PHYSIOLOGICAL AND CYTO-METRICAL STUDIES ON SPERMATOGENESIS OF SILKWORMS

本研究旨在探讨内分泌处理对三眠蚕育后精细胞出现时间的影响。通过使用DNA流式细胞术的单倍体细胞（1C细胞）的形成的一组来确定时间。保幼激素和KK-42（1-苄基-5-[（E）-2，6-二甲基-1，5-庚二烯基]咪唑）的处理以不影响幼虫蜕皮数量的低剂量进行。在未处理的三眠性不育睾丸中，1C细胞在第4龄第4天形成。保幼激素处理导致1C细胞形成的时间延迟2天。相反，KK-42处理加速了1C细胞的出现。1C细胞在4龄第4天至第0天出现一组变化。高剂量蜕皮激素引起的第4次多蜕皮，使三眠期幼虫1C细胞的形成时间稍有延迟。另一方面，以相同剂量的蜕皮激素处理显性三眠性幼虫，不引起额外（第4次）的幼虫蜕皮，但推迟1C细胞的出现一天。这些结果表明，保幼激素和蜕皮激素可能参与了雌蛾从精母细胞向精细胞转化的过程。

The purpose of the present studies was to investigate the effects of endocrine treatment on the timing of the appearance of sperm cells in ressesive trimolter silkworm. The timing was determined by the oneset of formation of the haploid cells (1C cells) using DNA flow cytometry. The treatments with juvenile hormone and KK-42 (1-benzyl-5-[(E)-2,6-dimethyl-1,5-heptadienyl] imidazole) were done at low doses that did not affect the number of larval molt. In the testis of untreated ressesive trimolter, 1C cells were formed on day 4 of 4th inster. Treatment with juvenile hormone caused a delay of 2 days in the oneset of formation of 1C cells. In contrast, KK-42 treatment hastened the appearance of 1C cells. The oneset of 1C-cell appearance changed from day 4 to day 0 of 4th instar by this treatment. High dose of ecdysteroid that caused the supernumerary (4th) larval molt had a few delay in the oneset of formation of 1C cells in ressesive trimolter. On the other hand, ecdysteroid treatment on dominant trimolter at same dose as on ressesive trimolter did not cause the supernumerary (4th) larval molt, but delayd the appearance of 1C cells for one day. These results suggest that juvenile hormone and ecdysteroid may involve a process from spermatocyte to sperm cell in ressesive trimolter.