Gonadal and Endocrine Analysis of a Gynandromorphic Chicken
Gonadal and Endocrine Analysis of a Gynandromorphic Chicken
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DOI：
10.1210/en.2018-00553
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发表时间：
2018-10-01
期刊：
影响因子：
4.8
通讯作者：
Smith, Craig A.
中科院分区：
文献类型：
--
作者：
Morris, Kirsten R.;Hirst, Claire E.;Smith, Craig A.
鸟类具有ZZ雄性和ZW雌性性染色体系统。通过对雌雄同体的研究，揭示了遗传和激素在调控鸟类性发育中的相对作用。雌雄同体是一种罕见的两性嵌合体，身体的一侧是雄性，另一侧是雌性。我们研究了一个自然发生的雌雄同体鸡，是外部男性在身体的右侧和左侧的女性。这只鸟是二倍体，但具有与不对称性表型相关的ZZ和ZW细胞的混合。男侧为96%ZZ，女侧为77%ZZ和23%ZW。性成熟时，这种鸟的性腺主要是睾丸。右侧性腺为睾丸，具有SOX 9（+）支持细胞、DMRT 1（+）生殖细胞和活跃的精子发生。左侧性腺主要是睾丸，但有一些周边芳香化酶表达卵泡。这只鸟的血清雌二醇水平较低，睾酮水平较高，这与雄性的预期一致。尽管这一侧的ZW细胞百分比较低，但左侧具有雌性伴性羽状，肌肉质量较小，腿和马刺较小，并且比雄性侧更小。这表明，这些性二态结构必须至少部分独立于性类固醇的影响。即使是一小部分ZW细胞也足以支持雌性的性分化。鉴于鸟类缺乏全染色体剂量补偿，由于性别之间的Z基因剂量差异，可能会出现各种性二态特征。
Birds have a ZZ male and ZW female sex chromosome system. The relative roles of genetics and hormones in regulating avian sexual development have been revealed by studies on gynandromorphs. Gynandromorphs are rare bilateral sex chimeras, male on one side of the body and female on the other. We examined a naturally occurring gynandromorphic chicken that was externally male on the right side of the body and female on the left. The bird was diploid but with a mix of ZZ and ZW cells that correlated with the asymmetric sexual phenotype. The male side was 96% ZZ, and the female side was 77% ZZ and 23% ZW. The gonads of this bird at sexual maturity were largely testicular. The right gonad was a testis, with SOX9(+) Sertoli cells, DMRT1(+) germ cells, and active spermatogenesis. The left gonad was primarily testicular, but with some peripheral aromatase-expressing follicles. The bird had low levels of serum estradiol and high levels of testosterone, as expected for a male. Despite the low percentage of ZW cells on that side, the left side had female sex-linked feathering, smaller muscle mass, smaller leg and spur, and smaller wattle than the male side. This indicates that these sexually dimorphic structures must be at least partly independent of sex steroid effects. Even a small percentage of ZW cells appears sufficient to support female sexual differentiation. Given the lack of chromosome-wide dosage compensation in birds, various sexually dimorphic features may arise due to Z-gene dosage differences between the sexes.