A CYTOPHOTOMETRIC STUDY OF THE EPITHELIAL NUCLEI OF THE HEPATOPANCREAS AND HINDGUT OF PORCELLIO SCABER DURING DEVELOPMENT AND AGING (ISOPOD, POLYPLOIDY)
Because of the dearth of information on somatic polyploidy in invertebrates other than insects and the contradictory nature of results of the few studies done on the somatic polyploidy in isopods, a comparative cytophotometric and autoradiographic study on the hindgut and hepatopancreas of Porcellio scaber, a terrestrial isopod, was undertaken. The hepatopancreas and hindgut were selected for study because of the difference of their growth pattern. In the hepatopancreas, the tissue is continually being renewed during development and aging by dividing cells in the regnerative region. In the hindgut, after embryonic development, there is no further mitotic division. In the hepatopancreas, polyploidy occurred by the time the animal had reached a head capsule width of 1.7 mm. and continued to increase along the length of the lobes as the animal developed. Diploid cells were present at the distal end of the lobes in all ages (head capsule widths) of animals studied, supporting the concept that growth occurs by proliferation of these cells. The degrees of ploidy increased as the animal increased in age. The highest level reached was 256C. In the hindgut, polyploidy occurred in animals of head capsule width 1.0 mm. No diploid nuclei were observed. As development and aging progressed, the range moved higher. The total range was from 4C to 512C. In the autoradiographic study, tritiated thymidine was incorporated into both tissues. Although incorporation was along the length of the hepatopancreas, it seemed densest at the tip.
FOGARTY, COLLEEN T, "A CYTOPHOTOMETRIC STUDY OF THE EPITHELIAL NUCLEI OF THE HEPATOPANCREAS AND HINDGUT OF PORCELLIO SCABER DURING DEVELOPMENT AND AGING (ISOPOD, POLYPLOIDY)" (1986). ETD Collection for Fordham University. AAI8615707.