Genmomic Studies on Ascogregarina Taiwanensis with Emphathysis on Regulation of Gene Trasncription

Ascogregarina taiwanensis commonly occurs in the mosquito Aedes albopictus with less deleterious effects on the host. However, this unique parasitism provides a useful model for the study on the interactions between the host and its parasite. At the initial step of infection, gregarine oocysts were ingested by young mosquito larvae, releasing sporozoites in the lumen of themidguts; from which they enter into the epithelial cells to become intracellular trophozoites.Within a short period of development, extracellular trophozoites are formed, attaching on the epithelium by their epimerites. Subsequently, they start migrating from the midgut to Malpighian tubules for sexual reproduction at the early stage of mosquito pupae; in which gametocysts containing a number of oocysts are formed. Gene regulation on the development of related parasites has recently been investigated in species such as Plasmodium, Toxoplasma, and Cryptosporidium, but remains relatively limited in gregarines, e.g., As. Taiwanensis. In this study, we are trying to move this on by establishing gene libraries from different developing stages, i.e., early and late stages of trophozoites. The goal is to identify unique genes that are involved in gregarine development, particularly those associated with the migration of trophozoites. According to preliminary results for this study, a type 1 multiprotein bridging factor (MBF1) gene was largely identified from extracellular trophozoites. The MBF1 gene has been known serving as an activator to bind the TATA-binding protein (TBP), cooperatively regulating the transcription of various genes. In this study, we would first established gene libraries as mentioned earlier for finding uniques genes in association with gregarine development and migration. Next, we would pay attentions on the MBF1 gene, especially focusing on its expression timing. A special task would be identification of genes that are co-activated by the MBF-1 in order to elucidate interactions between gregarines and it mosquito hosts.

Project ID:PC10001-1151
External Project ID:NSC99-2320-B182-012-MY3