نتایج جستجو برای: oocyte

تعداد نتایج: 14991  

2016
Ning Yao Wuqi Jiang Shuanggang Hu Yan Hong

Backgroud: Oocyte cryopreservation is critical in assisted reproduction techniques. However, the effect of cryopreservation on the oocyte has not been widely explored yet. Currently a thorough understanding of oocyte cryobiology is urgently required due to its far lag behind the forces propelling the clinical application of oocyte cryopreservation. Methods: In this study, we used two different ...

2003
Rebecca E Thomas David T Armstrong Robert B Gilchrist

31 32 In the growing follicle, communication between the oocyte and its surrounding follicular 33 cells is essential for normal oocyte and follicular development. Maturation of the fully34 grown oocyte in vivo is associated with the loss of cumulus cell-oocyte gap junctional 35 communication, preventing entry of meiotic-modulating factors such as cAMP into the 36 oocyte. We have previously show...

اسمعیل کاویانی, فاطمه, شعبانی پور, نادر, میرناطق, باهره,

Viviparity is an advanced reproducing process observed in certain bony fishes. Fish oocyte is protected by different coverings, the immediate one over oolemma being a non-cellular membrane known as Zona Radiata (ZR). ZR has shown variations in thickness, configuration and probably function at different fish oocyte and oocyte growth stages. In the present research work the ultrastructure of zona...

Journal: :Cold Spring Harbor protocols 2013
Yaping Lin-Moshier Jonathan S Marchant

In the four decades since the Xenopus oocyte was first demonstrated to have the capacity to translate exogenous mRNAs, this system has been exploited for many different experimental purposes. Typically, the oocyte is used either as a "biological test tube" for heterologous expression of proteins without any particular cell biological insight or, alternatively, it is used for applications where ...

Journal: :Fertility and sterility 2012
Dominic Stoop Lynn Vercammen Nikolaos P Polyzos Michel de Vos Julie Nekkebroeck Paul Devroey

OBJECTIVE To assess whether there is an increased risk of infertility in women that have previously undergone ovarian stimulation and oocyte retrieval for oocyte donation. DESIGN Cross-sectional survey. SETTING Tertiary referral center. PATIENT(S) A total of 194 past oocyte donors. INTERVENTION(S) Telephone questionnaire. MAIN OUTCOME MEASURE(S) Incidence of infertility after oocyte d...

Journal: :Cell 2005
Leta K. Nutt Seth S. Margolis Mette Jensen Catherine E. Herman William G. Dunphy Jeffrey C. Rathmell Sally Kornbluth

Vertebrate female reproduction is limited by the oocyte stockpiles acquired during embryonic development. These are gradually depleted over the organism's lifetime through the process of apoptosis. The timer that triggers this cell death is yet to be identified. We used the Xenopus egg/oocyte system to examine the hypothesis that nutrient stores can regulate oocyte viability. We show that pento...

Journal: :Genes & development 1997
J M Mach R Lehmann

Genetic experiments suggest that polarization of the oocyte is linked directly to the initial cell fate determination that singles out the oocyte from its 15 sister cells. Specification of oocyte cell fate as well as establishment and maintenance of a polarized microtubule network within the Drosophila oocyte require the activity of the egalitarian (egl) and BicaudalD (BicD) genes. We have isol...

Journal: :Cold Spring Harbor perspectives in biology 2009
Siegfried Roth Jeremy A Lynch

The orthogonal axes of Drosophila are established during oogenesis through a hierarchical series of symmetry-breaking steps, most of which can be traced back to asymmetries inherent in the architecture of the ovary. Oogenesis begins with the formation of a germline cyst of 16 cells connected by ring canals. Two of these 16 cells have four ring canals, whereas the others have fewer. The first sy...

Journal: :تحقیقات دامپزشکی 0
محمدحسن متدین موسسه تحقیقات واکسن و سرم سازی رازی فاطمه توده دهقان موسسه تحقیقات واکسن و سرم سازی رازی پرویز تاجیک دانشگاه تهران زهرا زندیه دانشگاه تهران

quality and quantity of ovum are major determinants in invitro fertilization. the aim of the present study was to determine effect of the time of oocyte collection and also distance of hcg injection to oviduct flushing on the quantity, quality and fertilizing ability of rabbit oocyte. accordingly, sixty two adult female rabbit selected and randomly allocated to seven groups. the rabbits were su...

Journal: :Frontiers in bioscience : a journal and virtual library 2007
Maoyong Fu Xiufen Chen Jun Yan Lei Lei Shiying Jin Jiange Yang Xiaoming Song Meijia Zhang Guoliang Xia

In the process of oocyte maturation, gonadotrophins are believed as main stimulators for oocyte meiosis resumption. However, which gonadotrophin (i.e. FSH or LH) is the key hormone in this process is still unknown. This study indicated a close relationship between LH and FSH on activating meiotic maturation of oocyte in vitro. FSH efficiently induced oocyte meiosis at concentration of 50 IU/L, ...

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