title: Association of prolactin haplotypes with reproductive traits in Tsaiya ducks.
abstract: A previous cDNA microarray study showed that the prolactin (PRL) gene may be involved in the duck ovarian follicle development and egg formation process. The purpose of this study was to investigate the relationship between PRL genotypes of single nucleotide polymorphism (SNP) and reproductive traits of Tsaiya ducks. Primer pairs for the coding regions in the PRL were designed based on the duck genomic sequence database. Polymorphisms were detected by polymerase chain reaction (PCR)-single strand polymorphism (SSCP) and were verified by DNA sequencing. Six novel SNPs (T233C, T295C, G309T, C381A, G3941T and A3975C) were identified in the 1972 bp region of duck PRL gene, and all of them were located in non-coding regions. Single SNP-trait association analysis showed that each SNP was associated with at least one duck reproductive trait (P<0.05). Haplotype combinations constructed on these SNPs were associated with egg weight at 40 weeks of age (EW40), fertility rate (FR) and maximum duration of fertility (MDF) (P<0.0001). In particular, diplotype H1H2 had positive effect on EW40, whereas it had negative effect on FR and MDF (P<0.05). Positive effects of the diplotype H1H5 were observed for FR and MDF, but a negative effect was observed for EW40 (P<0.05). This suggested that the PRL gene plays an important role in the regulation of egg weight and fertility-related traits and could be a potential marker in a marker assisted selection program during duck balancing selection. Further investigations on more duck populations with large sample sizes are needed to confirm this finding.
authors.affiliation: Department of Animal Science, National Chung Hsing University, Taichung, Taiwan. kind7222@yahoo.com.tw
authors.forename: Mu-Tzu
authors.initials: MT
authors.lastname: Chang
authors.forename: Yu-Shin
authors.initials: YS
authors.lastname: Cheng
authors.forename: Mu-Chiou
authors.initials: MC
authors.lastname: Huang
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004372:Ducks / Q000097:blood / Q000235:genetics / Q000502:physiology*; D004531:Eggs; D005260:Female; D005298:Fertility / Q000235:genetics / Q000502:physiology*; D006239:Haplotypes / Q000235:genetics / Q000502:physiology; D016018:Least-Squares Analysis; D016133:Polymerase Chain Reaction / Q000662:veterinary; D020641:Polymorphism, Single Nucleotide; D011388:Prolactin / Q000235:genetics / Q000502:physiology*; D019655:Quantitative Trait, Heritable; D017422:Sequence Analysis, DNA / Q000662:veterinary
chemical_list: D011388:Prolactin; D004247:DNA