Estrogen-related fecundity reduction of Lymnaea ollula following Fasciola gigantica infection.
Infection by trematode parasites generally affects life history traits of their intermediate hosts. Reduction in life expectancy and reproductive capacity have previously been documented in Fasciola gigantica-infected Lymnaea ollula, but the influence of the endocrine system on this specific host–parasite interaction has not been previously examined. In the present study, we observed survival, growth pattern, and reproductive output of L. ollula following exposure to F. gigantica. Both the survival and the growth pattern of infected snails were similar to those of the non-infected control group. However, a significant difference was apparent in fecundity, as infected snails consistently showed lower levels of egg and embryo production throughout a 7-wk observation period. Semi-quantitative RT-PCR also revealed down-regulation of estrogen receptor expression in infected snails during the first 4 wk of infection. Nonetheless, the inhibition of estrogen signaling was transient, as they regained expression in the later phase of infection. It is, therefore, suggested that other hormones of the complex endocrine system may be involved in the reduced fecundity of L. ollula following F. gigantica infection.
Kumkate
Supeecha
S
Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand. scskk@mahidol.ac.th
Onmek
Nuttajit
N
Boonburapong
Bongkoj
B
Singhakaew
Sombut
S
Leardkamolkarn
Vijittra
V
D000818:Animals; D005209:Fasciola / Q000502:physiology*; D005298:Fertility; D015870:Gene Expression; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D015993:Life Tables; D008195:Lymnaea / Q000469:parasitology* / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger; D011960:Receptors, Estrogen