SNPs of bovine HGF gene and their association with growth traits in Nanyang cattle

Molecular Genetic Characteristics of the Hoxc13 Gene and Association Analysis of Wool Traits

Homobox C13 (Hoxc13) is an important transcription factor in hair follicle cycle development, and its deletion had been found in a variety of animals leading to abnormal hair growth and disruption of the hair follicle system. In this study, we used immunofluorescence, immunohistochemistry, real-time fluorescence quantitative PCR (RT-qPCR), and Kompetitive Allele-Specific PCR (KASP) genotyping to investigate molecular genetic characteristics of the Hoxc13 gene in Gansu alpine fine-wool sheep. The results revealed that Hoxc13 was significantly expressed during both the anagen and catagen phases (p < 0.05). It was found to be highly expressed predominantly in the dermal papillae and the inner and outer root sheaths, showing a distinct spatiotemporal expression pattern. Two single nucleotide polymorphisms (SNPs) in the exon 1 of Hoxc13, both the individual locus genotypes and the combined haplotypes were found to be correlated with wool length (p < 0.05). It was determined the mutations led to changes in mRNA expression, in which higher expression of this gene was related with longer wool length. In summary, this unique spatiotemporal expression pattern of the Hoxc13 gene may regulate the wool length of Gansu alpine fine-wool sheep, which can be used as a molecular genetic marker for wool traits and thus improve the breed.

Insertion/deletions within the bovine FoxO1 gene and their association analysis with growth traits in three Chinese cattle breeds

FOXO1 (FKHR) gene, as a transcription factor, plays a vital role in animal growth and development, participating in many biological processes. The aim of this study was to ascertain Insertion/deletions (Indels) polymorphism within bovine FoxO1 gene in 679 Chinese adult cows and associate them with stature traits. Two Indels (named as Indel-3 and Indel-4, recorded as rs383545622 and rs525318770 in NCBI, respectively) were successfully genotyped by the Once PCR method, which was reliable, rapid and cost effective for simultaneous detection of two or more Indels. Indel-3 and Indel-4 were located at the second intron. All four different haplotypes (H1: D3D4, H2: I3D4, H3: D3I4, H4: I3I4) could be identified, and the D (del-) allele, DD (del-/del-) genotype and D3D4 haplotype retained the highest frequency. However, individuals with DI (D3I3, D4I4 or H1H4/H2H3 genotype) showed significantly better phenotypic traits than those with the other genotypes in Nanyang cattle, showing a hybrid vigor. The results implied that this DI genotype can be applied to early selective breeding to improve the productivity of Nanyang cattle. Our results suggested that these two Indels within the bovine FoxO1 gene might be used as genetic markers for marker-assisted selection (MAS) in cattle breeding and genetics.

Genome-wide association study for growth traits in Blanco Orejinegro and Romosinuano cattle

Growth traits are economically important characteristics for the genetic improvement of local cattle breeds. Genome-wide association studies (GWAS) provide valuable information to enhance the understanding on the genetics of complex traits. The aim of this study was to perform a GWAS to identify genomic regions and genes associated to birth weight, weaning weight adjusted for 240 days, 16 months, and 24 months weight in Romosinuano (ROMO) and Blanco Orejinegro (BON) cattle. A single-step genomic-BLUP was implemented using 596 BON and 569 ROMO individuals that were genotyped with an Illumina BovineSNP50 BeadChip. There were 25 regions of interest identified on different chromosomes, with few of them simultaneously associated with two or more growth traits and some were common to both breeds. The gene mapping allowed to find 173 annotations on these regions, from which 49 represent potential candidate genes with known growth-related functions in cattle and other species. Among the regions that were associated with several growth traits, that at 24 - 27 MB of BTA14, has important candidate genes such as LYPLA1, XKR4, TMEM68 and PLAG1. Another region of interest at 0.40-0.77 Mb of BTA23 was identified in both breeds, containing KHDRBS2 as a potential candidate gene influencing body weight. Future studies targeting these regions could provide more knowledge to uncover the genetic architecture underlying growth traits in BON and ROMO cattle. The genomic regions and genes identified in this study could be used to improve the prediction of genetic merit for growth traits in these creole cattle breeds.

Effects of genetic variations within goat PITX2 gene on growth traits and mRNA expression

Paired-like homeodomain 2 (PITX2), a key gene in hypothalamic-pituitary-adrena axis, influences animal growth and development. The objective of this study was to identify the association of the functional genetic variations within goat PITX2 gene with growth traits and mRNA expression levels. According to the reported single nucleotide polymorphisms (SNPs) information in Guanzhong dairy goat (GZDG), we identified genotypes of the known SNPs in Hainan black goat (HNBG). Association analysis uncovered that the SNPs of AC_000163: g.18117T > C, g.18161C > G and g.18353T > C loci were significantly associated with several growth traits (e.g., body height and body length) in HNBG and GZDG breeds. According to the quantitative real-time PCR assay, β-Actin and ribosomal protein L19 (RPL19) were the most stable expressed housekeeping genes in heart and skeletal muscle, respectively; meanwhile, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was the most stable expressed housekeeping gene in the other tissues. Based on the best housekeeping gene of varied tissues, we found the different genotypes of above loci were significantly associated with PITX2 mRNA expression in heart, muscle and small intestine. Briefly, the genetic variants of goat PITX2 associating with mRNA expression affected growth traits significantly, which would benefit for goat breeding in the future.

Evaluation of novel SNPs and haplotypes within the <i>ATBF1</i> gene and their effects on economically important production traits in cattle

Abstract. AT motif binding factor 1 (ATBF1) gene can promote the expression level of the growth hormone 1 (GH1) gene by binding to the enhancers of the POU1F1 and PROP1 genes; thus, it affects the growth and development of livestock. Considering that the ATBF1 gene also has a close relationship with the Janus kinase–signal transductor and activator of transcription (JAK–STAT) pathway, the objective of this work was to identify novel single-nucleotide polymorphism (SNP) variations and their association with growth traits in native Chinese cattle breeds. Five novel SNPs within the ATBF1 gene were found in 644 Qinchuan and Jinnan cattle for first time using 25 pairs of screening and genotyping primers. The five novel SNPs were named as AC_000175:g.140344C>G (SNP1), g.146573T>C (SNP2), g.205468C>T (SNP3), g.205575A>G (SNP4) and g.297690C<T (SNP5). Among them, SNP1 and SNP2 were synonymous coding SNPs, while SNP5 was a missense coding SNP, and the other SNPs were intronic. Haplotype analysis found 18 haplotypes in the two breeds, and three and five closely linked loci were revealed in Qinchuan and Jinnan breeds, respectively. Association analysis revealed that SNP1 was significantly associated with the height across the hip in Qinchuan cattle. SNP2 was found to be significantly related to chest circumference and body side length traits in Jinnan cattle. SNP3 was found to have significant associations with four growth traits in Qinchuan cattle. Moreover, the different combined genotypes, SNP1–SNP3, SNP1–SNP4 and SNP2–SNP5 were significantly associated with the growth traits in cattle. These findings indicated that the bovine ATBF1 gene had marked effects on growth traits, and the growth-trait-related loci can be used as DNA markers for maker-assisted selection (MAS) breeding programs in cattle.

Effect of pre-miRNA-1658 gene polymorphism on chicken growth and carcass traits

Objective

Polymorphisms occurring in the precursor region of microRNAs (miRNAs) affect the target gene and alter the biogenesis of miRNAs, resulting in phenotypic variation. The purpose of the study was to investigate the genetic effects of rs16681031 (C>G) mutation in the precursor region of gga-miR-1658 on the economic traits of the Gushi-Anka chicken F2 resource population.

Methods

To explore the effect of miR-1658 polymorphisms on chicken economic traits, the SNP was genotyped by MassArray matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The association between the SNP and chicken body size, growth and carcass traits was determined by linear mixed models.

Results

The SNP was not only significantly associated with body weight at the age of 6, 8, 10, 12 weeks, respectively, but also with the breadth of the chicken chest, body slanting length and pelvic breadth at 4 weeks, chest depth at 8 weeks of age, and body slanting length at 12 weeks (p<0.05), respectively.

Conclusion

Our data serve as a useful resource for further analysis of miRNA function, and represent a molecular genetic basis for poultry breeding.

Hepatocyte growth factor and alternative splice variants - expression, regulation and implications in osteogenesis and bone health and repair

INTRODUCTION

Bone marrow-derived mesenchymal stem cells (MSCs) can differentiate into multiple cell types, including osteoblasts, chondrocytes, and adipocytes. These pluripotent cells secrete hepatocyte growth factor (HGF), which regulates cell growth, survival, motility, migration, mitogenesis and is important for tissue development/regeneration. HGF has four splice variants, NK1, NK2, NK3, and NK4 which have varying functions and affinities for the HGF receptor, cMET. HGF promotes osteoblastic differentiation of MSCs into bone forming cells, playing a role in bone development, health and repair.

AREAS COVERED

This review will focus on the effects of HGF in osteogenesis, bone repair and bone health, including structural and functional insights into the role of HGF in the body.

EXPERT OPINION

Approximately 6.2 million Americans experience a fracture annually, with 5-10% being mal- or non-union fractures. HGF is important in priming MSCs for osteogenic differentiation in vitro and is currently being studied to assess its role during bone repair in vivo. Due to the high turnover rate of systemic HGF, non-classic modes of HGF-treatment, including naked-plasmid HGF delivery and the use of HGF splice variants (NK1 & NK2) are being studied to find safe and efficacious treatments for bone disorders, such as mal- or non-union fractures.

Effects of SNPs and alternative splicing within HGF gene on its expression patterns in Qinchuan cattle

Background

Identification of genetic variants, including SNPs (Single Nucleotide Polymorphisms), CNVs (Copy Number Variations) and alternative splicing, within functional genes has received increasing attention in animal science research. HGF (Hepatocyte Growth Factor) is a very important growth factor that works as a mitogen or a morphogen during tissue growth, development and regeneration. However, to date, the functions of genetic variants within the bovine HGF gene, particularly their effects on mRNA expression, have not been determined well.

Results

The present study aimed to perform association analysis between genetic variants and mRNA expression for the bovine HGF gene in Qinchuan cattle using various strategies, including PCR-RFLP (Restriction Fragment Length Polymorphism), qPCR (Quantitative Real-time quantitative PCR), TA cloning, DNA sequencing and bioinformatics analysis. A total of five SNPs were identified and only SV1 locus significantly affected HGF mRNA expression in fetal skeletal muscle (P < 0.05). Heterozygous genotype individuals showed significantly higher HGF expression (P < 0.05), which was significantly greater in the “CTCCAGGGTT” combined genotype than that in the “CCCCGGGGTT” combined genotype (P < 0.05). In addition, two alternative splicing variations, HGF-W and HGF-M, were identified, which resulted from alternative 3′ splice sites of exon 5, and HGF-W showed higher mRNA levels than HGF-M in all tissues.

Conclusion

In summary, genetic variations within the HGF gene affected mRNA expression. These findings provide new insight into the molecular characteristics and functions of bovine HGF.