Maternal transfer of photoperiodic information in Siberian hamsters. V. Effects of melatonin implants are dependent on photoperiod.
Maternal transfer of photoperiodic information in Siberian hamsters. V. Effects of melatonin implants are dependent on photoperiod.
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西伯利亚仓鼠光周期信息的母体传递。
DOI：
10.1095/biolreprod47.2.291
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发表时间：
1992
影响因子：
3.6
通讯作者：
Stetson,MH
中科院分区：
文献类型：
--
作者：
Horton,TH;Ray,SL;Rollag,MD;Yellon,SM;Stetson,MH
光周期信息在妊娠期间从雌性西伯利亚仓鼠转移到胎儿身上。尽管已知母体褪黑激素对于产前光周期信息的传递至关重要，但其具体作用尚不清楚。每日褪黑激素信号的持续时间（表示为母体循环中血清褪黑激素水平的升高）已被假设为向胎儿传达昼长信息。如果这个假设成立，它预测相同的母体褪黑激素信号应该对胎儿产生相同的影响，无论产前光周期如何。为了验证这一假设，成年女性接受了蜂蜡中的褪黑激素或单独的蜂蜡。它们与雄性配对，饲养在 12L:12D 或 16L:8D 的光周期下。分娩当天，母亲和幼崽被转移到恒定光（LL）下。在生命第28天处死年轻雄性，并测定睾丸的重量。单独使用蜂蜡进行产前治疗不会影响从母亲传递给胎儿的信号的性质；在 12L:12D 中妊娠并在 LL 中饲养的幼体发育出小睾丸，而在 16L:8D 中妊娠的幼体则具有大睾丸。另一方面，产前褪黑素治疗对 LL 产后睾丸发育的影响与产前光周期成反比：12L:12D 妊娠的幼崽睾丸生长受到刺激，但 16L:8D 妊娠的幼崽睾丸生长受到抑制。为了验证褪黑素颗粒在 12L:12D 和 16L:8D 中在成年雌性中产生相同的血清褪黑激素水平，未交配的成年雌性在接受褪黑素颗粒后 6-10 周被处死。两组的血清水平在白天和夜间均升高。这些结果表明，除了母体褪黑激素之外，其他因素也可能有助于向胎儿传递光周期信息。
Photoperiodic information is transferred from female Siberian hamsters to their fetuses during gestation. Although maternal melatonin is known to be essential for the transfer of prenatal photoperiodic information, its specific role is not well defined. The duration of the daily melatonin signal, expressed as an elevation of serum melatonin levels in the maternal circulation, has been hypothesized to convey day length information to the fetus. If this hypothesis is valid, it predicts that identical maternal melatonin signals should affect the fetuses identically, regardless of the prenatal photoperiod. To test this hypothesis, adult females received melatonin in beeswax or beeswax alone. They were paired with males and housed in photoperiods of 12L:12D or 16L:8D. On the day of parturition, mother and young were transferred to constant light (LL). Young males were killed on Day 28 of life, and weights of testes were determined. Prenatal treatment with beeswax alone did not affect the nature of the signal transferred from mother to fetus; young gestated in 12L:12D and reared in LL developed small testes, while those gestated in 16L:8D had large testes. On the other hand, the effect of the prenatal melatonin treatment on postnatal testicular development in LL was inversely dependent on the prenatal photoperiod: testicular growth was stimulated in young gestated in 12L:12D, but inhibited in young gestated in 16L:8D. To verify that the melatonin pellets produced equivalent serum melatonin levels in adult females in 12L:12D and 16L:8D, unmated adult females were killed 6–10 wk after receiving melatonin pellets. Serum levels were elevated in both groups throughout the day and night. These results demonstrate that factors in addition to maternal melatonin may contribute to the transmission of photoperiodic information to fetuses.