Appendix C: 

 Glossary 



Portions of the glossary text were 

 taken directly or modified from 

 definitions in the U.S. Congress 

 Office of Technology Assessment 

 document; Mapping Our Genes — 

 The Genome Projects: How Big. 

 How Fast? OTA-BA-373. 

 Washington, D.C.: U.S. 

 Government Printing Office. 

 April 1988. 



A word printed in a typeface different from that of the definition text is defined 

 within the glossary. 



Adenine (A): A nitrogenous base, one member of the base pair. A-T (adenine- 

 thymine). 



Alleles: Alternative forms of a genetic locus; a single allele for each locus is inherited 

 separately from each parent (e.g., at a locus for eye color, a certain allele might 

 result in brown eyes). 



Amino acid: Any of a class of 20 molecules that are combined to form proteins in 

 living things. The sequence of amino acids in a protein and hence protein function 

 are determined by the genetic code. 



Arrayed library: Arrayed libraries represent individual primary recombinant clones 

 (hosted in phage, COSmid, YAC, or other vector) that are placed in two- 

 dimensional arrays m microtiter dishes. Each primary clone can be identified based 

 on the identity of the plate and the clone location (row and column) on that plate. 

 Arrayed libraries of clones can be used for many applications including screening 

 for a specific gene or genomic region of interest as well as for physical mapping. 

 Information gathered for individual clones from various genetic linkage and 

 physical map analyses is entered into a relational database and used to construct 

 physical and genetic linkage maps simultaneously; clone identifiers serve to 

 interrelate the multilevel maps. Compare libraiy. genomic library. 



Autoradiography: A technique that uses X-ray film to visualize radioactively labeled 

 molecules or fragments of molecules; used in analyzing length and number of DNA 

 fragments after they are separated by gel electrophoresis. 



Autosome: A chromosome not involved in sex determination. The diploid human 

 genome consists of 46 chromosomes, 22 pairs of au'osomes. and 1 pair of sex 

 chromosomes (the x and y chromosomes). 



Bacteriophage: See phage. 



Base pair (bp): Two nitrogenous bases (adenine and thymine or guanine and 



cytOSine) held together by weak bonds. Two strands of DNA are held together in 

 the shape of a double helix by the bonds between base pairs. 



Base sequence analysis: A method, sometimes automated, for determining the 

 sequence of nucleotide bases in DNA. 



Blotting: See in situ colony hybridization. Southern blotting. 



Blunt ends: On linear duplex DNA molecules, ends that are fully double-stranded and 

 base-paired, without single-stranded tails. 



146 



