Asexual life history by quadriflagellate swarmers of Ulva spinulosa (Ulvales, Ulvophyceae) |
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| Authors: | Masanori Hiraoka Satoshi Shimada Masao Ohno Yukihiko Serisawa |
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| Institution: | Kochi Prefectural Deep Seawater Laboratory (NEDO fellow), Maruyama, Murotomisaki, Muroto, Kochi 781-7101, Japan;Center for Advanced Science and Technology, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan;Usa Marine Biological Institute, Kochi University, Usa-Inoshiri, Kochi 781-1164, Japan;Marine Biosystems Research Center, Chiba University, Amatu-kominato, Awa, Chiba 299-5502, Japan |
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| Abstract: | This is the first report of a Ulva species reproducing asexually solely by quadriflagellate swarmers. Ulva spinulosa Okamura et Segawa specimens were collected from Ukibuchi on the Pacific coast of Kochi Prefecture, southern Japan. Quadriflagellate swarmers were released from these specimens. The swarmers showed negative phototaxis before settlement. Thalli cultured from these swarmers also released quadriflagellate swarmers in culture. Microspectrophotometric studies demonstrated equivalent DNA in nuclei of vegetative cells in thalli of U. spinulosa and in sporo‐phytes of the other Ulva species with sexual life history (U. fasciata Delile). Furthermore, the quadriflagellate swarmers of U. spinulosa had the same DNA value, demonstrating that the quadriflagellate swarmers are produced without meiosis. |
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| Keywords: | asexual life history DNA microspectrophoto-metry negative phototaxis quadriflagellate swarmer Ulva |
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