حضور کلاد D زوگزانتله در مرجان های نرم و سخت غالب اطراف جزیره لارک، خلیج فارس
محورهای موضوعی : تک یاخته شناسی
محمد حسن شاه حسینی
1
(دانشگاه آزاد اسلامی، واحد شهرقدس، گروه میکروبیولوژی)
پر گل قوام مصطفوی
2
(دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، گروه بیولوژی دریا)
غلامحسین وثوقی
3
(دانشکده دامپزشکی دانشگاه تهران)
ساناز آزادبادی
4
(دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، گروه بیولوژی دریا)
کلید واژه: خلیج فارس, Symbiodinium, کلاد D, جلبک تک سلولی,
چکیده مقاله :
سابقه و هدف: مرجان‌های سخت و نرم خلیج فارس دارای جلبک تک سلولی هم‌زیستی به نام زوگزانتله می‌باشند که نقش مهمی در تأمین مواد آلی مورد نیاز مرجان‌ها ایفا می‌نماید. آبسنگ‌های مرجانی این ناحیه از خلیج به دلیل قرار گرفتن در عرض‌های جغرافیایی نیمه گرمسیری و وجود دامنه وسیع تغییرات دمای آب و شوری بالا همواره تحت تأثیرتنش های محیطی می‌باشند. این تنش ها می‌تواند منجر به تغییر زوگزانتله‌های همزیست با آن‌ها گردد. این مطالعه با هدف شناسایی کلادهای Symbiodinium به روش مولکولی و نیز بررسی حضور کلاد D زوگزانتله در مرجان‌های نرم و سخت جزیرۀ لارک در خلیج فارس انجام شده است. مواد و روش‌ها: 3 گونه از مرجان‌های نرم شمال و شمال شرق جزیره لارک و 5 گونه مرجان سخت در شمال جزیره جمع آوری گردید. پس از استخراج DNA، زیرواحد بزرگ ریبوزومی S28 با استفاده از واکنش زنجیره‌ای پلی‌مراز (PCR) تکثیر شد. سپس توالی زیرواحد بزرگ ریبوزومی S28 با استفاده از آنالیز فیلوژنی، مورد تجزیه و تحلیل قرار گرفت. یافته‌ها: به دنبال تکثیر قطعه‌ای از ژن زیرواحد بزرگ ریبوزومی S28، توالی bp780 به دست آمد. پس از توالی‌یابی قطعه ژنی تکثیر یافته و مقایسه آن با ترادف‌های ژنی موجود در بانک ژنی مشخص گردید که کلادهای همزیست با مرجان های نرم اطراف جزیره لارک، از نوع کلاد D می‌باشند. نتیجه گیری: غالب بودن کلاد D به علت درجه حرارت بالای خلیج فارس و نیز شرایط ناپایدار تنگۀ هرمز در مرجان‌های نرم و سخت جزیرۀ لارک کاملاً طبیعی می‌باشد.
Abstract Background and Objectives: Dominant sclerectinian and soft corals contain the symbiotic single cell called zooxanthellae which have important role in preparing organic material for coral requirements. The coral reefs of this area in the gulf are always under effects of environmental conditions, such as subtropical latitude, temperature and salinity variations, changing symbiotic zooxanthellae. The aims of this study was identification of Symbiodinium clades and presence of clade D in sclerectinian and soft corals of Larak island by molecular methods. Materials and Methods: Three soft coral species and five sclerectinian coral species were collected from north and north east of Larak island, respectively. After DNA extraction, partial 28S ribosomal DNA of Symbidinium were amplified by polymerase chain reaction (PCR). Then PCR products were analyzed by phylogenetic analyses of the partial 28S ribosomal sequence. Results: To follow amplification of 28S large ribosomal subunit gene, the 780 bp PCR products were sequenced and were compared to the gene bank. The results showed that all the symbiotic clades of soft corals in Larak Island belonged to clade D. Conclusion: Dominance of clade D in sclerectinian and soft corals in Larak island due to of high temperature in the Persian Gulf and unstable condition of Hormoz strait is normal and natural.
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