19 - THE DYNAMIC GENOME Flashcards
what was the expected vs observed results when pollen from a C1 (dominant negative) was crossed with C/C ovules? (yellow x black)
what was the hypothesis for this unexpected result (patchy kernels)?
what happens in the chromosome to cause this special phenotype
same thing with C/C and c/c and what happens
transposable elements being non-autonomous or autonomous
what does the size of the colored spot depend on, and why is it only some cells on the kernel?
what happens when Ds jumps out vs when Ds jumps in
c c is yellow
C c is black
in which organisms are transposable elements found
in all of them
studied in yeast and Drosophila
they are ancient
what are the two classes of transposable elements (or transposons)?
Class 1: Retrotransposons (eukaryotes)
Class 2: DNA transposons (prokaryotes and eukaryotes)
how do Class 2 DNA transposons work
The Ac gene encodes transposase at its sides
transposase binds the ends of the Ac and Ds elements
Ds needs Ac because it does not have a functional transposase
transposase helps cleave and insert the DNA to a target site, which now has Ac or Ds
what genes do retroviruses encode
what are Class 1 retrotransposons
how do retrotransposons move
what are the fractions of different transposable elements in the human genome
what is the relationship between genome size and transposable elements in plants
the amount of transposable elements can account for the differences in genome size between plants
plants that have more transposons have a larger genome
where are transposable elements found on the chromosome
what are the differences between LINEs and SINEs?
LINEs (Long Interspersed Nuclear Elements) are longer DNA sequences compared to SINEs (Short Interspersed Nuclear Elements), and while both are types of retrotransposons, LINEs are considered “autonomous” as they can replicate on their own, while SINEs are “non-autonomous” and rely on LINEs’ machinery to move within the genome; essentially, SINEs are shorter and need LINEs to function for transposition.
LINE: 1-5kb
SINE: 100-300bp
what rate of mutations causing disease results from transposition of LINE or SINE
1/600 spontaneous mutations causing important diseases
what is an example of a transposable element insertion that disrupts the gene’s coding sequence
how can transposable elements affect splicing by their insertion
how can transposable elements be associated with human cancers
