Heap R B, Hamon M H, Allen W R
AFRC Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, UK.
J Reprod Fertil. 1991 Sep;93(1):141-7. doi: 10.1530/jrf.0.0930141.
Aromatase distribution in membranes of preimplantation horse and donkey conceptuses was compared by measuring the incorporation of [3H]androstenedione into oestrone and oestradiol-17 beta. In the donkey conceptus, aromatase activity was similar in all the tissues examined (yolk sac, chorionic girdle and allantochorion), whereas in the horse it was generally lower and showed the relationship chorionic girdle greater than yolk sac greater than allantochorion. A higher proportion of labelled precursor was incorporated into oestradiol-17 beta by extra-embryonic tissues of the donkey compared with those of the horse. In contrast to previous results, aromatase in the chorionic girdle did not decline progressively before its migration into the endometrium on Day 36 to form the endometrial cups. The chorionic girdle of a donkey conceptus carried in the uterus of a mare failed to invade the surrogate horse endometrium and aromatase activity was still high in this tissue at Day 42. Aromatase distribution in 2 transferred donkey-in-horse conceptuses resembled that of the fetal, rather than the maternal, genotype indicating a lack of effect of the maternal environment.
通过测量[3H]雄烯二酮转化为雌酮和雌二醇-17β的情况，比较了植入前马和驴胚胎膜中芳香化酶的分布。在驴胚胎中，所检测的所有组织（卵黄囊、绒毛膜带和尿囊绒毛膜）中的芳香化酶活性相似，而在马胚胎中，其活性通常较低，且呈现出绒毛膜带大于卵黄囊大于尿囊绒毛膜的关系。与马的胚胎外组织相比，驴的胚胎外组织将更高比例的标记前体转化为雌二醇-17β。与先前的结果相反，绒毛膜带中的芳香化酶在第36天迁移到子宫内膜形成子宫内膜杯之前，并没有逐渐下降。在母马子宫内携带的驴胚胎的绒毛膜带未能侵入代孕马的子宫内膜，并且在第42天时该组织中的芳香化酶活性仍然很高。两个移植的马怀驴胚胎中芳香化酶的分布类似于胎儿而非母体的基因型，这表明母体环境没有影响。
