Ovine PAPPA2 gene coding variants are linked to decreased fecal egg shedding in native Turkish sheep naturally infected with gastrointestinal nematodes

In this study, the association between PAPPA2 coding variants and gastrointestinal (GI) nematode fecal egg count (FEC) score in adult Turkish sheep was investigated. For this purpose, the FEC score was determined in adult sheep from six breeds: Karacabey Merino (n = 137), Kivircik (n = 116), Cine capari (n = 109), Karakacan (n = 102), Imroz (n = 73), and Chios (n = 50). Sheep were classified as shedders or non-shedders within breeds and flocks. The first group was the fecal egg shedders (> 50 per gram of feces), and the second group was the no fecal egg shedders (<= 50 per gram of feces). The exon 1, exon 2, exon 5, exon 7, and a part of 5 ' UTR of the ovine PAPPA2 gene were genotyped by Sanger sequencing of these two groups. Fourteen synonymous and three non-synonymous single-nucleotide polymorphisms (SNPs) were found. The non-synonymous SNPs, D109N, D391H, and L409R variants, are reported for the first time. Two haplotype blocks were constructed on exon 2 and exon 7. The specific haplotype, C(391)G(424)G(449)T(473)C(515)A(542) on the exon 2 that carries the 391H variant, was tested against four other common haplotypes. Our results indicate that C(391)G(424)G(449)T(473)C(515)A(542) haplotype was significantly associated with fecal egg shedding status in adult Turkish sheep (p-value, 0.044).

Automated summary

This study investigated the relationship between PAPPA2 coding variants and gastrointestinal nematode fecal egg count score in adult Turkish sheep. The FEC score was determined in sheep from six different breeds. Fourteen synonymous and three non-synonymous single-nucleotide polymorphisms (SNPs) in the PAPPA2 gene were identified, including three variants that were reported for the first time. A specific haplotype in exon 2 was found to be significantly associated with fecal egg shedding status in adult Turkish sheep.