山羊卵母细胞生发泡染色质构型的研究
摘要
近年来哺乳动物卵母细胞体外成熟技术已取得长足的进展，但还存在很多问题没有解决。尽管在成熟培养前对卵丘-卵母细胞复合体(COCs)进行严格的选择，但是即使从同一个卵巢收集的卵母细胞其第一次减数分裂前期双线期的时相也各不相同，因而从不同个体的卵巢、不同大小的卵泡内收集的卵母细胞实际上是异质的。这很可能是卵母细胞IVM质量差异较大，造成体外胚胎发育能力差的原因之一。本实验应用荧光显微镜研究了山羊不同大小、健康程度卵泡来的和体内、外发育不同时间卵母细胞生发泡构型以及在此期间RNA合成情况的变化规律。实验结果表明：
1 采用活体荧光染料Hoechst 33342对山羊生发泡进行观察，根据染色质构型及核仁大小将其分为8种形态：GV0、GV1、GV2(GV2-1、GV2-2)、GV3(GV3-1、GV3-2)GV4和GVBD。
2 腔前卵泡卵母细胞生发泡都为GV0期；直径为0.5-0.8mm卵泡卵母细胞都为GV1期；随着卵泡的发育，GV3期卵母细胞比例明显增高。
3 体外成熟过程中，随着培养时间的延长，GV1，GV2及GV4的比率有所下降，而GV3和GVBD的比率明显上升。
4 健康卵泡中GV3的比率显著高于闭锁卵泡，而闭锁卵泡中GV4和GVBD的比率显著高于健康卵泡。
5 随着卵泡直径增大，卵母细胞核仁直径逐渐变小。
6 体内注射FSH和hCG后的排卵前卵泡卵母细胞生发泡染色质构型主要为GV3，其中GV3-1占绝对优势，而GV3-2的比率较低。
7 直径为0.5-0.8mm的卵泡卵生发泡内RNA大量合成，1-3mm卵泡中RNA合成较减弱，而＞3mm卵泡内卵母细胞RNA合成结束。
Although techniques of in vitro maturation (IVM) of mammalian oocytes have made great progress, some problems are still unsolved. Even though COCs were strictly selected before in vitro culture, the chromatin configuration of dictyate stage oocytes was different. Therefore, oocytes collected from follicles of different diameters in the same ovary were heterogeneous. This is one of the reasons for the poor quality of in vitro matured oocytes. In this study, we observed the changes of germinal vesicle chromatin configuration in goat oocytes from follicles of different diameter and health status, and during in vitro and vivo maturation using fluorescence microscopy.
The results are as follows:
1. Eight types of GV chromatin configurations were observed with Hoechst 33342 staining in the goat oocytes according to the morphology of chromatin and the size of nucleolus and they were GV0. GVK GV2 (GV2-1, GV2-2), GV3 (GV3-1, GV3-2) GV4 and GVBD.
2. Oocytes from the pre-antral follicles were all at GVO stage and oocytes from 0.5-0.8mm follicles were all at GV1 stage. With the follicular development, the proportion of GV3 stage was significantly increased.
3. During in vitro maturation, the proportion of GVK GV2 and GV4 declined but the proportion of GV3 and GVBD was significantly increased with time of culture.
4. The proportion of GV3 stage oocytes from healthy follicles was significantly higher than that from atretic follicles. The proportion of GV and GVBD stage oocytes from atretic follicles was significantly higher than that from healthy follicles.
5. With the increases of follicle diameter, the diameter of nucleoli in oocytes reduced.
6. The GV chromatin configuration of oocytes from preovulatory follicles after FSH and hCG injection was mainly at GV3 stage and the proportion of GV3-1 stage oocytes was much higher than that of the GV3-2 stage ones.
7. RNA synthesis was intensive in oocyes from follicles of 0.5-0.8mm diameter, became faint in oocytes from follicles of 1-3mm diameter and ceased in oocytes from follicles of >3mm diameter.
Candidate: Sui hongshu Specialty: Basic Veterinary Science
Advisor: Prof. Tan Jinghe
1 采用活体荧光染料Hoechst 33342对山羊生发泡进行观察，根据染色质构型及核仁大小将其分为8种形态：GV0、GV1、GV2(GV2-1、GV2-2)、GV3(GV3-1、GV3-2)GV4和GVBD。
2 腔前卵泡卵母细胞生发泡都为GV0期；直径为0.5-0.8mm卵泡卵母细胞都为GV1期；随着卵泡的发育，GV3期卵母细胞比例明显增高。
3 体外成熟过程中，随着培养时间的延长，GV1，GV2及GV4的比率有所下降，而GV3和GVBD的比率明显上升。
4 健康卵泡中GV3的比率显著高于闭锁卵泡，而闭锁卵泡中GV4和GVBD的比率显著高于健康卵泡。
5 随着卵泡直径增大，卵母细胞核仁直径逐渐变小。
6 体内注射FSH和hCG后的排卵前卵泡卵母细胞生发泡染色质构型主要为GV3，其中GV3-1占绝对优势，而GV3-2的比率较低。
7 直径为0.5-0.8mm的卵泡卵生发泡内RNA大量合成，1-3mm卵泡中RNA合成较减弱，而＞3mm卵泡内卵母细胞RNA合成结束。
Although techniques of in vitro maturation (IVM) of mammalian oocytes have made great progress, some problems are still unsolved. Even though COCs were strictly selected before in vitro culture, the chromatin configuration of dictyate stage oocytes was different. Therefore, oocytes collected from follicles of different diameters in the same ovary were heterogeneous. This is one of the reasons for the poor quality of in vitro matured oocytes. In this study, we observed the changes of germinal vesicle chromatin configuration in goat oocytes from follicles of different diameter and health status, and during in vitro and vivo maturation using fluorescence microscopy.
The results are as follows:
1. Eight types of GV chromatin configurations were observed with Hoechst 33342 staining in the goat oocytes according to the morphology of chromatin and the size of nucleolus and they were GV0. GVK GV2 (GV2-1, GV2-2), GV3 (GV3-1, GV3-2) GV4 and GVBD.
2. Oocytes from the pre-antral follicles were all at GVO stage and oocytes from 0.5-0.8mm follicles were all at GV1 stage. With the follicular development, the proportion of GV3 stage was significantly increased.
3. During in vitro maturation, the proportion of GVK GV2 and GV4 declined but the proportion of GV3 and GVBD was significantly increased with time of culture.
4. The proportion of GV3 stage oocytes from healthy follicles was significantly higher than that from atretic follicles. The proportion of GV and GVBD stage oocytes from atretic follicles was significantly higher than that from healthy follicles.
5. With the increases of follicle diameter, the diameter of nucleoli in oocytes reduced.
6. The GV chromatin configuration of oocytes from preovulatory follicles after FSH and hCG injection was mainly at GV3 stage and the proportion of GV3-1 stage oocytes was much higher than that of the GV3-2 stage ones.
7. RNA synthesis was intensive in oocyes from follicles of 0.5-0.8mm diameter, became faint in oocytes from follicles of 1-3mm diameter and ceased in oocytes from follicles of >3mm diameter.
Candidate: Sui hongshu Specialty: Basic Veterinary Science
Advisor: Prof. Tan Jinghe
引文
1 马所峰，山羊卵母细胞减数分裂进程及HX对其调控机理的研究。东北农业大学．硕士论文。2002：10-13
2 孙兴参，猪体细胞核移植及相关问题的研究。东北农业大学．博士论文．2001：23-26
3 Alm H, Hinrichs K, Effect of cycloheximide on nuclear maturation o fhorse oocytes and its relation to initial cumulus morphology. J Reprod Fertil.[J] 1996, 107:215-220
4 Bouniol Christine, Nguyen Eric, and Debey Pascale. Endogenous transcription occurs at the 1-Cell stage in the mouse embryo. Exprimental. Cell. Research [J] 1995, 218:57-62
5 Bouniol-Baly Christine, Lahcen Hamraoui, Juliette Guibert, Nathalie Beaujean, Maria S. Szllsi and Pascale Debey. Differential Transcriptional Activity Associated with Chromatin Configuration in Fully Grown Mouse Germinal Vesicle Oocytes. Biology of Reproduction. [J] 1999, 60: 580-587
6 Crozet N, Motlik J, Szollosi D. Nucleolar fine structure and RNA synthesis in porcine oocytes during early stages of antrum formation. Biol Cell.[J] 1981, 41:35-42
7 De Smedt V, Crozet N, Gall L. Morphological and functional changes accompanying the acquisition of meiotic competence of ovarian goat oocytes. J Exp Zool.[J] 1994, 269: 128-139
8 Debey P, Szllsi MS, Szllsi D, Vautier D, Girousse A, Besombes D. Competent mouse oocytes isolated from antral follicles exhibit different chromatin organization and follow different maturation dynamics. Mol Reprod Dev. [J] 1993, 36:59-74
9 Ding J, Foxcroft GR. Conditioned media produced follicular shells of different maturity affect maturation of pig oocytes. Biol Reprod. [J] 1994, 50:1377-1384
10 Faerge I, Mayes M, Hyttel P, and Sirard M. A. Nuclear Ultrastructure in Bovine Oocytes After Inhibition of Meiosis by Chemical and Biological Inhibitors. Mol Reprod Dev.[J] 2001, 59:459-467
11 Fair T, Hyttel P, and Greve T. Bovine Oocyte Diameter in Relation to Maturational Competence and Transcriptional Activity. Mol Reprod Dev.[J] 1995, 42:437-442
12 Fair T, Hulshof SCJ, Hyttel P, Boland M and Greve T. Bovine oocyte ultrastructure in primordial to tertiary follicles. Anatomy and Embryology. [J] 1997, 195:327-336
13 Fair T, Hyttel P, Greve T and Boland M. Nucleolus sructure and transcriptional activity in relation to oocyte diameter in cattle. Mol Reprod Dev. [J] 1996, 43:503-512
14 Fenselfeld G. Chromatin as an essential part of the transcriptional mechanism. Nature. [J] 1992, 355:219-224
15 Funahashi H., Cantley T C, Day BN. Preincubation of cumulus-oocyte complexes before exposure to gonadotropins improvement the developmental competence of porcine embryos matured and fertilized in vitro. Theriogenology. [J] 1997, 47:679-686
16 Gabke T. L. and Woods G. L. Confocal Microscopy of Germinal Vesicle-Stage Equine Oocytes. Theriogenology. [J] 2001, 55: 1417-1430
17 H. David Guthrie and Wesley M. Garrett. Changes in porcine oocyte germinal vesicle development as follcles approach preovlatory maturity. Theriogenology. [J] 2000, 54: 389-399
18 Hinrichs K., A. L. Schmidt, P. P. Friedman, J. P. Selgrath, and M. G. Martin. In vitro Maturation of Horse Oocytes: Characterization of Chromatin Configuration Using Fluorescence Microscopy. Biol of Reprod. [J] 1993, 48:363-370
19 Hinrichs K. and A. L. Schmidt. Meiotic Competence in Horse Oocytes: Interactions Among Chromatin Configuration, Follicle Size, Cumulus Morphology, and Season. Biol of Rerod. [J] 2000, 62: 1402-1408
20 Hinrichs K. and Kimberly A. Williams. Relationships among Oocyte-Cumulus Morphology, Follicular Atresia, Initial Chromatin Configuration, and Oocyte Meiotic Competence in the Horse. Biol of Reprod. [J] 1997, 57:377-384
21 Honglin Liu and Fugaku Aoki. Transcriptional activity associated with meiotic competence in fully grown mouse GV oocytes. Zygote. [J] 2002, 10(November): 327-332
22 Hyttel P, Greve T, and Callesen H. Ultrastmctural aspects of oocyte maturation and fertilization in Cattle. J Reprod Fert Suppl. [J] 1989, 38:35-47
23 Hyttel P, Viuff D, Fair T. Ribosomal RNA gene expression and chromosome aberrations in bovine oocytes and preimplantation embryos. Reproduction. [J] 2001, 122:21-30
24 Hyttel P, Fair T, Callesen and Greve T. Oocyte Growth Capacitation and final Maturation Cattle. Theriogenology. [J] 1997, 47:23-32
25 Ingram. DL. Aresia. In. The Ovary, Academic Press. [M] 1964, New York, Vol. 1: 247-274
26 Izquierdo D, Villamediana P, Lopez-Bejar M, Paramio MT. Effect of in vitro and in vivo culture on embryo development from prepubertal goat IVM-IVF oocytes. Theriogenology. [J] 2002, Mar 15; 57(5): 1431-41
27 King W A, Bousquet D, Greve T and Goff A K. Meiosis in bovine oocytes matured in vitro and in vivo. Acta Vet Scand. [J] 1986, 27:267-279
28 Lefevre B, Gougeon A, Nome F, Testart J. In vivo changes in oocyte germinal vesicle related to follicular quality and size at mid-follicular phase during stimulated cycles in the Cynomolgus monkey. Reprod Nutr Dev.[J] 1989, 29:523-532
29 Long CR, Dorbrinsky JR, Johnson LA. In vitro production of pig embros: comparaons of culture medium and boars. Theriogenology. 1997, 51:1375-1390
30 Mandl AM. Pre-ovulatory changes in the oocyte of the adult rat. Proc R Soc Lond B Biol Sci. [J] 1962, 158:105-118
31 Mattson BA, Albertini DF. Oogenesis: Chromatin and microtubule dynamics during meiotic prophase. Mol Reprod Dev. [J] 1990, 25:374-383
32 Moor, R. M, Crosby I. M. and Osbom, J. C. Growth and maturation of mammalian
oocytes. In:In vitro Fertilization and embryo tansfer. Academic Press Inc. (London)Ltd. [J] 1983, 39-63
33 Moore GP, Lintern-Moore S. A correlation between growth and RNA synthesis in the mouse oocyte. J Reprod Fertil.[J] 1974, Jul; 39(1): 163-6
34 Motilik J, Koefoed-Johnsen HH, Fulka J. Breakdown of the germinal vesicle in bovine oocyte cultivated in vitro. J. Exp Zool. [J] 1978, 205(3): 377-380
35 Motlik J, Fulka J. Breakdown of the germinal vesicle in pig oocyte in vivo and in vitro. J Exp Zool.[J] 1976, 198:155-162
36 N. Crozet, M. Dahirel and I. Gall. Meiotic competence of in vitro grown goat oocytes. Journal of Reproduction and Fertility. [J] 2000, 118:367-373
37 Nagai Takashi, Misa Ebihara, Akria Onishi and Masanori Kubo. Germinal vesicle stage in pig follicular oocyte collected by different methods J. Reproduction and Development.[J] 1997, Vol 43, No.4
38 Olga V. Zatsepina, Christine Bouniol-Baly, Claudine Amirand, and Pascale Debey. Functional and Molecular Reorganization of the Nucleolar Apparatus in Maturing Mouse Oocytes. Developmental Biology. [J] 2000, 223:354-370
39 Parfenov V, Potchukalina G, Dudina L, Kostyuchek D, Gruzova M. Human antral follicles: oocyte nucleus and the karyosphere formation (electron microscopic and autoradiographic data). Gamete Res. [J] 1989, 22:219-231
40 Raph D Schramm, Michael T, Tennier, Dorothy E. Boatman, Barry D, Bavisteret. Chromatin Configurations and Meiotic Competence of Oocytes Are Related to Follicular Diameter in Nonstimulated Rhesus Monkeys. Biol of Reprod. [J] 1993, 48:349-356
41 Rodman TC, Bachvarova R. RNA synthesis in preovulatory mouse oocytes. J Cell Biol. [J] 1976, Jul; 70(1): 251-7
42 Sirard MA, Blondin P. Oocyte maturation and IVF in cattle. Anim Reprod Sci. 1996, 42: 417-426
43 Tesarik J, Kopecny V, Kurilo LF. Pre-ovulatory RNA synthesis in human oocytes of large antral follicles. Histochem J. [J] 1984, Apr; 16(4): 438-40
44 Tsafriri A and Channing C. R. Influence of follicular maturation and culture condition of the meiosis of pig oocyte in vitro. J. Animal. Reprod. [J] 1975, 43:149-152
45 Wickramasinghe D, Ebert KM, Albertini DF. Meiotic competence acquisition is associated with the appearance of M-phase characteristics in growing mouse oocytes. Dev Biol.[J] 1991, 143:162-172
46 Wolffe AP. The transcription of chromatin templates. Curr Opin Gen Dev. [J] 1994, 4: 245-254
47 Zuccotti M, Piccinelli A, Rossi PG, Garagna S, Redi CA. Chromatin organization during mouse oocyte growth. Mol Reprod Dev. [J] 1995, 41:479-485
48 Zuccottl M, Giorgi Rossi P, Martinez A, Garagna S, Forabosco A, Redi CA. Meiotic and
developmental competence of mouse antral oocytes. Biol Reprod. [J] 1998, 58: 700-704
49 Zuccottl M, Michele Boiani, Silvia Garagna and Carlo Alberto Redi. Analysis of aneuploidy Rate in Antral and Ovulated Mouse Oocytes During Female Aging. Mol Reprod Dev.[J] 1998, 50:305-312
50 Zuccottl M, Michele Boiani, Stefano Guizzardi, Paolo Govoni. The analysis of chromatin organization allows selection of mouse antral oocytes competent for development to blastocyst. Zygote. [J] 2002, 10 (February): 73-78
2 孙兴参，猪体细胞核移植及相关问题的研究。东北农业大学．博士论文．2001：23-26
3 Alm H, Hinrichs K, Effect of cycloheximide on nuclear maturation o fhorse oocytes and its relation to initial cumulus morphology. J Reprod Fertil.[J] 1996, 107:215-220
4 Bouniol Christine, Nguyen Eric, and Debey Pascale. Endogenous transcription occurs at the 1-Cell stage in the mouse embryo. Exprimental. Cell. Research [J] 1995, 218:57-62
5 Bouniol-Baly Christine, Lahcen Hamraoui, Juliette Guibert, Nathalie Beaujean, Maria S. Szllsi and Pascale Debey. Differential Transcriptional Activity Associated with Chromatin Configuration in Fully Grown Mouse Germinal Vesicle Oocytes. Biology of Reproduction. [J] 1999, 60: 580-587
6 Crozet N, Motlik J, Szollosi D. Nucleolar fine structure and RNA synthesis in porcine oocytes during early stages of antrum formation. Biol Cell.[J] 1981, 41:35-42
7 De Smedt V, Crozet N, Gall L. Morphological and functional changes accompanying the acquisition of meiotic competence of ovarian goat oocytes. J Exp Zool.[J] 1994, 269: 128-139
8 Debey P, Szllsi MS, Szllsi D, Vautier D, Girousse A, Besombes D. Competent mouse oocytes isolated from antral follicles exhibit different chromatin organization and follow different maturation dynamics. Mol Reprod Dev. [J] 1993, 36:59-74
9 Ding J, Foxcroft GR. Conditioned media produced follicular shells of different maturity affect maturation of pig oocytes. Biol Reprod. [J] 1994, 50:1377-1384
10 Faerge I, Mayes M, Hyttel P, and Sirard M. A. Nuclear Ultrastructure in Bovine Oocytes After Inhibition of Meiosis by Chemical and Biological Inhibitors. Mol Reprod Dev.[J] 2001, 59:459-467
11 Fair T, Hyttel P, and Greve T. Bovine Oocyte Diameter in Relation to Maturational Competence and Transcriptional Activity. Mol Reprod Dev.[J] 1995, 42:437-442
12 Fair T, Hulshof SCJ, Hyttel P, Boland M and Greve T. Bovine oocyte ultrastructure in primordial to tertiary follicles. Anatomy and Embryology. [J] 1997, 195:327-336
13 Fair T, Hyttel P, Greve T and Boland M. Nucleolus sructure and transcriptional activity in relation to oocyte diameter in cattle. Mol Reprod Dev. [J] 1996, 43:503-512
14 Fenselfeld G. Chromatin as an essential part of the transcriptional mechanism. Nature. [J] 1992, 355:219-224
15 Funahashi H., Cantley T C, Day BN. Preincubation of cumulus-oocyte complexes before exposure to gonadotropins improvement the developmental competence of porcine embryos matured and fertilized in vitro. Theriogenology. [J] 1997, 47:679-686
16 Gabke T. L. and Woods G. L. Confocal Microscopy of Germinal Vesicle-Stage Equine Oocytes. Theriogenology. [J] 2001, 55: 1417-1430
17 H. David Guthrie and Wesley M. Garrett. Changes in porcine oocyte germinal vesicle development as follcles approach preovlatory maturity. Theriogenology. [J] 2000, 54: 389-399
18 Hinrichs K., A. L. Schmidt, P. P. Friedman, J. P. Selgrath, and M. G. Martin. In vitro Maturation of Horse Oocytes: Characterization of Chromatin Configuration Using Fluorescence Microscopy. Biol of Reprod. [J] 1993, 48:363-370
19 Hinrichs K. and A. L. Schmidt. Meiotic Competence in Horse Oocytes: Interactions Among Chromatin Configuration, Follicle Size, Cumulus Morphology, and Season. Biol of Rerod. [J] 2000, 62: 1402-1408
20 Hinrichs K. and Kimberly A. Williams. Relationships among Oocyte-Cumulus Morphology, Follicular Atresia, Initial Chromatin Configuration, and Oocyte Meiotic Competence in the Horse. Biol of Reprod. [J] 1997, 57:377-384
21 Honglin Liu and Fugaku Aoki. Transcriptional activity associated with meiotic competence in fully grown mouse GV oocytes. Zygote. [J] 2002, 10(November): 327-332
22 Hyttel P, Greve T, and Callesen H. Ultrastmctural aspects of oocyte maturation and fertilization in Cattle. J Reprod Fert Suppl. [J] 1989, 38:35-47
23 Hyttel P, Viuff D, Fair T. Ribosomal RNA gene expression and chromosome aberrations in bovine oocytes and preimplantation embryos. Reproduction. [J] 2001, 122:21-30
24 Hyttel P, Fair T, Callesen and Greve T. Oocyte Growth Capacitation and final Maturation Cattle. Theriogenology. [J] 1997, 47:23-32
25 Ingram. DL. Aresia. In. The Ovary, Academic Press. [M] 1964, New York, Vol. 1: 247-274
26 Izquierdo D, Villamediana P, Lopez-Bejar M, Paramio MT. Effect of in vitro and in vivo culture on embryo development from prepubertal goat IVM-IVF oocytes. Theriogenology. [J] 2002, Mar 15; 57(5): 1431-41
27 King W A, Bousquet D, Greve T and Goff A K. Meiosis in bovine oocytes matured in vitro and in vivo. Acta Vet Scand. [J] 1986, 27:267-279
28 Lefevre B, Gougeon A, Nome F, Testart J. In vivo changes in oocyte germinal vesicle related to follicular quality and size at mid-follicular phase during stimulated cycles in the Cynomolgus monkey. Reprod Nutr Dev.[J] 1989, 29:523-532
29 Long CR, Dorbrinsky JR, Johnson LA. In vitro production of pig embros: comparaons of culture medium and boars. Theriogenology. 1997, 51:1375-1390
30 Mandl AM. Pre-ovulatory changes in the oocyte of the adult rat. Proc R Soc Lond B Biol Sci. [J] 1962, 158:105-118
31 Mattson BA, Albertini DF. Oogenesis: Chromatin and microtubule dynamics during meiotic prophase. Mol Reprod Dev. [J] 1990, 25:374-383
32 Moor, R. M, Crosby I. M. and Osbom, J. C. Growth and maturation of mammalian
oocytes. In:In vitro Fertilization and embryo tansfer. Academic Press Inc. (London)Ltd. [J] 1983, 39-63
33 Moore GP, Lintern-Moore S. A correlation between growth and RNA synthesis in the mouse oocyte. J Reprod Fertil.[J] 1974, Jul; 39(1): 163-6
34 Motilik J, Koefoed-Johnsen HH, Fulka J. Breakdown of the germinal vesicle in bovine oocyte cultivated in vitro. J. Exp Zool. [J] 1978, 205(3): 377-380
35 Motlik J, Fulka J. Breakdown of the germinal vesicle in pig oocyte in vivo and in vitro. J Exp Zool.[J] 1976, 198:155-162
36 N. Crozet, M. Dahirel and I. Gall. Meiotic competence of in vitro grown goat oocytes. Journal of Reproduction and Fertility. [J] 2000, 118:367-373
37 Nagai Takashi, Misa Ebihara, Akria Onishi and Masanori Kubo. Germinal vesicle stage in pig follicular oocyte collected by different methods J. Reproduction and Development.[J] 1997, Vol 43, No.4
38 Olga V. Zatsepina, Christine Bouniol-Baly, Claudine Amirand, and Pascale Debey. Functional and Molecular Reorganization of the Nucleolar Apparatus in Maturing Mouse Oocytes. Developmental Biology. [J] 2000, 223:354-370
39 Parfenov V, Potchukalina G, Dudina L, Kostyuchek D, Gruzova M. Human antral follicles: oocyte nucleus and the karyosphere formation (electron microscopic and autoradiographic data). Gamete Res. [J] 1989, 22:219-231
40 Raph D Schramm, Michael T, Tennier, Dorothy E. Boatman, Barry D, Bavisteret. Chromatin Configurations and Meiotic Competence of Oocytes Are Related to Follicular Diameter in Nonstimulated Rhesus Monkeys. Biol of Reprod. [J] 1993, 48:349-356
41 Rodman TC, Bachvarova R. RNA synthesis in preovulatory mouse oocytes. J Cell Biol. [J] 1976, Jul; 70(1): 251-7
42 Sirard MA, Blondin P. Oocyte maturation and IVF in cattle. Anim Reprod Sci. 1996, 42: 417-426
43 Tesarik J, Kopecny V, Kurilo LF. Pre-ovulatory RNA synthesis in human oocytes of large antral follicles. Histochem J. [J] 1984, Apr; 16(4): 438-40
44 Tsafriri A and Channing C. R. Influence of follicular maturation and culture condition of the meiosis of pig oocyte in vitro. J. Animal. Reprod. [J] 1975, 43:149-152
45 Wickramasinghe D, Ebert KM, Albertini DF. Meiotic competence acquisition is associated with the appearance of M-phase characteristics in growing mouse oocytes. Dev Biol.[J] 1991, 143:162-172
46 Wolffe AP. The transcription of chromatin templates. Curr Opin Gen Dev. [J] 1994, 4: 245-254
47 Zuccotti M, Piccinelli A, Rossi PG, Garagna S, Redi CA. Chromatin organization during mouse oocyte growth. Mol Reprod Dev. [J] 1995, 41:479-485
48 Zuccottl M, Giorgi Rossi P, Martinez A, Garagna S, Forabosco A, Redi CA. Meiotic and
developmental competence of mouse antral oocytes. Biol Reprod. [J] 1998, 58: 700-704
49 Zuccottl M, Michele Boiani, Silvia Garagna and Carlo Alberto Redi. Analysis of aneuploidy Rate in Antral and Ovulated Mouse Oocytes During Female Aging. Mol Reprod Dev.[J] 1998, 50:305-312
50 Zuccottl M, Michele Boiani, Stefano Guizzardi, Paolo Govoni. The analysis of chromatin organization allows selection of mouse antral oocytes competent for development to blastocyst. Zygote. [J] 2002, 10 (February): 73-78