1. Sperm-induced calcium oscillations at fertilisation in ascidians are controlled by cyclin B1-dependent kinase activity
- Author
-
Mark Levasseur, Alex McDougall, Laboratoire de Biologie du Développement de Villefranche sur mer (LBDV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Male ,MESH: Sperm-Ovum Interactions ,MESH: Microinjections ,MESH: Animals ,Enzyme Inhibitors ,MESH: Oscillometry ,Cyclin B1 ,0303 health sciences ,MESH: Urochordata ,MESH: Kinetics ,Kinase ,MESH: Spermatozoa ,030302 biochemistry & molecular biology ,MESH: Purines ,Cell cycle ,Spermatozoa ,Cyclin-Dependent Kinases ,MESH: Nitriles ,Cell biology ,MESH: Cyclin-Dependent Kinases ,MESH: Enzyme Inhibitors ,MESH: Protein Biosynthesis ,MESH: Calcium ,Female ,MESH: Roscovitine ,medicine.medical_specialty ,Microinjections ,MESH: Cyclin B1 ,Recombinant Fusion Proteins ,chemistry.chemical_element ,[SDV.BC]Life Sciences [q-bio]/Cellular Biology ,Cyclin B ,Calcium ,Biology ,Fertilisation ,MESH: Oocytes ,Cyclin B1-CDK ,MESH: Butadienes ,03 medical and health sciences ,Cyclin-dependent kinase ,Oscillometry ,Internal medicine ,Nitriles ,Butadienes ,Roscovitine ,MESH: Recombinant Fusion Proteins ,medicine ,Animals ,RNA, Messenger ,Urochordata ,Kinase activity ,MESH: Protein Kinases ,Molecular Biology ,Metaphase ,MESH: RNA, Messenger ,030304 developmental biology ,Sperm-Ovum Interactions ,MESH: Cyclin B ,M-Phase Promoting Factor ,MESH: Male ,Kinetics ,Oscillation ,Endocrinology ,chemistry ,Purines ,Protein Biosynthesis ,Oocytes ,biology.protein ,MAP kinase ,Protein Kinases ,MESH: Female ,Developmental Biology - Abstract
The generation of calcium oscillations at fertilisation and during mitosis appears to be controlled by the cell cycle machinery. For example, the calcium oscillations in oocytes and embryos occur during metaphase and terminate upon entry into interphase. Here we report the manipulation of sperm-triggered calcium oscillations by cyclin-dependent kinase (CDK) activity, the major component of maturation/ M phase promoting factor (MPF). To control the CDK activity we microinjected mRNAs encoding full-length GFP-tagged cyclin B1 or a truncated and therefore stabilised form of cyclin B1 (Δ90) into unfertilised oocytes. In the presence of full-length cyclin B1, the calcium oscillations terminate when cyclin B1 levels fall along with the concomitant fall in the associated CDK activity. In addition, when the CDK activity is elevated indefinitely with Δ90 cyclin B1, the calcium oscillations also continue indefinitely. Finally, in oocytes that contain low mitogen- activated protein (MAP) kinase activity and elevated CDK activity, the sperm-triggered calcium oscillations are again prolonged. We conclude that the CDK activity of the ascidian oocyte can be regarded as a positive regulator of sperm-triggered calcium oscillations, a finding that may apply to other oocytes that display sperm-triggered calcium oscillations at fertilisation. Furthermore, these findings may have a bearing upon the mitotic calcium signals of early embryos.
- Published
- 2000
- Full Text
- View/download PDF