Molecular Genetics 2010 Welcome to the course!. Molecular Genetics 2008 Welcome to the course!. Describes the use of Molecular Genetics to study a range of different topics
Molecular Genetics 2010Welcome to the course!
Molecular Genetics 2008Welcome to the course!
Why do we use model systems genetics?
and why don’t we all study humans?
Yeasts as model organisms genetics?
S. pombe 4,900 E. coli 4,286
S. cerevisiae 5,570 Streptomyces >8,000
S. pombe: 3281 have homology with genes in S. cerevisiae/nematode
145 have homology with genes in nematode
769 have homolgy with genes in S. cerevisiae
681 are unique to S. pombe
S. pombe S. cerevisiae
if we find processes that are common to both yeasts, they may also occur in humans
Fission yeast Budding yeast
Genetic recombination genetics?
Homologous recombination genetics?
between sister chromatids
to repair the break
S. pombe cell
Homologous recombination (HR) genetics?
Comes from analysing
the products of meiosis
Pub John Wright
due to gene conversion or
How does this occur?
Its due to heteroduplex DNA
Pub John Wright
Aberrant segregation genetics?
Recombination events can result in mismatches
Mismatches might be repaired to give 2:4 or 1:3 segregation
or might not be repaired, in which case they will give 3:5
Will explain in more detail later
X T Y
Pairing (meiosis) genetics?
DNA seems too far apart for recombination
but can in some cases see ‘recombination
Unknown how homologous sequences
identify one another
possibly there is single stranded DNA
search for homology
From: M Westergaard
How does genetics?
From Chikashige et al.,
Science (1994) 264,
Timing of events genetics?