Abeydeera L.R, Wang W.H, Cantley T.C, Prather R.S, Day B.N (1998): Presence of β-mercaptoethanol can increase the glutathione content of pig oocytes matured in vitro and the rate of blastocyst development after in vitro fertilization. Theriogenology, 50, 747-756  https://doi.org/10.1016/S0093-691X(98)00180-0Alkrad Jamal Alyoussef, Mrestani Yahya, Stroehl Dieter, Wartewig Siegfried, Neubert Reinhard (2003): Characterization of enzymatically digested hyaluronic acid using NMR, Raman, IR, and UV–Vis spectroscopies. Journal of Pharmaceutical and Biomedical Analysis, 31, 545-550  https://doi.org/10.1016/S0731-7085(02)00682-9Appeltant R., Somfai T., Nakai M., Bodó S., Maes D., Kikuchi K., Van Soom A. (2015): Interactions between oocytes and cumulus cells during in vitro maturation of porcine cumulus-oocyte complexes in a chemically defined medium: Effect of denuded oocytes on cumulus expansion and oocyte maturation. Theriogenology, 83, 567-576  https://doi.org/10.1016/j.theriogenology.2014.10.026Assidi M., Dieleman S. J., Sirard M.-A. (): Cumulus cell gene expression following the LH surge in bovine preovulatory follicles: potential early markers of oocyte competence. Reproduction, 140, 835-852  https://doi.org/10.1530/REP-10-0248Assou S., Haouzi D., De Vos J., Hamamah S. (): Human cumulus cells as biomarkers for embryo and pregnancy outcomes. Molecular Human Reproduction, 16, 531-538  https://doi.org/10.1093/molehr/gaq032Bergandi L., Basso G., Evangelista F., Canosa S., Dalmasso P., Aldieri E., Revelli A., Benedetto C., Ghigo D. (): Inducible Nitric Oxide Synthase and Heme Oxygenase 1 Are Expressed in Human Cumulus Cells and May Be Used as Biomarkers of Oocyte Competence. Reproductive Sciences, , -  https://doi.org/10.1177/1933719114525268Chen Lin, Wert Susan E., Hendrix E. Michael, Russell Paul T., Cannon Michelle, Larsen William J. (1990): Hyaluronic acid synthesis and gap junction endocytosis are necessary for normal expansion of the cumulus mass. Molecular Reproduction and Development, 26, 236-247  https://doi.org/10.1002/mrd.1080260307Daen F. P., Sato E., Naito K., Toyoda Y. (1994): The effect of pig follicular fluid fractions on cumulus expansion and male pronucleus formation in porcine oocytes matured and fertilized in vitro. Reproduction, 101, 667-673  https://doi.org/10.1530/jrf.0.1010667Dadashpour Davachi N., Kohram H., Zainoaldini S. (2012): Cumulus cell layers as a critical factor in meiotic competence and cumulus expansion of ovine oocytes. Small Ruminant Research, 102, 37-42  https://doi.org/10.1016/j.smallrumres.2011.09.007DEKEL N. (1979): Maturational Effects of Gonadotropins on the Cumulus-Oocyte Complex of the Rat. Biology of Reproduction, 20, 191-197  https://doi.org/10.1095/biolreprod20.2.191Dekel Nava, Lawrence Theodore S., Gilula Norton B., Beers William H. (1981): Modulation of cell-to-cell communication in the cumulus-oocyte complex and the regulation of oocyte maturation by LH. Developmental Biology, 86, 356-362  https://doi.org/10.1016/0012-1606(81)90193-7Dragovic Rebecca A., Ritter Lesley J., Schulz Samantha J., Amato Fred, Armstrong David T., Gilchrist Robert B. (2005): Role of Oocyte-Secreted Growth Differentiation Factor 9 in the Regulation of Mouse Cumulus Expansion. Endocrinology, 146, 2798-2806  https://doi.org/10.1210/en.2005-0098Eppig John J. (1979): FSH stimulates hyaluronic acid synthesis by oocyte–cumulus cellcomplexes from mouse preovulatory follicles. Nature, 281, 483-484  https://doi.org/10.1038/281483a0Eppig John J. (1980): Role of Serum in FSH Stimulated Cumulus Expansion by Mouse Oocyte-Cumulus Cell Complexes in vitro. Biology of Reproduction, 22, 629-633  https://doi.org/10.1093/biolreprod/22.3.629Fagbohun C. F. (1990): Maturation of the mouse oocyte-cumulus cell complex: stimulation by lectins. Biology of Reproduction, 42, 413-423  https://doi.org/10.1095/biolreprod42.3.413Feuerstein Prisca, Puard Vincent, Chevalier Catherine, Teusan Raluca, Cadoret Veronique, Guerif Fabrice, Houlgatte Remi, Royere Dominique, Panepucci Rodrigo Alexandre (2012): Genomic Assessment of Human Cumulus Cell Marker Genes as Predictors of Oocyte Developmental Competence: Impact of Various Experimental Factors. PLoS ONE, 7, e40449-  https://doi.org/10.1371/journal.pone.0040449 Flechon J.E., Degrouard J., Kopecny V., Pivko J., Pavlok A., Motlik J. (2003): The extracellular matrix of porcine mature oocytes: origin, composition and presumptive roles. Reproductive Biology and Endocrinology, 1, 124. https://doi.org/10.1186/1477-7827-1-124Huang Z., Wells D. (): The human oocyte and cumulus cells relationship: new insights from the cumulus cell transcriptome. Molecular Human Reproduction, 16, 715-725  https://doi.org/10.1093/molehr/gaq031Kimura N. (2002): Expression of Hyaluronan Synthases and CD44 Messenger RNAs in Porcine Cumulus-Oocyte Complexes During In Vitro Maturation. Biology of Reproduction, 66, 707-717  https://doi.org/10.1095/biolreprod66.3.707Kubo Naoko, Cayo-Colca Ilse Silvia, Miyano Takashi (2015): Effect of estradiol-17β during in vitro growth culture on the growth, maturation, cumulus expansion and development of porcine oocytes from early antral follicles. Animal Science Journal, 86, 251-259  https://doi.org/10.1111/asj.12283Machado Mariana Fernandes, Caixeta Ester Siqueira, Sudiman Jaqueline, Gilchrist Robert B., Thompson Jeremy G., Lima Paula Fernanda, Price Christopher A., Buratini José (2015): Fibroblast growth factor 17 and bone morphogenetic protein 15 enhance cumulus expansion and improve quality of in vitro–produced embryos in cattle. Theriogenology, 84, 390-398  https://doi.org/10.1016/j.theriogenology.2015.03.031McKenzie L.J. (2004): Human cumulus granulosa cell gene expression: a predictor of fertilization and embryo selection in women undergoing IVF. Human Reproduction, 19, 2869-2874  https://doi.org/10.1093/humrep/deh535Motlík Jan, Fulka Josef (1976): Breakdown of the germinal vesicle in pig oocytes in vivo and in vitro. Journal of Experimental Zoology, 198, 155-162  https://doi.org/10.1002/jez.1401980205Nakayama T (1996): Effect of oocytectomy on glycosaminoglycan composition during cumulus expansion of porcine cumulus-oocyte complexes cultured in vitro. Biology of Reproduction, 55, 1299-1304  https://doi.org/10.1095/biolreprod55.6.1299Nemcova L., Nagyova E., Petlach M., Tomanek M., Prochazka R. (): Molecular Mechanisms of Insulin-Like Growth Factor 1 Promoted Synthesis and Retention of Hyaluronic Acid in Porcine Oocyte-Cumulus Complexes. Biology of Reproduction, 76, 1016-1024  https://doi.org/10.1095/biolreprod.106.057927 Nevoral J., Orsak M., Klein P., Petr J., Dvorakova M., Weingartova I., Vyskocilova A., Zamostna K., Krejcova T., Jilek F. (2014): Cumulus cell expansion, its role in oocyte biology and perspectives of measurement: A review. Scientia Agriculturae Bohemica, 45, 212–225.Procházka Radek, Nagyov Eva, Brem Gottfried, Schellander Karl, Motlík Jan (1998): Secretion of cumulus expansion-enabling factor (CEEF) in porcine follicles. Molecular Reproduction and Development, 49, 141-149  https://doi.org/10.1002/(SICI)1098-2795(199802)49:2<141::AID-MRD5>3.0.CO;2-PProchazka R., Petlach M., Nagyova E., Nemcova L. (): Effect of epidermal growth factor-like peptides on pig cumulus cell expansion, oocyte maturation, and acquisition of developmental competence in vitro: comparison with gonadotropins. Reproduction, 141, 425-435  https://doi.org/10.1530/REP-10-0418QIAN Yun, SHI Wei Qun, DING Jia Tong, SHA Jia Hao, FAN Bi Qin (2003): Predictive Value of the Area of Expanded Cumulus Mass on Development of Porcine Oocytes Matured and Fertilized In Vitro. Journal of Reproduction and Development, 49, 167-174  https://doi.org/10.1262/jrd.49.167 Salustri A., Yanagishita M., Hascall V.C. (1989): Synthesis and accumulation of hyaluronic acid and proteoglycans in the mouse cumulus cell-oocyte complex during follicle-stimulating hormone-induced mucification. Journal of Biological Chemistry, 264, 13840–13847. Salustri A., Camaioni A., Tirone E., D’Alessandris C. (1995): Hyaluronic acid and proteoglycan accumulation in the cumulus oophorus matrix. Italian Journal of Anatomy and Embryology, 100, 479–484.Solursh Michael (1976): Glycosaminoglycan synthesis in the chick gastrula. Developmental Biology, 50, 525-530  https://doi.org/10.1016/0012-1606(76)90171-8Takagaki Keiichi, Takeda Yusuke, Nakamura Toshiya, Daidouji Kouichi, Narita Hozumi, Endo Masahiko (1994): Analysis of glycosaminoglycans by high-performance liquid chromatography. Journal of Biochemical and Biophysical Methods, 28, 313-320  https://doi.org/10.1016/0165-022X(94)90007-8Vanderhyden B. C. (1993): Species differences in the regulation of cumulus expansion by an oocyte-secreted factor(s). Reproduction, 98, 219-227  https://doi.org/10.1530/jrf.0.0980219Vanderhyden Barbara C., Caron Philip J., Buccione Roberto, Eppig John J. (1990): Developmental pattern of the secretion of cumulus expansion-enabling factor by mouse oocytes and the role of oocytes in promoting granulosa cell differentiation. Developmental Biology, 140, 307-317  https://doi.org/10.1016/0012-1606(90)90081-SVolpi Nicola (2000): Hyaluronic Acid and Chondroitin Sulfate Unsaturated Disaccharides Analysis by High-Performance Liquid Chromatography and Fluorimetric Detection with Dansylhydrazine. Analytical Biochemistry, 277, 19-24  https://doi.org/10.1006/abio.1999.4366Yokoo Masaki, Tienthai Paisan, Kimura Naoko, Niwa Koji, Sato Eimei, Rodriguez-Martinez Heriberto (2002): Localisation of the hyaluronan receptor CD44 in porcine cumulus cells during in vivo and in vitro maturation. Zygote, 10, -  https://doi.org/10.1017/S0967199402004057YOKOO Masaki, SHIMIZU Takashi, KIMURA Naoko, TUNJUNG Woro Anindito Sri, MATSUMOTO Hiromichi, ABE Hiroyuki, SASADA Hiroshi, RODRIGUEZ-MARTINEZ Heriberto, SATO Eimei (2007): Role of the Hyaluronan Receptor CD44 During Porcine Oocyte Maturation. Journal of Reproduction and Development, 53, 263-270  https://doi.org/10.1262/jrd.18047YOKOO Masaki, KIMURA Naoko, SATO Eimei (2010): Induction of Oocyte Maturation by Hyaluronan-CD44 Interaction in Pigs. Journal of Reproduction and Development, 56, 15-19  https://doi.org/10.1262/jrd.09-173EYosizawa Zensaku, Ototani Noboru, Satake Shigeo (1983): A simple method for the quantitation of glycuronic acid-containing glycosaminoglycans with mucopolysaccharidases. Analytical Biochemistry, 128, 250-256  https://doi.org/10.1016/0003-2697(83)90373-1Yuan Ye, Ida Jennifer M., Paczkowski Melissa, Krisher Rebecca L. (2011): Identification of developmental competence-related genes in mature porcine oocytes. Molecular Reproduction and Development, 78, 565-575  https://doi.org/10.1002/mrd.21351Zhang Meijia, Tao Yong, Xia Guoliang, Xie Huirong, Hong Haiyan, Wang Fengchao, Lei Lei (2005): Atrial natriuretic peptide negatively regulates follicle-stimulating hormone-induced porcine oocyte maturation and cumulus expansion via cGMP-dependent protein kinase pathway. Theriogenology, 64, 902-916  https://doi.org/10.1016/j.theriogenology.2004.12.012Abeydeera L.R, Wang W.H, Cantley T.C, Prather R.S, Day B.N (1998): Presence of β-mercaptoethanol can increase the glutathione content of pig oocytes matured in vitro and the rate of blastocyst development after in vitro fertilization. Theriogenology, 50, 747-756  https://doi.org/10.1016/S0093-691X(98)00180-0Alkrad Jamal Alyoussef, Mrestani Yahya, Stroehl Dieter, Wartewig Siegfried, Neubert Reinhard (2003): Characterization of enzymatically digested hyaluronic acid using NMR, Raman, IR, and UV–Vis spectroscopies. Journal of Pharmaceutical and Biomedical Analysis, 31, 545-550  https://doi.org/10.1016/S0731-7085(02)00682-9Appeltant R., Somfai T., Nakai M., Bodó S., Maes D., Kikuchi K., Van Soom A. (2015): Interactions between oocytes and cumulus cells during in vitro maturation of porcine cumulus-oocyte complexes in a chemically defined medium: Effect of denuded oocytes on cumulus expansion and oocyte maturation. Theriogenology, 83, 567-576  https://doi.org/10.1016/j.theriogenology.2014.10.026Assidi M., Dieleman S. J., Sirard M.-A. (): Cumulus cell gene expression following the LH surge in bovine preovulatory follicles: potential early markers of oocyte competence. Reproduction, 140, 835-852  https://doi.org/10.1530/REP-10-0248Assou S., Haouzi D., De Vos J., Hamamah S. (): Human cumulus cells as biomarkers for embryo and pregnancy outcomes. Molecular Human Reproduction, 16, 531-538  https://doi.org/10.1093/molehr/gaq032Bergandi L., Basso G., Evangelista F., Canosa S., Dalmasso P., Aldieri E., Revelli A., Benedetto C., Ghigo D. (): Inducible Nitric Oxide Synthase and Heme Oxygenase 1 Are Expressed in Human Cumulus Cells and May Be Used as Biomarkers of Oocyte Competence. Reproductive Sciences, , -  https://doi.org/10.1177/1933719114525268Chen Lin, Wert Susan E., Hendrix E. Michael, Russell Paul T., Cannon Michelle, Larsen William J. (1990): Hyaluronic acid synthesis and gap junction endocytosis are necessary for normal expansion of the cumulus mass. Molecular Reproduction and Development, 26, 236-247  https://doi.org/10.1002/mrd.1080260307Daen F. P., Sato E., Naito K., Toyoda Y. (1994): The effect of pig follicular fluid fractions on cumulus expansion and male pronucleus formation in porcine oocytes matured and fertilized in vitro. Reproduction, 101, 667-673  https://doi.org/10.1530/jrf.0.1010667Dadashpour Davachi N., Kohram H., Zainoaldini S. (2012): Cumulus cell layers as a critical factor in meiotic competence and cumulus expansion of ovine oocytes. Small Ruminant Research, 102, 37-42  https://doi.org/10.1016/j.smallrumres.2011.09.007DEKEL N. (1979): Maturational Effects of Gonadotropins on the Cumulus-Oocyte Complex of the Rat. Biology of Reproduction, 20, 191-197  https://doi.org/10.1095/biolreprod20.2.191Dekel Nava, Lawrence Theodore S., Gilula Norton B., Beers William H. (1981): Modulation of cell-to-cell communication in the cumulus-oocyte complex and the regulation of oocyte maturation by LH. Developmental Biology, 86, 356-362  https://doi.org/10.1016/0012-1606(81)90193-7Dragovic Rebecca A., Ritter Lesley J., Schulz Samantha J., Amato Fred, Armstrong David T., Gilchrist Robert B. (2005): Role of Oocyte-Secreted Growth Differentiation Factor 9 in the Regulation of Mouse Cumulus Expansion. Endocrinology, 146, 2798-2806  https://doi.org/10.1210/en.2005-0098Eppig John J. (1979): FSH stimulates hyaluronic acid synthesis by oocyte–cumulus cellcomplexes from mouse preovulatory follicles. Nature, 281, 483-484  https://doi.org/10.1038/281483a0Eppig John J. (1980): Role of Serum in FSH Stimulated Cumulus Expansion by Mouse Oocyte-Cumulus Cell Complexes in vitro. Biology of Reproduction, 22, 629-633  https://doi.org/10.1093/biolreprod/22.3.629Fagbohun C. F. (1990): Maturation of the mouse oocyte-cumulus cell complex: stimulation by lectins. Biology of Reproduction, 42, 413-423  https://doi.org/10.1095/biolreprod42.3.413Feuerstein Prisca, Puard Vincent, Chevalier Catherine, Teusan Raluca, Cadoret Veronique, Guerif Fabrice, Houlgatte Remi, Royere Dominique, Panepucci Rodrigo Alexandre (2012): Genomic Assessment of Human Cumulus Cell Marker Genes as Predictors of Oocyte Developmental Competence: Impact of Various Experimental Factors. PLoS ONE, 7, e40449-  https://doi.org/10.1371/journal.pone.0040449 Flechon J.E., Degrouard J., Kopecny V., Pivko J., Pavlok A., Motlik J. (2003): The extracellular matrix of porcine mature oocytes: origin, composition and presumptive roles. Reproductive Biology and Endocrinology, 1, 124. https://doi.org/10.1186/1477-7827-1-124Huang Z., Wells D. (): The human oocyte and cumulus cells relationship: new insights from the cumulus cell transcriptome. Molecular Human Reproduction, 16, 715-725  https://doi.org/10.1093/molehr/gaq031Kimura N. (2002): Expression of Hyaluronan Synthases and CD44 Messenger RNAs in Porcine Cumulus-Oocyte Complexes During In Vitro Maturation. Biology of Reproduction, 66, 707-717  https://doi.org/10.1095/biolreprod66.3.707Kubo Naoko, Cayo-Colca Ilse Silvia, Miyano Takashi (2015): Effect of estradiol-17β during in vitro growth culture on the growth, maturation, cumulus expansion and development of porcine oocytes from early antral follicles. Animal Science Journal, 86, 251-259  https://doi.org/10.1111/asj.12283Machado Mariana Fernandes, Caixeta Ester Siqueira, Sudiman Jaqueline, Gilchrist Robert B., Thompson Jeremy G., Lima Paula Fernanda, Price Christopher A., Buratini José (2015): Fibroblast growth factor 17 and bone morphogenetic protein 15 enhance cumulus expansion and improve quality of in vitro–produced embryos in cattle. Theriogenology, 84, 390-398  https://doi.org/10.1016/j.theriogenology.2015.03.031McKenzie L.J. (2004): Human cumulus granulosa cell gene expression: a predictor of fertilization and embryo selection in women undergoing IVF. Human Reproduction, 19, 2869-2874  https://doi.org/10.1093/humrep/deh535Motlík Jan, Fulka Josef (1976): Breakdown of the germinal vesicle in pig oocytes in vivo and in vitro. Journal of Experimental Zoology, 198, 155-162  https://doi.org/10.1002/jez.1401980205Nakayama T (1996): Effect of oocytectomy on glycosaminoglycan composition during cumulus expansion of porcine cumulus-oocyte complexes cultured in vitro. Biology of Reproduction, 55, 1299-1304  https://doi.org/10.1095/biolreprod55.6.1299Nemcova L., Nagyova E., Petlach M., Tomanek M., Prochazka R. (): Molecular Mechanisms of Insulin-Like Growth Factor 1 Promoted Synthesis and Retention of Hyaluronic Acid in Porcine Oocyte-Cumulus Complexes. Biology of Reproduction, 76, 1016-1024  https://doi.org/10.1095/biolreprod.106.057927 Nevoral J., Orsak M., Klein P., Petr J., Dvorakova M., Weingartova I., Vyskocilova A., Zamostna K., Krejcova T., Jilek F. (2014): Cumulus cell expansion, its role in oocyte biology and perspectives of measurement: A review. Scientia Agriculturae Bohemica, 45, 212–225.Procházka Radek, Nagyov Eva, Brem Gottfried, Schellander Karl, Motlík Jan (1998): Secretion of cumulus expansion-enabling factor (CEEF) in porcine follicles. Molecular Reproduction and Development, 49, 141-149  https://doi.org/10.1002/(SICI)1098-2795(199802)49:2<141::AID-MRD5>3.0.CO;2-PProchazka R., Petlach M., Nagyova E., Nemcova L. (): Effect of epidermal growth factor-like peptides on pig cumulus cell expansion, oocyte maturation, and acquisition of developmental competence in vitro: comparison with gonadotropins. Reproduction, 141, 425-435  https://doi.org/10.1530/REP-10-0418QIAN Yun, SHI Wei Qun, DING Jia Tong, SHA Jia Hao, FAN Bi Qin (2003): Predictive Value of the Area of Expanded Cumulus Mass on Development of Porcine Oocytes Matured and Fertilized In Vitro. Journal of Reproduction and Development, 49, 167-174  https://doi.org/10.1262/jrd.49.167 Salustri A., Yanagishita M., Hascall V.C. (1989): Synthesis and accumulation of hyaluronic acid and proteoglycans in the mouse cumulus cell-oocyte complex during follicle-stimulating hormone-induced mucification. Journal of Biological Chemistry, 264, 13840–13847. Salustri A., Camaioni A., Tirone E., D’Alessandris C. (1995): Hyaluronic acid and proteoglycan accumulation in the cumulus oophorus matrix. Italian Journal of Anatomy and Embryology, 100, 479–484.Solursh Michael (1976): Glycosaminoglycan synthesis in the chick gastrula. Developmental Biology, 50, 525-530  https://doi.org/10.1016/0012-1606(76)90171-8Takagaki Keiichi, Takeda Yusuke, Nakamura Toshiya, Daidouji Kouichi, Narita Hozumi, Endo Masahiko (1994): Analysis of glycosaminoglycans by high-performance liquid chromatography. Journal of Biochemical and Biophysical Methods, 28, 313-320  https://doi.org/10.1016/0165-022X(94)90007-8Vanderhyden B. C. (1993): Species differences in the regulation of cumulus expansion by an oocyte-secreted factor(s). Reproduction, 98, 219-227  https://doi.org/10.1530/jrf.0.0980219Vanderhyden Barbara C., Caron Philip J., Buccione Roberto, Eppig John J. (1990): Developmental pattern of the secretion of cumulus expansion-enabling factor by mouse oocytes and the role of oocytes in promoting granulosa cell differentiation. Developmental Biology, 140, 307-317  https://doi.org/10.1016/0012-1606(90)90081-SVolpi Nicola (2000): Hyaluronic Acid and Chondroitin Sulfate Unsaturated Disaccharides Analysis by High-Performance Liquid Chromatography and Fluorimetric Detection with Dansylhydrazine. Analytical Biochemistry, 277, 19-24  https://doi.org/10.1006/abio.1999.4366Yokoo Masaki, Tienthai Paisan, Kimura Naoko, Niwa Koji, Sato Eimei, Rodriguez-Martinez Heriberto (2002): Localisation of the hyaluronan receptor CD44 in porcine cumulus cells during in vivo and in vitro maturation. Zygote, 10, -  https://doi.org/10.1017/S0967199402004057YOKOO Masaki, SHIMIZU Takashi, KIMURA Naoko, TUNJUNG Woro Anindito Sri, MATSUMOTO Hiromichi, ABE Hiroyuki, SASADA Hiroshi, RODRIGUEZ-MARTINEZ Heriberto, SATO Eimei (2007): Role of the Hyaluronan Receptor CD44 During Porcine Oocyte Maturation. Journal of Reproduction and Development, 53, 263-270  https://doi.org/10.1262/jrd.18047YOKOO Masaki, KIMURA Naoko, SATO Eimei (2010): Induction of Oocyte Maturation by Hyaluronan-CD44 Interaction in Pigs. Journal of Reproduction and Development, 56, 15-19  https://doi.org/10.1262/jrd.09-173EYosizawa Zensaku, Ototani Noboru, Satake Shigeo (1983): A simple method for the quantitation of glycuronic acid-containing glycosaminoglycans with mucopolysaccharidases. Analytical Biochemistry, 128, 250-256  https://doi.org/10.1016/0003-2697(83)90373-1Yuan Ye, Ida Jennifer M., Paczkowski Melissa, Krisher Rebecca L. (2011): Identification of developmental competence-related genes in mature porcine oocytes. Molecular Reproduction and Development, 78, 565-575  https://doi.org/10.1002/mrd.21351Zhang Meijia, Tao Yong, Xia Guoliang, Xie Huirong, Hong Haiyan, Wang Fengchao, Lei Lei (2005): Atrial natriuretic peptide negatively regulates follicle-stimulating hormone-induced porcine oocyte maturation and cumulus expansion via cGMP-dependent protein kinase pathway. Theriogenology, 64, 902-916  https://doi.org/10.1016/j.theriogenology.2004.12.012Abeydeera L.R, Wang W.H, Cantley T.C, Prather R.S, Day B.N (1998): Presence of β-mercaptoethanol can increase the glutathione content of pig oocytes matured in vitro and the rate of blastocyst development after in vitro fertilization. Theriogenology, 50, 747-756  https://doi.org/10.1016/S0093-691X(98)00180-0Alkrad Jamal Alyoussef, Mrestani Yahya, Stroehl Dieter, Wartewig Siegfried, Neubert Reinhard (2003): Characterization of enzymatically digested hyaluronic acid using NMR, Raman, IR, and UV–Vis spectroscopies. Journal of Pharmaceutical and Biomedical Analysis, 31, 545-550  https://doi.org/10.1016/S0731-7085(02)00682-9Appeltant R., Somfai T., Nakai M., Bodó S., Maes D., Kikuchi K., Van Soom A. (2015): Interactions between oocytes and cumulus cells during in vitro maturation of porcine cumulus-oocyte complexes in a chemically defined medium: Effect of denuded oocytes on cumulus expansion and oocyte maturation. Theriogenology, 83, 567-576  https://doi.org/10.1016/j.theriogenology.2014.10.026Assidi M., Dieleman S. J., Sirard M.-A. (): Cumulus cell gene expression following the LH surge in bovine preovulatory follicles: potential early markers of oocyte competence. Reproduction, 140, 835-852  https://doi.org/10.1530/REP-10-0248Assou S., Haouzi D., De Vos J., Hamamah S. (): Human cumulus cells as biomarkers for embryo and pregnancy outcomes. Molecular Human Reproduction, 16, 531-538  https://doi.org/10.1093/molehr/gaq032Bergandi L., Basso G., Evangelista F., Canosa S., Dalmasso P., Aldieri E., Revelli A., Benedetto C., Ghigo D. (): Inducible Nitric Oxide Synthase and Heme Oxygenase 1 Are Expressed in Human Cumulus Cells and May Be Used as Biomarkers of Oocyte Competence. Reproductive Sciences, , -  https://doi.org/10.1177/1933719114525268Chen Lin, Wert Susan E., Hendrix E. Michael, Russell Paul T., Cannon Michelle, Larsen William J. (1990): Hyaluronic acid synthesis and gap junction endocytosis are necessary for normal expansion of the cumulus mass. Molecular Reproduction and Development, 26, 236-247  https://doi.org/10.1002/mrd.1080260307Daen F. P., Sato E., Naito K., Toyoda Y. (1994): The effect of pig follicular fluid fractions on cumulus expansion and male pronucleus formation in porcine oocytes matured and fertilized in vitro. Reproduction, 101, 667-673  https://doi.org/10.1530/jrf.0.1010667Dadashpour Davachi N., Kohram H., Zainoaldini S. (2012): Cumulus cell layers as a critical factor in meiotic competence and cumulus expansion of ovine oocytes. Small Ruminant Research, 102, 37-42  https://doi.org/10.1016/j.smallrumres.2011.09.007DEKEL N. (1979): Maturational Effects of Gonadotropins on the Cumulus-Oocyte Complex of the Rat. Biology of Reproduction, 20, 191-197  https://doi.org/10.1095/biolreprod20.2.191Dekel Nava, Lawrence Theodore S., Gilula Norton B., Beers William H. (1981): Modulation of cell-to-cell communication in the cumulus-oocyte complex and the regulation of oocyte maturation by LH. Developmental Biology, 86, 356-362  https://doi.org/10.1016/0012-1606(81)90193-7Dragovic Rebecca A., Ritter Lesley J., Schulz Samantha J., Amato Fred, Armstrong David T., Gilchrist Robert B. (2005): Role of Oocyte-Secreted Growth Differentiation Factor 9 in the Regulation of Mouse Cumulus Expansion. Endocrinology, 146, 2798-2806  https://doi.org/10.1210/en.2005-0098Eppig John J. (1979): FSH stimulates hyaluronic acid synthesis by oocyte–cumulus cellcomplexes from mouse preovulatory follicles. Nature, 281, 483-484  https://doi.org/10.1038/281483a0Eppig John J. (1980): Role of Serum in FSH Stimulated Cumulus Expansion by Mouse Oocyte-Cumulus Cell Complexes in vitro. Biology of Reproduction, 22, 629-633  https://doi.org/10.1093/biolreprod/22.3.629Fagbohun C. F. (1990): Maturation of the mouse oocyte-cumulus cell complex: stimulation by lectins. Biology of Reproduction, 42, 413-423  https://doi.org/10.1095/biolreprod42.3.413Feuerstein Prisca, Puard Vincent, Chevalier Catherine, Teusan Raluca, Cadoret Veronique, Guerif Fabrice, Houlgatte Remi, Royere Dominique, Panepucci Rodrigo Alexandre (2012): Genomic Assessment of Human Cumulus Cell Marker Genes as Predictors of Oocyte Developmental Competence: Impact of Various Experimental Factors. PLoS ONE, 7, e40449-  https://doi.org/10.1371/journal.pone.0040449 Flechon J.E., Degrouard J., Kopecny V., Pivko J., Pavlok A., Motlik J. (2003): The extracellular matrix of porcine mature oocytes: origin, composition and presumptive roles. Reproductive Biology and Endocrinology, 1, 124. https://doi.org/10.1186/1477-7827-1-124Huang Z., Wells D. (): The human oocyte and cumulus cells relationship: new insights from the cumulus cell transcriptome. Molecular Human Reproduction, 16, 715-725  https://doi.org/10.1093/molehr/gaq031Kimura N. (2002): Expression of Hyaluronan Synthases and CD44 Messenger RNAs in Porcine Cumulus-Oocyte Complexes During In Vitro Maturation. Biology of Reproduction, 66, 707-717  https://doi.org/10.1095/biolreprod66.3.707Kubo Naoko, Cayo-Colca Ilse Silvia, Miyano Takashi (2015): Effect of estradiol-17β during in vitro growth culture on the growth, maturation, cumulus expansion and development of porcine oocytes from early antral follicles. Animal Science Journal, 86, 251-259  https://doi.org/10.1111/asj.12283Machado Mariana Fernandes, Caixeta Ester Siqueira, Sudiman Jaqueline, Gilchrist Robert B., Thompson Jeremy G., Lima Paula Fernanda, Price Christopher A., Buratini José (2015): Fibroblast growth factor 17 and bone morphogenetic protein 15 enhance cumulus expansion and improve quality of in vitro–produced embryos in cattle. Theriogenology, 84, 390-398  https://doi.org/10.1016/j.theriogenology.2015.03.031McKenzie L.J. (2004): Human cumulus granulosa cell gene expression: a predictor of fertilization and embryo selection in women undergoing IVF. Human Reproduction, 19, 2869-2874  https://doi.org/10.1093/humrep/deh535Motlík Jan, Fulka Josef (1976): Breakdown of the germinal vesicle in pig oocytes in vivo and in vitro. Journal of Experimental Zoology, 198, 155-162  https://doi.org/10.1002/jez.1401980205Nakayama T (1996): Effect of oocytectomy on glycosaminoglycan composition during cumulus expansion of porcine cumulus-oocyte complexes cultured in vitro. Biology of Reproduction, 55, 1299-1304  https://doi.org/10.1095/biolreprod55.6.1299Nemcova L., Nagyova E., Petlach M., Tomanek M., Prochazka R. (): Molecular Mechanisms of Insulin-Like Growth Factor 1 Promoted Synthesis and Retention of Hyaluronic Acid in Porcine Oocyte-Cumulus Complexes. Biology of Reproduction, 76, 1016-1024  https://doi.org/10.1095/biolreprod.106.057927 Nevoral J., Orsak M., Klein P., Petr J., Dvorakova M., Weingartova I., Vyskocilova A., Zamostna K., Krejcova T., Jilek F. (2014): Cumulus cell expansion, its role in oocyte biology and perspectives of measurement: A review. Scientia Agriculturae Bohemica, 45, 212–225.Procházka Radek, Nagyov Eva, Brem Gottfried, Schellander Karl, Motlík Jan (1998): Secretion of cumulus expansion-enabling factor (CEEF) in porcine follicles. Molecular Reproduction and Development, 49, 141-149  https://doi.org/10.1002/(SICI)1098-2795(199802)49:2<141::AID-MRD5>3.0.CO;2-PProchazka R., Petlach M., Nagyova E., Nemcova L. (): Effect of epidermal growth factor-like peptides on pig cumulus cell expansion, oocyte maturation, and acquisition of developmental competence in vitro: comparison with gonadotropins. Reproduction, 141, 425-435  https://doi.org/10.1530/REP-10-0418QIAN Yun, SHI Wei Qun, DING Jia Tong, SHA Jia Hao, FAN Bi Qin (2003): Predictive Value of the Area of Expanded Cumulus Mass on Development of Porcine Oocytes Matured and Fertilized In Vitro. Journal of Reproduction and Development, 49, 167-174  https://doi.org/10.1262/jrd.49.167 Salustri A., Yanagishita M., Hascall V.C. (1989): Synthesis and accumulation of hyaluronic acid and proteoglycans in the mouse cumulus cell-oocyte complex during follicle-stimulating hormone-induced mucification. Journal of Biological Chemistry, 264, 13840–13847. Salustri A., Camaioni A., Tirone E., D’Alessandris C. (1995): Hyaluronic acid and proteoglycan accumulation in the cumulus oophorus matrix. Italian Journal of Anatomy and Embryology, 100, 479–484.Solursh Michael (1976): Glycosaminoglycan synthesis in the chick gastrula. Developmental Biology, 50, 525-530  https://doi.org/10.1016/0012-1606(76)90171-8Takagaki Keiichi, Takeda Yusuke, Nakamura Toshiya, Daidouji Kouichi, Narita Hozumi, Endo Masahiko (1994): Analysis of glycosaminoglycans by high-performance liquid chromatography. Journal of Biochemical and Biophysical Methods, 28, 313-320  https://doi.org/10.1016/0165-022X(94)90007-8Vanderhyden B. C. (1993): Species differences in the regulation of cumulus expansion by an oocyte-secreted factor(s). Reproduction, 98, 219-227  https://doi.org/10.1530/jrf.0.0980219Vanderhyden Barbara C., Caron Philip J., Buccione Roberto, Eppig John J. (1990): Developmental pattern of the secretion of cumulus expansion-enabling factor by mouse oocytes and the role of oocytes in promoting granulosa cell differentiation. Developmental Biology, 140, 307-317  https://doi.org/10.1016/0012-1606(90)90081-SVolpi Nicola (2000): Hyaluronic Acid and Chondroitin Sulfate Unsaturated Disaccharides Analysis by High-Performance Liquid Chromatography and Fluorimetric Detection with Dansylhydrazine. Analytical Biochemistry, 277, 19-24  https://doi.org/10.1006/abio.1999.4366Yokoo Masaki, Tienthai Paisan, Kimura Naoko, Niwa Koji, Sato Eimei, Rodriguez-Martinez Heriberto (2002): Localisation of the hyaluronan receptor CD44 in porcine cumulus cells during in vivo and in vitro maturation. Zygote, 10, -  https://doi.org/10.1017/S0967199402004057YOKOO Masaki, SHIMIZU Takashi, KIMURA Naoko, TUNJUNG Woro Anindito Sri, MATSUMOTO Hiromichi, ABE Hiroyuki, SASADA Hiroshi, RODRIGUEZ-MARTINEZ Heriberto, SATO Eimei (2007): Role of the Hyaluronan Receptor CD44 During Porcine Oocyte Maturation. Journal of Reproduction and Development, 53, 263-270  https://doi.org/10.1262/jrd.18047YOKOO Masaki, KIMURA Naoko, SATO Eimei (2010): Induction of Oocyte Maturation by Hyaluronan-CD44 Interaction in Pigs. Journal of Reproduction and Development, 56, 15-19  https://doi.org/10.1262/jrd.09-173EYosizawa Zensaku, Ototani Noboru, Satake Shigeo (1983): A simple method for the quantitation of glycuronic acid-containing glycosaminoglycans with mucopolysaccharidases. Analytical Biochemistry, 128, 250-256  https://doi.org/10.1016/0003-2697(83)90373-1Yuan Ye, Ida Jennifer M., Paczkowski Melissa, Krisher Rebecca L. (2011): Identification of developmental competence-related genes in mature porcine oocytes. Molecular Reproduction and Development, 78, 565-575  https://doi.org/10.1002/mrd.21351Zhang Meijia, Tao Yong, Xia Guoliang, Xie Huirong, Hong Haiyan, Wang Fengchao, Lei Lei (2005): Atrial natriuretic peptide negatively regulates follicle-stimulating hormone-induced porcine oocyte maturation and cumulus expansion via cGMP-dependent protein kinase pathway. Theriogenology, 64, 902-916  https://doi.org/10.1016/j.theriogenology.2004.12.012