Experimental production of midgut tumours in Periplaneta americana L
Harker, J.E.
Jour Exptl Biol 35(2): 251-259
1958
Accession: 022614411
Transplantable tumors appear in the midgut of P. americana after the implantation into the hemocoele of sub-esophageal ganglia having secretory periods out of phase with those of the ganglion of the recipient cockroach. The period of secretion is imposed by the timing of the 24-hour alternation of light and darkness. When the secretory periods of the implanted ganglia occur at the normal time of day and those of the recipient's own ganglion at the abnormal time the incidence of tumors is lower than when these conditions are reversed. Growth of the tumors ceases after implantation of sub-esophageal ganglia secreting in phase with the ganglion of the recipient animal, but growth continues once implantation ceases. The tumor cells appear to originate from the regenerative nidi of the epithelium.