New "missing link" genus of the colonial volvocine green algae gives insights into the evolution of oogamy.
New "missing link" genus of the colonial volvocine green algae gives insights into the evolution of oogamy.
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DOI：
10.1186/1471-2148-14-37
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发表时间：
2014-03-03
影响因子：
3.4
通讯作者：
Nakada T
中科院分区：
文献类型：
--
作者：
Nozaki H;Yamada TK;Takahashi F;Matsuzaki R;Nakada T
卵同配的进化是一个重要的生物学事件，在异配过程中，形态相似的配子（同配子）分化为小的“雄”和大的“雌”运动配子，而不运动的雌配子（卵）则由此进化而来。volvocine绿藻代表了研究这种类型的性进化的一个模式谱系，并显示了两种类型的配子结合：亲代群体外的同配子之间的结合（同配子交配期间的外部受精）和雌性群体内的小运动配子（精子）和大配子（卵子）之间的受精（异配子交配和卵交配期间的内部受精）。尽管最近对藻藻的培养研究揭示了藻藻有性生殖的形态多样性和分子遗传数据，但尚未发现这两种配子结合之间的中间结合类型。我们发现了一个新的群体volvocine属，Colemanosphaera，它通过群体细胞的连续分裂产生成束的纺锤形雄性配子。雄性和雌性运动配子之间的专性异配子交配发生在雌性群体之外（异配子交配期间的外部受精）。这个新属含有16或32个细胞的球状菌落，类似于volvocine属Yamagishiella和Eudorina。然而，Colemanosphaera可以根据其与神秘的扁平殖民地volvocine Platydorina的姐妹系统发育位置和异种交配期间的外部受精明显区别于这两个属。在日本的一个湖泊中发现了两种水藻；根据奥地利菌株的已发表序列和乌克兰Pandorina charkowiensis的原始描述，这些物种也分布在欧洲淡水中。基于系统发育和形态学数据，这个新属显示了Platydorina和典型的球形群体volvocine成员（如Pandorina或Yamagishiella）之间缺失的联系。考虑到外部专性异配，卵配进化可能在藻藻异配过程中由外部受精过渡到内部受精之前。
The evolution of oogamy from isogamy, an important biological event, can be summarized as follows: morphologically similar gametes (isogametes) differentiated into small “male” and large “female” motile gametes during anisogamy, from which immotile female gametes (eggs) evolved. The volvocine green algae represent a model lineage to study this type of sex evolution and show two types of gametic unions: conjugation between isogametes outside the parental colonies (external fertilization during isogamy) and fertilization between small motile gametes (sperm) and large gametes (eggs) inside the female colony (internal fertilization during anisogamy and oogamy). Although recent cultural studies on volvocine algae revealed morphological diversity and molecular genetic data of sexual reproduction, an intermediate type of union between these two gametic unions has not been identified. We identified a novel colonial volvocine genus, Colemanosphaera, which produces bundles of spindle-shaped male gametes through successive divisions of colonial cells. Obligately anisogamous conjugation between male and female motile gametes occurred outside the female colony (external fertilization during anisogamy). This new genus contains 16- or 32-celled spheroidal colonies similar to those of the volvocine genera Yamagishiella and Eudorina. However, Colemanosphaera can be clearly distinguished from these two genera based on its sister phylogenetic position to the enigmatic flattened colonial volvocine Platydorina and external fertilization during anisogamy. Two species of Colemanosphaera were found in a Japanese lake; these species are also distributed in European freshwaters based on a published sequence of an Austrian strain and the original description of Pandorina charkowiensis from Ukraine. Based on phylogeny and morphological data, this novel genus exhibits a missing link between Platydorina and the typical spheroidal colonial volvocine members such as Pandorina or Yamagishiella. Considering the external obligate anisogamy, oogamy evolution may have been preceded by the transition from external to internal fertilization during anisogamy within the volvocine green algae.
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DOI：
10.1073/pnas.96.24.13892
发表时间：
1999-11-23
影响因子：
11.1
作者：
Coleman, AW
通讯作者：
Coleman, AW
DOI：
10.1073/pnas.0811205106
发表时间：
2009-03-03
影响因子：
11.1
作者：
Herron, Matthew D.;Hackett, Jeremiah D.;Michod, Richard E.
通讯作者：
Michod, Richard E.
DOI：
10.1126/science.1186222
发表时间：
2010-04-16
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Ferris P;Olson BJ;De Hoff PL;Douglass S;Casero D;Prochnik S;Geng S;Rai R;Grimwood J;Schmutz J;Nishii I;Hamaji T;Nozaki H;Pellegrini M;Umen JG
通讯作者：
Umen JG
影响因子：
2.9
作者：
Angeler, DG;Schagerl, M;Coleman, AW
通讯作者：
Coleman, AW
影响因子：
5.8
作者：
Hamada, Michiaki;Kiryu, Hisanori;Asai, Kiyoshi
通讯作者：
Asai, Kiyoshi