کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2841594 1165412 2007 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Autocrine activation of ecdysteroidogenesis in the prothoracic glands of the silkworm, Bombyx mori
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش حشره شناسی
پیش نمایش صفحه اول مقاله
Autocrine activation of ecdysteroidogenesis in the prothoracic glands of the silkworm, Bombyx mori
چکیده انگلیسی
Ecdysteroidogenesis in the prothoracic glands is activated by the neuropeptide, prothoracicotropic hormone (PTTH). The present study demonstrates autocrine activation of ecdysteroidogenesis in prothoracic glands of the silkworm, Bombyx mori. Using both a long-term in vitro organ culture system and an ecdysteroid radioimmunoassay, it was found that either decreasing the incubation volume, from 100 to 5 μl, or increasing the number of glands incubated per drop (50 μl) from 1 to 5 significantly increased ecdysteroid secretion. Prothoracic gland-conditioned medium was used to clarify the autocrine factor. The results showed that activation of ecdysteroidogenesis by the prothoracic gland-conditioned medium appeared to be dose dependent and a dramatic increase in ecdysteroid secretion was observed after 6 h of incubation in the conditioned medium. Moreover, it appeared that autocrine activation occurred when glands were incubated in large volumes of incubation medium and during a short incubation period, indicating that the factor may exert its action in situ at some specific developmental stages. This tropic factor was further characterized, and it was found that the factor seemed to be heat-stable, with a molecular weight estimated to be between 1000 and 3000 Da. Injection of the concentrated putative autocrine factor into day 5 last instar larvae greatly increased ecdysteroidogenic activity of the prothoracic glands compared to those injected with saline, indicating the possible in vivo function of the present factor.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Insect Physiology - Volume 53, Issue 6, June 2007, Pages 538-549
نویسندگان
,