Relationship between follicle size and oocyte developmental competence in prepubertal and adult pigs
Relationship between follicle size and oocyte developmental competence in prepubertal and adult pigs
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DOI：
10.1071/rd07018
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发表时间：
2007-01-01
影响因子：
1.9
通讯作者：
Grupen, Christopher G.
中科院分区：
文献类型：
--
作者：
Bagg, Melanie A.;Nottle, Mark B.;Grupen, Christopher G.
本研究比较了3-，4-和5 - 8- mm卵泡在青春期前和成年卵巢表面的分布和类固醇成分，并确定卵泡大小与孤雌激活后卵母细胞发育能力之间的关系。还测定了1 mm二丁酰cAMP（dbcAMP）在体外成熟（IVM）的前22小时对三个卵泡大小队列的青春期前卵母细胞胚胎发育的影响。与成人相比，青春期前卵巢含有较高比例的3- mm卵泡（46 v. 72%，分别），但较低比例的4- mm（33 v. 22%，分别）和5 - 8- mm卵泡（21 v. 6%，分别）。成年卵泡液（FF）中孕酮（P4）的水平比青春期前FF高11倍，在所有成年卵泡大小之间观察到相似的水平。在青春期前的FF中，P4浓度随着卵泡大小从3 - 4到5 - 8 mm而增加。来自所有三种卵泡大小的成年卵母细胞孤雌激活后的囊胚发育率相似（约55%），而来自青春期前卵母细胞的比率随着卵泡大小从3（17%）到4（36%）到5 - 8 mm（55%）的增加而增加。在IVM的前22小时用dbcAMP处理导致来自3 mm卵泡的青春期前卵母细胞的囊胚发育率增加1.5倍，但对来自4和5 - 8 mm类的青春期前卵母细胞没有影响。平均囊胚细胞数增加卵泡大小在青春期前卵巢和成人卵巢的所有卵泡大小相似。本研究表明，在体外胚胎生产中观察到的低效率使用青春期前与成年猪卵母细胞相比，是由于青春期前卵巢，其中含有较差的发育能力的卵母细胞的3毫米卵泡的比例较大。
The present study compared the distribution and steroid composition of 3-, 4- and 5 - 8- mm follicles on the surface of prepubertal and adult ovaries, and determined the relationship between follicle size and developmental competence of oocytes following parthenogenetic activation. The effect of 1mm dibutyryl cAMP ( dbcAMP) for the first 22 h of in vitro maturation ( IVM) on the embryo development of prepubertal oocytes from the three follicle size cohorts was also determined. Compared with adult, prepubertal ovaries contained a higher proportion of 3- mm follicles ( 46 v. 72%, respectively), but a lower proportion of 4- mm ( 33 v. 22%, respectively) and 5 - 8- mm follicles ( 21 v. 6%, respectively). Adult follicular fluid ( FF) contained 11- fold higher levels of progesterone ( P4) than prepubertal FF, with similar levels observed between all adult follicle sizes. In prepubertal FF, the P4 concentration increased with follicle size from 3 to 4 to 5 - 8 mm. Rates of blastocyst development following parthenogenetic activation of adult oocytes from all three follicles sizes were similar ( approximately 55%), whereas rates from prepubertal oocytes increased with increasing follicle size from 3 ( 17%) to 4 ( 36%) to 5 - 8mm ( 55%). Treatment with dbcAMP for the first 22 h of IVM led to a 1.5- fold increase in the rate of blastocyst development for prepubertal oocytes from 3- mm follicles, but had no effect on prepubertal oocytes from the 4 and 5 - 8mm classes. Mean blastocyst cell number increased with follicle size in prepubertal ovaries and was similar for all follicle sizes in adult ovaries. The present study demonstrates that the low efficiency of in vitro embryo production observed using prepubertal compared with adult pig oocytes is due to a greater proportion of 3- mm follicles on prepubertal ovaries, which contain oocytes of inferior developmental competence.