Cheating by exploitation of developmental prestalk patterning in Dictyostelium discoideum.
Cheating by exploitation of developmental prestalk patterning in Dictyostelium discoideum.
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DOI：
10.1371/journal.pgen.1000854
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发表时间：
2010-02-26
期刊：
影响因子：
4.5
通讯作者：
Shaulsky G
中科院分区：
文献类型：
--
作者：
Khare A;Shaulsky G
社会性阿米巴盘基网柄菌的合作发育系统很容易受到作弊者的利用，这些作弊者在嵌合体中产生的孢子超过了其应有的份额。盘基网柄菌属的实验室筛选表明，兼性作弊的遗传潜力很高，实地调查表明，作弊者在自然界中大量存在，但作弊机制很大程度上未知。在这里，我们描述了作弊者 C (chtC)，这是一种强兼性作弊者突变体，通过影响前茎分化来作弊。 chtC 基因受发育调控，其 mRNA 在发育末期变得富集。 chtC 突变体在维持前柄细胞命运方面存在缺陷，因为它们的一些前柄细胞转分化为前孢子细胞，但该缺陷不会影响总体发育形态或孢子形成效率。在野生型和chtC突变细胞之间的嵌合体中，野生型细胞优先产生前柄细胞，而chtC突变体增加了它们在孢子团中的代表性。将 chtC 突变体与其他细胞类型比例突变体混合表明，作弊行为与受害者的前茎分化倾向直接相关。这些发现表明，作弊者可以通过利用既定的发展途径来损害合作压力。合作系统很容易被作弊者利用，他们享受合作的好处而不支付成本。这种冲突存在于生物系统的各个层面，从细胞内的个体基因到社会中的个体。社会性变形虫盘基网柄菌具有独特的合作系统，其中大量单个细胞聚集形成具有生殖孢子的子实体，以及有助于孢子生存和传播的死亡茎细胞。子实体可以含有多种基因型，因此可以被作弊细胞利用，这些作弊细胞优先形成孢子，而不公平地为茎做出贡献。我们研究了一种突变体，骗子C（chtC），它在形成某些茎细胞方面有缺陷，但仍然能够自行形成子实体。然而，当野生型细胞与chtC细胞混合时，野生型细胞补偿了chtC的茎形成缺陷并形成更多的茎细胞。通过这种方式，chtC 细胞会利用通常调节细胞类型比例的发育过程来进行欺骗。这项研究表明，欺骗突变体可以利用现有的发育调节机制，而社会变形虫为研究此类机制提供了一个良好的系统。
The cooperative developmental system of the social amoeba Dictyostelium discoideum is susceptible to exploitation by cheaters—strains that make more than their fair share of spores in chimerae. Laboratory screens in Dictyostelium have shown that the genetic potential for facultative cheating is high, and field surveys have shown that cheaters are abundant in nature, but the cheating mechanisms are largely unknown. Here we describe cheater C (chtC), a strong facultative cheater mutant that cheats by affecting prestalk differentiation. The chtC gene is developmentally regulated and its mRNA becomes stalk-enriched at the end of development. chtC mutants are defective in maintaining the prestalk cell fate as some of their prestalk cells transdifferentiate into prespore cells, but that defect does not affect gross developmental morphology or sporulation efficiency. In chimerae between wild-type and chtC mutant cells, the wild-type cells preferentially give rise to prestalk cells, and the chtC mutants increase their representation in the spore mass. Mixing chtC mutants with other cell-type proportioning mutants revealed that the cheating is directly related to the prestalk-differentiation propensity of the victim. These findings illustrate that a cheater can victimize cooperative strains by exploiting an established developmental pathway. Cooperative systems are susceptible to exploitation by cheaters who enjoy the benefits of cooperation without paying the costs. Such conflict is seen in biological systems at every level from individual genes within a cell to individuals within societies. The social amoebae Dictyostelium discoideum have a unique cooperative system in which large numbers of individual cells aggregate to form fruiting bodies with reproductive spores, and dead stalk cells that may help the survival and dispersal of the spores. Fruiting bodies can contain several genotypes, and hence can be exploited by cheater cells that preferentially form spores without contributing fairly to the stalk. We have studied a mutant, cheater C (chtC), which is defective in forming certain stalk cells, but is still able to form fruiting bodies on its own. However, when wild-type cells are mixed with chtC cells, the wild-type cells compensate for the stalk-forming defect of chtC and form more of the stalk cells. In that way, chtC cells cheat by taking advantage of developmental processes that normally regulate cell-type proportions. This study shows that existing mechanisms of developmental regulation can be exploited by cheater mutants, and the social amoebae offer a good system to study such mechanisms.
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影响因子：
14.9
作者：
Faix, J;Kreppel, L;Kimmel, AR
通讯作者：
Kimmel, AR
影响因子：
2.7
作者：
Shaulsky, G;Loomis, WF
通讯作者：
Loomis, WF
影响因子：
--
作者：
Katoh, M;Curk, T;Shaulsky, G
通讯作者：
Shaulsky, G
DOI：
10.1073/pnas.0702723104
发表时间：
2007-05-22
影响因子：
11.1
作者：
Gilbert, Owen M.;Foster, Kevin R.;Queller, David C.
通讯作者：
Queller, David C.
影响因子：
64.8
作者：
Foster, KR;Shaulsky, G;Thompson, CRL
通讯作者：
Thompson, CRL