scholarly journals Effect of X-ray Irradiation on the Male Moths of Two Tropical Races of the Silkworm Bombyx mori and Inheritance of Induced Sterility in the Progenies

2010 ◽  
Vol 2 ◽  
pp. IJIS.S3655 ◽  
Author(s):  
G. Subramanya
Keyword(s):  
Bombyx Mori ◽  
X Rays ◽  
X Ray ◽  
Egg Hatchability ◽  
Untreated Female ◽  
Inherited Sterility ◽  
Silkworm Bombyx Mori

Newly emerged male moths of silkworm Bombyx mori were treated with in 24 h of eclosion irradiated with two independent doses of 50 Gy and 100 Gy X-rays. The effects of X-rays in the parental generation have indicated significant increase of unfertilized and unhatched eggs followed by significant reduction in the hatchability in the treated batches compared to control. The inheritance of induced sterility was examined in the succeeding generations by rearing the F1, F2 and F3 silkworm progenies and by crossing the progenies of treated males with untreated female moths. It is evident from the results that the number of hatched eggs gradually increased from F1–F3 generations. Thus, the results showed that the egg hatchability do not remain constant at every generation and hatching tendency of eggs increase in the progenies of treated batches. The mechanism of inherited sterility was discussed.

scholarly journals Chromosomal fragment responsible for genetic mosaicism in larval body marking of the silkworm, Bombyx mori

1991 ◽  
Vol 57 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Haruhiko Fujiwara ◽  
Osamu Ninaki ◽  
Masahiko Kobayashi ◽  
Jun Kusuda ◽  
Hideaki Maekawa
Keyword(s):  
Bombyx Mori ◽  
Short Chromosome ◽  
Larval Body ◽  
Chromosomal Fragment ◽  
X Ray ◽  
Chorion Genes ◽  
Genetic Mosaicism ◽  
Chromosome Fragments ◽  
Dna Fragment ◽  
Silkworm Bombyx Mori

SummarySeveral genetic mosaics for larval body marking of the silkworm, Bombyx mori, have been induced by X-ray irradiation. It is hypothesized that the occasional loss of chromosomal fragments carrying the genes for body marking during development may give rise to this type of mosaicism. Using pulsed field gel electrophoresis (PFGE), we find that a DNA molecule of about 2·5 megabases (Mb) is present in one type of mosaic (mottled striped strains pSm788 and pSm872), and not in any other strain. This DNA fragment hybridizes strongly with some chorion genes which are less than 6·9 cM away from the ps locus, and hence it corresponds to a chromosomal fragment containing genes for both striped marking (ps) and the chorion. In the non-mottled ps strain, the phenotype before X-ray irradiation, no band was detected either on a PFGE gel or after hybridization with the chorion probe. These results suggest that the mottled ps strains carry short chromosome fragments which are lost differentially during cell divisions.

The X-ray structure of juvenile hormone diol kinase from the silkworm Bombyx mori

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Jingxu Guo ◽  
Ronan M. Keegan ◽  
Daniel J. Rigden ◽  
Peter T. Erskine ◽  
Steve P. Wood ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Bombyx Mori ◽  
Calcium Ions ◽  
Sexual Maturation ◽  
Calcium Ion ◽  
Multiple Roles ◽  
Insect Development ◽  
X Ray ◽  
Ef Hand ◽  
Silkworm Bombyx Mori

Insect juvenile hormones (JHs) are a family of sesquiterpenoid molecules that are secreted into the haemolymph. JHs have multiple roles in insect development, metamorphosis and sexual maturation. A number of pesticides work by chemically mimicking JHs, thus preventing insects from developing and reproducing normally. The haemolymph levels of JH are governed by the rates of its biosynthesis and degradation. One enzyme involved in JH catabolism is JH diol kinase (JHDK), which uses ATP (or GTP) to phosphorylate JH diol to JH diol phosphate, which can be excreted. The X-ray structure of JHDK from the silkworm Bombyx mori has been determined at a resolution of 2.0 Å with an R factor of 19.0% and an R free of 24.8%. The structure possesses three EF-hand motifs which are occupied by calcium ions. This is in contrast to the recently reported structure of the JHDK-like-2 protein from B. mori (PDB entry 6kth), which possessed only one calcium ion. Since JHDK is known to be inhibited by calcium ions, it is likely that our structure represents the calcium-inhibited form of the enzyme. The electrostatic surface of the protein suggests a binding site for the triphosphate of ATP close to the N-terminal end of the molecule in a cavity between the N- and C-terminal domains. Superposition with a number of calcium-activated photoproteins suggests that there may be parallels between the binding of JH diol to JHDK and the binding of luciferin to aequorin.

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