ABSTRACT
Vertnin (VRTN) is involved in the variation of vertebral number in pigs and it is located on Sus scrofa chromosome 7. Vertebral number is related to body size in pigs, and many reports have suggested presence of an association between body length (BL) and meat production traits. Therefore, we analyzed the relationship between the VRTN genotype and the production and body composition traits in purebred Duroc pigs. Intramuscular fat content (IMF) in the Longissimus muscle was significantly associated with the VRTN genotype. The mean IMF of individuals with the wild-type genotype (Wt/Wt) (5.22%) was greater than that of individuals with the Wt/Q (4.99%) and Q/Q genotypes (4.79%). In addition, a best linear unbiased predictor of multiple traits animal model showed that the Wt allele had a positive effect on the IMF breeding value. No associations were observed between the VRTN genotype and other production traits. The VRTN genotype was related to BL. The Q/Q genotype individuals (100.0 cm) were longer than individuals with the Wt/Q (99.5 cm) and Wt/Wt genotypes (98.9 cm). These results suggest that in addition to the maintenance of an appropriate backfat thickness value, VRTN has the potential to act as a genetic marker of IMF.
Subject(s)
Breeding/methods , Spine/anatomy & histology , Swine/genetics , Adipose Tissue/anatomy & histology , Animals , Body Composition/genetics , Female , Gene Frequency , Genetic Markers , Genotype , Male , Models, Statistical , Swine/anatomy & histologyABSTRACT
We constructed a 5000-rad comprehensive radiation hybrid (RH) map of the porcine (Sus scrofa) genome and compared the results with the human genome. Of 4475 typed markers, 4016 (89.7%) had LOD >5 compared with the markers used in our previous RH map by means of two-point analysis and were grouped onto the 19 porcine chromosomes (SSCs). All mapped markers had LOD >3 as determined by RHMAPPER analysis. The current map comprised 430 microsatellite (MS) framework markers, 914 other MS markers, and 2672 expressed sequence tags (ESTs). The whole-genome map was 8822.1 cR in length, giving an average marker density of 0.342 Mb/cR. The average retention frequency was 35.8%. Using BLAST searches of porcine ESTs against the RefSeq human nucleotide and amino acid sequences (release 22), we constructed high-resolution comparative maps of each SSC and each human chromosome (HSA). The average distance between ESTs in the human genome was 1.38 Mb. SSC contained 50 human chromosomal syntenic groups, and SSC11, SSC12, and SSC16 were only derived from the HSA13q, HSA17, and HSA5 regions, respectively. Among 38 porcine terminal regions, we found that at least 20 regions have been conserved between the porcine and human genomes; we also found four paralogous regions for the major histocompatibility complex (MHC) on SSC7, SSC2, SSC4, and SSC1.
Subject(s)
Genome/genetics , Radiation Hybrid Mapping/methods , Sequence Analysis, DNA/methods , Sus scrofa/genetics , Animals , Cattle , Chromosomes, Mammalian/genetics , Genetic Markers , Humans , Major Histocompatibility Complex/genetics , Sequence Homology, Nucleic Acid , Synteny/geneticsABSTRACT
Many quantitative trait loci (QTL) for growth and reproductive traits have been detected on the porcine chromosome region 1qter (SSC1qter), making it one of the most important genomic regions for pig breeding. SSC1q corresponds to human chromosome 9, on which lies transforming growth factor beta receptor 1 (TGFBR1). We cloned the porcine TGFBR1 cDNA and gene (as a candidate for QTL) and analyzed the gene structure and polymorphism. Porcine TGFBR1 consists of 9 exons and 8 introns. Intron 2 is alternatively spliced at the acceptor site, resulting in two kinds of mRNA, with putative open reading frames of 1500 and 1512 bp in length. The shorter one encodes 499 amino acid residues. The amino acid sequence has 96.2 and 97.2% sequence similarity to those of human and bovine TGFBR1, respectively. The sequence similarity between porcine and murine TGFBR1 is 95.6%. We detected three single-nucleotide substitutions in exons 1, 2, and 7. Those in exons 1 and 7 are nonsynonymous substitutions resulting in Pro8Ser and Ile413Val substitutions, respectively.
Subject(s)
Polymorphism, Restriction Fragment Length , Protein Serine-Threonine Kinases/chemistry , Protein Serine-Threonine Kinases/genetics , Receptors, Transforming Growth Factor beta/chemistry , Receptors, Transforming Growth Factor beta/genetics , Swine/genetics , Alternative Splicing , Amino Acid Sequence , Amino Acid Substitution/genetics , Animals , Base Sequence , Chromosome Mapping , Exons , Genetic Markers , Microsatellite Repeats , Molecular Sequence Data , Polymerase Chain Reaction , Polymorphism, Single Nucleotide , Receptor, Transforming Growth Factor-beta Type IABSTRACT
Following several criteria, we collected, clustered, and functionally categorized 653 expressed sequence tags (ESTs) of 5' ends from porcine back fat libraries from the >15,000 porcine ESTs collected to date. By searching the LocusLink and Mapviewer database, we knew the positions of these 653 ESTs on human chromosomes (HSAs). Sus scrofa radiation hybrid (SSRH) mapping revealed that 298 porcine EST clusters out of 653 were localized near microsatellite (MS) markers. Among these EST clusters, we could assign 182 to their porcine chromosomes (SSCs) on the SSRH map.
