Effects of different oestrous stages of ovaries and sizes of follicles on generation of bovine embryos in vitro

Tan, Shao-Jing; Lu, Katherine

doi:10.1016/0093-691x(90)90759-m

Cited by 64 publications

(24 citation statements)

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“…This study showed that the majority of goat oocytes acquired competence for development up to the 8-16 cell stage in follicles larger than 2 mm, but did not gain the ability to form M/Bs until follicles larger than 3 mm in diameter. Overall, these results agree with that bovine oocytes from larger follicles tend to develop better in vitro (Tan & Lu 1990, Pavlok et al 1992, Lonergan et al 1994.…”

Section: Discussionsupporting

confidence: 82%

Interactive effects of granulosa cell apoptosis, follicle size, cumulus–oocyte complex morphology, and cumulus expansion on the developmental competence of goat oocytes: a study using the well-in-drop culture system

Han¹,

Lan²,

Wu³

et al. 2006

Reproduction

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Interactive effects of granulosa cell apoptosis, follicle size, cumulus-oocyte complex morphology, and cumulus expansion on the developmental competence of goat oocytes: a study using the well-in-drop culture system Zheng-Bin Han, Guo-Cheng Lan, Yan-Guang Wu, Dong Han, Wei-Guo Feng, Jun-Zuo Wang and Jing-He Tan AbstractUsing a well-in-drop (WID) oocyte/embryo culture system that allows identification of follicular origin, we have investigated the effects of granulosa cells (GCs) apoptosis, follicle size, cumulus-oocyte complexes (COCs) morphology, and cumulus expansion on the developmental competence of goat oocytes matured and cultured individually following parthenogenetic activation. The WID system supported oocyte maturation and embryo development to a level similar to the conventional group system. The majority of goat oocytes acquired competence for development up to the 8-16 cell stage in follicles larger than 2 mm, but did not gain the ability to form morula/blastocyst (M/Bs) until follicles larger than 3 mm in diameter. The extent of atresia affected M/Bs formation. This effect varied according to the follicle size. Cumulus expansion increased with follicle size and decreased with increasing incidence of GCs apoptosis. Oocyte developmental potential was also correlated with cumulus expansion. Regardless of the degree of follicle atresia, 73-84% of the floating cells in the follicular fluid (FF) underwent apoptosis. Correlation between floating cell density in FF and oocyte developmental potency suggests the possibility to use the floating cell density as a simple and non-invasive marker for oocyte quality. It is concluded that the developmental potential of an oocyte is determined by multifactor interactions, and multiple factors must be considered together to accurately predict the quality of an oocyte. Reproduction (2006) 132 749-758Introduction A number of studies have shown that in vitro development of pre-implantation stage mammalian embryos is better when cultured in groups (group culture) than cultured singly in microdrops (microdrop individual culture, MIC) (Gardner et al. 1994, Kato & Tsunoda 1994, Keefer et al. 1994, Moessner & Dodson 1995. However, apart from the large-scale production of embryos for experimental purposes, most commercial and human embryo culture systems require culturing individually or in small groups. The reason for this need is the small number of oocytes available (ovum pick-up (OPU) technology, single slaughtered valuable oocyte donors and human IVF) or the required identification after culture. Besides, sometimes zona-free eggs must be cultured in isolation from each other to prevent conglomeration. Therefore, the establishment of an individual culture system that is as efficient as group culture has become of prime importance. Furthermore, although there are quite a few reports on individual culture of embryos, studies on individual culture of oocytes during maturation are few and with conflicting results (Carolan et al. 1996, Hagemann et al. 1998, Jewgenow et al. 19...

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Section: Discussionsupporting

confidence: 82%

Interactive effects of granulosa cell apoptosis, follicle size, cumulus–oocyte complex morphology, and cumulus expansion on the developmental competence of goat oocytes: a study using the well-in-drop culture system

Han¹,

Lan²,

Wu³

et al. 2006

Reproduction

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“…When oocytes are pooled according to follicular size, oocytes from large follicles had a higher potential for development while oocytes from small follicles were incompetent (Tan and Lu 1990;Pavlok et al 1992Pavlok et al , 1993Lonergan et al 1994). Only one study has described the fate of individual oocytes according to the exact follicular size and the results obtained confirmed an increased competence with follicle size (Blondin and Sirard 1995).…”

supporting

confidence: 53%

Oocyte quality and embryo production in cattle

Sirard¹,

Blondin²

1998

Can. J. Anim. Sci.

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Sirard, M.-A. and Blondin, P. 1998. Oocyte quality and embryo production in cattle. Can. J. Anim. Sci. 78: 513-516. New evidence indicates that bovine oocytes are not always in synchrony with their surrounding follicles. During rapid follicular growth, the oocytes do not acquire a full developmental competence. The plateau phase at the end of the growth phase resulting in dominance or atresia seems important for oocytes to accumulate the information required to become viable embryos. The ovarian follicle has a behavior similar to a fruit where the seed must await the ripening of the envelope to achieve its full potential. This knowledge can now be applied to harvest oocytes of higher quality through transvaginal aspiration in cows.Key words: Oocyte, embryo, cattle Sirard, M.-A. et Blondin, P. 1998. La qualité ovocytaire et la production d'embryon chez la vache. Can. J. Anim. Sci. 78: 513-516. Des nouvelles données montrent que les oocytes bovins ne sont pas toujours en synchronisme avec les follicules qui les entourent. Durant la phase de croissance folliculaire rapide, les oocytes n'acquièrent pas leur pleine compétence pour le développe-ment embryonnaire. Le plafonnement survenant à la fin de la phase de croissance, qui se traduit par la dominance ou par l'atrésie du follicule, paraît important pour permettre aux oocytes d'accumuler l'information nécessaire pour devenir des embryons viables. Le follicule ovarien se comporte comme un fruit dont les graines doivent attendre la maturation de l'enveloppe charnue pour atteindre leur pleine compétence. Ces connaissances peuvent désormais être utilisées pour récolter des oocytes de haute qualité par aspiration transvaginale chez les vaches. Mots clés: Oocyte, embryon, vacheAccurately defining oocyte quality is quite difficult. In the cow, it is generally accepted that quality represents the potential of an oocyte to become a calf following fertilization. This signifies that an immature oocyte will be capable of normal nuclear maturation followed by appropriate interaction with sperm, including the processing of the male gamete nucleus. Macromolecules stored in the oocyte are responsible for the progression through the first cell divisions until the embryonic genome takes over. Simply put, there is a cellular program controlling all of these events and the correct development depends on the right programming. There is increasing evidence that the programming of the oocyte must be completed before leaving the ovarian follicle. The state of growth and differentiation of the follicle will have a determinant impact on the oocyte's capacities. Contrarily to some hypothesis, the synchrony between the follicular maturation (growth and differentiation) and the oocyte cytoplasmic maturation is not a simple linear relation. In the next few pages, we will review the progress made in understanding the follicular influence by looking at a series of experiments from our laboratory in which the different follicular states were modified to see the effect on oocyte quality.There is a...

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“…From the onset it must be emphasized that in vitro maturation, by and large, yields oocytes with a lowered potential for developmental capacity in comparison to in vivo matured oocytes (LeibfriedRutledge et al, 1986a(LeibfriedRutledge et al, , 1987Pavlok et al, 1988 (Leibfried and First, 1979;Fukui and Sakuma, 1980;Grimes and Ireland, 1986) or even to be fertilized in vitro (LeibfriedRutledge et al, 1985). Recent (Crozet et al, 1986;Crozet, 1989 This concept has recently been substantiated by Tan and Lu (1990 (Leibfried and First, 1979;Fukui and Sakuma, 1980;Greve et al, 1984;Hensleigh and Hunter, 1985;Xu et al, 1987;Shioya et al, 1988;Greve et al, 1989b;Sirard, 1989;Younis et al, 1989;Kruip et al, 1990;Gordon and Lu, 1990; (Xu et al, 1986a).…”

Section: Cumulus Oocyte Complexesmentioning

confidence: 99%

In vitro fertilization in cattle: a review

Greve¹,

Madison²

1991

Reprod. Nutr. Dévelop.

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Summary ― In vitro maturation and fertilization of cattle oocytes and subsequent in vitro culture of zygotes and embryos is discussed in the context of recent encouraging data. Mass production of embryos produced in this way in the future will have a great impact on animal production and animal breeding plans, for example the so-called MO-ET (multiple ovulation and embryo transfer) plan which aims at establishing nudeus breeding herds.

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Effects of different oestrous stages of ovaries and sizes of follicles on generation of bovine embryos in vitro

Cited by 64 publications

References 0 publications

Interactive effects of granulosa cell apoptosis, follicle size, cumulus–oocyte complex morphology, and cumulus expansion on the developmental competence of goat oocytes: a study using the well-in-drop culture system

Interactive effects of granulosa cell apoptosis, follicle size, cumulus–oocyte complex morphology, and cumulus expansion on the developmental competence of goat oocytes: a study using the well-in-drop culture system

Oocyte quality and embryo production in cattle

In vitro fertilization in cattle: a review

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