Genetic variants and effects on milk traits of the caprine paired-like homeodomain transcription factor 2 (PITX2) gene in dairy goats.
The paired-like homeodomain transcription factor 2 (PITX2) gene plays a critical role in cell proliferation, differentiation, hematopoiesis and organogenesis. This gene regulates several genes' expressions in the Wnt/beta-catenin and POU1F1 pathways, thereby probably affecting milk performance. The goal of this study was to characterize the genetic variants of the PITX2 gene and test their associations with milk traits in dairy goats. Herein, four novel single nucleotide polymorphisms (SNPs), AC_000163:g.18117T>C, g.18161C>G, g.18322C>A and g.18353T>C, within the caprine PITX2 gene, were found in two famous Chinese dairy goat breeds. These SNPs mapping at Cys28Arg, Pro42Pro, IVS1+79C>A and IVS1+110T>C, were genotyped by the MvaI, SmaI, MspI and RsaI aCRS-RFLP or PCR-RFLP methods, respectively. Accordingly, two main haplotypes (CGCT and CGCC) were identified among the specimens. Association testing revealed that the SmaI and RsaI polymorphisms were significantly associated with the milk fat content, milk lactose content and milk density (P<0.05 or P<0.01) in the Guanzhong (GZ) dairy goats, respectively. At the same time, the RsaI locus was also found to significantly link to the second lactation milk yield, milk fat content, milk lactose content, milk density and milk total solid content (P<0.05 or P<0.01) in the Xinong Saanen (XNSN) dairy goats, respectively. These results indicated that the caprine PITX2 gene had the significant effects on milk traits. Hence, the RsaI and SmaI loci could be regarded as two DNA markers for selecting superior milk performance in dairy goats. These preliminary findings not only would extend the spectrum of genetic variation of the goat PITX2 gene, but also would contribute to implementing marker-assisted selection (MAS) in breeding and genetics in dairy goats.
College of Animal Science and Technology, Northwest A&F University, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Yangling, Shaanxi 712100, PR China. Electronic address: haiyuzhao616@gmail.com.
Haiyu
H
Zhao
Xianfeng
X
Wu
Hanfang
H
Cai
Chuanying
C
Pan
Chuzhao
C
Lei
Hong
H
Chen
Xianyong
X
Lan
D000818:Animals; D001483:Base Sequence; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D006041:Goats / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D007774:Lactation / Q000235:genetics; D019344:Lactic Acid / Q000378:metabolism; D015810:Linkage Disequilibrium; D050356:Lipid Metabolism; D008892:Milk / Q000378:metabolism*; D020125:Mutation, Missense; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics*
D018398:Homeodomain Proteins; D014157:Transcription Factors; D019344:Lactic Acid
3′ UTR; 5′ UTR; Association; CPHD; Dairy goat; GH; GLM; HWE; Hardy–Weinberg equilibrium; He; LD; LHX3; LHX4; LIM homeobox 3 gene; LIM homeobox 4 gene; LSM; MAS; MTDEREML; Milk trait; Ne; PCR; PIC; PITX; PITX1; PITX2; PRL; PROP1; Paired-like homeodomain transcription factor 2 (PITX2) gene; Pit-1 (POU1F1); RFLP; SNP; Single nucleotide polymorphism (SNP); TSH; TSH-beta; WNT; a.m.; aCRS–RFLP; aa; amino-acid; amplification created restriction site–restriction fragment length polymorphism; ante meridiem; base pair; bp; combined pituitary hormone deficiency; effective allele numbers; five prime untranslated region; gene heterozygosity; general linear model; growth hormone; least squares means; linkage disequilibrium; marker-assisted selection; multiple trait derivative-free restricted maximum likelihood; nt; nucleotide; p.m.; paired-like homeodomain transcription factor; paired-like homeodomain transcription factor 1; paired-like homeodomain transcription factor 2; pituitary specific transcription factor 1; polymerase chain reaction; polymorphism information content; post meridiem; prolactin; prophet of Pit-1; restriction fragment length polymorphism; single nucleotide polymorphism; three prime untranslated region; thyroid stimulating hormone beta; thyrotropic-stimulating hormone; wingless-type MMTV integration site family