Integrative and Biomedical Physiology Program, University Park, Pennsylvania, USA.
Department of Animal Science, Center for Reproductive Biology and Health, The Pennsylvania State University, University Park, PA 16802, USA.
Poult Sci. 2019 Jul 1;98(7):3014-3021. doi: 10.3382/ps/pez100.
Determining whether follicle recruitment in the domestic hen is functionally linked to ovulation would inform investigations on the exact time of cyclic recruitment and subsequently, the earliest cellular event mediating recruitment. The objective of the present studies was to determine if the absence of ovulation results in the failure of cyclic recruitment. 3 groups of Hy-Line W-36 hens were studied: no-ovulation, first-ovulation, or late-ovulation within the sequence. Time and occurrence of oviposition and ovulation were documented by video recording and cloacal palpation. To determine the presence of a recently recruited follicle, ovaries were collected during the last hour of photoperiod, and follicles weighing 280 to 900 mg, with yellow yolk incorporated, and diameter of 9 to 12 mm, were considered recently recruited. To compare the amount of yolk uptake in recruited follicles, hens were fed Sudan IV dye 6 h before ovary collection. Percent dyed yolk was quantified from cross-sections of the recruited follicles. To confirm follicle viability, granulosa cell (GC) mitotic activity was assessed via flow cytometry. Initial results indicated the presence of a recently recruited follicle in 10 of 11, 7 of 10, and 9 of 10, no-ovulation, first-ovulation, and late-ovulation ovaries, respectively, with no significant differences in weight (543 ± 62 mg, 456 ± 71 mg, 620 ± 75 mg, respectively). There were no significant differences in yolk incorporation among the most recently recruited follicles with 19.0 ± 2.0%, 18.0 ± 3.7%, and 19.8 ± 3.2% dyed yolk in no-ovulation, first-ovulation, and late-ovulation ovaries, respectively. Finally, there were no significant differences in % GC in the S/G2-M phase of mitosis among recruited follicles (19.0 ± 5.0%, 22.0 ± 4.2%, 15.67 ± 1.0%, in no-ovulation, first-ovulation, and late-ovulation ovaries, respectively), confirming viability of all recruited follicles. We conclude that cyclic recruitment occurs independently of ovulation and propose that the order and timing of cyclic recruitment is predetermined at an earlier stage of follicle development.
确定家鸡的卵泡募集是否与排卵功能相关，将有助于研究准确的周期性募集时间，并进一步研究介导募集的最早细胞事件。本研究的目的是确定排卵缺失是否导致周期性募集失败。研究了 3 组海兰 W-36 母鸡：无排卵、第一次排卵和排卵后期。通过视频记录和泄殖腔触诊记录产卵和排卵的时间和发生。为了确定是否有新募集的卵泡，在光周期的最后 1 小时收集卵巢，并且将重 280 至 900mg、有黄色蛋黄掺入且直径为 9 至 12mm 的卵泡视为新募集的卵泡。为了比较募集卵泡中卵黄的摄取量，在收集卵巢前 6 小时给母鸡饲喂苏丹 IV 染料。通过对募集卵泡的横切片进行量化，来确定染色卵黄的百分比。为了确认卵泡的活力，通过流式细胞术评估颗粒细胞（GC）有丝分裂活性。初步结果表明，无排卵、第一次排卵和排卵后期卵巢中分别有 11、10 和 10 个卵巢中存在新募集的卵泡，其重量分别为 543±62mg、456±71mg 和 620±75mg，差异均不显著。在最新募集的卵泡中，卵黄掺入量无显著差异，无排卵、第一次排卵和排卵后期卵巢中的染色卵黄分别为 19.0±2.0%、18.0±3.7%和 19.8±3.2%。最后，在募集卵泡的 S/G2-M 期有丝分裂的 GC 比例无显著差异（无排卵、第一次排卵和排卵后期卵巢中的百分比分别为 19.0±5.0%、22.0±4.2%和 15.67±1.0%），这证实了所有募集卵泡的活力。我们得出结论，周期性募集独立于排卵发生，并且提出周期性募集的顺序和时间在卵泡发育的早期阶段就已预先确定。
