title: A genetically female brain is required for a regular reproductive cycle in chicken brain chimeras.
abstract: Sexual differentiation leads to structural and behavioural differences between males and females. Here we investigate the intrinsic sex identity of the brain by constructing chicken chimeras in which the brain primordium is switched between male and female identities before gonadal development. We find that the female chimeras with male brains display delayed sexual maturation and irregular oviposition cycles, although their behaviour, plasma concentrations of sex steroids and luteinizing hormone levels are normal. The male chimeras with female brains show phenotypes similar to typical cocks. In the perinatal period, oestrogen concentrations in the genetically male brain are higher than those in the genetically female brain. Our study demonstrates that male brain cells retain male sex identity and do not differentiate into female cells to drive the normal oestrous cycle, even when situated in the female hormonal milieu. This is clear evidence for a sex-specific feature that develops independent of gonadal steroids.
authors: Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
authors: Fumihiko
authors: F
authors: Maekawa
authors: Miyano
authors: M
authors: Sakurai
authors: Yuki
authors: Y
authors: Yamashita
authors: Kohichi
authors: K
authors: Tanaka
authors: Shogo
authors: S
authors: Haraguchi
authors: Kazutoshi
authors: K
authors: Yamamoto
authors: Kazuyoshi
authors: K
authors: Tsutsui
authors: Hidefumi
authors: H
authors: Yoshioka
authors: Shizuko
authors: S
authors: Murakami
authors: Ryo
authors: R
authors: Tadano
authors: Tatsuhiko
authors: T
authors: Goto
authors: Jun-ichi
authors: J
authors: Shiraishi
authors: Kohei
authors: K
authors: Tomonari
authors: Takao
authors: T
authors: Oka
authors: Ken
authors: K
authors: Ohara
authors: Teruo
authors: T
authors: Maeda
authors: Takashi
authors: T
authors: Bungo
authors: Masaoki
authors: M
authors: Tsudzuki
authors: Hiroko
authors: H
authors: Ohki-Hamazaki
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001921:Brain / Q000033:anatomy & histology / Q000166:cytology / Q000196:embryology / Q000502:physiology*; D002642:Chick Embryo; D002645:Chickens / Q000097:blood / Q000235:genetics* / Q000502:physiology*; D002678:Chimera / Q000235:genetics* / Q000502:physiology*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism; D010060:Ovulation; D012098:Reproduction / Q000235:genetics / Q000502:physiology*; D012661:Semen / Q000378:metabolism; D012727:Sex Characteristics; D012733:Sex Differentiation / Q000235:genetics*; D012741:Sexual Maturation / Q000502:physiology; D013094:Spermatozoa / Q000378:metabolism
chemical_list: D012739:Gonadal Steroid Hormones; D018377:Neurotransmitter Agents; D004958:Estradiol; D007986:Luteinizing Hormone