RRC ID 46264
Author Baker RH, Britton C, Roberts B, Loer CM, Matthews JB, Nisbet AJ.
Title Melanisation of Teladorsagia circumcincta larvae exposed to sunlight: a role for GTP-cyclohydrolase in nematode survival.
Journal Int J Parasitol
Abstract Trichostrongylid nematode parasites of livestock inhabit two very different niches during their life-cycle; within the host and free-living in the environment. UV radiation plays a significant role in the survival of free-living, pre-parasitic nematode larvae, with different species exhibiting differing levels of sensitivity. In many eukaryotes, melanisation is a key protective mechanism against UV damage, however there is little information about this process in parasitic nematodes. Caenorhabditis elegans cat-4 mutants, which are deficient in the enzyme guanosine triphosphate-cyclohydrolase I (GTP-CH), have both depleted levels of melanin in their cuticles and an increased sensitivity to anthelmintic drugs. Some parasitic nematodes have very high levels of GTP-CH transcript in their pre-parasitic stages, suggesting an important role for this biopterin synthetic enzyme. Here, we show that the Tci-cat-4 gene, which encodes GTP-CH in Teladorsagia circumcincta, has a role in melanisation and is also capable of rescuing C. elegans cat-4 mutants. In addition, following exposure of T. circumcincta L3s to sunlight, there is a 32% increase in GTP-CH enzyme activity (P=0.019), and a 21% increase in levels of melanin (P=0.031) compared with unexposed larvae. These data suggest that one explanation for the high level of GTP-CH present in pre-parasitic stages of trichostrongylid nematodes is to facilitate melanisation in response to UV exposure.
Volume 42(10)
Pages 887-91
Published 2012-9-1
DOI 10.1016/j.ijpara.2012.06.005
PII S0020-7519(12)00172-5
PMID 22884628
MeSH Animals Catalase / genetics Catalase / metabolism GTP Cyclohydrolase / genetics GTP Cyclohydrolase / metabolism* Gene Expression Regulation, Enzymologic / radiation effects* Larva / enzymology Larva / metabolism Larva / radiation effects Melanins / metabolism* Mutation Sunlight* Trichostrongyloidea / enzymology Trichostrongyloidea / metabolism* Trichostrongyloidea / radiation effects*
IF 3.53
Times Cited 4
WOS Category PARASITOLOGY
Resource
C.elegans tm773