19 Results
for term "sites"
- VARIATION OF MUTAGENIC ACTION ON NONSENSE MUTANTS AT DIFFERENT SITES IN THE ISO-1-CYTOCHROME c GENE OF YEAST...of tryptophan replacements in ochre revertants, could be corroborated rom the studies of two groups of suppressors that were shown to act on either the ochre or amber mutants. All five nonsense mutants are located at different sites in the C Y C ~ gene and all are a t sites that can be occupied by amino acids ~~~
- MOLECULAR ASPECTS OF GENETIC EXCHANGE AND GENE CONVERSION...: 1) After the premeiotic S phase, single strand gaps are left at the ends of repli- cons and these provide defined initiation points ( WHITEHOUSE 1969; HASTINGS 1972). 2) A nuclease binds to specific base sequences distributed at random along the chromosome. The enzyme has two binding sites and cuts ~~~
- REGULATION OF X-CHROMOSOME INACTIVATION IN MAMMALS...: 343-349 September, 1974. 344 H. S. CHANDRA AND S. W. BROWN the two components, the sensitive site, is somehow altered in the paternal-X chromosome prior to the completion of fertilization, either earlier, in the body of the male, or in the sperm en route to fertilization. The homologous sensitive ~~~
- SEGREGATION AND RECOMBINATION OF NON-MENDELIAN GENES IN CHLAMYDOMONAS...sites required for replication and segregation of UP genomes by the oriented mechanism proposed by SAGER (1972). These sites would be occupied preferentially by maternal genomes. In a biparental zygote, one or more attach- ment sites would become occupied by a paternal UP genome. In a paternal zygote ~~~
- INTRODUCTION BY THE CHAIRMAN...for the recognition of nucleotide sequences over and above the chemical reactions between mutagens and individual bases. So did the effects of neighboring bases on mutagenesis and suppression at a given site. An especially subtle type of inter- action between mutagen and site has been studied by DR. SHERMAN and his ~~~
- DNA METABOLISM DURING PACHYTENE IN RELATION TO CROSSING OVER...from premei- otic S phase through the end of pachytene (HOWELL and STERN, 1971). The temporal behavior of endonuclease activity is, schematically at least, appropriate for the role of regulating P-DNA synthesis by producing single-stranded nicks in chromosomal DNA, and thus providing sites for repair ~~~
- ADVANCES IN RECOMBINATION RESEARCH...and MORTIMER 1972) with Saccharomyces to de- crease in frequency, relative to the frequency of single-site conversion, with increasing distance between the mutant sites. This result is neatly explained by the hypothesis that excision is extensive in the correction of mispairing, with a modal length estimated ~~~
- GENETIC CONSERVATION: OUR EVOLUTIONARY RESPONSIBILITY...and ethics. H E time scaleof concern: The widespread concern with the fate of the nat- Tural and culturalsheritage now exposed to a hurricane of change is finding expression in the concept of the national estate. This concept denotes landscapes, sites or objects pf social, cultural, historical, aesthetic ~~~
- A COMBINED BACTERIAL AND LIVER TEST SYSTEM FOR DETECTION AND CLASSIFICATION OF CARCINOGENS AS MUTAGENS...mutagenicity and carcinogenicity in higher organisms. Specificity and Characterization of Tester Strains We have made good progress in characterizing our frameshift tester strains (AMES, LEE and DURSTON 1973). One of the frameshift testers has a repetitive C sequence at the site of the mutation and another has ~~~
- MOLECULAR BASIS FOR GENETIC RECOMBINATION...r - ence, depending on what other da t a ava i lab le) . FIGURE 1.-Different interpretations of gene conversion in primary tetrads and in mass populationc sion at locus C/c near the site of crossover. Since they would be thereby converted into aBcde we would have inferred from the mass mating ~~~