BackgroundInterferon tau (IFNT), which is secreted into the uterine cavity during the maternal recognition period (MRP), is a key factor for establishment of pregnancy. The present study aims to clarify the relationship between the ability of a bovine conceptus to produce IFNT during the MRP and the conceptus's ability to establish pregnancy.MethodsIn the first experiment, IFNT (0, 500, or 1000 micrograms) was administered into the uterine horn ipsilateral to the CL 16 or 17 d after standing estrus, and mRNA levels of IFN-stimulated gene 15-kDa protein (ISG15) and Mx2 in peripheral blood mononuclear cells (PBMCs) were determined. In the second experiment, we investigated ISG15 mRNA expression in PBMCs during the MRP in cattle after either artificial insemination (AI) or embryo transfer (ET).ResultsIntrauterine administration of IFNT stimulated ISG15 and Mx2 gene expressions in PBMCs in cattle, and there was a positive correlation between the expressions of peripheral markers and the quantity of IFNT administered. In pregnant and normal interestrous interval (< 25 d) cattle (nIEI cattle), expression levels of the ISG15 gene showed similar patterns after AI and ET, and ISG15 mRNA expression was increased in pregnant cattle but unchanged in nIEI cattle. In contrast, ISG15 gene expression in extended interestrous interval (greater than or equal to 25 d) cattle (eIEI cattle) differed after ET compared with AI. In eIEI cattle after ET, ISG15 gene expression increased, such that the value on day 18 was intermediate between those of pregnant and nIEI cattle. In eIEI cattle after AI, ISG15 gene expression did not increase throughout the observation period.ConclusionsThe results of the current study indicate that the quantity of conceptus-derived IFNT can be estimated by measuring ISG15 mRNA levels in PBMCs from cattle. Using this approach, we demonstrate that ISG15 gene expression during the MRP in eIEI cattle differed after ET compared with AI. In addition, the modest increase in ISG15 gene expression in eIEI cattle after ET suggests that late embryo losses were due to delayed or insufficient growth of the conceptus during the MRP in cattle.
Japanese Black fattening steers were used to examine relationships between carcass traits and mitochondria displacement loop (D-loop) variations. The D-loop region of Japanese Black cattle was sequenced and revealed 26 mitochondrial haplotypes defined by 25 polymorphic sites. The haplotypes were classified into five mitochondrial types (type 1 to 5) using the unweighted pair-group method with arithmetic means. Carcass weight, longissimus muscle area (LMA), rib thickness, subcutaneous fat thickness, yield estimate, and beef marbling score (BMS) were compared among five mitochondrial types with BLUP procedures. Significant differences between mitochondria types were detected for LMA and BMS. Difference (P < . 05) was observed between mitochondrial types 2 and 4 for LMA. There was a highly significant difference (P < .01) in BMS between types 2 and 4. Difference (P < .05) was also found between types 1 and 4 on BMS. These results suggest that cytoplasmic genetic effects are important sources of variation for carcass traits in Japanese Black cattle.
BackgroundThe aim of the present study was to compare the power of single nucleotide polymorphism (SNP)-based genome-wide association study (GWAS) and haplotype-based GWAS for quantitative trait loci (QTL) detection, and to detect novel candidate genes affecting economically important traits in a purebred Duroc population comprising seven-generation pedigree. First, we performed a simulation analysis using real genotype data of this population to compare the power (based on the null hypothesis) of the two methods. We then performed GWAS using both methods and real phenotype data comprising 52 traits, which included growth, carcass, and meat quality traits.ResultsIn total, 836 animals were genotyped using the Illumina PorcineSNP60 BeadChip and 14 customized SNPs from regions of known candidate genes related to the traits of interest. The power of SNP-based GWAS was greater than that of haplotype-based GWAS in a simulation analysis. In real data analysis, a larger number of significant regions was obtained by SNP-based GWAS than by haplotype-based GWAS. For SNP-based GWAS, 23 genome-wide significant SNP regions were detected for 17 traits, and 120 genome-wide suggestive SNP regions were detected for 27 traits. For haplotype-based GWAS, 6 genome-wide significant SNP regions were detected for four traits, and 11 genome-wide suggestive SNP regions were detected for eight traits. All genome-wide significant SNP regions detected by haplotype-based GWAS were located in regions also detected by SNP-based GWAS. Four regions detected by SNP-based GWAS were significantly associated with multiple traits: on Sus scrofa chromosome (SSC) 1 at 304 Mb; and on SSC7 at 35–39 Mb, 41–42 Mb, and 103 Mb. The vertnin gene (VRTN) in particular, was located on SSC7 at 103 Mb and was significantly associated with vertebrae number and carcass lengths. Mapped QTL regions contain some candidate genes involved in skeletal formation (FUBP3; far upstream element binding protein 3) and fat deposition (METTL3; methyltransferase like 3).ConclusionOur results show that a multigenerational pig population is useful for detecting QTL, which are typically segregated in a purebred population. In addition, a novel significant region could be detected by SNP-based GWAS as opposed to haplotype-based GWAS.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-016-0368-3) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.