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

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 chain in Ig polymerization has been questioned and, since the J chain can be expressed in lymphoid cells that do not produce Ig, it is possible that the J chain may have other functions. To explore this possibility, we have surveyed J-chain gene, mRNA, and protein expression by using reverse transcriptase-coupled PCR, Northern blot analysis, and immunoblot analysis in invertebrate species that do not produce Ig. We report that the J-chain gene is expressed in invertebrates (Mollusca, Annelida, Arthropoda, Echinodermata, and Holothuroidea), as well as in representative vertebrates (Mammalia, Teleostei, Amphibia). Furthermore, J-chain cDNA from the earthworm has a high degree of homology (68-76%) to human, mouse, and bovine J chains. Immunohistochemical studies reveal that the J chain is localized in the mucous cells of body surfaces, intestinal epithelial cells, and macrophage-like cells of the earthworm and slug. This study suggests that the J chain is a primitive polypeptide that arose before the evolution of Ig molecules and remains highly conserved in extent invertebrates and vertebrates.

Die Anatomie des Frosches : ein Handbuch für Physiologen, Ärzte und Studirende / von dr. Alexander Ecker.

abt. 1-3

Die Anatomie des Frosches : ein Handbuch für Physiologen, Ärzte und Studirende / von dr. Alexander Ecker.

Abt. 1-2

Variation in Bornean frogs of the Amolops jerboa species group, with description of two new species / Robert F. Inger, Paul A. Gritis.

n.s. no.19(1983)

The Cambridge natural history,

Vols. 1, 2, 5-7, 9 reprinted 1922; v. 3, 1927; and vols. 4, 8, 10, 1923.

Catalogue of the Batrachia salientia in the collection of the British Museum /

Índice.

Caroli a Linné ... Systema naturae per regna tria naturae Secundum Classes, Ordines, Genera, Species, cum Characteribus, Differentiis, Synonymis, Locis ... /

Contiene: T. 1: Pars I: Mammalia, Aves. Pars II: Aves. Pars III: Amphibia reptilia, Serpentes, Pisces. Pars IV: Insecta Coleoptera, Hemiptera. Pars V: Insecta lepidoptera. Pars VI: Vermes. Pars VII: Index ; T.2: Regnum vegetabile ; T.3: Regnum lapideum.

Beiträge zur Naturgeschichte von Brasilien /

Vols. 3 and 4 are in two parts each.

General zoology, or Systematic natural history,

Each volume in two parts, each with general engravings and special t.-p.; in v. 1-11 paged continuously.

Natural history of New York

Each v. has also individual t.-p.