Chapter 10

Sickle cell anemia

________ is caused by a SNA in the HbB gene, chromosome 11 (glutamic acid- GAG, valine- GTG.

Unequal crossing

________- over produces new alleles of copy number variants (CNVs)

CNVs

________ are tandem sequence repeats more than 10 bp long.

CODIS database

________ is maintained by the FBI: Data from all 20 STR loci can match DNA from crime scene to a person, or can establish innocence.

Genotype

________ is discovered through PCR at many STR loci: 20 pairs of PCR primers are labeled with fluorescent dyes, the probability that 2 people have the same alleles at 20 STR loci is very remote.

Positional cloning

________: from DNA markers to disease causing genes.

Preimplantation

________ embryo diagnosis: utilizes in vitro fertilization and PCR to genotype embryos before placing in womb.

Misalignment

________ during meiosis leads to unequal crossing over.

PCR

________ is extremely efficient- can amplify DNA from a single cell or from some archaeological samples.

chain reaction

Polymerase ________ (PCR): method of making many copies of a target region of DNA.

Compound heterozygote

________: individual with different mutant alleles of the same gene.

Multiplex FCR

________ is used fro DNA fingerprinting.

homozygous individuals

Genotyping can identify carriers and ________.

Sequence

________ and expression of candidate genes are determined in normal and diseased individuals.

Locus heterogeneity

________: disease caused by mutation in one of two or more different genes.

Fetal

________ and embryonic cells can be genotyped using PCR.

Fluorescent output

________ is proportional to the number of copies of each allele.

Allele specific oligonucleotides

________ (ASO) are attached to a solid support (like a silicon chip)

Codons

________ make up less than 2 % of the human genome.

High throughput

________ or massively parallel sequencing is like Sanger sequencing with a few modifications: individual DNA molecules anchored in place, each base is identified before the next one is added, increased sensitivity eliminates need for cloning or PCR.

Disease causing alleles

________ have 42 or more CAG repeats in Huntingtons.

short insertions

Deletion- insertion polymorphisms (DIPs): ________ or deletions of a single or a few base pairs.

Prenatal genetic diagnosis

________: genotypic fetal cells isolated by amniocentesis (getal cells in amniotic fluid extracted using a needle)

Huntingtons disease

________ is an autosomal dominant disorder.

STR loci

________ are highly polymorphic: many alleles exist in the population and an individual person carries only 2 alleles at a given locus.

Genome sequencing

________ reveals a sea of variation.

oligonucleotide primer

One ________ is complementary to one strand of DNA at one end of the target region.

Huntingtons

In ________, normal allele has <34 CAG repeats.

genotype

Determining ________ depends on isolating a gene and analyzing the alleles.

positional cloning

Steps for ________: Region of interest narrowed by finding closely linked DNA markers.

PCR

________ is a faster, less expensive, and more flexible way to amplify specific fragments of DNA (compared to molecular cloning)

Positional cloning

________: object is to identify disease- causing genes by genetic linkage to polymorphic loci.

PCR

________ was first developed in 1985 by Kary Mullis.

DNA polymorphisms

sequence differences

single nucleotide polymorphisms

only 1 base pair changes

deletion-insertion polymorphisms (DIPs)

short insertions or deletions of a single or a few base pairs

simple sequence repeats (SSRs or microsatellite)

1-10 base sequence repeated 15-100 times in tandem

copy number variants (CNVs)

large bocks of duplication or deletion with population frequency of <1%

Polymerase chain reaction (PCR)

method of making many copies of a target region of DNA

PCR is extremely efficient

can amplify DNA from a single cell or from some archaeological samples

steps of PCR

Denature strands, Base pairing of primers, Polymerization from primers along the templates

Prenatal genetic diagnosis

genotypic fetal cells isolated by amniocentesis (getal cells in amniotic fluid extracted using a needle)

Preimplantation embryo diagnosis

utilizes in vitro fertilization and PCR to genotype embryos before placing in womb

highly polymorphic

many alleles exist in the population and an individual person carries only 2 alleles at a given locus

Genotype is discovered through PCR at many STR loci

20 pairs of PCR primers are labeled with fluorescent dyes, the probability that 2 people have the same alleles at 20 STR loci is very remote

CODIS database is maintained by the FBI

Data from all 20 STR loci can match DNA from crime scene to a person, or can establish innocence

preparation of genomic DNA

fragmented, adapter attached, amplified by PCR and denatured to make single stranded, and fluorescent dye coupled to end of single-stranded DNA

Positional cloning

from DNA markers to disease causing genes

positional cloning

object is to identify disease-causing genes by genetic linkage to polymorphic loci

strategy for positional cloning

Same as linkage analysis using two phenotypes, except one gene tracked by phenotype, the other by DNA genotype

Steps for positional cloning

Region of interest narrowed by finding closely linked DNA markers

allelic heterogeneity

disease caused by different mutations in the same gene

compound heterozygote

individual with different mutant alleles of the same gene

locus heterogeneity

disease caused by mutation in one of two or more different genes

high-throughput or massively parallel sequencing is like Sanger sequencing with a few modifications

individual DNA molecules anchored in place, each base is identified before the next one is added, increased sensitivity eliminates need for cloning or PCR