Search results
Results From The WOW.Com Content Network
The underlying mutational event of duplication may be a conventional gene duplication mutation within a chromosome, or a larger-scale event involving whole chromosomes or whole genomes . A classic view, owing to Susumu Ohno , [ 1 ] which is known as Ohno model, he explains how duplication creates redundancy, the redundant copy accumulates ...
Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene .
Overview of chromosome duplication in the cell cycle. In cell biology, eukaryotes possess a regulatory system that ensures that DNA replication occurs only once per cell cycle. A key feature of the DNA replication mechanism in eukaryotes is that it is designed to replicate relatively large genomes rapidly and with high fidelity.
Diploid organisms (e.g., humans) contain two copies of each gene—a paternal and a maternal allele. Based on the occurrence of mutation on each chromosome, we may classify mutations into three types. A wild type or homozygous non-mutated organism is one in which neither allele is mutated. A heterozygous mutation is a mutation of only one allele.
The three major single-chromosome mutations: deletion (1), duplication (2) and inversion (3). The two major two-chromosome mutations: insertion (1) and translocation (2). When the chromosome's structure is altered, this can take several forms: [16] Deletions: A portion of the chromosome is
The 2R hypothesis saw a resurgence of interest in the 1990s for two reasons. First, gene mapping data in humans and mice revealed extensive paralogy regions - sets of genes on one chromosome related to sets of genes on another chromosome in the same species, indicative of duplication events in evolution. [9]
Eukaryotic DNA replication of chromosomal DNA is central for the duplication of a cell and is necessary for the maintenance of the eukaryotic genome. DNA replication is the action of DNA polymerases synthesizing a DNA strand complementary to the original template strand.
These are referred to by a variety of names, including non-homologous crossover, unequal crossover, and unbalanced recombination, and result in an insertion or deletion of genetic information into the chromosome. While rare compared to homologous crossover events, these mutations are drastic, affecting many loci at the same time.