HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by He, C. L. Articles by Fissore, R. A. Search for Related Content PubMed PubMed Citation Articles by He, C. L. Articles by Fissore, R. A. Agricola Articles by He, C. L. Articles by Fissore, R. A.

Isoforms of the Inositol 1,4,5-Trisphosphate Receptor Are Expressed in Bovine Oocytes and Ovaries: The Type-1 Isoform Is Down-Regulated by Fertilizationand by Injection of Adenophostin A¹

^a Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts 01003 ^b American Breeders Services, De Forest, Wisconsin 53532 ^c Department of Obstetrics/Gynecology and Anatomy/Cell Biology, Tufts University School of Medicine and New England Medical Center Hospital, Boston, Massachusetts 02111 ^d Biological Research Laboratories, Sankyo Co., Ltd., Tokyo, Japan ^e Laboratorium voor Fysiologie, Campus Gasthuisberg O/N, K.U. Leuven, Belgium

Mammalian fertilization is characterized by the presence of long-lasting intracellular calcium ([;t1Ca²⁺]_i) oscillations that are required to induce oocyte activation. One of the Ca²⁺ channels that may mediate this Ca²⁺ release is the inositol 1,4,5-trisphosphate receptor (IP₃R). Three isoforms of the receptor have been described, but their expression in oocytes and possible roles in mammalian fertilization are not well known. Using isoform-specific antibodies against IP₃R types 1, 2, and 3 and Western analysis, we determined the isoforms that are expressed in bovine metaphase II oocytes and ovaries. In oocytes, all isoforms are expressed, but type 1 is present in overwhelmingly larger amounts and is likely responsible for the majority of Ca²⁺ release at fertilization. In ovarian microsomes, all three isoforms appear well expressed, suggesting the participation of all IP₃R isoforms in ovarian Ca²⁺ signaling. We then investigated whether the reported cessation/reduction in amplitude of fertilization-associated [;t1Ca²⁺]_i oscillations, which is observed as pronuclear formation approaches, corresponded with down-regulation of the IP₃R-1 isoform. Fertilization resulted in approximately 40% reduction in the amount of receptor by 16 h postinsemination. In addition, injection of adenophostin A, a potent IP₃R agonist that elicits high-frequency [;t1Ca²⁺]_i oscillations in mammalian oocytes, induced similar reduction in receptor numbers. Together, these data show that 1) the three IP₃R isoforms are expressed in bovine oocytes; 2) IP₃R-1 is likely to mediate most of the Ca²⁺ release during fertilization; 3) its down-regulation may explain the decline in amplitude of sperm-induced [;t1Ca²⁺]_i rises as fertilization progresses toward pronuclear formation; and 4) agonists of the IP₃R induce down-regulation of the type-1 receptor in oocytes similar to that evoked by fertilization.

¹ These experiments were funded in part by a USDA NRI competitive grant 97-2919 to R.A.F. by Massachusetts Agricultural Experiment Station, under Project No. 734, and NIH (HD24191) to T.D. J.B.P. is Research Associate from the Fund for Scientific Research-Flanders and was supported by grant GOA99/08 of the Concerted Actions, Belgium.

² Correspondence: R.A. Fissore, Department of Veterinary and Animal Sciences University of Massachusetts, Amherst, MA 01003. FAX: 413 545 6326; rfissore{at}vasci.umass.edu

This article has been cited by other articles:

				J. K. Foskett, C. White, K.-H. Cheung, and D.-O. D. Mak Inositol Trisphosphate Receptor Ca2+ Release Channels Physiol Rev, April 1, 2007; 87(2): 593 - 658. [Abstract] [Full Text] [PDF]

				B. Lee, E. Vermassen, S.-Y. Yoon, V. Vanderheyden, J. Ito, D. Alfandari, H. De Smedt, J. B. Parys, and R. A. Fissore Phosphorylation of IP3R1 and the regulation of [Ca2+]i responses at fertilization: a role for the MAP kinase pathway Development, November 1, 2006; 133(21): 4355 - 4365. [Abstract] [Full Text] [PDF]

				G. FitzHarris, M. Larman, C. Richards, and J. Carroll An increase in [Ca2+]i is sufficient but not necessary for driving mitosis in early mouse embryos J. Cell Sci., October 1, 2005; 118(19): 4563 - 4575. [Abstract] [Full Text] [PDF]

				C. Malcuit, J. G. Knott, C. He, T. Wainwright, J. B. Parys, J. M. Robl, and R. A. Fissore Fertilization and Inositol 1,4,5-Trisphosphate (IP3)-Induced Calcium Release in Type-1 Inositol 1,4,5-Trisphosphate Receptor Down-Regulated Bovine Eggs Biol Reprod, July 1, 2005; 73(1): 2 - 13. [Abstract] [Full Text] [PDF]

				L. M. Solis-Garrido, A. J. Pintado, E. Andres-Mateos, M. Figueroa, C. Matute, and C. Montiel Cross-talk between Native Plasmalemmal Na+/Ca2+ Exchanger and Inositol 1,4,5-Trisphosphate-sensitive Ca2+ Internal Store in Xenopus Oocytes J. Biol. Chem., December 10, 2004; 279(50): 52414 - 52424. [Abstract] [Full Text] [PDF]

				M. Kurokawa and R. A. Fissore ICSI-generated mouse zygotes exhibit altered calcium oscillations, inositol 1,4,5-trisphosphate receptor-1 down-regulation, and embryo development Mol. Hum. Reprod., September 1, 2003; 9(9): 523 - 533. [Abstract] [Full Text] [PDF]

				S. A. Stricker and T. L. Smythe Endoplasmic reticulum reorganizations and Ca2+ signaling in maturing and fertilized oocytes of marine protostome worms: the roles of MAPKs and MPF Development, July 1, 2003; 130(13): 2867 - 2879. [Abstract] [Full Text] [PDF]

				A. C. Gordo, M. Kurokawa, H. Wu, and R. A. Fissore Modifications of the Ca2+ release mechanisms of mouse oocytes by fertilization and by sperm factor Mol. Hum. Reprod., July 1, 2002; 8(7): 619 - 629. [Abstract] [Full Text] [PDF]

				J. G. Knott, K. Poothapillai, H. Wu, C. L. He, R. A. Fissore, and J. M. Robl Porcine Sperm Factor Supports Activation and Development of Bovine Nuclear Transfer Embryos Biol Reprod, April 1, 2002; 66(4): 1095 - 1103. [Abstract] [Full Text] [PDF]

				H. Wu, J. Smyth, V. Luzzi, K. Fukami, T. Takenawa, S. L. Black, N. L. Allbritton, and R. A. Fissore Sperm Factor Induces Intracellular Free Calcium Oscillations by Stimulating the Phosphoinositide Pathway Biol Reprod, May 1, 2001; 64(5): 1338 - 1349. [Abstract] [Full Text]