TAG) in the exon 28. B. The genomic insertion of 51 bp can be detected on an agarose gel with PCR primers adjacent to the insertion. C. Tex14 expression (exons 17-19) is markedly lower in the SA affected testis compare to control boars. The expression difference was quantified with qPCR (P < 0.001) and is presented as percentage of the control testis expression. SOD1 gene was used as a loading control. D. TEX14 protein expression in the SA affected and control testis was evaluated by western blotting. TEX14 appeared to be absent in the SA affected testis. α-tubulin was used as a loading control.