1995 Fiscal Year Final Research Report Summary
Identification of species and hybrids in corals by DNA markers
| Project/Area Number |
06839027
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
海洋生物学
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| Research Institution | National Institute of Genetics |
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Principal Investigator |
HATTA Masayuki Natl.Inst.of Genet., Devel.Genet., associate researcher, 個体遺伝研究系, 助手 (00249947)
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| Co-Investigator(Kenkyū-buntansha) |
FUJISAWA Toshitaka Natl.Inst.of Genet., Devel.Genet., associate professor, 個体遺伝研究系, 助教授 (60000262)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Coral / Introgression / Speciation / Mini-collagen |
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| Research Abstract |
In this study, we combined morphological classification, DNA phylogenetic analysis and reproductive cross experiment to solve problems on speciation and gene introgression in major reef-building corals Genus Acropora possibly arising from mass spawning. At first we isolated a mini-collagen gene encoding a nematocyst capsule protein from A.donei and A.nasuta and determined the whole DNA sequences of them for about 5000 base pairs long respectively.Primes for PCR were designed according to the comparison of the genes, PCR amplification of a part of the gene was succeeded that spans from the 2nd exon to the 3rd exon from 14 species of Acropora. Obtained DNA fragment sequenced and compared by neighbor-joining method to figure out intraspecific polymorphisms and interspecific divergences. On the other hand the Acropora corals were subjected to experimental cross to ask reproductive isolation of the species. Results are following, 1 : A.nasuta and a morphologically similar species showed interspecific fertilization and their DNA differences are larger in intraspecies than in interspecies suggesting gene introgression by hybridization, 2 : A.nasuta and A.formosa, morphologically far related species, fertilized interspecifically at high frequency and A.formosa possessed two types of DNA sequence belonging to A.formosa group and A.nasuta group suggesting A.formasa as a hybrid species of A.nasuta and an unidentified species, 3 : a major table coral A.hyacinthus has small DNA variation but fertilized by small number of combination within this species suggesting rapid appearance of reproductive isolation in this species. Thus evidences were obtained to understand how Acropora evolving forming 'metaspecies' through mass spawning.
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