Filogeografía de Gracilaria flabelliformis (Gracilariaceae, Rhodophyta) en las costas del Golfo de México y Caribe mexicano
Gracilaria flabelliformis is a widely distributed species ranging from southern Florida to northern Brazil. In the Mexican Atlantic, it’s particularly found along the coasts of Veracruz and the Yucatán Peninsula. Currently, it’s considered part of the G. mammillaris complex, which encompasses five m...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:d791sg77f |
| Acceso en línea: | https://doi.org/10.24275/uami.d791sg77f |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Algas rojas info:eu-repo/classification/LEM/Phylogeography info:eu-repo/classification/LEM/Filogeografía info:eu-repo/classification/LEM/Red algae info:eu-repo/classification/cti/2 |
| Sumario: | Gracilaria flabelliformis is a widely distributed species ranging from southern Florida to northern Brazil. In the Mexican Atlantic, it’s particularly found along the coasts of Veracruz and the Yucatán Peninsula. Currently, it’s considered part of the G. mammillaris complex, which encompasses five morphologically similar Gracilaria species that exhibit sympatric distribution. Due to the overlap of morphological traits among these species, field discrimination has been challenging, making it difficult to estimate the true number of species present in the region. In this context, genetic diversity studies have provided solid evidence to clarify the different historical processes involved in the evolutionary history of sympatric species, integrating phylogeography to explain the microevolutionary process and phylogenetic systematics to explain the macroevolutionary process. This combined evidence helps address taxonomic issues like species complexes. In this regard, the present study offers a phylogeographic analysis of G. flabelliformis populations across its distribution range in the Mexican Atlantic. A total of 124 individuals were collected from eight populations across Veracruz, Campeche, and Quintana Roo. No populations of the species were found in Yucatán. For the phylogeographic analysis, molecular sequences were obtained from the RuBisCo spacer region, from which a statistical parsimony network was constructed, and various population genetics statistics were calculated, including diversity indices, AMOVA, SAMOVA, and MistMatch analyses. Ten different haplotypes were obtained, with haplotype R1 designated as the ancestral haplotype due to its higher number of individuals and connections to other haplotypes in the network. The haplotypic distribution revealed that R1 was present in all the sampled populations, while the other haplotypes were restricted to Veracruz. Veracruz. Additionally, the haplotypic distribution showed that Veracruz is a highly heterogeneous state, particularly the Playa Mocambo-Costa de Oro region, while the Mexican Caribbean region is highly homogeneous, with only a single haplotype (R1) in its populations. The calculated distance values and indices supported this homogeneity versus heterogeneity between the Mexican Caribbean and the Gulf of Mexico, respectively. Furthermore, rbcL sequences were obtained for each resulting haplotype to confirm their phylogenetic identity. The phylogenetic analysis revealed that the haplotypes corresponded to three phylogenetically distinct entities: G. isabellana (haplotype R4), related to G. damicornis (haplotypes R2, R3, 39, and R10), and G. flabelliformis (haplotypes R1, R5, R6, R7). The results suggest that a geological process is responsible for the isolation of populations from the three G. flabelliformis species with sympatric distributions in the Atlantic, which is responsible for their current taxonomic independence. However, all the obtained genetic diversity analyses reveal that this process is likely recent, as populations of all three species remain interconnected, while conserved markers like rbcL show that genetic isolation supports their phylogenetic independence. Furthermore, G. flabelliformis (with 15 morphotypes) is found throughout the Mexican Caribbean and Gulf of Mexico, while the other two species, G. isabellana (with 3 morphotypes) and G. damicornis (with 4 morphotypes), are only sympatric in Veracruz, where they have remained isolated, supporting the isolation between the Gulf of Mexico and the Mexican Caribbean. |
|---|