A teratocyte gene from a parasitic wasp that is associated with inhibition of insect growth and development inhibits host protein synthesis

Abstract

After parasitization, some wasps induce hosts prematurely to initiate metamorphic development that is then suspended in a postwandering, prepupal state. Following egression of the parasite larva, the host remains in this developmentally arrested state until death. Teratocytes, cells released at egg hatch from extra-embryonic serosal membranes of some wasp parasites, inhibit growth and development when injected into host larvae independent of other parasite factors (e.g. venom, polydnavirus). Synthesis of some developmentally regulated, abundantly expressed Heliothis virescens host proteins is inhibited in hosts parasitized by Microplitis croceipes and by teratocyte injection. A cDNA encoding a 13.9 kDa protein (TSP14) that inhibited protein synthesis, growth and development was isolated from a protein fraction secreted by teratocytes. TSP14 appears to be responsible, in part, for the teratocyte-mediated inhibition of host growth and development. Interestingly, this cDNA encoded a cysteine-rich amino acid motif similar to that described from Campoletis sonorensis polydnavirus, a mutualistic virus that enables wasp parasitization of lepidopteran larvae. Moreover, TSP14 inhibited protein synthesis in a dose-dependent manner in rabbit reticulocyte lysate and wheat germ extract translation systems. We hypothesize that some wasp parasites inhibit translation as a general means to regulate and redirect lepidopteran host physiology to support endoparasite development.

Polyploidy in Animals: Effects of Gene Expression on Sex Determination, Evolution and Ecology

“…These polyploid cells are considered virulence factors that control host growth and development, as well as repress the host's immune responses [e.g. Strand and Wong, 1991;Dahlman et al, 2003]. Both the arguments of enriched allelic diversity and genetic complexity, and the observation of so many immune-competent tissues showing endopolyploidy, suggest that polyploidy may be favored in the evolution of resistance and immunity.…”

Aphidius ervi teratocytes release an extracellular enolase

“…The teratocytes have been implicated in a number of different roles, such as the manipulation of host development, through inhibition of protein synthesis (Dahlman et al, 2003), or the disruption of the endocrine balance, which often modulates host biochemical changes nutritionally relevant for the developing parasitoid larvae (reviewed in Beckage and Gelman, 2004). The nutritional role of the teratocytes is more direct and evident in the host-parasitoid associations where these cells of embryonic origin perform a kind of extra-oral digestion of selected host tissues, in order to allow the release of nutrients in a suitable form for the developing sister larvae (Tremblay and Iaccarino, 1971;Falabella et al, 2000;Nakamatsu et al, 2002Nakamatsu et al, , 2004Suzuki and Tanaka 2007).…”

Parasitic castration of Plutella xylostella larvae induced by polydnaviruses and venom of Cotesia vestalis and Diadegma semiclausum

“…Teratocyte secreted proteins (TSPs) selectively inhibit protein synthesis in fat body (Schepers et al, 1998). Also TSP treatment consistently reduced protein synthesis in Heliothis viresens larval testes (Dahlman et al, 2003). Both fat body and testes synthesize the storage protein P 76 in abundance.…”