Genetics Chapter 20 - Robert J. Brooker

genome

all of the chromosomes and DNA sequences that an organism can possess.

genomics

the molecular analysis of an entire genome of a species.

structural genomics

the branch of genomics that determines the three-dimensional structures of proteins.

functional genomics

the study of gene function at the genome level. It involves the study of many genes simultaneously.

proteomics

the study of protein function at the genome level. It involves the study of many proteins simultaneously.

mapping

the experimental process of determining the relative locations of genes or other segments of DNA along individual chromosomes.

cytogenetic mapping

the mapping of genes or genetic sequences using microscopy

linkage mapping

the mapping of genes or other genetic sequences along a chromosome by analyzing the outcome of crosses

physical mapping

the mapping of genes or other genetic sequences using DNA cloning methods.

genetic map

any method used to determine the linear order of genes as they are linked to each other along the same chromosome. this term is also used to describe the use of genetic crosses to determine the linear order of genes.

chromosome map

a chart that depicts the linear arrangement of genes along a chromosome

locus

the physical location of a gene within a chromosome

in situ hybridization

a technique used to cytologically map the locations of genes or other DNA sequences within large eukaryotic chromosomes. in this method, a complementary probe is used to detect the location of a gene within a set of chromosomes.

FISH (fluorescence in situ hybridization)

a form of in situ hybridization in which the probe is fluorescently labeled.

chromosome painting

the use of probes to identify particular regions of chromosomes. the probes are usually assigned a computer-generated color.

molecular marker

a segment of DNA that is found at a specific site in the genome and has properties that enable it to be uniquely recognized using molecular tools such as a gel electrophoresis.

polymorphic

a term used to desrive a trait or gene of that is found in population

RFLPs (restriction fragment length polymorphisms)

genetic variation within a population in the lengths of DNA fragments are digested with particular restriction enzymes.

monomorphic

a term used to describe a gene that is found as only one allele in a population.

lod (logarithim of the odds) score method

a method that analyzes pooled data from alarge number of pedigrees or crosses to determine the probability that two genetic markers exhibit a certain degree of linkage.a lod score value >/= 3 is usually accepted as strong evidence that two markers are lin

RFLP map

a genetic map composed of many RFLP markers

microsatellites

short simple sequences (typically a couple hundred base pairs in length) that are interspersed throughout a genome and are quite variable in length among different individuals. they can be amplified by PCR.

STRs (short tandem repeats)

short DNA sequences that are repeated many times ina row. often found in centromeric and telomeric regions.

STS (sequence tagged site)

a short segment of DNA, usually between 100 and 400 bp long, the base sequence of which is found to be unique within the entire genome. these are identified by PCR.

founder

with regard to genetic diseases, an individual who lived many generations ago and was the person in which a genetic disease originated.

contig

a series of clones that contain overlapping pieces of chromosomal DNA.

artificial chromosomes

cloning vectors that can accommodate large DNA inserts and behave like chromosomes when inside of living cells.

YAC (yeast artificial chromosome)

a cloning vector propagated in yeast that can reliably contain very large insert fragments of DNA.

BACs (bacterial artificial chromosomes)

a cloning vector that propagates in bacteria and is used to clone large fragments of DNA.

PACs (P1 artificial chromosomes)

an artificial chromosome developed from P1 bacteriophage chromosomes.

cosmid

a vector that is a hybrid between a plasmid vector and phage lambda. cosmid DNA can replicate in a cell like a plasmid or be packaged into a protein coat like a phage. cosmid vectors can accept fragments of DNA that are typically tens of thousands of base

positional cloning

a cloning strategy in which a gene is cloned based on its mapped position along a chromosome.

chromosome walking

a common method used in positional cloning in which a mapped gene or RFLP marker provides a starting point to molecularly "walk" toward a gene of interest via overlapping clones.

subcloning

the procedure of making smaller DNA clones form a larger one.

PFGE (pulsed-field gel electrophoresis)

a method of gel electrophoresis used to separate small chromosomes or very large pieces of chromosomes.

genome sequencing projects

research endeavors that have the ultimate goal of determining the sequence of DNA bases of the entire genome of a given species.

hierarchial shotgun sequencing

a genome sequencing strategy in which small DNA fragments are mapped prior to DNA sequencing.

whole-genome shotgun sequencing

a genome sequencing strategy that bypasses the mapping step. the whole genome is subjected to shotgun sequencing.

double-barrel shotgun sequencing

a type of shotgun sequencing in which DNA fragments are randomly sequenced from both ends.

Human Genome Project

a worldwide collaborative project that provided a detailed map of the human genome and obtained a complete DNA sequence of the human genome.

high-throughput sequencing

rapid DNA sequencing on a micro scale in which many fragments of DNA are sequenced in parallel

next-generation sequencing technologies

newer DNA sequencing technologies that are more rapid and inexpensive

pyrosequencing

a type of next-generation DNA sequencing

SBS (sequencing by synthesis)

a next-generation form of DNA sequencing in which the synthesis of DNA is directly monitored to deduce the base sequence.

comparative genomics

uses information from genome projects to understand the genetic variation between different populations and evolutionary relationships among different species.

PCR (polymerase chain reaction)

DNA is copied multiple times to produce many copies of the original molecules helpful when there's only a small DNA sample

EcoRI

a restriction enzyme that specifically cuts DNA with sequence GAATTC and creates sticky ends