Ectopical expression of bacterial collagen-like protein supports its role as adhesin in host-parasite coevolution

For a profound understanding of antagonistic coevolution, it is necessary to identify the coevolving genes. The bacterium Pasteuria and its host, the microcrustacean Daphnia, are a well-characterized paradigm for co-evolution, but the underlying genes remain largely unknown. A genome-wide association study suggested a Pasteuria collagen-like protein 7 (Pcl7) as a candidate mediating parasite attachment and driving its coevolution with the host. Since Pasteuria ramosa cannot currently be genetically manipulated, we used Bacillus thuringiensis to express a fusion protein of a Pcl7 carboxy- terminus from P. ramosa and the amino-terminal domain of a B. thuringiensis collagen-like protein (CLP). Mutant B. thuringiensis (Pcl7-Bt) spores but not wild-type B. thuringiensis (WT-Bt) spores, attached to the same site of susceptible hosts as P. ramosa. Furthermore, Pcl7-Bt spores attached readily to susceptible host genotypes, but only slightly to resistant host genotypes. These findings indica...,

Daphnia were individually placed into a 96-well plate containing 150 μl of ADaM per well. A 10 μl of spore solution containing ~500 fluorescently labelled P. ramosa spores were added to each well and incubated in the dark for 5 min. For B. thuringiensis, 10 μl of spore solution containing ~50 000 labelled B. thuringiensis spores were added to each well and incubated in the dark for 5 min. The entire liquid volume in each well was removed and replaced with 150 μl fresh ADaM. This washing step was repeated twice, after which the entire liquid volume in each well was removed. The Daphnia were placed individually on a microscopy slide using a toothpick. A glass cover slide was applied to the Daphnia gently to avoid crushing it. Spore attachment was assessed by carefully assessment the entire depth of the field of vision in transparent animal, while the animal was alive.
To demonstrate the different phenotypes, we took pictures through the transparent body wall of the Daphnia. Using livi..., , # Ectopical expression of bacterial collagen-like protein supports its role as adhesin in host-parasite coevolution

[https://doi.org/10.5061/dryad.bk3j9kdjk](https://doi.org/10.5061/dryad.bk3j9kdjk)

## Description of the data and file structure

The data associated with this work are organized in an excel file with three sheets.
Each sheet refers to part of the entire dataset and are linked to the figures in the manuscript.
Each sheet also includes explanations to the names of the variables and abbreviations.

### Description of variables:

**Fig. 3**:

* Attachment: Indicates whether spores attached (1) or no attachment (0) was observed

* Isolate: Indicates which spores were used for the attachment test
C1 C1 P. ramosa clone
WT-Bt B. thuringiensis wild-type spores
Pcl7-Bt Mutant B. thuringiensis wild-type spores expressing Pcl7

* Resistotype: Indicates the resistance phenotype to the C1 P. ramosa clone
R Resistant, no attachment of C1
S Suscpetible, at...

若要深入理解拮抗协同进化机制，需鉴定参与协同进化的相关基因。巴氏芽孢杆菌属（Pasteuria）与其宿主——微甲壳类动物水蚤（Daphnia）是协同进化研究中特征明确的经典模型，但其协同进化的核心基因仍基本未知。全基因组关联研究（genome-wide association study）提示，巴氏芽孢杆菌胶原样蛋白7（Pasteuria collagen-like protein 7, Pcl7）是介导寄生虫附着、并驱动其与宿主协同进化的候选基因。
鉴于目前无法对梅氏巴氏芽孢杆菌（Pasteuria ramosa）进行遗传操作，本研究利用苏云金芽孢杆菌（Bacillus thuringiensis）表达融合蛋白：该融合蛋白由梅氏巴氏芽孢杆菌Pcl7的羧基末端，以及苏云金芽孢杆菌胶原样蛋白（CLP）的氨基末端结构域组成。携带Pcl7的苏云金芽孢杆菌突变株（Pcl7-Bt）孢子，而非野生型苏云金芽孢杆菌（WT-Bt）孢子，可像梅氏巴氏芽孢杆菌一样，附着于易感宿主的同一部位。此外，Pcl7-Bt孢子可轻松附着于易感宿主基因型，但仅微弱附着于抗性宿主基因型。上述研究结果表明……

将水蚤单只置于96孔板中，每孔加入150 μl ADaM培养基。向每孔加入10 μl 含约500个荧光标记梅氏巴氏芽孢杆菌孢子的孢子液，于黑暗中孵育5分钟。针对苏云金芽孢杆菌，则向每孔加入10 μl 含约50000个荧光标记苏云金芽孢杆菌孢子的孢子液，于黑暗中孵育5分钟。移除每孔内全部液体，更换为150 μl 新鲜ADaM培养基。该洗涤步骤重复两次后，再次移除每孔内全部液体。用牙签将水蚤单只转移至载玻片上，轻轻盖上盖玻片以避免压碎宿主。通过在宿主存活状态下仔细评估透明动物整个视野深度范围内的情况，评估孢子附着情况。为展示不同表型，我们通过水蚤透明的体壁拍摄照片。……

# 细菌胶原样蛋白的异位表达证实其作为黏附素参与宿主-寄生虫协同进化
https://doi.org/10.5061/dryad.bk3j9kdjk

## 数据与文件结构说明
本研究相关数据整理于一个包含3个工作表的Excel文件中。每个工作表对应完整数据集的一部分，并与论文中的图表相对应；每个工作表还包含变量名称与缩写的说明。

### 变量说明
**图3**：
- 附着情况：标记孢子是否发生附着，1为观察到附着，0为未观察到附着
- 分离株：标注附着实验所用的孢子类型：
C1：C1型梅氏巴氏芽孢杆菌克隆株
WT-Bt：野生型苏云金芽孢杆菌孢子
Pcl7-Bt：表达Pcl7的苏云金芽孢杆菌突变株孢子
- 抗性表型：标注宿主对C1型梅氏巴氏芽孢杆菌克隆株的抗性表型：
R：抗性，C1孢子无附着
S：易感，……