非同卵双生胎是两个受精卵同时在子宫着床的结果。

Non-identical twins are the result of two fertilized eggs implanting in the uterus at the same time.

《柯林斯英汉双解大词典》

在未受精卵中，这些物质是不活跃的，而且分布不均匀。

In the unfertilized egg, the substances are inactive and are not distributed homogeneously.

youdao

在滞育期间，小袋鼠呆在雌袋鼠的育儿袋里，因而推迟了子宫内第二个受精卵的发育。

During diapause, a young kangaroo stays in the female's pouch and growth of a second fertilized egg inside the uterus is delayed.

youdao

In fact, there are differences that can be detected upon the first cell division where this zygote divides through the process of mitosis.

事实上,受精卵在进行,第一次有丝分裂时,就会产生差异

耶鲁公开课 - 生物医学工程探索课程节选

Those two examples I just gave you, one had to directly inject a gene containing vector into the pronucleus of a fertilized egg and you don't have that opportunity in adults.

在我刚给出的两个例子里,一个必须得将带有目的基因的载体,直接注射到受精卵的原核中,这在成年人身上行不通

耶鲁公开课 - 生物医学工程探索课程节选

You could do the same thing in mammals and here's one quick example of that, using a different kind of a vector, but inserting a gene into the fertilized egg of a mammal, in this case, a sheep.

你也能在哺乳动物上做到同样的效果,这里有另一个简短的例子,用了另一种载体,把一段基因注入哺乳动物的受精卵中,在这里我们用了绵羊

耶鲁公开课 - 生物医学工程探索课程节选