Purine nucleotide content of developing ascaris lumbricoides eggs

Abstract

Farland W. H. & Macinnis A. J. 1978. Purine nucleotide content cf developing Ascaris lumbricoides eggs. International Journal for Parasitology 8: 177–186. Populations of Ascaris lumbricoides eggs obtained from the terminal portion of the uteri of mature females were shown to develop synchronously, allowing the detection of quantitative and qualitative changes in nucleotide content during development. Application of a method for the preparation of perchloric acid-soluble fractions from Ascaris eggs utilizing Alamine 336S in chloroform is described. This method was useful in neutralizing the extract and for removal of interfering lipids. Guanine nucleotides were found in high concentration in ovarian tissue of adult female worms, and comprise more than 80% of the total acid-soluble nucleotides in 0-day eggs. Muscle tissue contained a predominance of adenine nucleotides. To determine the fate of large concentrations of guanine nucleotides present in 0-day eggs, perchloric acid-soluble fractions were prepared from embryonating eggs on various days of development. Nucleotide content was determined after fractionation on DEAE-cellulose columns, A dramatic decrease (6·2 fold) in guanine nucleotides between 5 and 8 days' embryonation was seen; [GMP] and [GDP] showed the greatest change. ATP concentration increases 3·3 fold through 21 days' embryonation. The total acid-soluble nucleotide content decreased 60% during this time. Uric acid, an end product of purine metabolism, was detectable in 5-day eggs and accumulated through the course of embryonation. The decrease of guanine nucleotides correlates temporally with the increase in DNA content during embryonation. The methodology and results of this study provide a basis for additional study of nucleic acid metabolism during development of Ascaris eggs.