scholarly journals Diapause Hormone Action in the Silkworm, Bombyx mori L. (Lepidoptera : Bombycidae) : Enhancement of Trehalase Activity in Developing Ovaries Incubated In Vitro

1980 ◽  
Vol 15 (4) ◽  
pp. 439-446 ◽  
Author(s):  
Toshiaki MIYADAI ◽  
Okitsugu YAMASHITA
Keyword(s):  
Bombyx Mori ◽  
Hormone Action ◽  
Trehalase Activity ◽  
Bombyx Mori L ◽  
Diapause Hormone ◽  
Silkworm Bombyx Mori

Studies on the Mode of Action of the Diapause Hormone in the Silkworm, BOMBYX MORI L.,

1963 ◽  
Vol 40 (3) ◽  
pp. 517-530
Author(s):  
KINSAKU HASEGAWA
Keyword(s):  
Low Temperature ◽  
Juvenile Hormone ◽  
Bombyx Mori ◽  
Mode Of Action ◽  
Adult Emergence ◽  
Suboesophageal Ganglion ◽  
Bombyx Mori L ◽  
Diapause Hormone ◽  
The Brain ◽  
Silkworm Bombyx Mori

1. The action of the diapause hormone has been studied by injecting extracts of the heads of male moths or of the brain-suboesophageal ganglion complexes of pupae into pupae expected to produce non-diapause eggs. 2. The effect of the injection of hormone upon young oocytes is to make them develop into diapause eggs. Older oocytes, which have already acquired non-diapause characters, are not affected. 3. The hormone is almost completely inactivated when injected on the day of pupation. The hormone is most effective when injected into pupae 2-3 days old, at which stage the ovarioles have started to grow vigorously. It is ineffective 1-2 days before adult emergence, by which time all the oocytes have acquired non-diapause characters. 4. The hormone is inactivated in all pupae irrespective of whether they are destined to produce diapause eggs or non-diapause eggs. Inactivation of diapause hormone (in contrast to that of juvenile hormone) is partially relieved by exposure to low temperature or by simultaneous injection of indian ink. 5. The extracts prepared as in (1) above do not serve as a stimulant for the brain causing the suboesophageal ganglion to produce diapause hormone. The action of the extract faithfully reflects the function of the diapause hormone which originates in the suboesophageal ganglion.

scholarly journals Studies on the Mode of Action of the Diapause Hormone in the Silkworm, BOMBYX MORI L

1965 ◽  
Vol 43 (2) ◽  
pp. 271-277
Author(s):  
KINSAKU HASEGAWA ◽  
OKITSUGU YAMASHITA
Keyword(s):  
Carbohydrate Metabolism ◽  
Bombyx Mori ◽  
Mode Of Action ◽  
Fat Body ◽  
Glycogen Synthesis ◽  
Target Organ ◽  
Suboesophageal Ganglion ◽  
Bombyx Mori L ◽  
Diapause Hormone ◽  
Silkworm Bombyx Mori

1. Glycogen synthesis in the ovary of Bombyx mori is accelerated by the diapause hormone. 2. Such glycogen is derived, by way of the trehalose of the haemolymph, from carbohydrate in the fat body. 3. Extirpation of the suboesophageal ganglion has the converse effect: a fall in glycogen in the ovary and an increase in blood trehalose and fat-body glycogen. 4. Mobilization of fat-body glycogen is dependent on the presence of the ovaries, and of the suboesophageal ganglion. 5. The same results can be obtained in male pupae after the implantation of ovaries. 6. These observations on carbohydrate metabolism confirm the belief that the ‘target organ’ of the diapause hormone is the ovary itself. The changes in other tissues are due to feedback.

Studies on the Mode of Action of the Diapause Hormone in the Silkworm, Bombyx Mori L

1964 ◽  
Vol 41 (4) ◽  
pp. 855-863
Author(s):  
KINSAKU HASEGAWA
Keyword(s):  
Bombyx Mori ◽  
Adult Development ◽  
Mode Of Action ◽  
Sexual Difference ◽  
Pupal Stage ◽  
Suboesophageal Ganglion ◽  
Hormone Production ◽  
Bombyx Mori L ◽  
Diapause Hormone ◽  
Silkworm Bombyx Mori

1. The susceptibility of ‘non-diapause’ pupae to diapause hormone, the sexual difference in production of diapause hormone in the suboesophageal ganglion (SG), the changes in diapause hormone content of the SG during larval-pupal-adult development, and the hormone production in polyvoltine race, were studied by injecting diapause hormone extracts into pupae expected to produce non-diapause eggs. 2. The susceptibility of ‘non-diapause’ pupae of a bivoltine race (Daizo) was very low, or the hormone injected was almost inactivated. The susceptibility of ‘non-diapause’ race to diapause hormone is different in different races. 3. As for sexual differences in content of diapause hormone in moth heads, males are superior to females, which was further substantiated by injecting extracts from the SG of both sexes. 4. From the activity of diapause hormone extracts derived from larval, pupal and adult SG, the hormone production in SG is raised during the late pupal stage, especially in males. It is also observed that larval SG produces the hormone, and the hormone production in the SG of male moths after mating becomes weak. 5. Male moth heads of ‘non-diapause’ worms (polyvoltine race), as well as of ‘diapause’ worms, contain diapause hormone; though activity is less than in ‘diapause’ worms, which reflects the occurrence of diapause eggs caused by SG-transplantation. 6. It is highly probable that the bioassay by injecting diapause hormone extracts reveals the activity of the SG in the silkworm. 7. The activity of the SG in the polyvoltine race has been discussed from standpoint of diapause determination in the silkworm.

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