ISOLATION AND CHARACTERIZATION OF IMMUNOCLOBULIN‐LIKE PROTEINS OF THE AUSTRALIAN LUNGFISH (<i>NEOCERATODUS FORSTERI</i>)

Jj, Marchalonis

doi:10.1038/icb.1969.46

Cited by 63 publications

(23 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The compositions of these polypeptide chains are very similar to those reported for human (6,32), bullfrog (27), lungfish (33), and dogfish shark (34) macroglobulin heavy and light chains. A common feature of all these IgM heavy and light chains is the high content of serine, threonine, aspartic acid, and glutamic acid.…”

Section: Carbohydrate Determinationssupporting

confidence: 62%

Tetrameric Immune Macroglobulins in Three Orders of Bony Fishes

Acton¹,

Weinheimer²,

Hall³

et al. 1971

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The immune IgM-like macroglobulins were isolated from three species of bony fishes (Ictalurus punctatus, Lepisosteus osseus, and Polyodon spathula) representing the three orders of the subclass Actinopterygii. These macroglobulins were found to have sedimentation coefficients of 14 S and molecular weights of 600,000-630,000. The carbohydrate compositions were determined and found to be different from that of human macroglobulins. After reduction and alkylation, the heavy and light chains could be separated by gel filtration and were found to have molecular weights of approximately 70,000 and 23,000 respectively. The amino acid compositions of these chains were similar to those of mammalian IgM heavy and light chains. The macroglobulins were found by electron microscopy to have a tetrameric structure, in contrast to the pentameric structure found in mammalian, chicken, and shark IgM, i.e. in species later on the evolutionary scale.

show abstract

Section: Carbohydrate Determinationssupporting

confidence: 62%

Tetrameric Immune Macroglobulins in Three Orders of Bony Fishes

Acton¹,

Weinheimer²,

Hall³

et al. 1971

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…6 and 7), but little corresponding information is available for the fleshy-finned fish lineage. Three Ig isotypes have been identified so far at the protein level in two species of lungfishes (8)(9)(10)) that were generically designated: high molecular weight (IgM), intermediate molecular weight, and low molecular weight (IgN) (9,10). We report herein the cloning and characterization of several Ig heavy chain (IgH) cDNAs from Protopterus aethiopicus and present evidence for a phylogenetic relationship between these different isoforms and genes that have been identified in cartilaginous fishes, thus placing the divergence of IgH isotypes at a far earlier point in vertebrate phylogeny than considered previously.…”

mentioning

confidence: 99%

Lineage-restricted retention of a primitive immunoglobulin heavy chain isotype within the Dipnoi reveals an evolutionary paradox

Ota

Rast

Litman

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The lineage leading to lungfishes is one of the few major jawed vertebrate groups in which Ig heavy chain isotype structure has not been investigated at the genetic level. In this study, we have characterized three different Ig heavy chain isotypes of the African lungfish, Protopterus aethiopicus, including an IgM-type heavy chain and short and long forms of non-IgM heavy chains. Northern blot analysis as well as patterns of VH utilization suggest that the IgM and non-IgM isotypes are likely encoded in separate loci. The two non-IgM isotypes identified in Protopterus share structural features with the short and long forms of IgX͞W͞NARC (referred to hereafter as IgW), which were previously considered to be restricted to the cartilaginous fish. It seems that the IgW isotype has a far broader phylogenetic distribution than considered originally and raises questions with regard to the origin and evolutionary divergence of IgM and IgW. Moreover, its absence in other gnathostome lineages implies paradoxically that the IgW-type genes were lost from teleost and tetrapod lineages. T etrapods (land vertebrates) are thought to have shared a common ancestor with a group of fleshy-finned fishes that include the Crossopterygii (coelacanths) and the Dipneusti (lungfishes) (1, 2). Recent systematic studies using both morphological and molecular characters generally have supported a phylogeny in which the lungfishes are the closest relatives of the tetrapods (3-5). Comparative studies on the immunoglobulins at the molecular genetic level have focused on numerous ectothermic vertebrate groups, including chondrichthyans (sharks, rays, chimeras), teleosts (bony fishes), amphibians, and reptilians (reviewed in refs. 6 and 7), but little corresponding information is available for the fleshy-finned fish lineage. Three Ig isotypes have been identified so far at the protein level in two species of lungfishes (8-10) that were generically designated: high molecular weight (IgM), intermediate molecular weight, and low molecular weight (IgN) (9, 10). We report herein the cloning and characterization of several Ig heavy chain (IgH) cDNAs from Protopterus aethiopicus and present evidence for a phylogenetic relationship between these different isoforms and genes that have been identified in cartilaginous fishes, thus placing the divergence of IgH isotypes at a far earlier point in vertebrate phylogeny than considered previously. Materials and MethodsJuvenile P. aethiopicus specimens (10-20 cm) were maintained in laboratory aquaria before death, and removal of tissues. RNA, and DNA were isolated by using standard protocols (11). Liver RNA was used as the source for cDNA library construction, whereas erythrocyte DNA was used for genomic library construction.Generation of VH Probes. V H -specific probes were derived by amplifying Protopterus genomic DNA with primers that complement sequences in FR1 to FR3 that are common to vertebrate Ig V H structures (12). Appropriately sized PCR products were subcloned into pBluescript SKIIϩ and sequenced. A p...

show abstract

“…Analyses of the cDNA sequences for the heavy chain of this low molecular weight Ig have confirmed its unrelatedness to other known heavy chains (Harding et al, 1990). In some aquatic and amphibious species, including the Australian lungfish (Marchalonis, 1969) and some turtles (Chartrand et al, 1971;Leslie & Clem, 1972), a small Ig occurs which has heavy chains antigenically distinct from those of IgM. Its heavy chain mass is 35 to 40 kDa, conferring a total molecular mass of 120 to 130 kDa and a sedimentation coefficient (S 2 ow) of 5 to 6S.…”

mentioning

confidence: 93%