title: Atypical mechanoreceptors in larvae of biting midges Forcipomyia nigra (Diptera: Ceratopogonidae).
abstract: The dorsolateral setae of Forcipomyia nigra have been investigated. They are mechanoreceptors, sensilla trichoidea, innerved by a single neuron. The tubular body is located at the base of the hair shaft. Although the fine structure of the dorsolateral setae is similar to dorsal setae that perform a double function: secretion of a hygroscopic viscous substance through the pores and mechanoreception dorsolateral setae, they do not secrete any fluid. In both types of setae, trichogen cells (hair forming cells) produce the hair shafts and thereafter do not retract from the cavity of the setae. They contain a large polyploid nucleus and expanded bundles of microtubules. In dorsolateral mechanoreceptors, the microtubules form a network around the nucleus of the trichogen cell and are especially numerous in the cytoplasm invading the interior of the seta, which is evidenced by immunofluorescence light microscopy. No tormogen cell, responsible for the production of the setal socket, was found. Our observations indicate that the dorsolateral setae are solely mechanoreceptors but their trichogen cells reveal some glandular activity.
authors.affiliation: Department of Invertebrate Zoology and Parasitology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland. Electronic address: aleksandra.urbanek@biol.ug.edu.pl.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Urbanek
authors.affiliation: Department of Plant Cytology and Embryology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kapusta
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D002519:Ceratopogonidae / Q000502:physiology / Q000648:ultrastructure*; D007814:Larva / Q000033:anatomy & histology*; D008465:Mechanoreceptors / Q000473:pathology / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008870:Microtubules / Q000648:ultrastructure; D058618:Sensilla / Q000648:ultrastructure
keywords: Biting midges; Forcipomyia; Mechanoreceptor; Microtubule; Trichogen cell