Characterisation of a gene encoding a transcript localised during oogenesis in Drosophila melanogaster

• Main Author: McCormack, Angela
• Published: University of Edinburgh 1998
• Subjects: 591.35
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.666127

The localisation of maternal transcripts is known to play an important role in axis determination and pattern formation of the developing oocyte and embryo, so it was important that this transcript and its corresponding gene should be studied further. The entire gene was subsequently cloned and sequenced and found to encode a class V unconventional myosin and was therefore termed <I>myosinV</I>. The initial work of this project focused on the localisation of the <I>myosinV</I> transcript. In an attempt to establish the position of the gene within the genetic pathways of oogenesis, the localisation pattern of the transcript was assessed in flies mutant for genes involved in various aspects of oogenesis. The correct localisation of the <I>myosinV</I> transcript was found to require genes involved in oocyte determination, anterior patterning, posterior patterning, dorsoventral patterning and also neurogenic genes involved in follicle cell signalling. The localisation of maternal transcripts has been found in several instances, to depend on a signal in the 3'UTR of the transcript. A P-element mediated germline transformation approach was used to determine whether the 3'UTR of the <I>myosinV</I> transcript was capable of directing localisation. Work presented in this thesis indicates that the <I>myosinV</I> 3'UTR does not direct transcript localisation. However, localisation was found to depend upon the integrity of the microtubules. A development profile indicated that the <I>myosinV</I> transcript was also present in the testes and early embryos. The transcript was found to be unlocalised within early embryos and was initially presumed to be maternal transcript carried over from oogenesis. The testes transcript was smaller than the ovarian transcript and was localised to the developing sperm heads.