The gene pacman (pcm) in Drosophila melanogaster encodes the exoribonuclease XRN1,
which is highly conserved across eukaryotes and is the only known cytoplasmic
exoribonuclease that degrades RNA in the 5’ – 3’ direction. Hypomorphic mutations to
pacman have previously been shown cause developmental phenotypes, particularly during
wing and thorax development.
The focus of this thesis was twofold. Firstly, to create a null pacman allele and associated
control lines to further characterise the phenotypes of pcm. Two new alleles were created,
one of which was amorphic (pcm14). pcm14 is 100% lethal, and flies die during pupation. The
wing imaginal discs of pcm14 larvae are less than half the size of those in wild‐type larvae at
the same stage (3rd instar). It was also found that wing imaginal discs in the hypomorphic
mutant pcm5 are significantly smaller than wild‐type, by almost 20%. Therefore, pcm
appears to play a role in cell proliferation or apoptosis during the growth of wing imaginal
discs. Along with pcm14, a new deficiency that includes pcm was created using a DrosDel
Rearrangement Screen. The 17,963bp Df(1)ED7452 deficiency is >13 times smaller than the
two other publically available deficiencies that include pcm.
|Date of Award||May 2011|