Symphyocladia lithophila sp. nov. is newly described using both morphological and molecular analyses of samples collected from the southeastern coast of Korea. The new species is characterized by small size, ecorticate thallus, with 8–10 pericentral cells, lacking trichoblasts, and having 5–7 segments of congenital fusions. S. lithophila was observed to be a winter species, producing tetrasporangia from December to February. Plastid-encoded rbcL sequences were determined in four samples of S. lithophila from different locations and 21 samples of four putative relatives, including the most related genus Pterosiphonia. All four Symphyocladia lithophila replicates from three different locations had almost identical rbcL sequences, and interspecific sequence divergences were sufficient to warrant its separation as a natural entity. The phylogeny of the rbcL sequences also indicated monophyly of the genus Symphyocladia, which is separated from the genus Pterosiphonia. The specimens of Pterosiphonia, including the type species P. cloiophylla from its type locality in South Africa, form a monophyletic group.

Flumequine is a well-known second generation quinolone antibiotic that induces phototoxicity. However, the effect of flumequine on skin melanogenesis is unclear. Therefore, we, for the first time, investigated whether flumequine regulates melanogenesis. The present study showed that flumequine slightly inhibited in vitro mushroom tyrosinase activity but significantly increased extracellular and intracellular melanin content in B16F10 cells and promoted the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase. Additionally, flumequine remarkably increased melanin pigmentation in zebrafish larvae without any toxicity. We also found that flumequine stimulated p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) phosphorylation; inhibition of p38 MAPK and JNK resulted in significant downregulation of extracellular and intracellular melanin content in B16F10 cells and pigmentation of zebrafish larvae accompanied with suppression of MITF and tyrosinase expression, indicating that flumequine-mediated p38 and JNK promote melanogenesis in vitro and in vivo. According to the molecular docking prediction, flumequine targeted dual-specificity MAPK phosphatase 16 (DUSP16), which is a major negative regulator of p38 MAPK and JNK. Our findings demonstrate that flumequine induces an increase in melanin content in B16F10 cells and zebrafish larvae by activating p38 MAPK and JNK. These data show the potential of flumequine for use as an anti-vitiligo agent.

Background: DNA barcoding is becoming a widely applied tool for the quick and accurate identification of species. The evolution of the mitochondrial cytochrome c oxidase subunit I (COI) gene is sufficiently rapid to allow discrimination between closely related species and biogeographic subgroups within species. Gracilaria salicornia was originally described as being from Manila, the Philippines, and is distributed throughout Asia and the Indian Ocean. To more accurately define this species and its genetic diversity owing to the confusion of identification historically, DNA barcoding using the 5’ end of the COI gene of the mitochondrial genome was applied to specimens collected from the Philippines, Malaysia, Thailand, China, and Japan, and they were compared to other gracilarian species. Results: Within species, the COI marker yielded two clusters with nucleotide divergences of 0.0–1.3%. This divergence is slightly higher than the typical intraspecific variation for red algae. A total of eight COI haplotypes were found for G. salicornia, comprising the following groups: H1–H3 from the Philippines; H4 from Okinawa in Japan; H5–H7 from Malaysia, Thailand, and China; and H8 from Thailand. Conclusion: Although this work concentrated on a limited geographical region of a widespread taxon, the data shows intraspecific molecular divergences in G. salicornia and provides further evidence that DNA barcodes are useful tools for identifying species boundaries and examining biogeographical haplotypes for the genus Gracilaria.

Several species classified to the genus Ulva are primarily responsible for causing green tides all over the world. For almost two decades, green tides have been resulted in numerous ecological problems along the eastern coast of Jeju Island, Korea. In order to characterize the species of Ulva responsible for causing the massive blooms on Jeju Island, we conducted DNA barcoding of tufA and rbcL sequences on 183 specimens of Ulva from eight sites on Jeju Island. The concatenated analysis identified five bloom-forming species: U. australis, U. lactuca, U. laetevirens, U. ohnoi and a novel species, U. pseudo-ohnoi sp. nov. Among them, U. australis, U. lactuca, and U. laetevirens caused to the blooms coming mainly from the substratum. U. ohnoi and U. pseudo-ohnoi sp. nov. were causative the free-floating blooms. Four species, except U. australis, are characterized by marginal teeth. A novel species, U. pseudo-ohnoi sp. nov., is clearly diverged from the U. lactuca, U. laetevirens, and U. ohnoi clade in the concatenated maximum likelihood analysis. Accurate species delimitation will contribute to a management of massive Ulva blooms based on this more comprehensive knowledge.

Chondracanthus teedei and C. chamissoi are regarded as cosmopolitan and endemic species, respectively. To verify the geographic distribution of these two species, we analyzed specimens of C. teedei from the Western Pacific and the Atlantic coast of Spain, as well as of C. chamissoi from Chile using plastid rbcL and mitochondrial COI genes. The phylogenetic tree of rbcL revealed that “C. teedei” from Asia and Chondracanthus sp. from France are conspecific with C. chamissoi from Chile, but distinct from the clade of C. teedei from the Atlantic. These results indicate that C. chamissoi is not exclusively distributed in the southeastern Pacific, but is also found in Korea/Japan and France, whereas C. teedei is found in the Atlantic and not in the western Pacific region. This study demonstrated that the range of C. chamissoi is wider than previously thought, raising interesting questions regarding the transportation vector and the absence of C. teedei from Korea and Japan. In addition, we confirmed that molecular analyses can be used to examine the geographic distribution of marine macroalgae.