Morphologic indicators predict the stage of chromatin condensation of human germinal vesicle oocytes recovered from stimulated cycles

Escrich, L.; Grau, N.; Meseguer, Marcos; Pellicer, António; Escribá, Marı́a-José

doi:10.1016/j.fertnstert.2009.05.077

Cited by 26 publications

(21 citation statements)

References 14 publications

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“…From mouse and rabbit to sheep, goat, cow, horse and human, the progressive configuration from diffuse to more condensed and from non-surrounded nucleolus to surrounded nucleolus seems to be associated with a slow shutdown of the transcriptional machinery [15]. A similar change in chromatin configuration has also been observed in human oocytes [17]. This simple transformation might indicate that the oocyte finally has all the RNA required to proceed.…”

Section: The Links Between Follicle and Oocytementioning

confidence: 62%

Follicle environment and quality of in vitro matured oocytes

Sirard

2011

J Assist Reprod Genet

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In mammalian reproduction, the oocyte depends on the ovarian follicle for most of its growth. They form a bipolar partnership and the status of one will impact the functioning of the other. When oocytes are removed from their follicle by ovulation, they have normally completed all the steps required to begin their journey into the oviduct and drive the early embryonic development. When oocytes are removed from their follicle before natural ovulation, the process by which they acquire all the important components for their journey might not be completed and their ability to mature, fertilize or develop into embryos or to term might be compromised. Animal models have been useful to define the important steps required for the oocyte's growth phase, and in the mouse, when the oocyte has reached its full size, the program is ready. This is not the case in larger mammals where the completion of growth does not ensure that the oocyte is fully capable of undergoing all the steps to the embryo and to term. The final steps of oocyte preparation also involve a progressive condensation of the chromatin that may facilitate normal maturation but may also indirectly reduce the lifespan of the oocyte. In such a scenario, the oocyte would have an expiration date when fully competent. In humans, a number of indications may justify the aspiration of oocytes from unstimulated patients and the development of an in vitro maturation (IVM) process that would allow fertilization and subsequent development. This objective could be realized by a better understanding of the essential follicular contribution required before removing the oocyte. Therefore, this review will focus on the large animal models where IVM has been used and studied for more than 25 years. The status of the follicle at the time of oocyte recovery and the status of the oocyte's chromatin will be described in detail as they have a significant impact on the outcome.

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Section: The Links Between Follicle and Oocytementioning

confidence: 62%

Follicle environment and quality of in vitro matured oocytes

Sirard

2011

J Assist Reprod Genet

View full text Add to dashboard Cite

show abstract

“…OCTAX software for image analysis was employed to measure oocyte size (cytoplasmic diameter, excluding zona pellucida, ZP), nuclear diameter and largest nucleolus-like body (NLB) diameter. These morphometric measurements are presented in μm as either mean±SD or 95% confidence interval values (CI95) and were recorded three times by two observers (16).…”

Section: Oocyte Collectionmentioning

confidence: 99%

“…Morphometry revealed no significant differences between the mean diameter of the GV (average 106. Morphological and morphometrical data compilation using the previously described mathematical model allowed the chromatin condensation state of 127 GV oocytes to be determined (16). The majority of GV oocytes displayed compacted chromatin (85.5% vs. extended 14.5%, p<0.05).…”

Section: Description Of the Gv Populationmentioning

confidence: 99%

“…A cohort can include mature metaphase II (MII) oocytes, which usually have reproductive potential, and immature oocytes, which are discarded from IVF protocols. Immature oocytes also vary in their chromatin configuration (9)(10)(11)(12)(13)(14)(15)(16), ability to progress to meiosis (9,10,17), and cytoplasmic and developmental competence (10,13,18,19).…”

Section: Introductionmentioning

confidence: 99%

“…Firstly, we characterized our population of immature GV by morphometric and morphologic examination of different parameters (13,14,16) and established their chromatin condensation stage (16).…”

Section: Introductionmentioning

confidence: 99%

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