Tez No	İndirme	Tez Künye	Durumu
740321		Differential expression of a bromoperoxidase-like gene between sporophytes and gametophytes of a red alga, porphyra yezoensis / Bromoperoksidaz benzeri genin kırmızı alg porphyra yezoensis sporofit ve gametofitlerinde farklı ifadeleri Yazar:RENGİN ÖZGÜR UZİLDAY Danışman: PROF. DR. SUSUMU TAKIO Yer Bilgisi: Kumamoto Daigaku / Yurtdışı Enstitü / Biyoloji Ana Bilim Dalı Konu:Biyoloji = Biology Dizin:	Onaylandı Yüksek Lisans İngilizce 2010 30 s.
Many halogens such as I, Br, Cl are found abundantly in seawater unlike fresh water. Halogenated organic compounds are synthesized by marine algae with the aid of haloperoxidase. Bromoperoxidase (BPOX) is a member of haloperoxidases and catalyzes the bromination reaction of organic compounds. Genes and activities of BPOXs are reported for various species of marine macroalgae incuding red algae. However, the red alga Porphyra collected from its natural habitats is known to contain no or little amount of halogenated compounds. There is no information about BPOX in Porphyra, although BPOX-like gene fragments are present in public EST database of Porphyra yezoensis. In this study, I investigated the expression pattern of the BPOX-like gene in P. yezoensis using sporophytes and gametophytes. A partial DNA fragment (1504 bp) of BPOX-like gene was isolated using P. yezoensis EST database. Genomic Southern blot analysis suggested that Porphyra BPOX-like gene exists as a single copy per haploid genome. RT-PCR results revealed that the expression of BPOX-like gene in gametophytes was strongly suppressed under normal growth conditions but induced by supply of excess copper. On the other hand, the expression of BPOX-like gene in sporophytes was high under normal conditions and was not affected by excess copper. In contrast to BPOX-like gene, Mn-superoxide dismutase gene did not show any variation in transcript abundance between sporophytes and gametophytes. Application of bromate and vanadium (prosthetic group of BPOX) did not affect the expression of BPOX-like gene in both gametophytes and sporophytes. Spectrophotometric assay for BPOX activity suggested that sporophytes have much higher activity compared to gametophytes. BPOX activity staining on native PAGE gel revealed that the in vitro BPOX activity was strictly dependent on bromate and the in vivo synthesis of BPOX was promoted by bromate in sporophytes, in contrast to that gametophytes have no BPOX activity in these conditions. In this study, I found that the differential expression of BPOX–like gene in P. yezoensis between gametophytes and sporophytes. Some marine macro-algae including red algae are known to use brominated organic compounds as the protectants against pathogenic organisms. To know the physiological role of BPOX in P. yezoensis, the synthesis of the brominated compounds must be analyzed in unstressed sporophytes or in stressed gametophytes.
Many halogens such as I, Br, Cl are found abundantly in seawater unlike fresh water. Halogenated organic compounds are synthesized by marine algae with the aid of haloperoxidase. Bromoperoxidase (BPOX) is a member of haloperoxidases and catalyzes the bromination reaction of organic compounds. Genes and activities of BPOXs are reported for various species of marine macroalgae incuding red algae. However, the red alga Porphyra collected from its natural habitats is known to contain no or little amount of halogenated compounds. There is no information about BPOX in Porphyra, although BPOX-like gene fragments are present in public EST database of Porphyra yezoensis. In this study, I investigated the expression pattern of the BPOX-like gene in P. yezoensis using sporophytes and gametophytes. A partial DNA fragment (1504 bp) of BPOX-like gene was isolated using P. yezoensis EST database. Genomic Southern blot analysis suggested that Porphyra BPOX-like gene exists as a single copy per haploid genome. RT-PCR results revealed that the expression of BPOX-like gene in gametophytes was strongly suppressed under normal growth conditions but induced by supply of excess copper. On the other hand, the expression of BPOX-like gene in sporophytes was high under normal conditions and was not affected by excess copper. In contrast to BPOX-like gene, Mn-superoxide dismutase gene did not show any variation in transcript abundance between sporophytes and gametophytes. Application of bromate and vanadium (prosthetic group of BPOX) did not affect the expression of BPOX-like gene in both gametophytes and sporophytes. Spectrophotometric assay for BPOX activity suggested that sporophytes have much higher activity compared to gametophytes. BPOX activity staining on native PAGE gel revealed that the in vitro BPOX activity was strictly dependent on bromate and the in vivo synthesis of BPOX was promoted by bromate in sporophytes, in contrast to that gametophytes have no BPOX activity in these conditions. In this study, I found that the differential expression of BPOX–like gene in P. yezoensis between gametophytes and sporophytes. Some marine macro-algae including red algae are known to use brominated organic compounds as the protectants against pathogenic organisms. To know the physiological role of BPOX in P. yezoensis, the synthesis of the brominated compounds must be analyzed in unstressed sporophytes or in stressed gametophytes.