Relationships between weight changes, protein content, and protein synthesis in the left colleterial gland during the reproductive cycle of the cockroach Periplaneta americana

Abstract

1.1. This study compares the wet weight, protein content, and protein synthesis in the left colleterial gland at different time points of the reproductive cycle of the cockroach Periplaneta americana.2.2. The wet weight of the left colleterial gland fluctuates throughout the cycle. Only one of these changes can be related to egg-case synthesis.3.3. The protein content of the left colleterial gland also fluctuates with three cyclic changes. Again only one of these changes can be correlated with egg-case synthesis.4.4. Leucine incorporation in vitro into colleterial proteins is not uniform throughout the cycle. The highest incorporation coincides with the greatest increase in the protein content of the gland, and with the greatest rate of growth of oocytes.5.5. Electrophoretic analysis of the proteins extracted from the left colleterial gland reveal qualitative and quantitative changes. Of all the protein species detected in the left colleterial gland extract, at least eight are also detected in the artificially induced colleterial secretion, material collected from the genital vestibulum and the newly formed egg-case. All these proteins are synthesized in the gland.6.6. In general, the protein species synthesized and their relative amounts vary during the cycle except over the twenty-four hours prior to egg-case synthesis.7.7. The timing of synthesis in relation to ootheca synthesis of some major colleterial proteins and the lack of long term accumulation after synthesis, suggest that the left colleterial gland may be involved in the production of proteins for export as well as for egg-case synthesis.