Molecular phylogenetic analyses of the Japanese Ulva and Enteromorpha (Ulvales, Ulvophyceae), with special reference to the free-floating Ulva

Abstract

In order to elucidate the species composition of freefloating Ulva that cause green tide in several bays in Japan, and to clarify the generic status of Ulva and Enteromorpha (Ulvales, Ulvophyceae), the nuclear encoded internal transcribed spacer (ITS) region including the 5.8S gene and the plastid encoded large subunit of ribulose-1, 5-bisphosphate carboxylase/ oxgenase ( rbc L) gene sequences for 15 species were determined. Both ITS and rbc L analyses indicate that free-floating Ulva samples are divided into four different lineages that correspond to Ulva lactuca Linnaeus, U. pertusa Kjellman, U. armoricana Dion et al . and U. fasciata Delile. These four species are distinguished by cell morphology including the arrangement of cells, the shape and size of cells and the position of chloroplasts. Molecular data also indicated that Ulva and Enteromorpha are not separated as respective monophyletic groups within a large monophyletic clade and congeneric as shown by previous molecular studies using the ITS sequences alone. This strongly suggests that these genera are congeneric and Enteromorpha should be reduced to the synonym of Ulva .

Ulva flexuosa(Ulvaceae, Chlorophyta) inhabiting inland aquatic ecosystems: molecular, morphological and ecological discrimination of subspecies

“…Polymerase chain reaction (PCR) amplifications of the ITS1-5.8S-ITS2 (rRNA) and the chloroplast rbcL gene were performed (Shimada et al, 2003). DNA sequencing was performed as described by Leskinen & Pamilo (1997) and Kawai et al (2007) using a HITACHI 3130 xL Genetic Analyzer (Applied Biosystems, CA, USA) automated sequencer.…”

Cryptic diversity ofUlva(Ulvales, Chlorophyta) in the Great Bay Estuarine System (Atlantic USA): introduced and indigenous distromatic species

“…Further complications in differentiating between species based on morphology result from the ability of some individuals within the same species to exist as either a foliose blade or hollow tube, both of which are characteristic of the genus (Tan et al, 1999;Blomster et al, 2002;Hayden et al, 2003). Due to the unreliability of morphological characteristics for species identification in the genus Ulva, molecular analysis (the nuclear genome, nuclear ribosomal ITS sequences and the chloroplast rbcL gene) has become useful for differentiating taxa (Blomster et al, 1998Coat et al, 1998;Malta et al, 1999;Tan et al, 1999;Hayden & Waaland, 2002Hayden et al, 2003;Shimada et al, 2003;Loughnane et al, 2008). However, even when molecular analyses are used, specimens can still be misidentified if the determination is based on comparison to sequences posted on databases like GenBank (National Institutes of Health) and not validated against nomenclatural type material.…”

<i>Ulva partita</i> sp. nov., a Novel <i>Enteromorpha</i>-Like <i>Ulva</i> Species from Japanese Coastal Areas

“…PCR amplifications of the nuclear-encoded internal transcribed spacer 2 (nrITS2) region and the plastid-encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxgenase gene (rbcL) were performed according to Shimada et al (2003Shimada et al ( , 2004, respectively. PCR products were sequenced by Eurofins Genomics (Ota-ku, Tokyo, Japan).…”

“…PCR products were sequenced by Eurofins Genomics (Ota-ku, Tokyo, Japan). In this study, we used six amplification primers: ITS3-ITS4 for nrITS2 (Malta et al 1999); and rbcL RH1, rbcL 650F, rbcL 750R, and rbcL 1385R for rbcL (Manhart 1994, Shimada et al 2003. …”