RRC ID 12239
Author Kamei Y, Hasegawa Y, Niimi T, Yamashita O, Yaginuma T.
Title Trehalase-2 protein contributes to trehalase activity enhanced by diapause hormone in developing ovaries of the silkworm, Bombyx mori.
Journal J. Insect Physiol.
Abstract Diapause hormone (DH) targets developing ovaries in female pupae to induce embryonic diapause immediately after completion of mesoderm segregation of the silkworm, Bombyx mori. At the same time, DH enhances trehalase activity on the oolemma, which leads to higher concentrations of glycogen in oocytes through the stimulated incorporation of hemolymph trehalose. In B. mori, the treh-1 and -2 genes encoding soluble trehalase (68 kDa) and integral-membrane trehalase (74kDa) have been isolated. DH stimulates mRNA expression of both of these genes. In this study, we aimed to clarify whether ovarian trehalase originates from Treh-1 or Treh-2. Western blotting of the developing ovaries showed positive bands in the membrane-bound fraction, containing trehalase activity, only with antibodies against Treh-1&2 and Treh-2, but not Treh-1, irrespective of nondiapause or diapause egg-producers. The intensities of the positively stained 74 kDa bands were increased approximately 4-fold in ovaries from pupae with intact subesophageal ganglion (SG, a unique DH-biosynthesizing organ), and from pupae that were injected with DH at the middle pupal stage after their SGs were removed on the day of pupation. Furthermore, quantitative real-time PCR data showed that in developing ovaries, copy number of treh-2 mRNA per one copy of rp49 mRNA was approximately 1000-fold higher than that of treh-1 mRNA. These results demonstrate that trehalase activities enhanced by DH originate mainly from treh-2 protein regulated at the transcriptional level.
Volume 57(5)
Pages 608-13
Published 2011-5
DOI 10.1016/j.jinsphys.2010.10.001
PII S0022-1910(10)00284-2
PMID 20965194
MeSH Animals Bombyx / enzymology Bombyx / genetics Bombyx / growth & development* Bombyx / metabolism* DNA Copy Number Variations Endocrine Glands / surgery Female Gene Expression Regulation, Enzymologic Genes, Insect Neuropeptides / metabolism* Ovary / enzymology Ovary / metabolism Polymerase Chain Reaction Pupa RNA, Messenger / genetics RNA, Messenger / metabolism Transcription, Genetic Trehalase / biosynthesis Trehalase / genetics Trehalase / metabolism*
IF 2.733
Times Cited 14
Silkworms NA