Figure 1.

(A) Intron 20 of O-linked N-acetylglucosamine transferase (OGT) from European and Chinese pig breeds. Fragments containing intron 20 of OGT were compared by amplifying the region containing a part of exon 20, intron 20, and a part of exon 21 of OGT. All of polymerase chain reaction amplicons from Minzu (MI)×White composite (WC), Meishan (ME) ×WC, and Fengzing (FE)×WC sows had both 825-bp and 544-bp bands, while those from Duroc (DU)×WC sows and a WC boar had only the 825-bp band. (B) Schematic diagram of intron 20 of OGT in Chinese and European pigs. The intron 20 of Chinese pigs including MI, ME, and FE was 233 bp, while that of European pigs including WC, DU, Landrace (L), and Yorkshire (Y) was 514 bp, resulting in the 281-bp difference. The longer 514-bp intron 20 of OGT from European pigs contained an inserted 276-bp element (·····) near the beginning of the intron and GACTT (--) insertion at nucleotides 401–405 of the 514 bp intron 20. The 276-bp element (chrX:64993408–64993683) of the European pigs is located after the first 14-bp TGCTTGTTCTTTTT (chrX:64993394–64993407) sequence and the 3′-end of the element ends with the second 14-bp TGCTTGTTCTTTTT (chrX:64993670–64993683) sequence, shown as blue narrow rectangles and the Chinese pigs have only one such sequence. Black rectangle indicates the 33-bp (TTG)₇ simple repeat (chrX:64993397–64993429) and it included the 4 to 14 bp of the 14-bp TGCTTGTTCTTTTT sequence and the (TTG)₇ repeat sequence. The 240-bp SINE element (chrX:64993430–64993669), following the 33-bp (TTG)₇ simple repeat, is shown by the white rectangle. The rs323323004 at chromosome position 64993390 on intron 20 is shown with *. The version of the swine genome assembly used to obtain sequence position information was the Swine Genome Sequencing Consortium Sscrofa10.2.