Reinvestigation of DNA ligase I in axolotl and Pleurodeles development.
We have recently shown that the exclusion process causing the replacement of DNA ligases II by DNA ligase I in amphibian eggs after fertilization does not occur in the case of Xenopus laevis [Hardy, S., Aoufouchi, S., Thiebaud, P., and Prigent, C., (1991) Nucleic Acids Res. 19, 701-705]. Since this result is in contradiction with the situation reported in axolotl and Pleurodeles we decided to reinvestigate such results in both species. Three different approaches have been used: (1) the substrate specificity of DNA ligase I; (2) the DNA ligase-AMP adduct reaction and (3) the immunological detection using antibodies raised against the X.laevis DNA ligase I. Our results clearly demonstrate that DNA ligase I activity is associated with a single polypeptide which is present in oocyte, unfertilized egg and embryo of both amphibians. Therefore, the hypothesis of a change in DNA ligase forms, resulting from an expression of the DNA ligase I gene in axolotl and Pleurodeles early development must be rejected. We also show that, in contradiction with published data, the unfertilized sea urchin egg contains a DNA ligase activity able to join blunt ended DNA molecules.
Aoufouchi
S
S
Laboratoire de Biologie et Génétique du Dévelopement, URA CNRS 256, Université de Rennes I, France.
Hardy
S
S
Prigent
C
C
Philippe
M
M
Thiebaud
P
P
D000249:Adenosine Monophosphate / Q000378:metabolism; D000557:Ambystoma / Q000196:embryology / Q000378:metabolism*; D000818:Animals; D004247:DNA / Q000378:metabolism; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000378:metabolism*; D015870:Gene Expression / Q000502:physiology; D015151:Immunoblotting; D010063:Ovum / Q000201:enzymology*; D010999:Pleurodeles / Q000196:embryology / Q000378:metabolism*; D012617:Sea Urchins / Q000196:embryology / Q000201:enzymology; D013379:Substrate Specificity; D014982:Xenopus laevis / Q000196:embryology / Q000378:metabolism
D000249:Adenosine Monophosphate; D004247:DNA; D011088:DNA Ligases; D000072481:DNA Ligase ATP