Mitochondrial (mt) DNAs from 17 aboriginal Australians, predominantly from the coastal region of the Northern Territory were isolated and digested with four four-base restriction endonucleases, two of which revealed variation between samples. The observed fragment patterns were used directly in parsimony analyses of phylogenetic relationships between the samples, and were also converted to estimates of the number of substitutions per nucleotide position between samples (delta), which estimates were then used in distance analyses of phylogeny. The inferred fragment patterns of the completely sequenced 'Cambridge' human mtDNA were also included in these analyses. No strong evidence of geographic variation was found, consistent with previous findings of Australian aborigines and other humans generally, although the most divergent sample was one of two from Sydney, indicating that further work is desirable. The estimate of mean difference between samples (diversity), 0.0017 +/- 0.0003 (mean +/- 95% confidence interval), is significantly lower than that reported previously for humans generally.
The incorporation of long-chain fatty acids into phospholipids has been detected in adipocyte ghosts that were incubated with [1-14 C] stearic, [1-14 C] linoleic or [1-14 C] arachidonic acid. Adrenaline and adenosine activated this incorporation within 15 s of exposure of the ghosts to the hormones and the response was dose dependent. Maximum incorporation of labelled linoleic acid occurred at 10(-5) M adrenaline and 10(-7) M adenosine. The alpha-agonist phenylephrine and the beta-agonist isoproterenol were also shown to stimulate the incorporation of fatty acid in a dose dependent manner. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were each labelled preferentially with linoleic or arachidonic acid. p-Bromophenacylbromide, quinacrine and centrophenoxine inhibited the adrenaline-stimulated incorporation of fatty acids into ghost membrane phospholipids, and p-bromophenacylbromide also reduced the activation of adenylate cyclase by adrenaline. NaF, an activator of adenylate cyclase, like adrenaline, stimulated the incorporation of linoleic acid into ghost membrane phospholipids.
Coculture of mouse morulae/early blastocysts with isolated endometrial epithelial cells reduced incorporation of glucose carbon into embryonic glycogen but had no significant effect on incorporation into other internal carbon pools during a 5-h culture in serum-supplemented Dulbecco's modification of Eagle's minimum essential medium. Turnover of glycogen pools during 24-h chase culture of pulse-labelled embryos was unaffected by the presence of uterine epithelial cells recovered from day-4 pregnant or non-pregnant mice. However, significantly more label was retained in non-glycogen macromolecules during chase in the presence of endometrium recovered from non-pregnant than from pregnant uteri.
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