Development Of Silkworm Research Articles

Structural requirement of sterol nucleus for the silkworm growth and development

Several cholesterol analogs structurally modified in nuclear substitutions were tested for sustaining the growth of the silkworm Bombyx mori . 5α-Cholest-7-en-3β-ol, 5,7-cholestadien-3β-ol and cholesteryl acetate can replace cholesterol as sterol source for B. mori. Considerably good growth was also obained with 5α-cholest-14-en-3β-ol and 5α-cholesta-6,8(14)-dien-3β-ol. Other sterols tested were either partially effective or ineffective as nutrients.

Variation of cation concentrations in the haemolymph of the silkworm, Bombyx mori, with diet and larval-pupal development

The concentrations of haemolymph cations were studied from the early 5th instar to a new pupal stage in the silkworm, Bombyx mori, reared on either mulberry leaves or an artificial diet. 1. 1. The potassium level in the haemolymph changed little during feeding and mature stage and] averaged 50 μequiv/ml in the silkworm larvae reared on both diets. It increased during larval-pupal development to 90 μequiv/ml at pupation. 2. 2. The magnesium level in the haemolymph of the silkworm larvae reared on mulberry leaves increased as the larval growth proceeded. On the other hand in the silkworm on artificial diet the level was maintained at a steady-state level of 100 μequiv/ml. In both groups it declined remarkably during larval-pupal development. 3. 3. The haemolymph sodium concentration was higher in the larvae on the artificial diet than those fed on mulberry leaves. 4. 4. The calcium level was higher in the larvae on the mulberry leaves diet than those on the artificial one during the feeding stage, reflecting the content of diets.

Structural requirement of sterol side chain for the silkworm growth and development

Several cholesterol analogs with modifications in the side chain were added to the artificial diet of the silkworm, and their effects on insect growth and development were determined. It was found that slight deviations of the cholesterol's side chain induced pronounced growth-retarding effects, suggesting an important functional role of the isooctane side chain of cholesterol.

Quantitative Changes of Asparagine and Glutamine in Hemolymph of the Silkworm, Bombyx mori, during Larval and Pupal Development

Quantitative Changes of Asparagine and Glutamine in Hemolymph of the Silkworm, Bombyx mori, during Larval and Pupal Development

CONTRIBUTIONS TO THE BIOCHEMISTRY OF THE SILKWORM. XXVII. TREHALOSE, TREHALASE AND MOLTING

AbstractDuring the development of the Silkworm, the amount of blood trehalose sharply decreases at each moult, and also during the fasting period corresponding to spinning. the fall of blood trehalose concentration during the moults is related to the release of the inhibition of the trehalase present in the hemolymph.The presence of a trehalase in the muscles and in the digestive tract is confirmed. This enzyme has not been detected in the fat body, in the epidermis or in the silkglands.In the fat body, there exists an inverse relationship between glycogen and trehalose, the former disappearing almost completely at each moult, whereas the amount of trehalose tends to remain at a nearly constant level. On the other hand, the bulk of the fat body is consumed to a large extent during the periods of chitin synthesis.The gluconeogenesis during the silkworm development and the metabolism of chitin synthesis at each moult, are discussed in the light of these experimental data.

蠶兒ノ發生期

蠶兒ノ發生期

Societies and Academices

PARIS. Academy of Sciences, August 19.—M. Fouqué in the chair—The chairman announced the death of two members of the Academy, Admiral de Jonquiéres and Baron de Nordenskiöld, and added a short account of their life-work.—The relations of psoriasis with neurasthenia: treatment by injections of orchitin, by M. F. Bouffé. Psoriasis is a trophonevrosis having its seat in the nervous centres and especially in the great sympathetic.. It presents a great analogy with neurasthenia in its origin; in both diseases there is constantly a diminution in nervous activity, characterised by a fall in the urographic line of phosphoric acid. The treatment of both should consist in the invigoration without stimulation of the nervous system by injections oforchitin, the average dose being from 10 to 12 c.c. three times a week.—On a problem of d'Alemhert, by M. F. Siacci.—On a particular critical point of the solution of the equations of elasticity, in the case where the forces on the boundaries are given, by MM. Eugenè and Francois Cosserat.—On the general principles of mechanisms, by M. G. Koenigs.—On the absolute value of the potential in isolated nets of conductors having a capacity, by M. Ch. Eug. Guye.—Researches on the mechanism of etherification in plants, by MM. E. Charabot and A. Hébert. Etherification in plants is produced by the direct action of the acid upon the alcohol, the action being favoured by a particular substance playing the part of a dehydrating agent, the latter being a diastase the dehydrating action of which is exercised in a chlprophyll medium.—Littoral deposits and movements of the soil during the secondary era in the Quercy and western Rouergue strata, by M. Armand Thevenin.—On the origins of the source of the Loue, by M. André Berthelot. Through the accjdent of a fire at an absinthe factory and the consequent liberation of a large quantity of absinthe, it became evident that the Loue represents a subterranean arm of the Doubs.—Observations of M:Berthelot on the preceding communication.—Influence of colour upon the production of the sexes, by M. C. Flammarion. A study of the effect of light of various colours upon the development of silkworms.