The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
In genetics, chromosomal translocation refers to type of interchange of chromosome pieces of DNA following breakage, in which segments are transferred between nonhomologous chromosomes. When this exchange occurs without a net loss or gain of genetic material, it is called a balanced, or reciprocal, translocation, and there is no phenotypic change in the individual. When the exchange results in a deletion or duplication of chromosomal material, in gametes or somatic cells, severe phenotypic changes may result.
With chromosomal translocations, there is a physical movement of genes located on one segment of DNA to another location (locus) on another chromosomal segment of DNA. Because translocations involve changes to genes the are also termed translocation mutations.
In cell biology, translocation is a term also used to describe the movement of proteins or other substances through membranes. Translocation is also said to occur at the level of the ribosome during translation (protein synthesis) and involves the step-by-step movement along mRNA codons as each codon is read to determine which amino acid to insert into the lengthening protein chain. At the site of translation a translocation is said to occur as the mRNA moves one codon at a time through the ribosome complex (i.e., through the A site).
The process of ribosomal translocation involves specialized enzymes termed translocase enzymes.
Unbalanced chromosomal translocations, where the deleted segment, fragment, of portion of a chromosome attaches to another chromosome are rare in humans.