Immunohistochemical analysis of the role of hemocytin in nodule formation in the larvae of the silkworm, Bombyx mori.
Hemocytin, a multidomain protein from Bombyx mori L. (Lepidoptera: Bombycidae), is an ortholog of von Willebrand factor and is expected to be a major mediator of hemocyte aggregation. Antiserum was generated against hemocytin, and immune staining of hemocytes, hemolymph, and nodules was performed. Hemocytin was observed in steady-state hemocytes but not in plasma, even after bacterial injection. When hemolymph was smeared on glass slides, hemocytin-containing fibrous structures formed a cellular network mainly consisting of granulocytes and oenocytoids. Hemocytin was stained only in the granules of the granulocytes. When nodule-like aggregates formed 30 sec after bacterial injection, both granulocytes and bacterial cells were observed binding to hemocytin-containing fibrous structures. When nodule sections were stained with antiserum, hemocytin was seen in the matrix of the nodules surrounding the hemocytes. These data suggest that hemocytin plays a major role in nodule formation as a component of the sticky fibrous structure exocytosed from granulocytes.
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei 2-24-16, Tokyo 184-8588, Japan.
Ikuyo
I
Arai
Masayuki
M
Ohta
Asahi
A
Suzuki
Shiho
S
Tanaka
Yasutaka
Y
Yoshizawa
Ryoichi
R
Sato
D000818:Animals; D015153:Blotting, Western; D012831:Bombyx / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology; D004926:Escherichia coli / Q000502:physiology; D005455:Fluorescent Antibody Technique; D006434:Hemocytes / Q000378:metabolism*; D006458:Hemolymph / Q000378:metabolism*; D007113:Immunity, Innate; D019476:Insect Proteins / Q000378:metabolism*; D007814:Larva; D037102:Lectins / Q000378:metabolism*; D016982:Micrococcus luteus / Q000502:physiology
D019476:Insect Proteins; D037102:Lectins; C092374:hemocytin protein, Bombyx mori