title: Influence of age and juvenile hormone on brain dopamine level in male honeybee (Apis mellifera): association with reproductive maturation.
abstract: Dopamine (DA) is a major functional biogenic amine in insects and has been suggested to regulate reproduction in female honeybees. However, its function has not been investigated in male drones. To clarify developmental changes of DA in drones, brain DA levels were investigated at various ages and showed a similar pattern to the previously reported juvenile hormone (JH) hemolymph titer. The DA level was lowest at emergence and peaked at day 7 or 8, followed by decline. Application of JH analog increased brain DA levels in young drones (2-4-days-old), suggesting regulation of DA by JH in drones. In young drones, maturation of male reproductive organs closely matched the increase in brain DA. The dry weight of testes decreased and that of seminal vesicles increased from emergence to day 8. The dry weight of mucus glands increased up to day 4. Consequently, DA regulated by JH might have reproductive behavior and/or physiological functions in drones.
authors.affiliation: Honeybee Science Research Center, Research Institute, Tamagawa University, Machida, Tokyo 194-8610, Japan. harano@lab.tamagawa.ac.jp
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Harano
authors.forename: Ken
authors.initials: K
authors.lastname: Sasaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagao
authors.forename: Masami
authors.initials: M
authors.lastname: Sasaki
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D001516:Bees / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000378:metabolism*; D005837:Genitalia, Male / Q000033:anatomy & histology / Q000502:physiology; D007605:Juvenile Hormones / Q000378:metabolism*; D008297:Male; D009929:Organ Size; D012741:Sexual Maturation / Q000502:physiology*
chemical_list: D007605:Juvenile Hormones; D004298:Dopamine