QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by HARKER, J. E. Search for Related Content PubMed Articles by HARKER, J. E. Social Bookmarking                         What's this?

Journal of Experimental Biology 35,251-259 (1958)
Published by Company of Biologists 1958

Experimental Production of Midgut Tumours in Periplaneta Americana L

JANET E. HARKER ¹

¹ Department of Zoology, University of Cambridge

1. Sub-oesophageal ganglia taken from Periplaneta americana L. which had been kept in reversed conditions of light and darkness have been implanted into the abdomens of cockroaches living in normal light: dark conditions. When implantation was continued for 4 days transplantable tumours appeared by the eighteenth day in the midgut of the majority of cockroaches.

2. No tumours appeared in the guts of cockroaches when the implanted suboesophageal ganglia had been taken from animals kept in normal conditions of light and darkness, nor when brains or corpora allata were implanted.

3. Injection of an extract of five sub-oesophageal ganglia in 0.05 ml. Ringer solution produced tumours only when injection took place during the inactive phase of the 24 hr. locomotory rhythm.

4. The implantation of sub-oesophageal ganglia taken from animals kept in normal light:dark conditions into animals kept in reversed light:dark conditions was followed by tumour formation only if the implantation was carried out daily for 8 clays. The incidence of tumour formation is lower than under the conditions described in 1.

5. Details are given of the histology of the developing tumours.

6. When tumour formation had begun the implantation of sub-oesophageal ganglia with secretory phases in phase with that of the animal's own ganglion prevented further growth of the tumour. The cells of the tumour had, however, undergone an irreversible change for, as soon as implantation ceased, growth began once more.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				C. S. Pittendrigh Circadian Rhythms and the Circadian Organization of Living Systems Cold Spring Harb Symp Quant Biol, January 1, 1960; 25(0): 159 - 184. [Abstract] [PDF]

				J. E. Harker Endocrine and Nervous Factors in Insect Circadian Rhythms Cold Spring Harb Symp Quant Biol, January 1, 1960; 25(0): 279 - 287. [Abstract] [PDF]

				F. Halberg Temporal Coordination of Physiologic Function Cold Spring Harb Symp Quant Biol, January 1, 1960; 25(0): 289 - 310. [Abstract] [PDF]