Rizki R M, Rizki T M
Department of Biology, University of Michigan, Ann Arbor 48109.
J Exp Zool. 1991 Feb;257(2):236-44. doi: 10.1002/jez.1402570214.
Female parasitoid Leptopilina heterotoma inject a factor, lamellolysin, along with their eggs into the host hemocoel to destroy selectively host hemocytes that encapsulate foreign objects. In parasitized Drosophila melanogaster larvae, these hemocytes (lamellocytes) change from discoidal cells to bipolar cells that no longer adhere to each other to form capsules. To study the effects of lamellolysin on Drosophila lamellocytes in vitro, a giant strain of D. melanogaster was constructed to yield hemolymph with an abundance of lamellocytes. The effect of lamellolysin on the adhesivity of lamellocytes in vitro was demonstrated when the cells were gently rotated in the culture medium. Under these conditions, the bipolar shape of the affected lamellocytes resembled that of lamellocytes in parasitized hosts. When lamellocytes were exposed to lamellolysin in stationary culture medium, the elongation of the bipolar cells continued until they became threadlike. Lamellocytes fragmented in both stationary and rotating culture medium in the presence of lamellolysin, although loss of cellular material was more pronounced in the latter. This study demonstrates that lamellolysin acts directly and destructively on lamellocytes.
雌性寄生蜂异腹细蜂（Leptopilina heterotoma）会将一种名为层状溶素的因子与卵一起注入宿主血腔，以选择性地破坏包裹异物的宿主血细胞。在被寄生的黑腹果蝇幼虫中，这些血细胞（扁平细胞）会从盘状细胞转变为不再相互黏附以形成包囊的双极细胞。为了在体外研究层状溶素对果蝇扁平细胞的影响，构建了一种黑腹果蝇的巨型品系，以产生富含扁平细胞的血淋巴。当细胞在培养基中轻轻旋转时，证明了层状溶素对体外扁平细胞黏附性的影响。在这些条件下，受影响的扁平细胞的双极形状类似于被寄生宿主中的扁平细胞。当扁平细胞在静止培养基中暴露于层状溶素时，双极细胞的伸长会持续到它们变成丝状。在层状溶素存在的情况下，扁平细胞在静止和旋转培养基中都会破碎，尽管在后者中细胞物质的损失更为明显。这项研究表明层状溶素对扁平细胞有直接的破坏作用。
