Alkaline phosphatases (ALP) can be found widely from bacteria to human, of which common ancestral gene evolved only once in prokaryote, and are thought to play essential roles for the living organisms. But the biological significance of ALPs is not fully elucidated. In order to clarify the fine characteristic of ALPs in insects, we examined localization of the two isozymes, membrane-bound ALP (mALP) and soluble ALP (sALP), in the larval midgut of the silkworm, Bombyx mori. By immunohistochemical analyses with null mutants, we found the two enzymes are co-localized to the brush border of the columnar cells at the posterior portion of the larval midgut. sALP was detected not only in the cavity of the goblet cell, but also at the brush border of the columnar cells, while mALP was located only to the latter. This coexistence and a tendency of compensation between their doses suggest, at least some functional overlapping of the two ALPs.
We developed a new incision sealing method using a paraffin coated paper (PP) instead of melted paraffin (MP) as in the previous method, to improve the ovary transplantation in silkworm, Bombyx mori. Thus, we succeeded in simplifying the incision sealing without reducing the survival rate of recipient larvae. The survival rate of MP, PP, and no sealing (control) was 65.0% (SE 12.6), 75.6% (SE 13.1), and 50.6% (SE 14.0), respectively. Although, among the above three ways, there was no statistical significance, the PP treatment was easier than the MP one. Next, to effectively use cryopreserved resources, we compared three transplantation methods using normal silkworms as recipients and transgenic silkworms as donors: (A) both recipient ovaries were transplanted, (B) only one of the ovaries was transplanted, and the other recipient ovary was removed, and (C) only one of the ovaries was operated like in (B), but the other was still kept in the recipient body. Consequently, the method (C), only one-ovary transplantation, was as high as, or more than, other methods in the effectiveness of the reproduction from the frozen-thawed ovary. Our results suggest that the two methods using PP sealing and one ovary transplantation could be convenient and effective in cryopreservation technology using ovary of silkworm.