Amino-acid Sequences of Kangaroo Myoglobin and Haemoglobin and the Date of Marsupial-Eutherian Divergence

Air, Gillian M.; Thompson, Eop; Richardson, Barry J.; Sharman, G. B.

doi:10.1038/229391a0

Cited by 103 publications

(25 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Baldwin and Riggs (personal communication) have found that the # chain of adult hemoglobin from R. catesbeiana differs from that of R. esculenta (25) by more than 30 aminoacid replacements. This sequence difference exceeds that usually found between the #i chains of hemoglobins from mammals of different orders (6). We also have preliminary evidence for the existence of large sequence differences among the fibrinopeptides of species within the genus Ranat.…”

Section: Discussionmentioning

confidence: 71%

Albumin Evolution in Frogs: A Test of the Evolutionary Clock Hypothesis

Wallace

Maxson

Wilson

1971

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

View full text Add to dashboard Cite

Frogs are an ancient group compared to placental mammals. Yet, although there are about as many species of frogs as there are of mammals, zoologists consider that frogs have undergone only limited morphological divergence, while placental mammals have diversified greatly in morphology and way of life. The serum albumins of numerous frog species were compared by the quantitative microcomplement fixation technique. Frogs that are morphologically similar enough to merit taxonomic distinction at only the species level often exhibit differences in the serological properties of their albumins larger than those usually seen between mammals placed in distinct families or suborders. Thus, there seems to be a contrast between albumin evolution and evolution at the organismal level. The large differences between albumins among frogs can be explained by the hypothesis that albumin evolution has proceeded at the same rate in frogs as in mammals.The hypothesis that serum albumin behaves as an evolutionary clock was proposed in 1967 (1, 2) to account for the results of immunological comparisons of albumins from a wide variety of primate species. Albumin appeared to have been evolving at about the same rate in all primate lineages tested, including the human lineage. More recent immunological studies of primate albumins substantiate this hypothesis (3). A similar rate of evolutionary change, approximately 100 units of immunological distance per 60 million years, has also been detected in the albumins of other mammals (4), as well as of lizards and crocodilians (5). Evidently, the rate of fixation of mutations causing amino-acid substitutions is approximately constant for albumin regardless of the species, mammal or reptile, in which it occurs. A similar phenomenon has been encountered by those who have studied the evolution of other proteins, for example, haemoglobin (6).We thought it important to determine whether a similar rate of albumin evolution occurred in frogs, because although frogs are an ancient group their morphological uniformity makes them the most easily diagnosed of all vertebrate groups. Thus, zoologists place all living frogs in the single order Anura, even though several of the lineages leading to modern frogs probably diverged from each other about 150 million years ago (7-12). By contrast, the placental mammals, for example, are divided into 16 orders because of their great morphological diversity. Yet the diversification of extant placental lineages began only about 75 million years ago (13). The clock hypothesis predicts that we should find enormous albumin differences between distantly related frogs, far larger than those within or between orders of placental mammals.If, on the other hand, morphological resemblance were used as a basis for prediction, we should expect to find moderate albumin differences among frogs. A comparative immunological study of frog albumins has, accordingly, been performed. MATERIALS AND METHODSSerum samples were obtained from representatives of 26 species belonging to ...

show abstract

Section: Discussionmentioning

confidence: 71%

Albumin Evolution in Frogs: A Test of the Evolutionary Clock Hypothesis

Wallace

Maxson

Wilson

1971

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

View full text Add to dashboard Cite

show abstract

“…This work was supported by the National Health and The number of point accepted mutations (PAM) per 100 amino acid residues is plotted against the time since divergence of species. These times, in millions of years, were assumed to be 30 for rats/mice (Wilson et al, 1977;Brownell, 1983;Janke et al, 1994), 70 for rabbitdrodents (Novacek, 1992), 80 for the mammalian radiation (McLaughlin and Dayhoff, 1972), 80 for AmericadAustralian marsupials (Reig et al, 1987;Westerman et al, 1990), 130 for eutherians/marsupials (Air et al, 1971;Carroll, 1988;Novacek, 1992;Janke et al, 1994), 220 for birdreptiles (McLaughlin and Dayhoff, 1972), and 300 for eutherians/birds-reptiles (McLaughlin and Dayhoff, 1972).…”

Section: Resultsmentioning

confidence: 99%

Evolution of Transthyretin in Marsupials

Duan

Richardson

Babon

et al. 1995

European Journal of Biochemistry

View full text Add to dashboard Cite

The evolution of the expression and the structure of the gene for transthyretin, a thyroxine-binding plasma protein formerly called prealbumin, was studied in three marsupial species : the South American polyprotodont Monodelphis domestica, the Australian polyprotodont Sminthopsis macroura and the Australian diprotodont Petaurus breviceps. The transthyretin gene was found to be expressed in the choroid plexus of all three species. In liver it was expressed in P. breviceps and in M. domestica, but not in S.macroura. This, together with previous studies [Richardson, S. J., Bradley, A. J., Duan, W., Wettenhall, R. E. H., Harms, P. J., Babon, J. J., Southwell, B. R., Nicol, S., Donnellan, S. C. & Schreiber, G. (1994) Am. .I. Physiol. 266, R1359 -R1370], suggests the independent evolution of transthyretin synthesis in the liver of the American Polyprotodonta and the Australian Diprotodonta.The results obtained from cloning and sequencing of the cDNA for transthyretin from the three species suggested that, in the evolution of the structure of transthyretin in vertebrates, marsupial transthyretin structures are intermediate between birdreptile and eutherian transthyretin structures. In marsupials, as in birds and reptiles, a hydrophobic tripeptide beginning with valine and ending with histidine was found in transthyretin at a position which has been identified in eutherians as the border between exon 1 and intron 1. In humans, rats and mice, the nine nucleotides, coding for this tripeptide in marsupials/reptiles/ birds, are found at the 5' end of intron 1. They are no longer present in mature transthyretin mRNA. This results in a change in character of the N-termini of the subunits of transthyretin from hydrophobic to hydrophilic. This change might affect the accessibility of the thyroxine-binding site in the central channel of tr,ansthyretin, since, at least in humans, the N-termini of the subunits of transthyretin are located in the vicinity of the channel entrance [Hamilton,

show abstract

“…There are only three species extant; the platypus (Ornithorhynchus anatinus) and two echidna (so-called "spiny anteater") species. Monotremes diverged from the marsupial and eutherian lineage (subclass Theria) 150-170 million years before present, early in the 200-million-year history of mammals (7).…”

mentioning

confidence: 99%

The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation.

Watson

Spencer

Riggs

et al. 1990

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

View full text Add to dashboard Cite

Eight genes, located on the long arm of the human X chromosome and present on the marsupial X chromosome, were mapped by in situ hybridization to the chromosomes of the platypus Ornithorhynchus anatinus, one of the three species of monotreme mammals. All were located on the X chromosome. We conclude that the long arm of the human X chromosome represents a highly conserved region that formed part of the X chromosome in a mammalian ancestor at least 150 million years ago. Since three of these genes are located on the long arm of the platypus X chromosome, which is G-band homologous to the Y chromosome and apparently exempt from X chromosome inactivation, the conservation of this region has evidently not depended on isolation by X-Y chromosome differentiation and X chromosome inactivation.

show abstract

Amino-acid Sequences of Kangaroo Myoglobin and Haemoglobin and the Date of Marsupial-Eutherian Divergence

Cited by 103 publications

References 13 publications

Albumin Evolution in Frogs: A Test of the Evolutionary Clock Hypothesis

Albumin Evolution in Frogs: A Test of the Evolutionary Clock Hypothesis

Evolution of Transthyretin in Marsupials

The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation.

Contact Info

Product

Resources

About