National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2006

28. Tick glutamine: Fructose-6-phosphate 3 aminotransferase (GFAT) plays a critical role in host blood feeding

Japanese

  We have characterized potential functions of GFAT from the ixodid tick Haemaphysalis longicornis (HlGFAT). HlGFAT was expressed at all stages of development and in multiple organs. The transcription levels in the cuticle and midgut were enhanced significantly by blood feeding during the first 3 days and decreased on the fifth day, while those in the salivary glands maintained almost the same level during the first 3 days and decreased to a rather low level at 5 days postinfestation. Endogenous HlGFAT was identified in all developmental stages and in multiple organs, such as the epidermis, midgut epithelium, salivary gland, ovary, Malpigian's tubule and trachea. Following RNA interference with HlGFAT, engorgement by adult females was reduced significantly. One of the potential mechanisms for this effect may be that the inhibition of HlGFAT limits chitin biosynthesis, therefore disrupting cuticle growth and possibly peritrophic matrix formation during blood feeding.
(Research Team for Zoonosis, TEL +81-29-838-7749)

Reference:

Huang et al. (2007) Int. J. Parasitol. 37 : 383-392.

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