A factor causing stable stimulation of juvenile hormone synthesis by Diploptera punctata corpora allata in vitro

1998 ◽  
Vol 44 (11) ◽  
pp. 1027-1037 ◽  
Author(s):  
G.C. Unnithan ◽  
T.D. Sutherland ◽  
D.W. Cromey ◽  
R. Feyereisen
1981 ◽  
Vol 59 (9) ◽  
pp. 1744-1748 ◽  
Author(s):  
H. S. Injeyan ◽  
J. F. Dale ◽  
S. S. Tobe

The fertility of aging Schistocerca gregaria females of both solitary and gregarious phases is markedly reduced in comparison with that of young females. Examination of eggs (from both young and aging females) maintained in vitro revealed that the decreased fertility of aging females of both phases could be attributed to a decrease in viability of eggs. This, in turn, was found to be in large part due to an increase in the proportion of embryos showing inhibited development. The proportion of inhibited embryos, in pods from young and old females, respectively, increased from 5 to 42% for gregarious animals and from 3 to 38% for solitary animals. Inhibition was found to occur at all stages from blastokinesis to ecdysis of the provisional cuticle. These morphogenetic aberrations were very similar to those obtained after treatment of S. gregaria eggs with exogenous juvenile hormone (JH). Investigation of the JH synthetic activity of corpora allata from aging females of each phase revealed a marked increase in the rates of JH synthesis in comparison with those of young females of the same phase. Furthermore, injection of JH into young females increased the proportion of embryos showing inhibited development from 7% (in control females) to 30% (in JH-treated females). These results suggest a possible correlation between reduced viability of eggs and high rates of JH synthesis in aging S. gregaria of both phases.


1983 ◽  
Vol 38 (9-10) ◽  
pp. 856-858 ◽  
Author(s):  
Hans-Joerg Ferenz ◽  
Ingrid Diehl

Abstract In Locusta migratoria the gonotrophic cycles are regulated by juvenile hormone. The cyclical changes of juvenile hormone synthesis in locust corpora allata seem to be regulated by a neuro-hormonal factor. Such an allatotropin could be extracted from corpora cardiaca and brains of Locusta migratoria. It is a small pronase-sensitive and heat-stable peptide. Extract of one corpus cardiacum stimulates corpus allatum biosynthetic activity in vitro 5 to 20-fold.


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