Genomics I: Ch 23 Flashcards
(20 cards)
Genomics def
begins with the mapping of the genome & progresses ultimately to its complete sequencing
Functional genomics def
examines how the interactions of genes produce the traits of an organism
Proteomics def
study of all the proteins encoded by the genome & their interactions
2 common ways to organize DNA regions:
- cytogenetic mapping: relies on microscopy; genes are mapped relative to band locations on the chromosomes
- linkage mapping: relies on genetic crosses; genes are mapped relative to reach other - distance computed in map units
describe cytogenic mapping
in situ hybridization can locate the position of a gene at a particular site with an intact chromosome
- used to map location of genes or DNA sequences within large eukaryotic chromosomes
- researchers use it to detect “target” DNA
- most common method uses fluorescently labeled DNA probes
what is FISH?
fluorescence in situ hybridization
monomorphic def
a certain protein comes only in 1 particular formula
describe linkage mapping via crosses
relies on the frequency of recombinant offspring to map genes
- uses molecular markers ( DNA segment found at a specific site, uniquely recognized)
RFLP?
restriction fragment length polymorphs
- restriction frags come from DNA restriction enzymes that cut the sequence
What molecular markers used for?
- gene might cause human disease
- can follow markers in family pedigrees
- can be starting point to clone gene by chromosome walking
- used to follow genes involved in quantitative traits
**most likely used for diseases
microsatellite def
- short, repetitive sequences
- abundantly dispersed throughout a species’ genome
- variable in length in individuals
the most common human microsatellite is ___
(CA)n, where n = 5 - 50+
found in every 10k bases in genome
physical mapping requires _____
previous knowledge (need to have done some linkage or cytogenetic mapping)
STS def
sequence tagged site
what do researchers need for cloning?
a series of clones that contain overlapping chromosomal DNA?
this collection = contig
def YAC, BAC, PAC & why they’re important
ac = artificial chromosome
yeast, bacterial, P1
these can accept large chromo fragments (that plasmids & viral vectors cannot)
common method used for positional cloning ______
chromosome walking
what is needed in chromosome walking?
must know the relative position of target gene to marker
shotgun sequencing def
method where small DNA fragments are randomly generated from larger pieces and sequenced.
most efficient & inexpensive way to sequence genomes
open reading frame def
anything between start & stop codons
- can start with the 1st 2nd or 3rd nucleotides
- cannot contain stop codons
