+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Cyclic juvenile hormone biosynthesis in the cockroach, Blattella germanica: effects of ovariectomy and corpus allatum denervation

General and Comparative Endocrinology 82(2): 163-171

Cyclic juvenile hormone biosynthesis in the cockroach, Blattella germanica: effects of ovariectomy and corpus allatum denervation

The corpora allata (CA) of ovariectomized adult Blattella germanica females exhibited delayed but high rates of juvenile hormone biosynthesis in vitro. Using the onset of sexual receptivity as a probe of the degree of CA activation in females, we demonstrated at least one cycle of CA activity in the experimentally synchronized ovariectomized females. Following their activation, the CA exhibited a partial and transient decline in activity, but in contrast to the CA of intact females, this decline was not accompanied by a regression in CA volume. CA of intact and ovariectomized females that were denervated from the brain were activated, but the subsequent decline in CA activity at the end of the cycle was prevented in ovariectomized females. The presence of an egg-case suppressed the reactivation of the inactive CA in intact females but not in CA-denervated females. We conclude that activation of the CA in B. germanica is not dependent upon either the presence of the ovary or intact nervous connections between the CA and the brain. The brain exerts a partial inhibition on CA activity through intact nerves which is relieved (by disinhibition) in the presence of young ovary but is enhanced and sustained in the presence of the egg-case. Inhibition of the CA also occurs independently of nervous connections with the brain through factors that originate in the mature ovary and affect both CA activity and morphology.

Accession: 002063546

PMID: 1855641

DOI: 10.1016/0016-6480(91)90180-e

Download PDF Full Text: Cyclic juvenile hormone biosynthesis in the cockroach, Blattella germanica: effects of ovariectomy and corpus allatum denervation

Related references

Correlation among corpus allatum volume, cell size, and juvenile hormone biosynthesis in ovariectomized adult Blattella germanica. Archives of insect biochemistry and physiology8(1): 37-44, 1991

Effect of juvenile hormone and moulting hormone on biosynthesis of aggregation pheromone of the German cockroach, Blattella germanica (L.). 2008

Correlation between haemolymph juvenile hormone titre, corpus allatum volume, and corpus allatum in vivo and in vitro activity during oocyte maturation in a cockroach (Nauphoeta cinerea). General and Comparative Endocrinology, 363: 339-345, 1978

Ovarian regulation of cyclic changes in size and activity of corpus allatum cells in Blattella germanica. Journal of insect physiology7(12): 907-917, 1991

Effects of C18 juvenile hormone on the oxygen consumption rate of the cockroach Blattella germanica (L). Developments in endocrinology5(15): 295-298, 1981

Effects of juvenile hormone analogs on the German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae). Dissertation Abstr lnt, 3610: 4840, 1976

Effects of a juvenile hormone analogue on the development and metamorphosis of the german cockroach blattella germanica. Proceedings North Central Branch Entomological Society of America 28: 166, 1973

Effects of three juvenile hormone analogs on the female German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae). Experientia 30(9): 1093-1095, 1974

Effects of two juvenile hormone analogs r 20458 ro 203600 and three juvenile hormones jh 1 jh 2 jh 3 on the external morphology and length of the spiculum copulatus sc in the male cockroach blattella germanica l. dictyoptera blattellidae. Zoological Science (Tokyo) 4(5): 861-866, 1987

Cyclic volumetric changes in corpus allatum cells in relation to juvenile hormone biosynthesis during ovarian cycles in cockroaches. Archives of Insect Biochemistry & Physiology 27(1): 53-64, 1994