From Mosquito Ovaries to Ecdysone; from Ecdysone to : One Woman's Career in Insect Biology

In anautogenous mosquitoes, synchronous development of terminal ovarian follicles after a blood meal provides an important model for studies on insect reproduction. Removal and implantation of ovaries, in vitro culture of dissected tissues and immunological assays for vitellogenin synthesis by the fat body showed that the (L.) (Diptera, Culicidae) mosquito ovary produces a factor essential for egg production. The discovery that the ovarian factor was the insect steroid hormone, ecdysone, provided a model for co-option of the larval hormones as reproductive hormones in adult insects. In later work on cultured mosquito cells, ecdysone was shown to arrest the cell cycle, resulting in an accumulation of diploid cells in G1, prior to initiation of DNA synthesis. Some mosquito species, such as L. (Diptera, Culicidae), harbor the obligate intracellular bacterium, Hertig (Rickettsiales, Anaplasmataceae), in their reproductive tissues. When maintained in mosquito cell lines, abundance increases in ecdysone-arrested cells. This observation facilitated the recovery of high levels of from cultured cells for microinjection and genetic manipulation. In female , it will be of interest to explore how hormonal cues that support initiation and progression of the vitellogenic cycle influence replication and transmission to subsequent generations via infected eggs.