Genetics Exam 3 Vocab

chromatin

complexes of DNA, protein, and RNA in the eukaryotic nucleus

nucleosome

beadlike structure consisting of DNA wound around histone proteins

histones

small basic proteins that bind to DNA and form the core of the nucleosome

G bands

regions of a chromosome that are distinguished by Giemsa staining differences

constitutive heterochromatin

is always heterochromatic

facultative heterochromatin

can switch between heterochromatic and euchromatic

basal factors

bind to promoters

repressors

bind to enhancers

TAD

DNA loop in which promoters and enhancers can interact

miRNA

prevents or reduces gene expression posttranscriptionally

coactivators

bind to activators

insulator

binds CTCF to organize enhance/promoter interactions; limit the effects of enhancers to the correct genes forming topologically associating domains (TADs)

enhancer

activates gene transcription temporal- and tissue- specifically; only works within the domain they’re in

ChIP-Seq

identifies DNA binding sites of transcriptional factors

oligonucleotide

a short DNA fragment that can be synthesized by a machine

vector

a DNA molecule used for transporting, replicating, and purifying a DNA fragment

recombinant DNA

contains genetic material from two different organisms

ddNTPs

DNA chain-terminating subunits

genomic library

a collection of the DNA fragments of a given species, inserted into a vector

gel electrophoresis

method for separating DNA molecules by size

hybridization

stable binding of single-stranded DNA molecules to each other

primer

oligonucleotide extended by DNA polymerase during replication

de novo gene

recently evolved from intergenic DNA sequences

gene desert

gene-poor region of the genome

pseudogene

a nonfunctional member of a gene family

natural selection

progressive elimination of individuals whose fitness is low and survival of individuals of high fitness

gene family

set of genes related by processes of duplication and divergence

DNA polymorphism

a DNA sequence that occurs in two or more variant forms

phase

arrangement of alleles of two linked genes in a diploid

ASO

a short oligonucleotide that will hybridize to only one allele at a chosen SNP locus

SNP

two different nucleotides appear at the same position in genomic DNA from different individuals

SSR

DNA element composed of short tandemly repeated sequences

locus

location on a chromosome

compound heterozygote

individual with two different mutations in the same gene

exome

all exons in a genome

southern analysis

probing DNA on a gel

Northern analysis

probing RNA on a gel

FISH

(fluorescence in situ hybridization) probing DNA in situ

cDNA

complimentary DNA; made from mRNA so that it reflects what genes were expressed in the particular cells from which the mRNA was isolated