In the social amoeba Dictyostelium discoideum, density, not farming status, determines predatory success on unpalatable Escherichia coli.
In the social amoeba Dictyostelium discoideum, density, not farming status, determines predatory success on unpalatable Escherichia coli.
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DOI：
10.1186/s12866-014-0328-x
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发表时间：
2014-12-20
期刊：
影响因子：
4.2
通讯作者：
Strassmann JE
中科院分区：
文献类型：
--
作者：
DiSalvo S;Brock DA;Smith J;Queller DC;Strassmann JE
社会阿米巴与细菌的相互作用方式多种多样。它是细菌的捕食者，可以被细菌感染或伤害，并可以与细菌形成共生关系。一些盘状芽孢杆菌的克隆起到了原始农场主的作用，因为它们携带细菌通过通常不育的盘状芽孢杆菌的社会阶段，然后在扩散后释放它们，这样细菌就可以增殖并被收获。一些与农民相关的细菌产生小分子，促进宿主农民的生长，但抑制非农民竞争对手的生长。为了测试农民的耐受性是特异性的，还是延伸到其他生长抑制细菌，我们测试了农民和非农民阿米巴是否受到不同致病性的大肠杆菌菌株的不同影响。由于每种微生物的数量可能会影响阿米巴与细菌相互作用的结果，我们还检测了阿米巴和细菌密度对盘状螺旋体在不同细菌菌株上生长和发育能力的影响。一组大肠杆菌菌株不支持阿米巴在富含介质上的增殖，无论阿米巴是农民还是非农民。然而，如果阿米巴数量相对于细菌数量较高，则阿米巴可以在这些菌株上增殖，但盘形藻农场主和非农场主克隆之间的这种能力没有差异。我们的结果表明，农民和非农民在消费新型大肠杆菌的能力上没有差异，这表明农民对自己携带的细菌的抗药性并不延伸到外来细菌。我们看到，增加细菌或阿米巴的数量会增加它们各自赢得竞争胜利的可能性，从而显示出Allee效应。我们假设，更高的细菌数量可能会导致有毒产品的浓度更高，或者减少对阿米巴生存至关重要的资源，从而产生一个不适合阿米巴捕食者的环境。更多的阿米巴数量可能会抵消这种生长抑制，可能是通过增加捕食率来减少细菌数量，或者通过产生某种东西来中和潜在的有毒细菌产品。本文的在线版本(doi：10.1186/s12866-0140328-x)包含补充材料，授权用户可以使用。
The social amoeba Dictyostelium discoideum interacts with bacteria in a variety of ways. It is a predator of bacteria, can be infected or harmed by bacteria, and can form symbiotic associations with bacteria. Some clones of D. discoideum function as primitive farmers because they carry bacteria through the normally sterile D. discoideum social stage, then release them after dispersal so the bacteria can proliferate and be harvested. Some farmer-associated bacteria produce small molecules that promote host farmer growth but inhibit the growth of non-farmer competitors. To test whether the farmers’ tolerance is specific or extends to other growth inhibitory bacteria, we tested whether farmer and non-farmer amoebae are differentially affected by E. coli strains of varying pathogenicity. Because the numbers of each organism may influence the outcome of amoeba-bacteria interactions, we also examined the influence of amoeba and bacteria density on the ability of D. discoideum to grow and develop on distinct bacterial strains. A subset of E. coli strains did not support amoeba proliferation on rich medium, independent of whether the amoebae were farmers or non-farmers. However, amoebae could proliferate on these strains if amoebae numbers are high relative to bacteria numbers, but again there was no difference in this ability between farmer and non-farmer clones of D. discoideum. Our results show that farmer and non-farmers did not differ in their abilities to consume novel strains of E. coli, suggesting that farmer resistance to their own carried bacteria does not extend to foreign bacteria. We see that increasing the numbers of bacteria or amoebae increases their respective likelihood of competitive victory over the other, thus showing Allee effects. We hypothesize that higher bacteria numbers may result in higher concentrations of a toxic product or in a reduction of resources critical for amoeba survival, producing an environment inhospitable to amoeba predators. Greater amoeba numbers may counter this growth inhibition, possibly through reducing bacterial numbers via increased predation rates, or by producing something that neutralizes a potentially toxic bacterial product. The online version of this article (doi:10.1186/s12866-014-0328-x) contains supplementary material, which is available to authorized users.
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影响因子：
3.4
作者：
Alibaud, Laeticia;Koehler, Thilo;Cosson, Pierre
通讯作者：
Cosson, Pierre
影响因子：
3.1
作者：
Bingen-Bidois, M;Clermont, O;Bingen, E
通讯作者：
Bingen, E
影响因子：
3.7
作者：
Matz C;Webb JS;Schupp PJ;Phang SY;Penesyan A;Egan S;Steinberg P;Kjelleberg S
通讯作者：
Kjelleberg S
影响因子：
5.1
作者：
Matz, C;Bergfeld, T;Kjelleberg, S
通讯作者：
Kjelleberg, S
DOI：
10.1073/pnas.1118131109
发表时间：
2012-05-22
影响因子：
11.1
作者：
Darch, Sophie E.;West, Stuart A.;Diggle, Stephen P.
通讯作者：
Diggle, Stephen P.