title: A conditional Orco requirement in the somatic cyst cells for maintaining spermatids in a tight bundle in Drosophila testis.
abstract: Odorant receptors (OR) heterodimerizes with the OR co-receptor (Orco), forming specific odorant-gated cation channels, which are key to odor reception at the olfactory sensory neurons (OSN). Mammalian ORs are expressed in many other tissues, including testis. However, their biological implications are yet to be fully ascertained. In the mosquito, Orco is localized along the sperm tail and is indicated to maintain fidelity. Here, we show that orco expresses in Drosophila testis. The levels are higher in the somatic cyst cells. The orco-null mutants are perfectly fertile at 25 degree C. At 28 degree C, the coiled spermatid bundles are severely disrupted. The loss of Orco also disrupts the actin cap, which forms inside the head cyst cell at the rostral ends of the spermatid nuclei after coiling, and plays a key role in preventing the abnormal release of spermatids from the cyst enclosure. Both the defects are rescued by the somatic cyst cell-specific expression of the UAS-orco transgene. These results highlight a novel role of Orco in the somatic tissue during sperm release.
authors.affiliation: Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400 005, India.
authors.forename: Pankaj
authors.initials: P
authors.lastname: Dubey
authors.forename: Prakash
authors.initials: P
authors.lastname: Joti
authors.forename: Krishanu
authors.initials: K
authors.lastname: Ray
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D008297:Male; D018034:Olfactory Receptor Neurons / Q000378:metabolism; D018035:Receptors, Odorant / Q000096:biosynthesis / Q000235:genetics*; D013087:Spermatids / Q000254:growth & development; D013094:Spermatozoa / Q000254:growth & development; D013737:Testis / Q000254:growth & development*
chemical_list: D029721:Drosophila Proteins; C492465:Orco protein, Drosophila; D018035:Receptors, Odorant