Oogenesis and Effects of Neuroendocrine Tissues on in Vitro Synthesis of Protein by the Ovary of the Red Swamp Crayfish Procambarus Clarkii (Girard)

Abstract

ABSTRACT In the red swamp crayfish Procambarus clarkii oocyte development was classified into seven stages according to morphological characters: (1) oogonial (< 10 μm), (2) immature (10-65 μm), (3) avitellogenic (66-160 μm), (4) early vitellogenic (161-245 μm), (5) midvitellogenic (246― 455 μm), (6) late vitellogenic (456-980 μm), and (7) postvitcllogenic and resorptive. Stage 1 (oogonial) is a multiplication stage, and oocyte maturation occurs in stages 2-6. Follicle cells become arranged around the oocytes in stage 3. Stages 4, 5, and 6 are the yolk granule development stages, with strongly acidophilic yolk granules accumulating in the cytoplasm. Yolk granules first appear at the periphery and then gradually spread throughout the cytoplasm. The ovarian index increases steadily up to stage 6, but in stage 7 the ovarian index decreases. The incorporation of 14C-leucine into ovarian or oocyte proteins occurs throughout vitellogenesis. When ovarian tissue was incubated with the eyestalk neuroendocrine tissues, leucine incorporation was inhibited, whereas when other neuroendocrine tissues, brain, subesophageal ganglion, or thoracic ganglia, were added to the incubation medium, leucine incorporation into ovarian proteins increased significantly. The inhibition produced by the eyestalk tissues was presumably due to the well-documented ovary-inhibiting hormone, whereas the stimulation produced by the other organs was presumably due to an ovary-stimulating hormone.