Host avoidance and resistance vary independently and are specific to parasite genotype

Hosts can reduce the negative fitness effects of parasite infection by avoiding contact with parasites or by resisting infection after contact. Because of their shared outcome, avoidance and resistance have been hypothesized to trade off with one another. Assuming these defenses carry fitness costs, hosts are expected to have high levels of one defense or the other, but not both. Alternatively, avoidance and resistance may covary positively, if, for example, they complement one another or are genetically or mechanistically linked. Testing these hypotheses requires measuring avoidance and resistance independently, which is challenging because they are functionally linked. In this study, we separated avoidance and resistance of the host C. elegans against the bacterial parasite S. marcescens and tested for a correlation between them. We phenotyped a panel of 12 genetically divergent hosts using two distinct bacterial strains and multiple experimental contexts. We found no evidence of a co..., Overview We examined the relationship between avoidance and resistance to two distinct strains of the opportunistic bacterial parasite S. marcescens across 12 genetically divergent strains of C. elegans. We chose parasite strains that we expected to differ in their virulence and the avoidance they elicit. We assayed resistance independently of avoidance by measuring survival after directly dosing hosts in liquid, which prevents hosts avoiding the parasite. We used two assays to measure avoidance: a lawn-leaving assay (Pradel et al., 2007) and a choice assay (Schulenburg & Müller, 2004). These are two common designs used for assessing behavioral responses to bacteria, and we expected they would capture different aspects of behavioral variation. We used data from these assays to test whether resistance and avoidance covaried across C. elegans strains. Each assay was conducted in a blocked design, with a different subset of host strains tested in each of four to five experimental block..., # Data from: Host avoidance and resistance vary independently and are specific to parasite genotype Dataset DOI: [10.5061/dryad.gxd254804](10.5061/dryad.gxd254804) ## Description of the data and file structure This study examined the correlation between avoidance and resistance of the nematode host *Caenorhabditis elegans* to the bacterial parasite *Serratia marcescens*. We measured avoidance with two behavioral assay: a lawn-leaving assay and a choice assay. We measured resistance as survival in liquid culture with the parasite. The host strains were assigned a numeric label to facilitate interpretation of the figures in the main text. This is the assignment of labels to host strains, which can also be found in the electronic supplementary materials. | Label | Host strain | | :---- | :---------- | | 1 | DL238 | | 2 | MY16 | | 3 | JT11398 | | 4 | N2 | | 5 | EG4725 | | 6 | CB4856 | | 7 | CX11314 | | 8 | MY23 ...,宿主可通过避开寄生虫接触，或在接触后抵抗感染，以减轻寄生虫感染对自身适合度的负面影响。由于二者最终效应一致，规避行为与抵抗能力曾被假设存在权衡（trade-off）关系。假设两类防御策略均携带适合度成本，则宿主应倾向于高水平表达其中一种防御策略，而非同时兼具两者。反之，若二者存在互补关系，或在遗传、机制层面存在关联，则规避行为与抵抗能力可能呈现正相关。检验此类假说需要独立测量规避行为与抵抗能力，但二者在功能上相互关联，这给研究带来了挑战。本研究中，我们区分并独立测定了宿主秀丽隐杆线虫（Caenorhabditis elegans）对细菌寄生虫粘质沙雷氏菌（Serratia marcescens）的规避行为与抵抗能力，并检验二者间的相关性。我们使用两种不同的细菌菌株与多种实验环境，对12个遗传背景各异的宿主菌株队列进行了表型分析。我们未发现二者存在共... ## 研究概况 我们针对12个遗传背景各异的秀丽隐杆线虫菌株，检验了其对两种不同机会致病性细菌寄生虫——粘质沙雷氏菌的规避行为与抵抗能力之间的关联。我们选取了预期在毒力与诱导宿主规避行为能力上存在差异的寄生虫菌株。为独立测定抵抗能力，我们通过直接向液体培养基中的宿主接种寄生虫的方式测量宿主存活率，该方法可阻断宿主对寄生虫的规避行为。我们采用两种行为学实验测定规避行为：草坪离开实验（lawn-leaving assay，Pradel等，2007）与选择实验（choice assay，Schulenburg & Müller，2004）。这二者是评估宿主对细菌行为反应的经典实验设计，我们预期它们可捕捉到行为变异的不同维度。我们利用这些实验的数据，检验不同秀丽隐杆线虫菌株的抵抗能力与规避行为是否存在相关性。每项实验均采用区组设计，每4至5个实验区组中测试不同的宿主菌株子集... # 数据来源：宿主规避行为与抵抗能力独立变异且具有寄生虫基因型特异性 数据集DOI：[10.5061/dryad.gxd254804](10.5061/dryad.gxd254804) ## 数据与文件结构说明 本研究探究了线虫宿主秀丽隐杆线虫对细菌寄生虫粘质沙雷氏菌的规避行为与抵抗能力之间的相关性。我们通过两种行为学实验测定规避行为：草坪离开实验与选择实验；并以液体培养基中宿主与寄生虫共培养后的存活率作为抵抗能力的衡量指标。 为便于正文中图表的解读，我们为宿主菌株分配了数字标签。以下为宿主菌株与标签的对应关系，该信息亦可在电子补充材料中获取： | 标签 | 宿主菌株 | | :---- | :---------- | | 1 | DL238 | | 2 | MY16 | | 3 | JT11398 | | 4 | N2 | | 5 | EG4725 | | 6 | CB4856 | | 7 | CX11314 | | 8 | MY23 ... |