Complete Mitochondrial Genomes Reveal Population-Level Patterns in the Widespread Red Alga Gelidiella fanii (Gelidiales, Rhodophyta)

Abstract

Although complete mitogenomic data have been widely applied in human and other animal population studies, they are extremely limited for florideophycean red algal populations. Gelidiella fanii is a recently described rhodophyta, previously misidentified as G. acerosa, a cosmopolitan agar-yielding species from tropical to subtropical waters. To decipher patterns in genetic diversity and geographic distribution for G. fanii, we obtained 10 complete mitogenomes including two outgroups, G. acerosa and G. flabella. The mitogenomes ranged in size from 25,223 to 25,281 bp and had 48 genes, which are similar in general structure, gene order and content, and presence of a group II intron. Phylogenomic analysis revealed that G. fanii was monophyletic and clearly separate from G. acerosa. The range of G. fanii was extended from Southeast Asia and northern Australia to Eritrea, Juan de Nova Island, and Kenya in the west, and to Hawai'i and Tetiaroa Atoll to the east. Haplotype network analysis of cox1 revealed seven geographically structured groups: Southeast Asia, Kenya/Juan de Nova Island, Indonesia, northern Australia, the Philippines, Tetiaroa Atoll, and Hawai'i. This regional structure has likely resulted from the separation and isolation of an ancient widespread population during the Pleistocene. This study demonstrates that mitogenome sequencing is a powerful genotyping tool for studies of genetic diversity, biogeography, and conservation of economically valuable marine algal species.

Ancient Tethyan Vicariance and Long-Distance Dispersal Drive Global Diversification and Cryptic Speciation in the Red Seaweed Pterocladiella

“…DNA extraction, PCR amplification, and sequencing were followed by Boo et al (2016a , c) . Five markers, known to be phylogenetically informative in the Gelidiales ( Freshwater and Rueness, 1994 ; Freshwater et al, 2010 ; Boo et al, 2016c , 2020 ), were selected for molecular analyses: two mitochondrial (COI-5P and cob ) and three plastid ( psa A, psb A, and rbc L) markers. Primer sequences for the five markers are provided in Supplementary Table 2 .…”

Genetic Diversity and Phylogeography of a Turf-Forming Cosmopolitan Marine Alga, Gelidium crinale (Gelidiales, Rhodo-Phyta)

“…Phylogenies of COI-5P and rbc L sequences support well the monophyly of G. crinale and its separation from G. americanum and G. calidum . The pairwise divergence of COI-5P (0.2–3.6%) within the species is similar to that (0.7–3.4%) of Gelidiella fanii S.-M.Lin, a cosmopolitan species [ 26 ]. In addition, our study demonstrates the occurrence of G. crinale in Easter Island, India, and Tanzania, as well as many locations in the Atlantic and Pacific Ocean regions.…”

“…Of five markers used in the phylogeny of the Gelidiales, both rbc L and cox 1 represent the highly informative values at the species level [ 25 ]. However, COI-5P, a short region of the cox 1 (around 664 bp), is similarly variable to cox 1 and turns out to be the most suitable marker at the population level, given the number of haplotype and nucleotide diversity among geographical populations of Gelidiella fanii S.-M.Lin, the Indo-Pacific species in the Gelidiales [ 26 ]. The COI-5P also has a higher mutation rate than rbc L, which is useful for uncovering phylogeographic structure and genetic diversity [ 8 , 13 , 18 ].…”

Marine Flora of French Polynesia: An Updated List Using DNA Barcoding and Traditional Approaches

“…A limited number of molecular-assisted alpha-taxonomic studies have been conducted in French Polynesia, encompassing the Rhodophyta (Gelidiales [ 54 ], Gibsmithia [ 55 ], Asparagopsis [ 56 ], Grateloupia filicina [ 57 , 58 ], Corallinophycidae [ 59 , 60 , 61 , 62 ], Laurencieae [ 63 ]), Chlorophyta ( Halimeda [ 64 , 65 , 66 , 67 , 68 ]), Ochrophyta ( Dictyota [ 69 , 70 , 71 , 72 ], Lobophora [ 13 , 73 ], Newhousia [ 21 ], Sargassum [ 74 ], Turbinaria [ 75 ]), and Cyanobacteria [ 20 ], but nothing on seagrasses. These molecular-based studies generated over 500 sequences, but from a limited number of taxa, and a bulk from the genus Lobophora (>350 sequences [ 13 ]), followed by Halimeda (>90 sequences [ 64 , 65 , 66 , 67 , 76 ]), Sargassum (>30 sequences [ 74 ]), and Newhousia (20 sequences [ 21 ]).…”