The mitochondrial genome sequence of Syagrus coronata (Mart.) Becc. (Arecaceae) is characterized by gene insertion within intergenic spaces

Abstract

Syagrus coronata (Mart.) Becc. belongs to the Arecaceae family. It is a species native to Brazil of ecological, social, and economic importance. To date, there are few mitochondrial genomes in Arecaceae (Cocos nucifera and Phoenix dactylifera L.), and studies of the mitochondrial genome are essential to understand the evolution of the Arecaceae family. This study reports and compares the newly sequenced genome of S. coronata. Single-end and paired-end reads were used to obtain de novo contigs. The mitochondrial contigs were selected using C. nucifera as a reference and were merged using mate paired-end reads. The mitochondrial genome showed 642,817 bp, circular structure, containing 73 predicted functional genes, including four ribosomal RNA (rRNA) genes, 27 transfer RNA (tRNA) genes, and 42 coding protein genes. Large chloroplast genomic fragments were identified in the mitochondrial genome, and large DNA repetitive fragments were into intergenic space regions. Arecaceae mitochondrial genomes showed partial similarities in size, genome structure, and gene content. However, they exhibited numerous rearrangements. In summary, (1) we sequenced the mitochondrial genome of S. coronata and compared with other mitogenomes of Arecaceae. (2) Genomic rearrangements and gene transfer have been identified from the chloroplast genome to the mitochondrial genome. (3) The mitochondrial genome of Arecareae showed similarities in size, structure, and gene content. (4) The expansion of intergenic space size occurs due to the insertion of genes originating from the nucleus.