The effects of polyclonal and monoclonal antibodies on amino acid transport by the amphibian (Xenopus) embryonic jelly coat

Abstract

Polyclonal antibodies have been produced against the components of the Xenopus laevis jelly coat. Ouchterlony tests have shown that polyclonal antibodies react with the ‘jelly coat antigens, producing three distinct bands. In contrast to the polyclonal antibodies, the monoclonal 51-A antibody taken from ascities fluid, produced one distinct band. These Ouchterlony tests have also shown that the polyclonal antibodies react against homogenized embryos, thereby indicating that there may be some homology between the components of the jelly coat and the embryo. On the other hand, the monoclonal antibody does not react with any of the embryonic components. This study has also shown that polyclonal and monoclonal antibodies react with the jelly coats of intact embryos. The characteristics of the jelly coat were changed to a degree whereby the treated embryos were unable to hatch. The jelly coat had become opaque and appeared to have a rubbery texture. The epidermis of intact and dejellied embryos also appear to be affected by these antibodies. Preliminary studies at the ultrastructural level (not reported in the results) show dissociated tight junctions of the epidermis. The [¹⁴C] glycine and [¹⁴C] alanine uptake studies of these jelly coat dependent amino acids indicate that the polyclonal and monoclonal antibodies reduce these amino acids' transport into the embryo. In this study, [¹⁴C] lysine appeared to be transported independently of the jelly coat. When [¹⁴C] lysine uptake was tested, the results indicated no reduction in the amino acid's transport into the embryo. The uptake of this amino acid was reduced in embryos treated with antibodies to the jelly coat. These results have clearly demonstrated that the prior treatment of jelly coats with these antibodies reduces the uptake of those amino acids which have been shown to be jelly coat and sodium dependent for their transport.