Thesis Defense Announcement
To: the George Mason Community
>
> *Jessica L. Keating
> Master of Science in Biology
> Molecular Biology concentration
> *
> Date: Tuesday December 1, 2009
> Time: 10:00 a.m. - 12:00 Noon
> Place: Discovery Hall, Room 224
> Prince William campus
>
> Thesis Chair: Dr. Karl Fryxell, MMB Dept.
>
> *Title:* Mapping of the 1(3)DTS4 Gene and Analysis of its Role in the 
> Notch Pathway _//_
> *Abstract:*
> l(3)DTS4 is an ethyl methanesulfonate (EMS) directed mutation that 
> exhibits temperature sensitive dominant lethality and is one of the 
> only mutations that expresses conditional dominant lethality in one 
> dose in triploids (HOLDEN and SUZUKI 1973). l(3)DTS4 is of particular 
> note, not only because it is a dominant temperature sensitive lethal 
> mutation, but also because our lab has shown it to have an 
> unexpectedly dramatic interaction with two different Notch (N) 
> alleles: N55e11 and N60g11 (JORDAN 2005). N55e11 /l(3)DTS4 and N60g11 
> /l(3)DTS4 heterozygotes showed significantly reduced wing
> notching in comparison to internal (N55e11 or N60g11/TM3, Sb) controls 
> (JORDAN 2005). A single copy of l(3)DTS4 was sufficient to 
> significantly prevent the wing notching caused by either Notch allele 
> at the permissive temperature for l(3)DTS4. This indicates that 
> l(3)DTS4 plays a key role in the development of the outer wing margin, 
> and its probable involvement in the Notch signaling cascade that 
> regulates this type of cell differentiation.The goal of this project 
> was to map and identify the gene(s) disrupted by the l(3)DTS4 mutation 
> and to further understand their role in the Notch processes that 
> determine outer wing growth. To this aim, complementation testing was 
> used in order to create a deletion map indicating regions of possible 
> interest. Two deletions, Df(3L)ZP1 and Df(3L)BSC113 were found to be 
> non complementary to l(3)DTS4. That is, l(3)DTS4/Df(3L)ZP1 and 
> l(3)DTS4/Df(3L)BSC113 heterozygotes had 100% fatality at all three 
> tested temperatures. Together with polytene chromosome analysis, the 
> complementation testing indicated that l(3)DTS4 resides within a 
> region from 67B3 -- 67B5. Additionally, qualitative analyses were 
> conducted in order to better understand the behavior of l(3)DTS4. Its 
> effect on Serrate and dally were analyzed, and the development of 
> l(3)DTS4 homozygous embryos was also examined.
>
> *All members of the George Mason University community are invited to 
> attend.*
>