A study of sexual and asexual populations of Scytosiphon lomentaria (Scytosiphonaceae, Phaeophyceae) in Hokkaido, northern Japan, using molecular markers
A study of sexual and asexual populations of Scytosiphon lomentaria (Scytosiphonaceae, Phaeophyceae) in Hokkaido, northern Japan, using molecular markers
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DOI：
10.1080/09670260500193008
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发表时间：
2005-08-01
影响因子：
2.4
通讯作者：
Masuda, M
中科院分区：
文献类型：
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作者：
Kogame, K;Uwa, S;Masuda, M
以采自日本北方北海道的大正郎、阿沙里和室兰3个地点的藻体为材料，研究了雌雄异株和同花受精的棕色花管藻Scytosiphonlomentaria（Scytosiphonaceae，Phaeophyceae）配子融合的存在与否。在每个地方都发现了有性和无性的菌体。这些有性（35个样品）和无性的菌体（15个样品）用于建立单藻培养物。在所有培养物中测定ITS 2序列，在14种培养物中测定rbcL-spacer-S序列，在25种培养物中测定cox 3序列。ITS 2序列（241-252 bp）中有1 - 3种单倍型（A1-4，B; C1-4 D E1-3）。在有性样本中发现了10种单倍型（A1-4、B、C1-4和D），其中A型和B型见于大少郎，C型和D型见于朝里，C型见于室兰。单倍型E1-3见于无性系。有性（A、B、C、D型）和无性（E型）之间的序列差异（包括空位信息）均小于4.03%，无性与有性之间的差异（包括空位信息）为4.39-5.70%，无性与有性之间的差异（包括空位信息）为0.38-0.77%。在线粒体cox 3基因区（543 bp），共获得6种单倍型（K1 -3、L、M和N）。在ITS 2-A型中发现cox 3-K型，在ITS 2-B型中发现cox 3-L型，在ITS 2-C和D型中发现cox 3-M型，在ITS 2-E型中发现cox 3-N型。cox 3序列在有性生殖（K型、L型和M型）之间的差异为0.18-4.42%，而在有性生殖与无性生殖（N型）之间的差异为8.66-10.31%。在部分rbcL（174 bp）-spacer（188 bp）-部分rbcS（90 bp）序列中，发现了6种单倍型（R-W），尽管这些单倍型之间存在1-4 bp的核苷酸差异。有性生殖的样品中有R、U和W型，无性生殖的样品中有S、T和V型。序列分析的结果表明，我们假定的无性菌体在遗传上不同于有性菌体，可能来自缺乏有性生殖的种群。
The presence or absence of gamete fusion in the dioecious and isogamous brown alga Scytosiphon lomentaria (Scytosiphonaceae, Phaeophyceae) was investigated for thalli collected from three localities, Oshoro, Asari and Muroran in Hokkaido, northern Japan. Both sexual and asexual thalli were found in each locality. These sexual (35 samples) and asexual thalli (15 samples) were used to establish unialgal cultures. ITS2 sequences were determined in all cultures, the rbcL-spacer-S in 14, and cox3 in 25 cultures. Thirteen haplotypes (A1-4, B; C1-4 D E1-3) were found in ITS2 sequences (241-252 bp). Ten haplotypes (A1-4, B, C1-4 and D) were found in sexual samples: haplotypes A and B were found in Oshoro, C and D in Asari, and C in Muroran. Haplotypes E1-3 were found in asexual samples. Sequence divergence values (including gap information) were less than 4.03% among sexual samples (A, B C and D types), 0.38-0.77% among asexual samples (E types) and 4.39-5.70% between sexual and asexual samples. In the mitochondrial cox3 gene region (543 bp), six haplotypes (K 1-3, L, M and N) were obtained. Cox3-K types were found in samples of ITS2-A types, cox3-L type in ITS2-B type, cox3-M type in ITS2-C and D types, and cox3-N type in ITS2-E types. For cox3 sequences, nucleotide differences were 0.18-4.42% among sexual samples (K, L and M types), but 8.66-10.31% between sexual and asexual samples (N type). In partial rbcL (174 bp)-spacer (188 bp)-partial rbcS (90 bp) sequences, six haplotypes (R-W) were found although there were 1-4 bp nucleotide differences among these haplotypes. R, U and W types were found in sexual samples, and S, T and V types in asexual samples. Results of the sequence analyses suggest that our presumed asexual thalli are genetically different from sexual thalli and may be derived from populations that lack sexual reproduction.