Utilization of the growth phase of the first follicular wave for bovine oocyte collection improves blastocyst production

Machatkova, Marie; Jokešová, E.; Horký, F.; Krepelova, A.

doi:10.1016/s0093-691x(00)00369-1

Cited by 46 publications

(14 citation statements)

References 24 publications

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“…A recent study (Salamone et al 1999) revealed that during the growth of the first follicular wave, oocytes from the subordinate follicles remain viable through the static phase, but undergo degenerative changes in the regressing phase following the appearance of the dominant follicle. Another study evaluated the number of blastocysts obtained when aspiration was made on days 3, 4 or 5 of the first follicular wave; three times more viable embryos were produced at day 5 when dominance has occurred, compared with day 3 where all follicles are growing (Machatkova et al 2000). A recent paper (Lodde et al 2008) described the progressive chromatin condensation of the nucleus in bovine oocytes as they are harvested from follicles of different size and health status.…”

Section: Follicular Size and Health Effectmentioning

confidence: 99%

Factors Affecting Oocyte and Embryo Transcriptomes

Sirard

2012

Reprod Domestic Animals

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Contents The most important factor affecting the oocyte and early embryo transcriptome is the legacy from the follicular environment prior to meiotic resumption. Up to the 8‐cell stage, the oocyte responds to maternal instructions stored before resumption of the meiotic division. Recent evidence suggests that properly prepared or programmed oocytes (in vivo) can achieve close to 100% blastocyst rates in standard in vitro conditions/media. Therefore, the optimal oocyte requires perfect follicular timing and differentiation, but the intra‐oocyte mechanisms involved in such preparation are not completely understood. In addition, the influence of maternal mRNA storage and degradation, as well as the length of the poly A tail that influences the general pattern of the oocyte/early embryo transcriptome, is an important factor. Several hypotheses have been put forth to explain the depletion of the maternal store, including the potential role of microRNA (miRNA) in this process. The activation of the embryonic genome could be dependent on, or associated with, the process of maternal mRNA degradation, but obviously other functions are being activated at this critical time point. This review will focus on the period from full‐size oocytes to the eight‐cell stage and will summarize the impact of the important factors, that is, follicle, maternal RNA storage and embryonic genome activation, on the transcriptome.

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Section: Follicular Size and Health Effectmentioning

confidence: 99%

Factors Affecting Oocyte and Embryo Transcriptomes

Sirard

2012

Reprod Domestic Animals

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“…Non invasive criteria for oocyte selection can rely on the morphology of the ovary [3,4] and its ovarian phase [5]. The size of the follicle [6][7][8], its level of atresia [9,10] and the progesterone concentration of the follicular fluid [11] are also good indicators.…”

Section: Introductionmentioning

confidence: 99%

Influence of antral follicle size on oocyte characteristics and embryo development in the bovine

et al. 2005

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The developmental competence of bovine oocytes isolated from antral follicles of different sizes was assessed in three European laboratories (Belgium, UCL; Denmark, DIAS; France, INRA). Using the same protocol for in vitro production of embryos, the oocytes isolated from follicles with a diameter !6 mm always gave a higher blastocyst rate than oocytes from follicles <4 mm (UCL: 42% versus 14%, DIAS: 50% versus 35%, INRA: 39% versus 22%; P < 0.05). Blastocyst cell number was not affected by follicle size. Several parameters were investigated for these oocytes. The energy metabolism of cumulus-oocyte-complexes and of denuded oocytes was assessed by the oxygen and pyruvate uptake and by lactate release both at the beginning and the end of the maturation. No effect of follicle size could be detected but lactate release increased after maturation. The global profile of transcripts, the pattern of protein neosynthesis and the kinetics of meiosis resumption were not affected by follicle size. The developmental kinetics of derived embryos was also analysed. Whatever the follicle size, viable embryos had a shorter first and third embryonic cell cycle. Among the viable embryos, the size of the follicle interfered with the fourth cell cycle duration. A higher percentage of blastocysts issued from large follicle presented a short fourth cell cycle (9 h) (35% versus 6%; P < 0.05). Beside, blastocysts derived from small follicles had a delayed cavitation and expansion. Thereby, a higher developmental competence for oocytes from follicle !6 mm versus <4 mm was Theriogenology 63 (2005) [841][842][843][844][845][846][847][848][849][850][851][852][853][854][855][856][857][858][859]

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“…During the estrous cycle, the follicle population changes under the influence of follicular waves. We have shown by our previous work that the development of in vitro produced embryos improves if oocytes from donors are collected in the growth phase of follicular waves (Machatkova et al, 2000.…”

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confidence: 99%

Collection of oocytes from donors in the growth phase of follicular development can enhance the production of bovine embryos for cryopreservation

Machatkova¹,

Hanzalova²,

Horakova³

et al. 2006

Vet. Med. - Czech

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232The application of biotechnology in cattle breeding has allowed us to reduce the generation interval and to increase selection pressure in animal populations on the basis of more objective evaluation of the genotype. It facilitates more effective utilization of the reproductive potential of animals, makes a broader range of parental combinations available and thus allows for modification of the animal population in a desired way.The prerequisite for achieving these goals involves efficient cryopreservation methods for long-term storage of embryos, exchange of genetic material and creation of genetic resources. Today the embryos obtained by superovulation can be fro- ABSTRACT: The present study was designed to compare the efficiency of bovine embryo production for cryopreservation between oocytes collected from donors in the growth phase of follicular development (GPFD) and those recovered from donors in the undefined phase (UPFD). Cyclic cows, Czech Siemental or Holstein dairy breeds, 4-6 years of age, slaughtered at the local abbatoir were used. They were divided into two groups based on ovarian morphology: I. GPFD donors with ovaries corresponding to the growth phase of the first follicular wave (estrus cycle days 3-4; n = 52), and II. UPFD donors with ovaries in any other phase of follicular development (undefined estrus cycle days; n = 89). A total of 3 771 oocytes were collected and 1 134 embryos were prepared as two separate populations by standard protocol. In total 352 excellent or good quality embryos at the early, advanced or expanded blastocyst stage from both donor groups were pooled and used for cryotolerance assessment. They were frozen on day 7 (D7) or day 8 (D8) after fertilization by the standard procedure. After thawing, the embryos were cultured for 72 h to the hatching stage. The percentages of both D7 embryos and advanced blastocysts were significantly higher (P ≤ 0.01) for oocytes collected from GPFD donors than for oocytes collected from UPFD donors (33.7 vs 28.6% and 43.0 vs 29.5%, respectively). The percentages of excellent or good quality embryos obtained from both D7 embryos and fertilized oocytes were significantly higher (P ≤ 0.01) for oocytes collected from GPFD donors than for oocytes collected from UPFD donors (63.6 vs 49.4% and 21.4 vs 14.1%, respectively). The post-thaw survival rates were significantly higher (P ≤ 0.01) for D7 than D8 embryos (80.4 vs 66.3%). In relation to the developmental stage, the development and hatching rates were significantly higher (P ≤ 0.01) for D7 than D8 early blastocysts (75.0 vs 41.2% and 50.0 vs 5.9%, respectively) and for D7 than D8 advanced blastocysts, (73.7 vs 57.1 and 52.6 vs 28.6%, respectively). No differences were found between D7 and D8 expanded blastocysts after freezing-thawing. In conclusion, the collection of oocytes from donors in the growth phase positively influenced the in vitro production of bovine embryos for cryopreservation. The development of embryos produced with oocytes from GPFD donor group was accelerated and more ex...

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Utilization of the growth phase of the first follicular wave for bovine oocyte collection improves blastocyst production

Cited by 46 publications

References 24 publications

Factors Affecting Oocyte and Embryo Transcriptomes

Factors Affecting Oocyte and Embryo Transcriptomes

Influence of antral follicle size on oocyte characteristics and embryo development in the bovine

Collection of oocytes from donors in the growth phase of follicular development can enhance the production of bovine embryos for cryopreservation

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