Davis T A, Ackerman R A
J Exp Zool Suppl. 1987;1:357-64.
Domestic chicken eggs that lost 25.1% of their initial mass during incubation produced embryos with smaller wet masses than control eggs that lost 12.5% of their initial mass. However, water-stressed embryos did not differ from control embryos in dry body mass, indicating that water-stressed embryos were dehydrated. Yolk, albumen, heart, and gizzard wet and dry masses were not different between water-stressed and control groups during the last week of incubation. However, wet mass of the liver was significantly greater and that of the right leg significantly less in water-stressed embryos. Tarsometatarsal length, dry mass of the liver and right leg, and daily rates of oxygen consumption were not different between groups. Hatching success was 20.5% for water-stressed eggs and 85% for control eggs. These results show that increased egg water loss during the last week of incubation results in embryos that weigh less because they have a lower water content, not because they grow more slowly. The reduction in water content, with respect to the individual organs and body parts examined, is due primarily to a difference in leg tissue water content. We conclude that embryos do not alter their growth in response to a change in the amount of water available in the egg.
在孵化过程中失重25.1%的家鸡蛋所产生的胚胎，其湿重比失重12.5%的对照蛋所产生的胚胎小。然而，水分胁迫的胚胎与对照胚胎在干体重上并无差异，这表明水分胁迫的胚胎出现了脱水现象。在孵化的最后一周，水分胁迫组和对照组的蛋黄、蛋白、心脏和砂囊的湿重和干重并无差异。然而，水分胁迫胚胎的肝脏湿重显著更大，而右腿湿重显著更小。跗跖长度、肝脏和右腿的干重以及每日耗氧率在两组之间并无差异。水分胁迫蛋的孵化成功率为20.5%，对照蛋为85%。这些结果表明，在孵化的最后一周，蛋内水分损失增加会导致胚胎体重较轻，原因是其含水量较低，而非生长速度较慢。就所检查的各个器官和身体部位而言，水分含量的降低主要是由于腿部组织水分含量的差异。我们得出结论，胚胎不会因蛋内可用水量的变化而改变其生长情况。
