New microsatellite markers for Ulva intestinalis (Chlorophyta) and the transferability of markers across species of Ulvaceae

Authors: Kostamo, K., Blomster, J., Korpelainen, H., Kelly, J., Maggs, C.A. and Mineur, F.

Journal: Phycologia

Volume: 47

Issue: 6

Pages: 580-587

ISSN: 0031-8884

DOI: 10.2216/08-16.1

Abstract:

Macroalgal blooms are a growing environmental problem in eutrophicated coastal ecosystems. Members of the green algal genus Ulva are significant contributors to blooms, which are typically dominated by only one of several co-occurring opportunistic species. Our understanding of bloom dynamics, such as the importance of clonality, is limited because previously used genetic markers such as internal transcribed spacer sequences have shown very little resolution. Microsatellites are the marker of choice for such studies, but to date, only five primer pairs have been developed for a single member of this genus, Ulva intestinalis. We have now developed four new microsatellite markers for U. intestinalis using genome screening and restriction-ligation and tested them on individuals from six populations in the Gulf of Finland, Finland. All new markers exhibited polymorphism in U. intestinalis, with the numbers of alleles ranging from 6 to 10. On the basis of assignment tests, FST estimates and analysis of molecular variance, there was genetic differentiation among populations. Where significantly different, expected heterozygosity (HE) was higher than observed heterozygosity (HO), indicating a trend toward heterozygote deficiency. This may indicate that although Ulva spores can disperse relatively efficiently, asexual reproduction can result in genetic differentiation among populations. We also tested the cross-species amplification of our primers and the five primer pairs reported previously on seven species of Ulva, Ulvaria obscura and Umbraulva olivascens (all members of the Ulvaceae). In each species, from five to nine of the loci produced an amplification product, and one to four alleles were discovered at each locus. These markers therefore have great potential for testing hypotheses about the formation and maintenance of multispecies macroalgal blooms.

Source: Scopus

New microsatellite markers for <i>Ulva intestinalis</i> (Chlorophyta) and the transferability of markers across species of Ulvaceae