Resolving the infection process reveals striking differences in the contribution of environment, genetics and phylogeny to host-parasite interactions

Table 1 Results of infection trials, spore activation tests and attachment-tests.

			Infection trial			Spore activation			Attachment-test (attached out of five)
Clones of D. magna		Pasteuria	C19	C1	C14	C19	C1	C14	C19	C1	C14
	Origin
HO1	Hungary		R	R	R	Yes	Yes	Yes	0	0	0
HO2	Hungary		S	S	S	Yes	Yes	Yes	5	5	5
HO3	Hungary		R	R	R	Yes	Yes	Yes	0	0	0
M5	Belgium		R	R	R	Yes	Yes	Yes	0	0	0
M10	Belgium		S	S	S	Yes	Yes	Yes	5	5	5
Iinb1*	Germany*		R	R	R	Yes	Yes	Yes	0	0	0
Mu12	Germany		R	R	R	Yes	Yes	Yes	0	0	0
DG-1-106	Germany		S	R	R	Yes	Yes	Yes	5	0	0
AL144	Finland		R	S	S	Yes	Yes	Yes	0	5	5
Xinb3*	Finland*		S	R	R	Yes	Yes	Yes	5	0	0
XI*	Finland*		R	R	R	Yes	Yes	Yes	0	0	0
Xfa6*	Finland*		S	R	R	Yes	Yes	Yes	5	0	0
Kela-39-09	Finland		R	S	S	Yes	Yes	Yes	0	5	5
Kela-18-10	Finland		S	R	R	Yes	Yes	Yes	5	0	0

We tested all combinations of three Pasteuria ramosa clones (C19, C14, C1) with 14 Daphnia magna clones. Infection trials results are defined by exposing Daphnia to the parasites and determining the infection status after 20 days. Resistant means that none of the replicates were infected. Activation was determined by observing spores in the gut of the host with a sombrero-like shape. R means that the host clone is totally resistant to the concerned parasite clone. S means that the host clone is susceptible to the concerned parasite clone. Yes means that the spores were activated.
Labcross: 'Iinb1' is 'Mu11' (Belgium) selfed once; 'Xinb3' is 'X' (Finland) selfed three times; 'Xfa6' is 'AL144' selfed three times and crossed with 'Xinb3'; 'XI' is a cross between 'Iinb1' and 'Xinb3'.

ISSN: 1741-7007