Náttúrufræðingurinn - 1970, Síða 44

18«
NÁTTÚ R U F RÆÐINGURINN
Water-soluable proteins from heart and breast muscle (Fig. 6)
At lcast 14—15 protein fractions were resolved on the zymogram. These were
divided into zones A—F, where A—E are anodally and F cathodally migrating.
Differences between these two tissues are very clear as Fig. 6 shows.
Discussion
Serum could only be obtained from Icelandic birds. No qualitative poly-
morphism could be found, neitlier in the general protein pattern nor the
esterase pattern. This does not agree with findings in Phasianus colchicus
(Baker et al., 1966) Gallus gallus, Anser and Branía species, and Columba
species (Baker, 1966, Ferguson, pers. communication), which all show poly-
morphism in the serum. Tliis is difficult to explain, but isolation and extensive
geneflow within Iceland might have something to do with this.
As mentioned above there is a clear-cut difference between tlie American
and European groups as regards liveresterases. The absence of zonc B in L.
mutus mulus means the absence of the gene responsible for this zone. By
studying the diffcrent subspecies of L. mutus around the world, we would
get a clearer picture of the evolution of these esterase-ntolecules and thus of
the species. Other animals show similar differences in liveresterases, e.g. An-
quilla anquilla and Anquilla rostrata (Arnason et al., in press) and in Apo-
demus sylvaticus (Árnason, unpublished).
Cardiac and skeletal muscle proteins do not show differences among L.
mutus from different countries. This is true also of A. sylvalicus (Árnason,
unpublished). 'I liis could mean different rate ol evolution of different pro-
teins. Because of this a great amount of preliminary work is needed, before
one selects llie appropriate protein-system for genetical studies. As mentioned
above, this is only a preliminary work. The original plan was to compare also
the Scottish Rock l’tarmigan witli the other subspecies, but samples could not
be obtained. It is not unreasonable to suggest that they would be similar to
the L. mutus mutus, but it is also possible that a long geographicttl isolation
has changed the pattern somewhat.