Characterization of the complete mitochondrial genome of Meira sp. (Exobasidiales: Brachybasidiaceae) with phylogenetic analysis.

In this study, the complete mitochondrial genome of Meira sp. was sequenced and assembled. The complete mitochondrial genome of Meira sp. has 15 protein-coding (PCG) genes, 2 ribosomal RNA (rRNA) genes, and 22 transfer RNA (tRNA) genes. The mitochondrial genome of Meira sp. has a total size of 23,353 bp, with the base composition as follows: A (30.62%), T (32.82%), G (17.84%) and C (18.73%). Phylogenetic analysis indicated that the mitogenome of Meira sp. exhibited a close relationship with the mitogenome of Jaminaea angkorensis.

The genus Meira was first proposed to accommodate two anamorphic yeastlike fungi, namely Meira geulakonigii and Meira argovae (Boekhout et al. 2003). Meira species are usually distributed in plant tissues or on the leaf surface of plants (Yasuda et al. 2006; Limtong et al. 2017). So far, several molecular markers have been used in phylogenetic studies of Meira species, including nuclear rRNA genes, the D1/D2 region of the LSU rRNA gene, the SSU rRNA gene, and so on (Rush and Aime 2013; Wang et al. 2015). However, no complete mitochondrial genome from the genus Meira has been published. The mitochondrial genome of Meira sp. will promote the understanding of the taxonomy, phylogeny and evolution of the anamorphic yeast-like fungi.

The specimen (Meira sp.) was isolated from a plant tissue in Yanbian, Jilin, China (129.32 E; 43.11 N). The specimen was stored in Culture Collection Center of Chengdu University (No. Msp003). The total genomic DNA of Meira sp. was extracted using a Fungal DNA Kit D3390-00 (Omega Bio-Tek, Norcross, GA, USA) according to the instructions. We purified the extracted total DNA using a Gel Extraction Kit (Omega Bio-Tek, Norcross, GA, USA). Purified DNA was stored in Chengdu University (No. DNA_ Msp003). We constructed sequencing libraries with purified genomic DNA using the NEBNext® Ultra™ II DNA Library Prep Kit (NEB, Beijing, China). Whole genomic sequencing (WGS) was conducted by the Illumina HiSeq 2500 Platform (Illumina, SanDiego, CA). We The de novo assembled the complete mitogenome of Meira sp. using SPAdes 3.9.0 (Bankevich et al. 2012). The obtained complete mitogenome of Meira sp. was annotated according to the methods described by Li et al. (Li, Chen, et al. 2018; Li, Liao, et al. 2018; Li, Ren, et al. 2019; Li, Wang et al. 2018).

The complete mitogenome of Meira sp. is 23,353 bp in length, with the base composition as follows: A (30.62%), T (32.82%), G (17.84%) and C (18.73%). The complete mitogenome contains 15 protein-coding genes, 2 ribosomal RNA genes (rns and rnl), and 22 transfer RNA (tRNA) genes. To investigate the phylogenetic status of Meira sp., we constructed a phylogenetic tree for 18 species. We constructed the phylogenetic tree using Bayesian analysis (BI) method based on the combined 14 core protein-coding genes according to methods described by Li et al (Li, Wang, Jin, Chen, Xiong, Li, Liu, et al. 2019; Li, Wang, Jin, Chen, Xiong, Li, Zhao, et al. 2019; Li et al. 2020). As shown in the phylogenetic tree (Figure 1), the mitogenome of Meira sp. exhibited a close relationship with the mitogenome of Jaminaea angkorensis (Hegedusova et al. 2014).

Figure 1.

Bayesian phylogenetic analysis of 18 species based on the combined 14 core protein-coding genes. Accession numbers of mitochondrial sequences used in the phylogenetic analysis are listed in brackets after species.