Meiotic drive Flashcards
What did Fishman and Saunders (2008) find in monkey flowers, genus Mimulus?
That M. guttatus, when crossed with M. nastus, always shows 100% segregation i.e. never ends up in the polar body.
Segregation distortion in D. melanogaster: on chromosome 2 mutants have Sd gene that produces a toxin, linked to an immune Rsp gene. Wildtypes have no Sd gene and a sensitive Rsp gene. Therefore Sd mutant chromosome 2s can invade wildtype populations. Recombination is rare are Sd and Rsp are either side of the centromere, there are lots of inversions and recombination produces suicide or immune chromosome 2s. Who found this?
Larracuenta and Presgraves (2012)
What did Kingan et al. (2010) find about linked suppressors in Sd mutants?
Creates a three-way cycle:
- Sd mutants invade WT pops
- Immune recombinants invade Sd pops
- WT can invade immune pops
What did Price et al. (2008) find in D. pseudoobscura?
As females are XX and males are XY, a sex-ratio (SR) distorter resides on the X chr and kills all Y-bearing sperm. These SR males are worse competitors as half their sperm die.
What did Kingan et al. (2010) find about non-linked suppressors in D. simulans?
X-linked SR distorter on chr 2 is Dox gene. Nmy on chr 3 is a retrotransposed duplicate of Dox. Therefore Nmy RNA is antisense to Dox RNA and binds it, DS-RNA perceived as a virus and not translated, thus Dox is inactivated.
Who found that polyandry can prevent against meiotic drive? This is because multiple matings increases sperm competition, and SR male D. pseudoobscura males are weak sperm competitors as half their sperm die.
Price et al. (2008)
Who found that sexual selection can prevent against drive in stalk-eyed flies? What did they observe?
Cotton et al. (2014)
Found that in Teleopsis dalmanni females prefer males with long eyespan, but SR males show shorter eyespans and are thus selected against.
