Journal of Invertebrate Pathology

Ment, D., ARO, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Gindin, G., ARO, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Soroker, V., ARO, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Glazer, I., ARO, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Rot, A., Kimron Veterinary Institute, P.O.B. 12, Bet-Dagan, 50250, Israel
Samish, M., Kimron Veterinary Institute, P.O.B. 12, Bet-Dagan, 50250, Israel

Conidial germination and the formation of appressoria are important events in the interactions between entomopathogenic fungi and their arthropod hosts. In this study, we demonstrate the effects of lipids extracted from tick epicuticle and the surface of a mammalian host (calf) on conidial germination and the development of appressoria in two subspecies of Metarhizium anisopliae, M. anisopliae var. anisopliae (M.an.an.-7) and M. anisopliae var. acridum (M.an.ac.-5), which have different levels of virulence toward ticks. Pentane extracts of epicuticles of ticks susceptible and resistant to fungal infection always stimulated the germination of M.an.an.-7 conidia and the development of their appressoria; whereas the effects of dichloromethane (DCM) extracts of tick epicuticle varied depending on the tick. The DCM extracts from most of the tick species and developmental stages stimulated conidial germination and/or the formation of appressoria in M.an.an.-7. However, a DCM extract of lipids from the most resistant tick, engorged Hyalomma excavatum female, inhibited the germination of M.an.an.-7 conidia. Conidia of the non-virulent M.an.ac.-5 did not germinate on agarose amended with any of the examined tick extracts. However, when the tick extracts were placed on bactoagar, conidial germination increased 7- to 8-fold. Extracts from the skin, hair and ear secretions of a calf stimulated conidial germination and the formation of appressoria in M.an.an.-7, but not M.an.ac.-5. This study demonstrates that lipids from tick epicuticles and mammalian skin selectively affect the germination of conidia of entomopathogenic fungi. The effects of these lipids may explain the variability in tick control these fungi provide for different hosts. © 2009 Elsevier Inc. All rights reserved.
פותח על ידי קלירמאש פתרונות בע"מ -
הספר "אוצר וולקני"
אודות
תנאי שימוש
Metarhizium anisopliae conidial responses to lipids from tick cuticle and tick mammalian host surface
103

Ment, D., ARO, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Gindin, G., ARO, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Soroker, V., ARO, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Glazer, I., ARO, The Volcani Center, P.O.B. 6, Bet-Dagan, 50250, Israel
Rot, A., Kimron Veterinary Institute, P.O.B. 12, Bet-Dagan, 50250, Israel
Samish, M., Kimron Veterinary Institute, P.O.B. 12, Bet-Dagan, 50250, Israel

Metarhizium anisopliae conidial responses to lipids from tick cuticle and tick mammalian host surface
Conidial germination and the formation of appressoria are important events in the interactions between entomopathogenic fungi and their arthropod hosts. In this study, we demonstrate the effects of lipids extracted from tick epicuticle and the surface of a mammalian host (calf) on conidial germination and the development of appressoria in two subspecies of Metarhizium anisopliae, M. anisopliae var. anisopliae (M.an.an.-7) and M. anisopliae var. acridum (M.an.ac.-5), which have different levels of virulence toward ticks. Pentane extracts of epicuticles of ticks susceptible and resistant to fungal infection always stimulated the germination of M.an.an.-7 conidia and the development of their appressoria; whereas the effects of dichloromethane (DCM) extracts of tick epicuticle varied depending on the tick. The DCM extracts from most of the tick species and developmental stages stimulated conidial germination and/or the formation of appressoria in M.an.an.-7. However, a DCM extract of lipids from the most resistant tick, engorged Hyalomma excavatum female, inhibited the germination of M.an.an.-7 conidia. Conidia of the non-virulent M.an.ac.-5 did not germinate on agarose amended with any of the examined tick extracts. However, when the tick extracts were placed on bactoagar, conidial germination increased 7- to 8-fold. Extracts from the skin, hair and ear secretions of a calf stimulated conidial germination and the formation of appressoria in M.an.an.-7, but not M.an.ac.-5. This study demonstrates that lipids from tick epicuticles and mammalian skin selectively affect the germination of conidia of entomopathogenic fungi. The effects of these lipids may explain the variability in tick control these fungi provide for different hosts. © 2009 Elsevier Inc. All rights reserved.
Scientific Publication