Erin Weston, Jimmy Goncalves, and Karina Gonzalez

Gene Function in Vulval Morphogenesis of C. elegans

Introduction • Tubulogenesis in early development is an important process in

the function of many organisms. • Vulval development of C. elegans is the working model• Specifically the role of egl-26

• Egl-26 is active in the maintenance of the shape of the vulva towards the end of the development of the vulva• This is the only gene that has been found to control vulF in this way

• Why haven’t more genes been found to have this role? • Forward genetics

• RNAi should give better insight. Why?

Vulval Morphogenesis • Made up of 7 multi-nucleated

toroids stack on top of each other • Form the connection between the

vulval and uterine lumens to the outside environment • Formation begins when anchor cell

(AC) sends out an EGF-like signal to 3 precursor cells • P6.p adopts the primary fate while

P5.p and P7.p both adopt a secondary fate

• Precursor cells go through division creating 22 cells • Cells begin to move proximally which causes the

invagination of the epithelial lining• AC punches hole through top of vulva to create the

connection to the uterine lumen then retracts

egl-26

Normal L4 vulva egl-26 vulva

• Encodes a protein that is essential in the morphology of the dorsally located vulF cell

• In mutants, the vulF cell collapses after the retraction of the AC

• Expressed non-cell autonomously in the vulE cell and is evident in L4

• Required in the primary lineage of the vulva

Hypothesis •Of a set of genes found to affect vulval development, through the use of RNAi, some of those genes act closely with EGL-26 • To test this hypothesis, RNAi was used to knockdown the expression of a desired gene to observe the loss of function phenotype• Special attention was given to genes in which vulval morphogenesis had been compromised

Procedure

Results• Around 50 genes have been screened• dcp-66, F27C1.6, ncbp-2, egl-30 are of interest because

phenotypes expressed in the vulva are similar to egl-26

dcp-66 F27C1.6 ncbp-2

What’s next?• Continue screening • Rescreen genes of interest • More careful phenotypical analysis

• Transcriptional and translational GFP reporters • Protein localization• Gene expression