The joining (J) chain is present in invertebrates that do not express immunoglobulins.

@article{Takahashi1996TheJ,
  title={The joining (J) chain is present in invertebrates that do not express immunoglobulins.},
  author={Tomihisa Takahashi and Teruhiko Iwase and Norihiro Takenouchi and Makiko Saito and Kazuo Kobayashi and Zina Moldoveanu and Jiri F. Mestecky and Itaru Moro},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  year={1996},
  volume={93 5},
  pages={1886-91}
}
Joining (J) chain is a component of polymeric, but not monomeric, immunoglobulin (Ig) molecules and may play a role in their polymerization and transport across epithelial cells. To date, study of the J chain has been confined to vertebrates that produce Ig and in which the J chain displays a considerable degree of structural homology. The role of the J… CONTINUE READING