Effects of low O2 and ageing on spindles and chromosomes in mouse oocytes from pre-antral follicle culture

Hu, Yao; Betzendahl, Ilse; Cortvrindt, R.; Smitz, Johan; Eichenlaub-Ritter, Ursula

doi:10.1093/humrep/16.4.737

Cited by 100 publications

(63 citation statements)

References 54 publications

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“…Both increased FSH dose and higher serum peak estradiol levels were associated with the lack of spindle detection with the PolScope. Although, increased FSH stimulation Several investigators have reported that the meiotic spindle is a dynamic structure and that various environm e n t a l c o n d i t i o n s c a n p r o d u c e t e m p o r a r y depolymerisation without the occurrence of a real impairment of oocyte quality [16][17][18]. This depolymerisation may be caused by changes in culture conditions such as temperature and pH.…”

Section: Discussionmentioning

confidence: 99%

Relationship between pre-ICSI meiotic spindle angle, ovarian reserve, gonadotropin stimulation, and pregnancy outcomes

Mahfoudh¹,

Moon

Henderson³

et al. 2017

J Assist Reprod Genet

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Purpose The goals of this study are to analyze the clinical pregnancy rate as a function of the pre-intracytoplasmic sperm injection (ICSI) oocyte spindle angle and determine factors which can be associated with different spindle angles, if clinically relevant. Methods Fifty-eight patients, who underwent their first ICSI cycle from January to December 2013, were included. Eight hundred thirty oocytes were collected, and 648 were metaphase II (MII) on retrieval day. Spindles were characterized in terms of visibility and position in relation to the first polar body (PB). Oocytes were separated into four groups based on angle: (group 1, n = 297) 0°-29°; (group 2 n = 212) 30°-89°; (group 3, n = 72) ≥90°; and those with no visible spindle (group 4, n = 67). Results The rate of blastocyst development was associated with the spindle angle (p = 0.002). The rate of good quality blastocysts were as follows: group 1 (42%), group 2 (30%), group 3 (35%), and group 4 (19%) (p = 0.02). Pregnancy and live birth rates were also affected (p = 0.007 and p = 0.046, respectively). Antral follicle count (AFC) (p = 0.001), total FSH stimulating dose (p = 0.0001), and peak serum estradiol level (p = 0.0001) were associated with spindle angle grouping. Miscarriage rates trended different (p = 0.07). On the other hand, day 3 follicle-stimulating hormone (FSH) levels and female and male age were not associated with spindle angle grouping. Conclusions Embryos resulting from oocytes with pre-ICSI spindle angles between 0°and 29°were associated with better blastocyst, pregnancy, live birth, and miscarriage rates when compared to oocytes that had no visible spindle. Low ovarian reserve and excessive stimulation were also associated with lack of spindle and therefore lower pregnancy outcomes.

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Section: Discussionmentioning

confidence: 99%

Relationship between pre-ICSI meiotic spindle angle, ovarian reserve, gonadotropin stimulation, and pregnancy outcomes

Mahfoudh¹,

Moon

Henderson³

et al. 2017

J Assist Reprod Genet

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“…Since the 1970s, the study of oxygen concentration during mouse oocyte maturation has almost exclusively involved the use of 5 or 20% oxygen mixtures (Eppig and Wigglesworth, 1995;Hu et al, 2001;Adam, 2004). This is largely due to previous studies showing that a 5% oxygen concentration is optimal for oocyte nuclear maturation (as measured by extrusion of a polar body) in both mouse and hamster (Haidri et al, 1971;Gwatkin and Haidri, 1974) and that mouse embryo culture is widely performed under 5% O 2 (Harlow and Quinn, 1979).…”

Section: Discussionmentioning

confidence: 99%

Oxygen concentration during mouse oocyte in vitro maturation affects embryo and fetal development

et al. 2007

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BACKGROUND: Little is known of how the oxygen environment in the ovarian follicle affects oocyte and embryo development, but this has an important impact on the conditions used for in vitro maturation (IVM) of oocytes. We investigated the effect of varying oxygen concentrations during IVM on subsequent pre and post-implantation development. METHODS: IVM of mouse cumulus-oocyte complexes (COCs) was performed under 2, 5, 10 or 20% O 2 (6% CO 2 , balance N 2 ). In vivo-matured COCs were collected post ovulation. Embryos were generated by IVF and culture. Blastocyst development, cell number and apoptosis were assessed, and fetal and placental outcomes analysed following embryo transfer at day 18 of pregnancy. RESULTS: Oxygen concentration during IVM did not affect oocyte maturation or subsequent fertilization, cleavage and blastocyst development rates. Maturation of oocytes under 2% O 2 increased blastocyst trophectoderm cell number compared with all groups and numbers at 5% were higher than 20% (both P < 0.05). Percentage of apoptotic cells was increased in blastocysts developed from 2% O 2 -matured oocytes, compared with maturation at 5% O 2 or in vivo (P < 0.05). Rates of embryo implantation and development into a viable fetus were not altered by IVM oxygen. However, fetal weight was reduced following oocyte maturation at 5% O 2 compared wiht 20% O 2 and maturation at 5% O 2 also reduced placental weight, when compared with in vivo-matured oocytes (both P < 0.05). CONCLUSIONS: Level of O 2 exposure during oocyte maturation can alter the cellular composition of blastocysts, but these changes in cell number do not correlate with the altered fetal and placental outcomes after transfer.

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“…For example, although murine ovarian tissue is exposed to plasma oxygen levels of about 5% in vivo, mouse follicles grown in vitro in 5% oxygen had a higher frequency of mature oocytes with incorrectly aligned chromosomes and many died prematurely when compared with follicles cultured in 20% oxygen (Hu et al 2001). Similarly, sheep follicles grown in 5% oxygen had reduced antral cavity formation and increased lactate and glucose consumption when grown under hypoxic conditions of 5% oxygen relative to sized matched counterparts that were grown in 20% oxygen .…”

Section: The Follicle Culture Environment In Vitromentioning

confidence: 99%

The in vitro growth and maturation of follicles

Picton

Harris²,

Muruvi³

et al. 2008

Reproduction

239

190

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The development of technologies to grow oocytes from the most abundant primordial follicles to maturity in vitro holds many attractions for clinical practice, animal production technology and research. The production of fertile oocytes and live offspring has been achieved in mice following the long-term culture of oocytes in primordial follicles from both fresh and cryopreserved ovarian tissue. In contrast, in non-rodent species advances in follicle culture are centred on the growth of isolated preantral follicles. As a functional unit, mammalian preantral follicles are well-suited to culture but primordial and primary follicles do not grow well after isolation from the ovarian stroma. The current challenges for follicle culture are numerous and include: optimisation of culture media and the tailoring of culture environments to match the physiological needs of the cell in vivo; the maintenance of cell-cell communication and signalling during culture; and the evaluation of the epigenetic status, genetic health and fertility of in vitro derived mature oocytes. In large animals and humans, the complete in vitro growth and maturation of oocytes is only likely to be achieved following the development of a multistage strategy that closely mimics the ovary in vivo. In this approach, primordial follicle growth will be initiated in situ by the culture of ovarian cortex. Isolated preantral follicles will then be grown to antral stages before steroidogenic function is induced in the somatic cells. Finally, cytoplasmic and nuclear maturation will be induced in the in vitro derived oocytes with the production of fertile metaphase II gametes.

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Effects of low O2 and ageing on spindles and chromosomes in mouse oocytes from pre-antral follicle culture

Cited by 100 publications

References 54 publications

Relationship between pre-ICSI meiotic spindle angle, ovarian reserve, gonadotropin stimulation, and pregnancy outcomes

Relationship between pre-ICSI meiotic spindle angle, ovarian reserve, gonadotropin stimulation, and pregnancy outcomes

Oxygen concentration during mouse oocyte in vitro maturation affects embryo and fetal development

The in vitro growth and maturation of follicles

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