Worm Breeder's Gazette 9(3): 108

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

MAbs and mabs

C. Link and W.B. Wood

We are combining genetic and immunological approaches to study male 
tail morphogenesis. Currently, we are developing a panel of monoclonal 
antibodies directed against male tail components. There are two 
reasons for developing these antibodies. First, they can serve as 
molecular markers for normal development, so that the phenotype of 
male tail mutants can be rapidly and precisely defined. Secondly, 
these antibodies may identify important morphogenic components which 
cannot be easily identified genetically, either because they are 
polygenic, or because they are involved in other essential 
developmental processes. To illustrate the latter point, one could 
imagine a cuticle protein essential for maintenance of the fan-like 
shape of the bursa. If this protein was encoded by a multigene family, 
or served an essential function earlier in development, it would be 
difficult to identify mutations in the gene coding for this protein. 
For our initial fusion, mice were immunized with L4 males. Hybridomas 
were prepared and screened by immunofluorescence microscopy of whole 
mounts of methanol-fixed animals. As expected, most positive 
hybridomas produced antibodies directed against antigens present 
throughout the animal. However, two hybridomas produced antibodies 
with interesting specificities. One (A117) appears to bind to the 
entire bursal fan as well as some material in and around the ventral 
nerve cord. The other (A27) binds to a ring-like structure which 
surrounds the cloaca. In hermaphrodites, two posterior cell bodies 
appear to react with this antibody. Since the A27 antibody recognizes 
a clearly sexually dimorphic structure, it may be useful in 
distinguishing male tail mutants that result from partial sexual 
transformation. We have recently generated hybridomas from a mouse 
which was first injected with L4 hermaphrodites, immunosuppressed with 
cyclophosphamide, and then immunized with L4 males and used to prepare 
hybridomas. From the initial screening of these hybridomas, the 
immunosuppression regimen appears to have been successful in reducing 
the number of hybridomas producing antibody to common antigens (e.g., 
muscle). However, we have not observed a concomitant increase in the 
number of male tail-specific clones. We have also been screening for 
new mab (male abnormal) mutations, primarily in mutator backgrounds (
of course!). For our initial, brutally inelegant screen, we have 
constructed mut;him-5 strains, using MT2878 (Mike Finney's version of 
Phil Anderson's TR674 mutator). We have been screening under the 
dissecting microscope for clones producing males with defective tails; 
initial results suggest that this is a feasible approach. If anyone 
has recovered any unwanted, mutator-induced mab mutations (sometimes 
they are hard to avoid), please let us know.