Front Back
Pedigree Analysis
a diagram showing the ancestral relationships and transmission of genetic traits over several generations
How will the symbol look if the phenotype is expressed?
Completely shaded in
Oculocutaneous albinism type 1 (OCA-1)
-Autosomal Recessive disorder -Absence of pigment -Locus 11q14-q21
Oculocutaneous albinism type II (OCA2)
-Autosomal Recessive Disorder -Locus 15q11.2-q12
What is unique about Albinism?
There are two different types of mutations within the genome on different chromosomes
Cystic Fibrosis
-Autosomal recessive disorder -Effects the lungs and pancreas, creates excess mucus -Mutation in the CFTR gene
Marfan syndrome
-Autosomal Dominant -elongated fingers and arm bones
Brachydactyly
-Autosomal dominant trait -size of digits (fingers) are not developed normally
Huntington's Disease
-Autosomal dominant -Effects central nervous system -50% chance of passing it along -Phenotypes don't show until your 40s
Achondroplasia
-Dwarfism -Autosomal dominant -Effects bone growth -Mutation in genes that code for "Fibroblast Growth Factor Receptor"
Color Blindness
-X-linked recessive -female will usually not show phenotype unless homozygous for mutant allele on X chromosome
Duchenne Muscular Dystroophy (DMD)
-X-linked disorder -Primarily found in males -mutated in the gene that encodes dystrophin. Locus- Xp21.2 12q21 -Skeletal and cardiac muscles are severely affected
Hemophilia
-X-linked -Bleeding disorder, can't form clots -Locus Heterogenity -Two types of hemophilia
Locus Heterogeneity
Same clinical phenotype (disease) can result from mutations at any one of several different loci ex: hearing loss
Sporadic Mutations
-New mutations that have no known family history -Usually can't produce offspring -Occurs during meiosis, mutated germ cell is produced
Hutchinson-Gilford progeria Syndrom
-"Progeria, or HGPS" -Accelerated aging in children -Die at an average age of 13
Allelic Heterogeneity
-Different mutations within a given gene can be seen in different patients with a certain genetics -Same gene is effected although the phenotypes are different. -Relates to the severity of the phenotype ex: muscular dystrophy
Clinical Heterogeneity
-Mutations in the same gene produce two or more different diseases ex: CFTR mutation can lead to CF or bilateral absence of vas deferens
complementation
normal phenotype when two mutations are combined
Variable expression
-Non-penetrance: -Other genes, or the environment can influence development of phenotypes
Cerebral Cavernous Malformation (CCM)
-Autosomal dominant -Vascular malformation disease -Irregular structure of smaller blood vessels -Symptoms occur later in life (30-50) -Seen freq in hispanic families
aneuploidy
cells having too many or too few copies of a chromosome
Sex Determination
X-Y sytems Humans, fruit flies Male xy, Female xx X-O systems grasshoppers Male x, Female xx S-W systems Birds, fish, butterflies males zz, females zw Haplo-diplidy bees, ants males N, females 2N
dosage compensation
Equalization in males and females of the amount of protein produced by X-linked genes. In placental mammals, dosage compensation is accomplished by the random inactivation of one X chromosome in the cells of females
Barr Body
dark staining body in interphase cells of females
X-Inactivation
Occurs in all sexual reproducing female organisms at about 200 cells Inactivate one x chromosome (have two in each cell, one from each parent) Initial inactivation is random Inactivated chromosomes form Barr bodies Results in mosaicism
Nondisjunction
occurs when chromosomes fail to separate at either the first or second meiotic division
Lyon hypothesis
in a given cell there is only one active X chromosome (allows for dosage compensation) inactivated X forms Barr body.
monosomy
only one of a particular type of chromosome
trisomy
extra copy of chromosome ex) down's syndrome/trisomy 21
gene family
two or more loci with similar nucleotide sequences that have been derived from a common ancestral sequence
In situ hybridization
technique used to localize the expression of a specific DNA or RNA sequence in tissue
phosphodiester bond
the linkage between two sugars in the backbone of a nucleic acid molecule
hydrogen bond
type of bonds that link the base pairs on each strand of DNA
Chromatin
Granular material visible within the nucleus; consists of DNA tightly coiled around proteins
Chromosome
tightly coiled threadlike structure along which the genes are organized, like beads on a necklace- consist primarily of DNA
Nucleosome
Together the DNA & histone proteins forms a bead-like structure
Nucleotide
includes phosphate group, sugar deoxyribose and nitrogen bases
nucleoside
base (purine/pyrimidine) + sugar Ex: adenosine, guanosine, citidine, thymidine, uridine
nucleoside monophosphate
AKA: nucleotides names this way because of the single-phosphate linked to the sugar-base unit
Codon
Triplets of nucleotides in mRNA that encode the info for a specific amino acid in a protein
Transcription
The process of making a RNA strand from a DNA template
Cis-Effect or cis-acting element
A DNA sequence that must be adjacent to the gene(s) it regulates and is mediated by sequences that bind regulatory proteins. Example the lac operator.
What is Trans element?
Region of DNA/ RNA that regulate the expression of a gene located on a different molecule of DNA
transciption factor
generic term that includes both repressors and activators; have three functional domains: 1. DNA-binding domain 2. polymerase binding domain 3. effector binding pocket
sigma factor
a protein that allows RNA polymerase to bind properly to the promoter region
Promoter
The region of the gene where the RNA-synthesizing enzyme, RNA polymerase, binds to initiate transcription
TATA box
a short DNA sequence within the promotor region. Along with Basal transcription factors, the TATA Box allows RNA Polymerase to contact the DNA
alternative splicing
splicing the same pre-RNA in two or more ways to yield two or more different mRNA that produce two or more different protein products
RNA polymerase
produces primary transcript of RNA Uses DNA tempate to make RNA chains
spliceosome
a large complex that splices pre-mRNA in eukaryotes
exon
sequence of DNA that codes info for protein synthesis
Intron
a section of DNA that does not code for an amino acid and that is transcribed into RNA but is removed before it is translated.
Wobble Hypothesis
complete set of 61 sense codons can be read by 40 distinct tRNAs because of pairing properties of the bases in the anticodon
enhancer
DNA seqeunce that controls the rate and efficiency of the polymerase. bind multiple TFs
Group I Splicing
...
General transcription factors
Transcription Components Template binding and initiation of transcription Chain elongation
Forward Genetic Screen: Isolation of mutants that show differences in phenotype for the process of interest
...
Reverse Genetic Screen
- gene-centric - mutate the gene of interest (requires prior knowledge about gene in question) - looking for an expected phenotypic change
RNA interference
small RNA molecules bind to mRNA- gets cleaved and degraded. Can also bind to DNA and allow for DNA methylation
EMS
ethyl methanesulfonate alkylating agent induces a point mutation (bp substitution) and causes a transition (GC to AT). It is soluable and can be taken up by cells. However it causes random mutations, there is no selection, often more than one mutation per mutant, singl ebase pair change…
What is a temperature-sensitive mutant?
One that has a mutation in amino acid of a protein, so that protein is no longer functional at higher temperatures [nonpermissive temperature], but still functions at lower temperatures [permissive temperatures]
Does the genome get altered in animals that have been subjected to RNAi?
Expression is decreased
Dr. Lee Hartwell: Steps used to identify genes that regulate cell division
Exposed yeast to mutagen --- Plated yeast cells(replica plate) --- Screened for mutants that are (ts) for growth and collected 1500 ts mutants which can grow at 30°C but not 36°C Used microscope to subscreen 148 cultures with 32 distinct genes (unique cells) Identified genes for regulat…
Genetic model for: Mitochondria structure
...

Access the best Study Guides, Lecture Notes and Practice Exams

Login

Join to view and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?