The isolation and study of genes that are differentially expressed in malaria infected mosquitoes is important for the elucidation of basic molecular mechanisms underlying vector parasite interactions. When screening against a previously established cDNAs pool representing specifically expressed genes in the mosquito Anopheles stephensi infected by Plasmodium yoelii, it was found that one of these encodes a protein with extensive sequence similarity to the Drosophila melanogaster ubiquitin C terminal hydrolase(UCTH). Similarity alignment showed that the fragment is 89% identical at amino acid level to the corresponding region of the known An. gambiae EST sequence, as well as 63% identical to that of both the fruitfly and human sequence. Virtual Northern blot expression dynamics of the gene indicated that it was up regulated significantly in the mosquito at least 1 7 days post infection, consistent with the critical transition stages of midgut invasion and relocation of sporozoites from the oocysts to the salivary glands during parasite development. Rather little is known about the role of the ubiquitin pathway in the activation of the mosquito innate immune system. The results indicate that the gene is related to malaria infection in mosquito. The cloning and expression profile analysis of As UCTH enables us to make predictions as to the roles it may play during malaria infection.
Anopheles dirus complex is a major malaria vector in Southeast Asia and South China.But the role played by different member of the species complex in malaria transmission is not clearly known. Correct identification of the sibling species is a foundational requirament for working out a sound scheme in mosquito biosystematics. This paper reports the resuets of biosystematic studies on the chromosomal karyotype, egg microstructure, ribosomal DNA sequences of a second internal transcribed spacer region and polymerase chain reactions of the complex in China. Specimens of species A and D from Hainan and Yunnan Provinces were carefully analyzed and the importance of development aspect of the mosquito biosystematics in malaria control is discussed.
