Circadian Clock mutation in dams disrupts nursing behavior and growth of pups
Circadian Clock mutation in dams disrupts nursing behavior and growth of pups
复制标题
DOI：
10.1210/en.2005-1343
复制
发表时间：
2006-04-01
期刊：
影响因子：
4.8
通讯作者：
Shibata, S
中科院分区：
文献类型：
--
作者：
Hoshino, K;Wakatsuki, Y;Shibata, S
为了了解昼夜节律分子钟在小鼠繁殖中的作用，我们研究了在明暗饲养条件下饲养的时钟突变小鼠与哺乳和幼崽生长相关的每日节律。在野生型母鼠中，与母体蹲伏行为相关的每日节律有一个强的日间峰值和两个弱的夜间峰值，而纯合子（Clock/Clock）则没有表现出明显的活动峰值。野生型（而非时钟突变型）的母鼠血清中催乳素含量呈高水平、有节奏，与蹲伏相对应。在所有实验条件下，当幼崽数量在 10-15 之间时，时钟突变母鼠的幼崽体重增长速度明显慢于野生型母鼠。杂合子母鼠同样繁殖出野生型、杂合子或纯合子幼崽。根据哺乳过程中幼仔体重增加的情况计算，时钟突变小鼠的母鼠分泌的乳汁量低于野生型小鼠。当时钟突变的母鼠产下超过 10 只幼崽时，后代在断奶之前的存活率都很低。目前的结果表明，时钟突变会扰乱母体的日常行为以及幼崽的生长和存活率，特别是在繁殖超过 10 只幼崽的情况下。
To understand the role of the circadian molecular clock in mouse reproduction, we investigated the daily rhythms associated with nursing and pup growth in Clock-mutant mice maintained under light-dark housing conditions. The daily rhythm associated with the maternal behavior of crouching had a strong diurnal peak and two weak nocturnal peaks in wild-type dams, whereas homozygotes (Clock/Clock) exhibited no significant peaks in activity. Wild-type, but not Clock-mutant, dams showed high, rhythmic levels of prolactin content in serum that corresponded with crouching. Pup body weight increased at a significantly slower rate in Clock-mutant dams compared with wild-type dams under all experimental conditions when the pups ranged from 10-15 in number. Heterozygote dams equally bred wild-type, heterozygote, or homozygote pups. The amount of milk secreted from dams, as calculated by the increase in pup body weight through suckling, was lower in Clock-mutant mothers vs. wild-type mice. When Clock-mutant dams gave birth to more than 10 pups, survival was poor for offspring until the time of weaning. The present results demonstrate that Clock mutation disrupts daily maternal behavior and the growth and survival rate of pups, especially with the breeding of more than 10 pups.