Although many of the genes and pathways involved in Drosophila embryogenesis have been thoroughly investigated, a complete understanding of the mechanisms behind these processes is still lacking. In order to gain a better perspective, the main objective of current research is to identify additional components of the signaling pathways that are crucial for normal Drosophila development. / One such developmental process is germ band retraction, which occurs in mid-embryogenesis and consists of the movement of the tail end of the germ band, or embryo proper, to its final posterior position. One of our primary objectives is to identify the signaling pathways behind this process. To this end, we investigated the 7T2 mutant, which fails to retract. This zygotic lethal mutant was originally uncovered in a screen for maternal-effect U-shaped embryonic phenotypes. Using a combination of meiotic recombination with molecularly mapped P-element insertions and complementation tests with deficiencies, we mapped the 7T2 mutant to the chromosomal region containing the gene pellino. Here, we show that both pellino mRNA and Pellino protein are missing in the 7T2 mutant tissue, indicating that 7T2 is a loss of function allele of pellino. / Further characterization of the 7T2 mutant revealed three distinct phenotypes: germ band retraction defects, twisted germ bands and head defects. Based on these observations, we propose that pellino is involved in several biological processes during early Drosophila development. Here we show that pellino is involved in the JNK pathway through genetic interaction with hemipterous, an upstream member of the JNK pathway. In addition, we provide preliminary evidence suggesting that the expression of Twist, a protein induced by the Toll pathway, is affected in the absence of pellino, suggesting a role for pellino in dorsal-ventral pattern formation.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.100208 |
| Date | January 2007 |
| Creators | Sarac, Amila. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Biology.) |
| Rights | © Amila Sarac, 2007 |
| Relation | alephsysno: 002669325, proquestno: AAIMR38433, Theses scanned by UMI/ProQuest. |
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