Midterm 1 Flashcards
(65 cards)
What is genetic mapping?
Figuring out the order and distance between genes and a chromosome based on recombination frequency
Genetic mapping helps in understanding gene linkage and inheritance patterns.
Define recombination frequency.
The likelihood that two genes will be inherited together during recombination.
Closer distance between genes results in lower recombination frequency.
What are the units used in genetic mapping?
Centimorgan (cM) or Relative map units (m.u.)
1 cM = 1 Mbp.
What are markers in genetic mapping?
Landmarks used to help map the genes.
Markers can be phenotypic or genetic.
What are phenotypic markers?
Observed traits used to indicate the presence/absence of certain genes/alleles.
Example: Red eyes in flies indicating a close association with white skin.
What are genetic markers?
Using polymorphisms - unique DNA sequences - as a landmark.
Genetic markers help in locating genes on chromosomes.
Define Restriction fragment length polymorphism (RFLP).
Using changes in restriction site activity to predict the relative location of a given gene.
RFLP analysis helps identify disease-related genes.
What are Single Nucleotide Polymorphisms (SNPs)?
Using the minor allele frequency (MAF) and/or a haplotype as a landmark to predict the relative location of a gene.
SNPs are critical for genetic variation studies.
What is a Simple sequence length polymorphism (SSLP)?
Using the variation in tandem repeated sequences as a landmark for relative gene position.
SSLPs can be microsatellites or minisatellites.
What are microsatellites?
Uses the variation of repeated sequences as a landmark.
Microsatellites are more stable and predictable due to shorter repeats.
What are minisatellites?
Less stable due to long repeated sequences and more complex.
Minisatellites are typically located at telomeres and centromeres.
Define biochemical markers.
Uses changes in physiological changes to manipulate the environment to see if the culture grows or not when a given gene is present.
Biochemical markers help understand gene functions in specific conditions.
What is physical mapping?
The actual positions of the gene on the chromosome, independent of recombination and polymorphisms.
Physical mapping provides high and low resolution data.
What units are used in physical mapping?
Base pairs (bp) or million base pairs (Mbp).
1 Mbp = 1 cM.
What are physical markers?
Physical landmarks that show the actual location of a given gene.
Typically, there is 1 marker for every 100 kb.
Define restriction site mapping.
Identifying non-polymorphic restriction sites by mixing DNA with specific restriction enzymes to determine the exact location of the restriction sites.
This method uses variation in fragment length.
What is Fluorescence in Situ Hybridization (FISH)?
Uses fluorescent probes that are complementary to a known non-polymorphic unique sequence to visualize their location in the chromosome.
Visualization occurs only if the probe is 100% complementary.
What are Sequence Tag Sites (STS)?
Using primers that are complementary to the flank regions of a known unique non-polymorphic sequence to properly identify its location.
STS serves as a landmarker in physical mapping.
What are clones in genomic research?
Fragments of DNA that match certain regions of a given genome.
Clones allow for further analysis into physical marker identification.
What is genomic sequencing?
Figuring out the order and location of an unknown sequence of DNA.
Genomic sequencing is crucial for understanding genetic information.
What is the Shot-Gun Method?
Sequences small fragments of DNA that are completely unknown.
This method includes organizing fragments by size and inserting them into vectors.
What are paired-end reads?
Both the 3’ to 5’ and the 5’ to 3’ ends are sequenced.
This method enhances the accuracy of sequencing.
What is the Contig Method?
Assembles reads into contiguous sequences and anchors those contigs to a physical map using physical markers.
This method helps in assembling large genomic regions.