Geographically specific heteroplasmy of mitochondrial DNA in the seaweed, Fucus serratus (Heterokontophyta: Phaeophyceae, Fucales)

Abstract

The presence of more than one type of mitochondrial DNA within the same organism (mtDNA heteroplasmy) has been reported in vertebrates, invertebrates, basidiomycetes and some angiosperms, but never in marine (macro)algae. We examined sequence differences in a 135-base pair (bp) region of the nad11 gene in mitochondria of the intertidal rockweed, Fucus serratus, using single-strand conformation polymorphism (SSCP). Each of 70 and 22 individuals from Blushøj (Denmark) and Oskarshamn (Sweden), respectively, displayed haplotypes 2, 3, and 4 (= mtDNA heteroplasmy), whereas only haplotype 2 was found in each of 24 individuals from locations in Spain, France, Ireland, Iceland and Norway. As Blushøj and Oskarshamn were among the last areas to emerge from ice cover during the Last Glacial Maximum (18000-20000 years BP), the geographically specific heteroplasmy may represent a founder effect and therefore, a valuable marker for understanding the role of post-Ice Age recolonization. Geographically specific heteroplasmy also has important implications in phylogeographical studies based on mtDNA sequences.

Intraspecific Genetic Diversity of Undaria pinnatifida in Japan, based on the Mitochondrial cox3 Gene and the ITS1 of nrDNA

“…Although ITS and IGS regions are reportedly polymorphic within single species of brown algae, it is sometimes difficult to determine their sequences clearly maybe due to intraindividual polymorphism. In contrast, mitochondrial markers are usually maternally inherited in brown algae, and therefore, intraindividual polymorphism is less known (also see, Steel et al, 2000;Coyer et al, 2004). Therefore, although substitutions were infrequent in Undaria, we consider cox3 useful for intra-and interspecific studies of Phaeophyceae as an organelle-genomic marker.…”

Mitochondrial Genome Recombination in the Zone of Contact Between Two Hybridizing Conifers

“…In plants, heteroplasmy seems to be a rare phenomenon, which is usually associated with paternal leakage in natural populations (Fauron et al 1995;Coyer et al 2004;McCauley et al 2005). In conifers, some exceptional cases of paternal leakage have been detected in controlled crosses between Pinus banksiana and P. contorta (Wagner et al 1991) and in embryos from Pseudotsuga menziesii (Owens and Morris 1991;Mogensen 1996).…”

Evolution and diversification within the intertidal brown macroalgae Fucus spiralis/F. vesiculosus species complex in the North Atlantic

“…The presence of more than one mitochondrial genotype in an individual (heteroplasmy) has been detected in animals, angiosperms, and heterokonts, including in the genus Fucus (Coyer et al, 2004;Kmiec et al, 2006). It can lead to mtDNA recombination (Hoarau et al, 2002), which would affect phylogeographic and demographic inferences (e.g., Schierup and Hein, 2000;Posada and Crandall, 2002).…”