The complete mitochondrial genome of Membranipora villosa Hincks, 1880 (Bryozoa: Gymnolaemata: Cheilostomatida): phylogenetic relationship of two kelp-encrusting bryozoans within the suborder Membraniporina

TL;DR

This paper reports the complete mitochondrial genome of Membranipora villosa and uses it to clarify the phylogenetic relationship between two similar kelp-encrusting bryozoans.

Contribution

The study provides a new mitogenome sequence and confirms the species distinction between M. villosa and M. membranacea using molecular data.

Findings

The mitogenome of M. villosa is 15,407 bp long with typical gene content for membraniporids.

M. villosa and M. membranacea differ by 20% in mitogenome sequence and 16.1% in protein-coding genes.

Phylogenetic analysis shows M. villosa is closely related to M. membranacea within the suborder Membraniporina.

Abstract

The two commonest kelp-encrusting bryozoans, Membranipora villosa and M. membranacea, are difficult to distinguish morphologically. Molecular studies of M. villosa should thus be helpful for the identification of both species because the mitogenome of M. membranacea was already sequenced. The complete mitogenome of M. villosa collected from Sinjido was determined in this study through Illumina NovaSeq sequencing. Maximum-likelihood (ML) analysis was based on concatenated 13 protein-coding genes dataset from nine bryozoan species. The mitogenome length was 15,407 bp, and its gene arrangement was similar to those of the mitogenome of other membraniporids, having 13 PCGs, two ribosomal RNAs, and 22 tRNAs. It had an overall A + T content of 63.7% (29.7% A, 16.7% C, 19.6% G, and 34.0% T). M. villosa and M. membranacea showed sequence differences of 20% for the total length of mitogenome and 16.1.% for 13 PCGs. Molecular data definitely consider them to be separate species. Phylogenetic analyses based on the amino acids of 13 PCGs indicated that M. villosa has the closest relationship with another kelp-encrusting bryozoan, M. membranacea of membraniporids. The phylogenetic position of genera and families within the suborder Membraniporina coincides with the Bayesian phylogenetic analysis of the mixed concatenated alignment consisting of three partitions.

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