The quantity and distribution of nucleic acids in the early cleavage stages of the mouse embryo

Thesis (Ph.D.)--Boston UniversityDeoxyribonucleic acid (DNA), a nucleotide polymer containing deoxyadenylic, thymidylic, deoxycytidylic, and deoxyguanylic acids, is arranged in a double helix with adenine in one chain bound to thymine in the other, and cyti.dine bound to guanine. This structure accounts for the.purine and pyrimidine molar proportions observed in biochemical analyses of cells, and also for the ability of the genetic material to replicate in complementary fashion. The DNA code directs the order of nucleotides in ribonucleic acid (RNA). Ribonucleic acid is a nucleotide polymer containing adenylic, uridylic, cytidylic, and guanylic acids. RNA occurs in the nucleus and cytoplasm in several forms. Messenger RNA which is coded by DNA, transmits the genetic information to soluble RNA (sRNA); sRNA accepts activated amino acids to form an RNA-amino acid intermediate, and functions as an adaptor for positioning the amino acids on ribosomal RNA where peptide linkages and protein formation occur. The DNA and RNA codes leading to protein synthesis were discussed. Studies on nuclear DNA have shown the constancy per species of this nucleic acid. Somatic cells contain the diploid amount with gametes containing one-half, or the haploid, amount. However, investigation of invertebrate and amphibian ova and embryos has disclosed a large excess of DNA in these cells ...[TRUNCATED