A molecular re-examination of speciation in the intertidal red algaMastocarpus stellatus(Gigartinales, Rhodophyta) in Europe

Abstract

Mastocarpus stellatus is a common intertidal red alga in the north Atlantic. Previous work showed that the species was divided into at least two breeding groups in the northeastern Atlantic, a northern one (absent in Spain and Portugal) and a southern one, which were almost completely inter-sterile. It also showed that, in laboratory culture, at least two types of life history were evident in this species (a sexual one and a 'direct' one). The distribution of these life histories appeared to have a north-south distribution. We have used molecular markers to confirm these results and expand the sampling in certain populations. Organellar markers showed that the breeding groups have different plastid and mitochondria haplotypes and appear to be distributed along a north-south gradient. Populations in southern England and northern France (Brittany) have mixed northern and southern breeding groups, except for the Rade du Brest, as was shown previously from culture studies. Results also show that most asexual plants have a plastid haplotype corresponding to the northern breeding group and a mitochondrial haplotype corresponding to the southern breeding group, a possible case of differential organellar inheritance and hybrid formation of an asexual life history. These results using molecular markers support previous conclusions and again emphasize the high levels of genetic variation in marine algae in Brittany.

New, resurrected and redefined species ofMastocarpus(Phyllophoraceae, Rhodophyta) from the northeast Pacific

“…Moreover, these Vancouver Island populations are odd because specimens with ITS of Mastocarpus agardhii have organelle sequences from other species as noted above. (Zuccarello et al 2005 also observed mixed genotypes in European Mastocarpus, with asexual thalli having the plastid haplotype of the northern breeding group and the mitochondrial haplotype of the southern breeding group.) The occurrence of Mastocarpus latissimus in Chile, with little genetic differentiation from some California specimens, also raises the possibility of modern, anthropogenic dispersal.…”

The Lessonia Nigrescens Species Complex (Laminariales, Phaeophyceae) Shows Strict Parapatry and Complete Reproductive Isolation in a Secondary Contact Zone1

“…Discrepancies between molecular markers have uncovered cases of putative hybridization between different species (e.g., red algae: Zuccarello et al. 2005, Brodie and Zuccarello 2006, Niwa et al.…”

SPECIES DELIMITATION, TAXONOMY, AND BIOGEOGRAPHY OF DICTYOTA IN EUROPE (DICTYOTALES, PHAEOPHYCEAE)1

“…2009, Destombe et al. 2010), and the resulting offspring is often sterile or reproduces exclusively apomictically (Zuccarello et al. 2005, Kamiya and West 2008).…”