Genome assembly and annotation of the heterotrophic microalga Schizochytrium mangrovei PQ6 in Viet Nam

Abstract

Heterotrophic marine microalga Schizochytrium mangrovei PQ6 is an endemic strain of Vietnam which is isolated in Phu Quoc island, Kien Giang Province, Viet Nam. This species has a great potential of applications to synthesise polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA; C226 n-3). This study aims at constructing and annotating the genome, and then finding unsaturated fatty acid biosynthesis pathways. The whole DNA of S. mangrovei PQ6 has been sequenced by Illumina Miseq® to obtain 54200442 reads. After preprocessing and de novo assembly, the authors have obtained a draft genome of S. mangrovei PQ6 containing 2601 contigs with the length arranging from 501 bp to 320542 bp (~59.26 Mb), and with N50 as 59034 bp and the GC content of 45.19%. Applying gene prediction methods, the authors have been able to identify 4128 gene models. The results have shown that 3970 genes and 2383 genes  have been functionally annotated on NCBI-NR database and Gene Ontology database respectively. Moreover, the authors have also found 16 PUFA-related genes. These results is only the initial information about S. mangrovei PQ6 genome, but they are really improtant for future studies, especially for the studies relating to PUFA and DHA systhesis.