Animal Breeding and Genomics Centre, Wageningen University, De Elst 1, 6708WD Wageningen, The Netherlands.
BMC Genomics. 2012 Aug 14;13:391. doi: 10.1186/1471-2164-13-391.
The turkey (Meleagris gallopavo) is an important agricultural species and the second largest contributor to the world's poultry meat production. Genetic improvement is attributed largely to selective breeding programs that rely on highly heritable phenotypic traits, such as body size and breast muscle development. Commercial breeding with small effective population sizes and epistasis can result in loss of genetic diversity, which in turn can lead to reduced individual fitness and reduced response to selection. The presence of genomic diversity in domestic livestock species therefore, is of great importance and a prerequisite for rapid and accurate genetic improvement of selected breeds in various environments, as well as to facilitate rapid adaptation to potential changes in breeding goals. Genomic selection requires a large number of genetic markers such as e.g. single nucleotide polymorphisms (SNPs) the most abundant source of genetic variation within the genome.
Alignment of next generation sequencing data of 32 individual turkeys from different populations was used for the discovery of 5.49 million SNPs, which subsequently were used for the analysis of genetic diversity among the different populations. All of the commercial lines branched from a single node relative to the heritage varieties and the South Mexican turkey population. Heterozygosity of all individuals from the different turkey populations ranged from 0.17-2.73 SNPs/Kb, while heterozygosity of populations ranged from 0.73-1.64 SNPs/Kb. The average frequency of heterozygous SNPs in individual turkeys was 1.07 SNPs/Kb. Five genomic regions with very low nucleotide variation were identified in domestic turkeys that showed state of fixation towards alleles different than wild alleles.
The turkey genome is much less diverse with a relatively low frequency of heterozygous SNPs as compared to other livestock species like chicken and pig. The whole genome SNP discovery study in turkey resulted in the detection of 5.49 million putative SNPs compared to the reference genome. All commercial lines appear to share a common origin. Presence of different alleles/haplotypes in the SM population highlights that specific haplotypes have been selected in the modern domesticated turkey.
火鸡（Meleagris gallopavo）是一种重要的农业物种，也是世界家禽肉产量的第二大贡献者。遗传改良主要归因于选择性育种计划，这些计划依赖于高度可遗传的表型特征，如体型和胸肌发育。商业养殖中，小的有效种群大小和上位性可能导致遗传多样性的丧失，这反过来又会导致个体适应性降低和选择响应降低。因此，家畜种属的基因组多样性非常重要，是快速准确地遗传改良各种环境下的特定品种以及促进对潜在的育种目标变化的快速适应的前提。基因组选择需要大量的遗传标记，如单核苷酸多态性（SNP），这是基因组内遗传变异的最丰富来源。
对来自不同群体的 32 只火鸡的下一代测序数据进行比对，发现了 549 万个 SNP，并随后用于分析不同群体之间的遗传多样性。所有商业品系相对于传统品种和南墨西哥火鸡群体，均从一个单一的节点分支出来。来自不同火鸡群体的所有个体的杂合度范围为 0.17-2.73 SNP/Kb，而群体的杂合度范围为 0.73-1.64 SNP/Kb。个体火鸡的异质 SNP 平均频率为 1.07 SNP/Kb。在火鸡中发现了 5 个基因组区域，这些区域的核苷酸变异非常低，表现出与野生等位基因不同的等位基因固定状态。
与鸡和猪等其他家畜种属相比，火鸡的基因组多样性要低得多，异质 SNP 的频率相对较低。火鸡全基因组 SNP 发现研究在参考基因组中检测到了 549 万个可能的 SNP。所有商业品系似乎都有一个共同的起源。SM 群体中不同等位基因/单倍型的存在表明，特定的单倍型已在现代驯化火鸡中被选择。
