IMMUNOHISTOCHEMICAL DETECTION OF VITELLOGENIN IN THE OVARY AND FAT BODY DURING A REPRODUCTIVE CYCLE OF THE COCKROACH, BLATTELLA GERMANICA

Abstract

was immunohistochemically demonstrated in .the ovary and fat body during a reproductive cycle. In terminal oocytes of 4-day adults, vitdogenin began t o appear in yolk spherules at the cell periphery. The vitellogenin-containing spiierules increased in size and number t o occupy the whole cell 2 days later. In the female fat body, vitellogenin began to appear in 3-day adults. It was distributed diffusely in the cytoplasm, at a much lower concentration than in the oocytes, during the vitellogenic period. In 1 I-day adults whose vitellogenesis had terminated, a higher concentration of vitellogenin was found in the cytoplasmic inclusions of the fat body. Vitellogenin was not detected in the male fat body.

Secretory and internalization pathways of mosquito yolk protein precursors

“…This observation is in agreement with numerous biochemical studies (reviewed in Kunkel and Nordin 1985;Kanost et al 1990;Raikhel and Dhadialla 1992). Visualization of Vg in the fat body trophocytes has been previously performed for several insects by means of immunocytochemical techniques for fluorescent light microscopy (Tanaka and Yokizaki 1974) and electron microscopy (Couble et al 1979;Thomsen et al 1980;Mazzini et al 1989) and is particularly detailed for A. aegypti (Raikhel and Lea 1983;Raikhel 1986a, b;1987).…”