The snow sheep, Ovis nivicola, which is endemic to the mountain ranges of northeastern Siberia, are well adapted to the harsh cold climatic conditions of their habitat. In this study, using long reads of Nanopore sequencing technology, whole-genome sequencing, assembly, and gene annotation of a snow sheep were carried out. Additionally, RNA-seq reads from several tissues were also generated to supplement the gene prediction in snow sheep genome. The assembled genome was ∼2.62 Gb in length and was represented by 7,157 scaffolds with N50 of about 2 Mb. The repetitive sequences comprised of 41% of the total genome. BUSCO analysis revealed that the snow sheep assembly contained full-length or partial fragments of 97% of mammalian universal single-copy orthologs (n = 4,104), illustrating the completeness of the assembly. In addition, a total of 20,045 protein-coding sequences were identified using comprehensive gene prediction pipeline. Of which 19,240 (∼96%) sequences were annotated using protein databases. Moreover, homology-based searches and de novo identification detected 1,484 tRNAs; 243 rRNAs; 1,931 snRNAs; and 782 miRNAs in the snow sheep genome. To conclude, we generated the first de novo genome of the snow sheep using long reads; these data are expected to contribute significantly to our understanding related to evolution and adaptation within the Ovis genus.

中文翻译：

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雪羊（Ovis nivicola）基因组组装初稿。


雪羊Ovis nivicola是西伯利亚东北部山区的特有种，非常适应其栖息地严酷的寒冷气候条件。本研究利用纳米孔长读长测序技术，对一只雪羊进行了全基因组测序、组装和基因注释。此外，还生成了来自多个组织的 RNA-seq 读数，以补充雪羊基因组中的基因预测。组装的基因组长度约为 2.62 Gb，由 7,157 个支架组成，N50 约为 2 Mb。重复序列占总基因组的 41%。 BUSCO分析显示，雪羊组装体包含97%的哺乳动物通用单拷贝直系同源物的全长或部分片段（ n = 4,104），说明了组装体的完整性。此外，使用综合基因预测管道总共鉴定了 20,045 个蛋白质编码序列。其中 19,240 个（∼96%）序列是使用蛋白质数据库注释的。此外，基于同源性的搜索和从头鉴定检测到 1,484 个 tRNA； 243 rRNA； 1,931 个 snRNA；以及雪羊基因组中的 782 个 miRNA。总之，我们使用长读长生成了雪羊的第一个从头基因组；这些数据预计将极大地促进我们对绵羊属进化和适应的理解。