THE ELEMENTARY COMPOSITION OF
            <i>Latimeria chalumnae</i>
            SMITH

Cowgill, U. M.; Hutchinson, G. Evelyn; Skinner, Hubert C.

doi:10.1073/pnas.60.2.456

Cited by 10 publications

(2 citation statements)

References 4 publications

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“…confidence in these results. The very low values reported by Cowgill et al (1968) for Cl are extraordinary and must be regarded as spurious, since they would indicate that this animal had a negligible to zero extracellular space in its muscle tissue.…”

Section: Discussionmentioning

confidence: 85%

OSMOTIC CONSTITUENTS OF THE COELACANTHLATIMERIA CHALUMNAESMITH

Lutz¹,

Robertson²

1971

The Biological Bulletin

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The coelacanth Latimeria chalnmiiae occupies a unique position in the phylogenetic tree of the vertebrates as the only living representative of the crossopterygians, a group generally thought to lead from the ancestral bony fishes to the amphibians (Berg, 1958;Young, 1962; Romer, 1966). This, together with the fact that until 1939 the crossopterygians had been considered long extinct, dying out in the Cretaceous, accounts for the great interest shown in these "living fossils." However, in spite of an almost continual search since the end of the Second World War only two females and 30 males have been found to date, and there has been chemical analysis on only one specimen. On this fish, a large frozen male, Pickford and Grant (1967) analyzed the blood, Brown and Brown (1967) searched for the ornithine cycle enzymes and urea in the liver, and Cowgill, Hutchinson and Skinner (1968) looked at the mineral content of its hard and soft tissues. The offer to us by the Royal Scottish Museum of access to another specimen was therefore accepted with enthusiasm and it was thought worthwhile to confirm and perhaps extend the results on the first. As our fish was also frozen a small study was made to find the gross effect of prolonged freezing on the distribution of ions in a common fish (the freshwater perch) to help us interpret our data. MATERIALS AND METHODS141, 553-560.

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Section: Discussionmentioning

confidence: 85%

OSMOTIC CONSTITUENTS OF THE COELACANTHLATIMERIA CHALUMNAESMITH

Lutz¹,

Robertson²

1971

The Biological Bulletin

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“…Except from the anatomical point of view (Millot & Anthony, 1958, few investigations have been made on coelacanth muscle. Until recently, the only biochemical determinations available were related to the lipid content (Nevenzel et al 1966), the elementary composition (Cowgill, Hutchinson & Skinner, 1968) and the osmotic constituents (Lutz & Robertson, 1971). These last determinations on various tissues have made it clear that the coelacanth is adapted to sea water in a similar manner to the elasmobranchs, by way of urea retention.…”

Section: G Hamoir and Othersmentioning

confidence: 99%

Muscle Proteins of the CoelacanthLatimeria ChalumnaeSmith

et al. 1973

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Although the anatomy of the coelacanth muscles has been examined very thoroughly, their protein composition has, until recently, not been investigated. Thanks, however, to the 1972 British–French–American expedition to the Comores, frozen material has been made available and some results on myoglobin and four glycolytic enzymes have already been published. We have carried out a comparison of the sarcoplasmic proteins of red and white muscle by starch-gel electrophoresis. The ninhydrin-positive dialysable constituents and the myofibrillar proteins of white muscle have also been examined.A few puzzling results obtained with the white muscle extracts have been related to the occurrence of o.1 M ammonia, due presumably to the splitting of urea by a bacterial urease, and to an alteration of the active thiol groups of GAPDH and PK. If due account is taken of these unusual post-mortem changes, the extractability of the proteins and their properties are strikingly similar to those of teleosteans. The comparison of the sarcoplasmic proteins of white and red muscle by starch-gel electrophoresis revealed also that the differentiation observed in the coelacanth was similar to that occurring in the carp. A study of the low-molecular-weight proteins, or parvalbumins, of white muscle and of the myofibrillar proteins also shows the expected differences between the two muscle types.The only abnormal features observed in this study were the high concentration of parvalbumins, 1.5–2 times that found in other species examined, and the occurrence of an unusual globulin fraction which was easily extracted at ionic strength 0.5 and insoluble at ionic strength 0.35 and neutral pH.

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