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Cite this page: Hill, M.A. (2020, February 26) Embryology Fly Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Fly_Development
Drosophila Hox and Sex-Determination Genes Control Segment Elimination through EGFR and extramacrochetae Activity
PLoS Genet. 2012 Aug;8(8):e1002874. Epub 2012 Aug 9.
Foronda D, Martín P, Sánchez-Herrero E. Source Centro de Biología Molecular Severo Ochoa (C.S.I.C.-U.A.M.), Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
The formation or suppression of particular structures is a major change occurring in development and evolution. One example of such change is the absence of the seventh abdominal segment (A7) in Drosophila males. We show here that there is a down-regulation of EGFR activity and fewer histoblasts in the male A7 in early pupae. If this activity is elevated, cell number increases and a small segment develops in the adult. At later pupal stages, the remaining precursors of the A7 are extruded under the epithelium. This extrusion requires the up-regulation of the HLH protein Extramacrochetae and correlates with high levels of spaghetti-squash, the gene encoding the regulatory light chain of the non-muscle myosin II. The Hox gene Abdominal-B controls both the down-regulation of spitz, a ligand of the EGFR pathway, and the up-regulation of extramacrochetae, and also regulates the transcription of the sex-determining gene doublesex. The male Doublesex protein, in turn, controls extramacrochetae and spaghetti-squash expression. In females, the EGFR pathway is also down-regulated in the A7 but extramacrochetae and spaghetti-squash are not up-regulated and extrusion of precursor cells is almost absent. Our results show the complex orchestration of cellular and genetic events that lead to this important sexually dimorphic character change.
Scanning electron microscopy of Drosophila
- Scanning electron microscopy of Drosophila embryogenesis. I. The structure of the egg envelopes and the formation of the cellular blastoderm. Turner FR, Mahowald AP. Dev Biol. 1976 May;50(1):95-108. No abstract available. PMID: 817949
- Scanning electron microscopy of Drosophila melanogaster embryogenesis. II. Gastrulation and segmentation. Turner FR, Mahowald AP. Dev Biol. 1977 Jun;57(2):403-16. No abstract available. PMID: 406152
- Scanning electron microscopy of Drosophila melanogaster embryogenesis. III. Formation of the head and caudal segments. Turner FR, Mahowald AP. Dev Biol. 1979 Jan;68(1):96-109. PMID: 1081572