RAPD를 이용한 한국 김 집단의 유전적 다양성과 표현형 관계

Studying the Genetic Diversity and Phenetic Relationships of Porphyra yezoensis Populations in Korea Using Random Amplified Polymorphic DNA (RAPD)

Abstract

김(Porphyra yezoensis)은 김속의 홍조류이다. RAPD (random amplified polymorphic DNA) 마커를 이용하여 한국 내 네 집단의 표현형과 유전적 다양성을 조사하였다. 전체적으로 20 시발체로 김에서 55분절이 관찰되었다. 이들 밴드 중 30개(54.5%)는 다형성을 나타내었다. OPA-18-02 밴드는 낙동 김 집단에서만 증폭되었다. OPA-20-02 밴드는 서천 김 집단에서만 증폭되었다. 이 두 밴드는 특별한 집단을 구별해주는 특이밴드로 판정되었다. 대립유전자좌위의 수(Ae)는 1.161에서 1.293로 평균은 1.366였다. 서천 김 집단이 가장 높은 다형성을 나타내었다(0.163). 다른 집단과 격리되고 조간대에 위치한 낙동 김 집단은 가장 낮은 다형성을 나타내었다(0.092). 샤논의 표현형 다양성(I)은 서천 김 집단이 가장 높았다(0.238). 전체 유전적 다양도($H_T$)는 0.132(OPA-02)에서 0.420(OPA-19)로 나타났다. 대립유전자좌위에서 유전적 다양성($H_S$)은 0.059(OPA-18)에서 0.339(OPA-19)였다. 대립유전자좌위에 근거에서 전체 유전적 다양도에서 집단 간 차이($G_{ST}$)는 0.012(OPA-11)에서 0.762(OPA-18)이였으며 평균은 0.415였다. 이는 전체 변이의 약 42%는 집단 간에서 발견된다는 것을 의미한다. 종 내 다양도의 58.5%는 집단 내에 있었다. 유전자 흐름(Nm)은 0.705로 낮았다.

Porphyra yezoensis is a red algal species in the genus Porphyra. The phenetics and genetic diversity of four populations of P. yezoensis in Korea were reconstructed using random amplified polymorphic DNA (RAPD) markers. Overall, 55 fragments were generated among the tested P. yezoensis array with 20 OPERON primers. A total of 30(54.5%) of these bands were polymorphic. The OPA-18-02 band was amplified in the samples of Nakdong population and absent in them of other three populations. The OPA-20-02 band was only amplified in the Seocheon population. Both bands exhibited distinctive patterns in specific populations. The effective number of alleles per locus (Ae) ranged from 1.161 to 1.293 with a mean of 1.366. The Seocheon population had a high expected diversity (0.163). The Nakdong population was an isolated endemic and intertidal zone. Thus the narrow distributed Nakdong population had a low expected diversity (0.092). Shannon's index of phenotypic diversity (I) of the Seocheon population (0.238) was the highest among all populations. Total genetic diversity ($H_T$) varied between 0.132 for OPA-02 and 0.420 for OPA-19. The interlocus variation of genetic diversity ($H_S$) was 0.059 for OPA-18 and 0.339 for OPA-19. On a per locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) ranged from 0.012 for OPA-11 to 0.762 for OPA-18 with a mean of 0.415, indicating that 42% of the total variation was found among these populations. In an assessment of the proportion of diversity present within this species, 58.5% (100%-41.5%) of genetic variation resided within the populations studied. The Nm was estimated to be low (0.705).

Fig. 1. A phenogram showing the relationships among four populations of Porphyra yezoensis and one outgroup (Ulva prolifera) based on data of genetic distance obtained by RAPD.

Table 1. Codes and geographic locations of four Porphyra yezoensis populations

Table 2. List of decamer oligonucleotides utilized as primers, their sequences, and associated polymorphic fragments amplified in Porphyra yezoensis

Table 3. Measures of genetic variation for Porphyra yezoensis. The number of polymorphic loci (Np), percentage of polymorphism (Pp), mean number of alleles per locus (A), effective number of alleles per locus (A_E), gene diversity (H), and Shannon's information index (I)

Table 4. Estimates of genetic diversity of Porphyra yezoensis. Total genetic diversity (H_T), genetic diversity within populations (H_S) proportion of total genetic diversity partitioned among populations (G_ST), and gene flow (Nm)

Table 5. Genetic identity (upper diagonal) among four populations of Porphyra yezoensis and genetic distances (low diagonal) based on RAPD analysis