title: Role of allatostatin-like factors from the brain of Tenebrio molitor females.
abstract: The effect of brain extract from females of freshly emerged Tenebrio molitor on ovary, oocyte development, total protein content of hemolymph, and ovary was studied in 4-day-old adult mealworm females. Injections of extracts of 2-brain equivalents into intact (unligatured) Tenebrio females did not affect ovarian and oocyte development. Injections of ligated females, however, with 2-brain equivalents on day 1 and 2 after adult emergence strongly inhibited ovarian growth and oocyte development. At day 4, ligated and injected females did not develop their ovaries and pre-vitellogenic oocytes were not found. The changes in ovarian development correlated with an increase in the concentration of soluble proteins in the hemolymph as compared with the saline-injected controls. Additionally, a strong reduction of total protein content in ovarian tissue was observed. Reverse phase HPLC separation of a methanolic brain extract of T. molitor females showed that fraction 5 has a similar retention time to synthetic cockroach allatostatin. Fraction 5 was eluted at 12.88 min, which was closest to the internal standard Dippu-AST I, which eluted at 12.77 min. An ELISA of fraction 5 from the methanolic brain extract using antibodies against allatostatins Grybi-AST A1 and Grybi-AST B1 from cricket Gryllus bimaculatus showed that fraction 5 cross-reacted with Grybi-AST A1 antibodies. The cross-reactivity was similar to the synthetic allatostatin from D. punctata, which was used as a positive control. These observations demonstrate a possible role for allatostatin-like brain factor(s) in regulating the reproductive cycle of Tenebrio molitor.
authors.affiliation: Department of Zoology, University of Life Sciences, Poznań, Poland. oskarw@au.poznan.pl
authors.forename: O
authors.initials: O
authors.lastname: Wasielewski
authors.forename: M
authors.initials: M
authors.lastname: Skonieczna
authors.forename: D
authors.initials: D
authors.lastname: Kodrík
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D048429:Cell Size; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006458:Hemolymph / Q000378:metabolism; D006727:Hormone Antagonists / Q000302:isolation & purification / Q000494:pharmacology; D019476:Insect Proteins / Q000302:isolation & purification / Q000494:pharmacology / Q000502:physiology*; D009479:Neuropeptides / Q000302:isolation & purification / Q000494:pharmacology / Q000502:physiology*; D009865:Oocytes / Q000166:cytology / Q000187:drug effects; D010053:Ovary / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013712:Tenebrio / Q000378:metabolism*
chemical_list: D006727:Hormone Antagonists; D019476:Insect Proteins; D009479:Neuropeptides; C076523:allatostatin