Development and cellular differentiation of an insect telotrophic ovary (Rhodnius prolixus).
Differentiation events accompanying the larval-adult ovarian transformation in Rhodnius prolixus can be divided into three phases: proliferative phase (unfed to 3 days post-feed or DPF), early differentiation phase (9-15 DPF) and late differentiation phase (16 DPF to moult at 21 DPF). Ovarioles remain morphologically larval until feeding initiates development. The unfed ovariole contains germ cells surrounding a central trophic core region with the 'germarial lumen' occupying the basal region of the tropharium immediately above the pre-follicular tissue. Mitosis of germ cells during the proliferative phase results in a progressive increase in tropharial size with no differentiation of tissues. Regional specialization within the ovariole marks the beginning of the early differentiation phase. A zone of oocytes is established at the base of the tropharium with nuclei containing synaptonemal complexes and condensing chromosomes. Nurse cell differentiation is characterized by nucleolar elaboration and nucleo-cytoplasmic transport, the cytoplasm becoming rich in ribosomes. Autoradiographic results suggest that functional nurse cell-oocyte divergence occurs concurrently with morphological divergence. Pre-follicular tissue is divided into apical and basal zones with apical zone differentiation occurring during early and late differentiation phases.
D000818:Animals; D002454:Cell Differentiation; D005260:Female; D008675:Metamorphosis, Biological; D008854:Microscopy, Electron; D009865:Oocytes / Q000166:cytology; D009940:Organoids / Q000648:ultrastructure; D010053:Ovary / Q000166:cytology / Q000254:growth & development; D012239:Rhodnius / Q000166:cytology* / Q000254:growth & development; D014225:Triatominae / Q000166:cytology*