23 Results
for term "sites"
- The effect of constraint on the rate of evolution in neutral models with biased mutation....in the number of potential neutral alleles can lead to an increase in the rate of evolution. The approach taken is to consider the rate of evolution at single sites, comparing the rates at sites which have two, three or four neutral alleles (with all other alleles being very deleterious). Note that a site ~~~
- Molecular definition of the PAS1-1 mutation which affects silencing in Saccharomyces cerevisiae...., these loci. One such silencer sequence, HMR-E, is composed of three elements: a binding site for the RAP1 protein, a binding site for the ABFl protein and an ARS con- sensus sequence. In a s effort to understand the control of sporulation by MAT, KASSIR and SIMCHEN (1985) screened for mutations ~~~
- Gene trees, species trees and the segregation of ancestral alleles....to analyze an infinite-site model. In this model, only one mutation can occur at any particular site, but more than one mutation can occur in the whole region sequenced. The mutation rate at individual sites is infinitesimal, but M , the mutation parameter for the entire region sequenced, is not necessarily ~~~
- IS THE SEGREGATION DISTORTION PHENOMENON IN DROSOPHILA DUE TO RECURRENT ACTIVE GENETIC TRANSPOSITION?...1967). The SD system consists essentially of two interacting sites: Sd, which is located close to the centromere-but outside of the heterochromatic region-on the left arm of chromosome ZZ and Responder (Rsp), which is lo- cated in the right centromeric heterochromatin, also of chromosome ZZ (SAN ~~~
- Approximate variance of nucleotide divergence between two sequences estimated from restriction fragment data....analysis (CLARKE and LAN- NEI and LI ( 1979) developed a method to estimate the number, d, of nucleotide substitutions per site be- tween two DNA sequences when restriction fragment data are available for both species. The number d can be approximated by IGAN 1993). d = - - I n G, ( 1 ) where G is e-, r ~~~
- More on the overdispersed molecular clock....and MARKOWITZS (1970) covarion model. This model assumes that, at any point in time, all of the evolution is restricted to a small subset of the amino acid sites. T o understand the problem with this argument, recall that FITCH and MARKOWITZ arrived at the covarion model as an explanation for the excess ~~~
- The GCR1 gene of Saccharomyces cerevisiae is a split gene with an unusually long intron...., Wisconsin). DNA sequence analysis of the cDNA clones confirmed the existence of an intron (Figure 1). The 5 splice junc- tion is at nucleotide position 103/104 (G/gtatg . . .)just upstream from the BcZl site, and the 3 junction is at position 854/855 (. . . tag/T), thus bordering an intron that is 751 ~~~
- Theories of Allelic Complementation...LETTER TO THE EDITORS KORCH (Genetics 74: 307-329, 1973) in an interesting paper on complementation commented on a paper of mine (MCGAVIN, J. Mol. Bid. 37: 239-24&?,1968) in terms of specific binding sites. The main arguments which I used, however, apply equally to any essential regions of "tact ~~~
- More on the episodic clock....substitution rates through time. Usually not all sites in a gene can accept substitutions. There are so-called invariant sites where amino acids or nucleotides are strongly conserved. We can show that unless the proportion of invariant sites changes within or between lineages, R(t) is not affected ~~~
- Overdominant vs. frequency-dependent selection at MHC loci....histocompatibility complex (MHC) loci. This has arisen since the confirmation, using nucleotide sequence data from the antigen binding sites, that balancing selection is mainly responsible for the ob- served polymorphism (HUGHES and NEI 1988, 1989). So far, only one study has addressed the question directly ~~~