<div style="text-align: justify;">Pregnancy-associated plasma protein A, pappalysin1 (PAPPA) and pappalysin2 (PAPPA2) genes were implicated in regulation of hen ovarian follicular development and growth. Four novel single nucleotide polymorphisms (SNPs) were identified using PCR-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing. Among them, A/G transition at position 172864 and T/C mutation at position 172952 in 3&lsquo;-untranslated region (UTR) of PAPPA named SNP A172864G and T172952C, respectively. A/G transition at position 77421 and T/C at position 77455 in 3&lsquo;-UTR of PAPPA2 gene named as SNP A77421G and T77455C, respectively. For SNP A172864G and T172952C (PAPPA), 360 Dagu hens were classified as AA, AB and BB genotypes based on PCR-SSCP patterns, and BB genotype correlated significantly (P&lt;0.05) with higher hen-housed egg production (HHEP) at 30 and 57 weeks (wks) of age and higher egg weight (EW) at 43 wks of age. Consequently, these SNPs identified will be potential genetic markers to improve egg productivity in chicken breeding.</div>

<div style="text-align:justify">New polymorphisms of <em>PAPPA</em> and <em>PAPPA2 </em>genes and their associations with egg production traits in Chinese Dagu chickens</div>

New polymorphisms of PAPPA and PAPPA2 genes and their associations with egg production traits in Chinese Dagu chickens