Abstract
in
English,
Chinese
Avian genomes exhibit compact organization and remarkable chromosomal stability. However, the extent and mechanisms by which structural variation in avian genomes differ from those in other vertebrate lineages are poorly explored. This study generated a diploid genome assembly for the golden pheasant ( Chrysolophus pictus), a species distinguished by the vibrant plumage of males. Each haploid genome assembly included complete chromosomal models, incorporating all microchromosomes. Analysis revealed extensive tandem amplification of immune-related genes across the smallest microchromosomes (dot chromosomes), with an average copy number of 54. Structural variation between the haploid genomes was primarily shaped by large insertions and deletions (indels), with minimal contributions from inversions or duplications. Approximately 28% of these large indels were associated with recent insertions of transposable elements, despite their typically low activity in bird genomes. Evidence for significant effects of transposable elements on gene expression was minimal. Evolutionary strata on the sex chromosomes were identified, along with a drastic rearrangement of the W chromosome. These analyses of the high-quality diploid genome of the golden pheasant provide valuable insights into the evolutionary patterns of structural variation in avian genomes.
结构紧凑和染色体稳定是鸟类基因组的标志性特征。然而，鸟类基因组的结构性变异模式是否及如何与其他脊椎动物谱系不同，目前尚未得到充分研究。在该研究中，我们组装了一个高质量的红腹锦鸡二倍体基因组，每个单倍型基因组组装都包含完整的染色体模型，包括所有的微染色体。我们发现，最小的微染色体（即点染色体）上存在免疫基因的串联扩增，其平均拷贝数为54。此外，我们发现两个单倍型基因组之间的结构性变异主要由大片段插入与缺失造成的，而倒位或重复的影响较小。约28%的大片段插入与缺失与近期插入的转座子有关，尽管转座子在鸟类基因组中的活跃程度通常较低。然而，我们没有发现转座子在改变基因表达的有力证据。最后，我们分析了性染色体上的演化断层，并描绘了W染色体的剧烈重排现象。通过对红腹锦鸡高质量二倍体基因组的分析，我们揭示了鸟类基因组结构性变异的演化模式。.
Keywords:
Chromosome evolution; Golden pheasant; Structural variation; Transposable elements.