title: Improved conditions for culture of biosynthetically active cockroach corpora allata.
abstract: Currently, short-term culture of insect corpora allata is most often performed in TC199. We now show that L-15B, a medium widely used in arthropod tissue culture, is superior to TC199 for both short- and long-term culture of cockroach corpora allata. In 3-h and 48-h incubations, juvenile hormone biosynthesis by corpora allata from Diploptera punctata was significantly higher in L-15B than in TC199. In addition, in both media, corpora allata activity was significantly improved by flotation of glands at the medium surface. Characteristics of L-15B responsible for its superiority were examined by comparison of gland activities in several TC199 formulations that had been modified in different ways to be more similar to L-15B. Adjusting the osmotic pressure of TC199 (288 mOsm/l) to near that of L-15B (362 mOsm/l) and D. punctata hemolymph (360 mOsm/l) significantly improved gland activity during the second 12 h of a 36-h incubation. Increasing the concentrations of amino acids, sugars, and organic acids in TC199 to the same levels as in L-15B significantly improved gland activity during both the second and third 12-h intervals of a 36-h incubation. These results suggest that L-15B is superior to TC199 because L-15B is isoosmotic with D. punctata hemolymph and because L-15B, like cockroach hemolymph, contains a high level of organic constituents. It is therefore more appropriate to use L-15B than TC199 for short-term in vitro assays of juvenile hormone biosynthesis and for extended corpora allata culture.
authors.affiliation: Department of Entomology, North Carolina State University, Raleigh 27695-7613, USA.
authors.forename: G L
authors.initials: GL
authors.lastname: Holbrook
authors.forename: A S
authors.initials: AS
authors.lastname: Chiang
authors.forename: C
authors.initials: C
authors.lastname: Schal
mesh_terms: D000818:Animals; D003058:Cockroaches / Q000166:cytology* / Q000378:metabolism; D003335:Corpora Allata / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D003470:Culture Media / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000494:pharmacology; D007605:Juvenile Hormones / Q000096:biosynthesis*; D008297:Male; D009924:Organ Culture Techniques / Q000379:methods*; D014199:Trehalose / Q000494:pharmacology
chemical_list: D003470:Culture Media; D007605:Juvenile Hormones; D014199:Trehalose; D005947:Glucose