ABSTRACT
The domesticated turkey, Meleagris gallopavo, is believed to be a single breed with several varieties whose relatedness and origins remain poorly understood. Using the mitochondrial genome sequence (GenBank accession no. EF153719) that our group first reported, we investigated the relationships among 15 of the most widely occurring turkey varieties using D-loop and 16S RNA sequences. We included, as a non-traditional outgroup, mtDNA sequence information from wild turkey varieties. A total of 24 SNPs, including 18 in the D-loop and 6 in the 16S rRNA, was identified, validated and used. Of the 15 haplotypes detected based on these SNPs, 7 were unique to wild turkeys. Nucleotide diversity estimates were relatively low when compared to those reported for chickens and other livestock. Network and phylogenetic analyses showed a closer relationship among heritage varieties than between heritage and wild turkeys. The mtDNA data provide additional evidence that suggest a recent divergence of turkey varieties.
Subject(s)
DNA, Mitochondrial/genetics , Genome, Mitochondrial , Phylogeny , RNA, Ribosomal, 16S/genetics , Turkeys/genetics , Animals , Animals, Domestic , Animals, Wild , Haplotypes , Nucleic Acid Conformation , Polymorphism, Single Nucleotide , Sequence Analysis, DNA , Turkeys/classificationABSTRACT
Determining variation in genes is fundamental to understanding their function in the disease state. Cardiac troponin T (cTnT) and phospholamban (PLN) genes have been implicated in dilated cardiomyopathy (DCM) in human and model species. To investigate the role of these 2 candidate genes in DCM in the turkey Meleagris gallopavo, understanding sequence variants and map position distribution is necessary. To this end, a total of 1854 and 1771 bp of cTnT and PLN gene sequences, respectively, were scanned for single nucleotide polymorphisms (SNPs) in a randomly bred population. A total of 15 SNPs was identified in the cTnT and PLN genomic sequences. Nine haplotypes, 5 in cTnT and 4 in PLN, were identified. Observed heterozygosities (0.02-0.39) in the turkey population were low for both genes. Within each gene, 1 SNP corresponding to a restriction enzyme site was identified and used to develop a PCR-restriction fragment length polymorphism (RFLP) genotyping assay. The PLN gene was genetically mapped to turkey chromosome 2, equivalent to Gallus gallus chromosome 3, and cTnT mapped to a turkey microchromosome. Although limited because of the relatively small sample size of 55 birds, the data from this SNP analysis of PLN and cTnT provide a foundation from which to evaluate the function of cTnT and PLN in the turkey. Information about the distribution of the SNPs and haplotypes will facilitate future association and linkage studies.
