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

Author(s)

Faria, Andre V. F. ; Martins, Nuno T. ; Ayres-Ostrock, Ligia M. ; Gurgel, Carlos F. D. ; Plastino, Estela M.

• Document type: Journal article
• Source: JOURNAL OF PHYCOLOGY; v. N/A, p. 12-pg., 2023-07-12.

Abstract

Changes in the sea level during the Holocene are regarded as one of the most prevalent drivers of the diversity and distribution of macroalgae in Brazil, influenced by the emergence of the Vitoria-Trindade seamount chain ( VTC). Gracilariopsis tenuifrons has a wide geographic distribution along the Brazilian coast, from Maranhao state (2 degrees 48'64.3 '' S) to Santa Catarina state (27.5 degrees 73'83 '' S). The knowledge of historical processes affecting diversity may allow the development of conservation strategies in environments against anthropogenic influence. Therefore, knowledge about phylogeography and populational genetic diversity in G. tenuifrons is necessary. Six populations were sampled along the northeastern tropical (Maranhao-MA, Rio Grande do Norte-RN, Alagoas-AL, and Bahia-BA States) and southeastern subtropical (Sao Paulo "Ubatuba"-SP1 and Sao Paulo "Itanhaem"-SP2 States) regions along the Brazilian coast. The genetic diversity and structure of G. tenuifrons were inferred using mitochondrial (COI-5P and cox2-3 concatenated) DNA markers. Gracilariopsis tenuifrons populations showed an evident separation between the northeast (from 2 degrees 48'64.3 '' S to 14 degrees 18'23 '' S; 17 haplotypes) and the southeast (from 23 degrees 50'14.9 '' S to 24 degrees 20'04.7 '' S; 10 haplotypes) regions by two mutational steps between them. The main biogeographical barrier to gene flow is located nearby the VTC. The southeast region (Sao Paulo State) is separated by two subphylogroups (SP1, three haplotypes and SP2, six haplotypes), and Santos Bay (estuary) has been considered a biogeographical barrier between them. The presence of genetic structure and putative barriers to gene flow are in concordance with previous studies reporting biogeographic breaks in the southwest Atlantic Ocean, including the genetic isolation between northeast and southeast regions for red and brown algae in the vicinity of the VTC. (AU)

• FAPESP's process: 17/13983-3 - Population studies in Gracilariopsis tenuifrons (Gracilariales, Rhodophyta): physiological and molecular approaches
• Grantee: André Vinicius Fonseca de Faria
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 21/12806-6 - Gracilarioid algae (Rhodophyta): strains selections, reproductive aspects and gene expression
• Grantee: Estela Maria Plastino
• Support Opportunities: Regular Research Grants