Due to DNA heterozygosity and repeat content, assembly of non-model plant genomes is challenging. Herein, we report a high-quality genome reference of one of the oldest known domesticated species, fig (Ficus carica L.), using Pacific Biosciences single-molecule, real-time sequencing. The fig genome is ~333 Mbp in size, of which 80% has been anchored to 13 chromosomes. Genome-wide analysis of N6 -methyladenine and N4 -methylcytosine revealed high methylation levels in both genes and transposable elements, and a prevalence of methylated over non-methylated genes. Furthermore, the characterization of N6 -methyladenine sites led to the identification of ANHGA, a species-specific motif, which is prevalent for both genes and transposable elements. Finally, exploiting the contiguity of the 13 pseudomolecules, we identified 13 putative centromeric regions. The high-quality reference genome and the characterization of methylation profiles, provides an important resource for both fig breeding and for fundamental research into the relationship between epigenetic changes and phenotype, using fig as a model species.

中文翻译：

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单倍型定相无花果（Ficus carica L.）基因组内的表观遗传模式。

由于 DNA 杂合性和重复内容，非模式植物基因组的组装具有挑战性。在此，我们使用 Pacific Biosciences 单分子实时测序报告了已知最古老的驯化物种之一无花果 (Ficus carica L.) 的高质量基因组参考。无花果基因组大小约为 333 Mbp，其中 80% 已锚定在 13 条染色体上。N6-甲基腺嘌呤和 N4-甲基胞嘧啶的全基因组分析揭示了基因和转座因子的高甲基化水平，以及甲基化基因高于非甲基化基因。此外，N6-甲基腺嘌呤位点的表征导致鉴定了 ANHGA，这是一种物种特异性基序，在基因和转座元件中普遍存在。最后，利用 13 个假分子的连续性，我们确定了 13 个假定的着丝粒区域。