Phylogeography of Colpomenia sinuosa (Ectocarpales, Phaeophyceae) along the Brazilian coast

Abstract

Colpomenia sinuosa is a cosmopolitan brown macroalgal species complex and hence a great candidate for evolutionary studies in the marine environment. Since 2009, three major C. sinuosa phylogenetic lineages, subdivided into eight subgroups, have been identified based on cox3 DNA sequences from worldwide collections. However, worldwide sampling remains limited and spotty. To date molecular data from Brazilian C. sinuosa populations have been limited to 10 specimens collected in a single locality. Nonetheless, C. sinuosa populations occur along the entire ~8,000 km Brazilian coast. Consequently, knowledge on population genetic diversity and spatial genetic structuring along most of the Brazilian coastline is nonexistent. To fulfill this gap in knowledge, we performed a phylogeographic analysis of C. sinuosa populations in Brazil. The highly variable cox3 marker was sequenced for 148 individuals collected in 12 localities in Brazil. Results identified two genetically distinct population groups (north vs. south) separated at 20.5°S latitude. Genetic diversity in northern populations is 14.6 and 15.5 times greater than southern populations in terms of haplotype and nucleotide diversity, respectively. Among northern populations, the Bahia state holds the largest genetic diversity. The southern populations had lower genetic diversity and no internal genetic sub-structure suggesting past bottlenecks followed by recent colonization from northern haplotypes. Our results do not indicate recent introductions of foreign haplotypes in Brazil and reinforce the crucial importance of historical and extant allopatric, parapatric, and sympatric processes driving marine macroalgal evolution in the Southwestern Atlantic Ocean.

Phylogeography of the red alga Gracilariopsis tenuifrons (Gracilariales) along the Brazilian coast

“…However, due to the divergence age of the haplotypes, the Vitória‐Trindade seamount chain is more likely the main physical historical barrier responsible for the differences observed between the northeastern and southeastern phylogroups (Table 1). This pattern is similar to that reported for the other three marine macroalgal species, Hypnea pseudomusciformis (Nauer et al, 2019), Gracilaria caudata (Ayres‐Ostrock et al, 2019), and Colpomenia sinuosa (Martins, Cassano, & Gurgel, 2022). In contrast to our findings, these studies showed only two phylogroups along the Brazilian coast (a northeastern and a southeastern phylogroup) without significance within phylogroup subdivisions.…”

“…Five of these populations had already their ecotypic differences revealed by eco‐physiological experiments (Faria & Plastino, 2022). Moreover, near the same G. tenuifrons sampling sites, other species evidenced some putative barriers to gene flow (Ayres‐Ostrock et al, 2019; Martins, Cassano, & Gurgel, 2022; Nauer et al, 2019). Therefore, we hypothesized that physical barriers to gene flow and past isolation in climate refugia were the major drivers shaping the current genetic structure and diversity of G. tenuifrons .…”

“…Despite the wide Brazilian coast and its large number of seaweed species, few studies have addressed marine macroalgal phylogeography. Historically, only three species have been studied in this regard, and relatively high levels of intraspecific genetic diversity and structure among populations were observed: Gracilaria caudata (Ayres‐Ostrock et al, 2019), Hypnea pseudomusciformis (Nauer et al, 2019), and Colpomenia sinuosa (Martins, Cassano, & Gurgel, 2022). These studies provided evidence of putative barriers to gene flow between populations influenced by the Vitoria‐Trindade seamount chain, as well as the existence of phylogroups along the Brazilian coast.…”

The complete mitochondrion genome of Colpomenia sinuosa and phylogenetic analysis

“…Colpomenia sinuosa belongs to Eukaryota; Sar; Stramenopiles; Ochrophyta; PX clade; Phaeophyceae; Ectocarpales; Scytosiphonaceae; Colpomenia [1] , and is a representative species of this genus. C. sinuosa is a cosmopolitan brown macroalgal species complex and hence a great candidate for evolutionary studies in the marine environment.…”

Estudos populacionais em Gracilariopsis tenuifrons (Gracilariales, Rhodophyta): aspectos fisiológicos e moleculares.

“…2016), poliquetas(Paiva et al, 2019), e outras espécies de macroalgasNauer et al 2019;Martins et al 2022). Durante os máximos glaciais do Quaternário, o desnível do mar emergiu grandes áreas da plataforma continental, incluindo o topo dos montes submarinos de Vitória-Trindade, dividindo o litoral do continente brasileiro em uma região norte mais quente, possivelmente tropical, e uma subtropical mais fria, possivelmente quente-temperada, região Sul.Pela primeira vez, em Gp.…”