[
Worm Breeder's Gazette,
1983]
In a previous newsletter (WBG 7[1]:75), we described the making of a library of monoclonal antibodies (MoAbs) to C. elegans in order to identify tissue- or cell-specific antigens in the animal. We recently reported on three germline-specific MoAbs, two of which react with granules unique to germline cells (Yamaguchi et al. 1983. Develop., Growth and Differ. 25:121-131). In an attempt to obtain more germline-specific (and also early embryo-specific) MoAbs, we used fertilized eggs and 1- to 4-cell stage embryos for immunization. Of 800 hybridomas obtained by fusing P3U-1 myeloma cells to splenocytes from immunized BALB/c mice, about 60 hybridomas were found to secrete antibodies to C. elegans by indirect immunofluorescent staining of C. elegans whole mount preparations. Five hybridoma lines, 704D, 904A, 911F, 1003B, and 1108E, out of these 60 were identified as secretors of Abs that react with germline granules (G-granules). We are at present characterizing these cell lines together with the line M32 isolated previously. The table shows preliminary results on the cross-reactivity of the Abs to various nematodes. The Abs of all 6 hybridomas reacted with the G-granules of both C. elegans and C. briggsae, possibly reflecting the taxonomic closeness. However, the Ab of only one hybridoma line, 1003B, stained G-granules of a free-living diecious nematode recently isolated from soil of Wakayama-ken. The nematode Bursaphelenchus is parasitic and considered a prime culprit of recent disastrous damage to pine trees in Japan. The G-granules of this nematode were stained also with the 1003B Ab and tentatively with 904A and M32. The result with the 1003B Ab indicates that the G-granules of all the nematodes listed here possess some structure common to them. The difference observed of cross-reactivity among the Abs may reflect either various antigenic determinants of a single element in the granules or a complex of multiple elements constituting the granules. Further study on cross-reactivity and biochemical characterization are under way. [See Figure 1]