𝔖 Bobbio Scriptorium
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The origin of yolk-DNA inXenopus laevis

✍ Scribed by Opresko, Lee ;Wiley, H. Steven ;Wallace, Robin A.

Book ID
102890184
Publisher
John Wiley and Sons
Year
1979
Tongue
English
Weight
778 KB
Volume
209
Category
Article
ISSN
0022-104X

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✦ Synopsis

Abstract

Xenopus laevis serum and plasma was found to contain an average of 25 μg DNA/ml. Isolated X. laevis oocytes incubated in medium containing 25 μg DNA/ml labeled with either ^125^I, ^32^P or ^14^C and from three different sources (bovine, E. coli and X. laevis), incorporated the label at an average rate of 0.11 ng·mm^−^·hr^−1^. Sucrose gradient fractionation of oocytes revealed that 40–75% of the acid‐precipitable label incorporated was associated with the yolk platelets. Additional incubations of oocytes in unlabeled medium demonstrated that the DNA incorporated into the yolk platelets was undergoing turnover; only 20% of the yolk‐associated DNA was still present after a one‐week incubation. Our data suggest that yolk‐DNA arises by the adventitious uptake of DNA present in the maternal serum by vitellogenic oocytes.

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