Ruizhi Feng1, Zheng Yan2, Bin Li2, Min Yu3, Qing Sang1, Guoling Tian4, Yao Xu1, Biaobang Chen1, Ronggui Qu1, Zhaogui Sun5, Xiaoxi Sun3, Li Jin6, Lin He7, Yanping Kuang8, Nicholas J Cowan4, Lei Wang1. 1. State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, The People's Republic of China Institutes of Biomedical Sciences, Fudan University, Shanghai, The People's Republic of China. 2. Reproductive Medicine Center, Shanghai Ninth hospital, Shanghai Jiao Tong University, Shanghai, The People's Republic of China. 3. Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, The People's Republic of China. 4. Department of Biochemistry and Molecular Pharmacology, New York Langone University Medical Center, New York, USA. 5. Shanghai Institute of Planned Parenthood Research, Shanghai, The People's Republic of China. 6. State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, The People's Republic of China. 7. Institutes of Biomedical Sciences, Fudan University, Shanghai, The People's Republic of China Bio-X Center, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, The People's Republic of China. 8. Reproductive Medicine Center, Shanghai Ninth hospital, Shanghai Jiao Tong University, Shanghai, The People's Republic of China Shanghai Key Laboratory of Reproductive Medicine, Shanghai, The People's Republic of China.
Abstract
BACKGROUND: TUBB8 is a primate-specific β-tubulin isotype whose expression is confined to oocytes and the early embryo. We previously found that mutations in TUBB8 caused oocyte maturation arrest. The objective was to describe newly discovered mutations in TUBB8 and to characterise the accompanying spectrum of phenotypes and modes of inheritance. METHODS AND RESULTS: Patients with oocyte maturation arrest were sequenced with respect to TUBB8. We investigated the effects of identified mutations in vitro, in cultured cells and in mouse oocytes. Seven heterozygous missense and two homozygous mutations were identified. These mutations cause a range of folding defects in vitro, different degrees of microtubule disruption upon expression in cultured cells and interfere to varying extents in the proper assembly of the meiotic spindle in mouse oocytes. Several of the newly discovered TUBB8 mutations result in phenotypic variability. For example, oocytes harbouring any of three missense mutations (I210V, T238M and N348S) could extrude the first polar body. Moreover, they could be fertilised, although the ensuing embryos became developmentally arrested. Surprisingly, oocytes from patients harbouring homozygous TUBB8 mutations that in either case preclude the expression of a functional TUBB8 polypeptide nonetheless contained identifiable spindles. CONCLUSIONS: Our data substantially expand the range of dysfunctional oocyte phenotypes incurred by mutation in TUBB8, underscore the independent nature of human oocyte meiosis and differentiation, extend the class of genetic diseases known as the tubulinopathies and provide new criteria for the qualitative evaluation of meiosis II (MII) oocytes for in vitro fertilization (IVF). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
BACKGROUND:TUBB8 is a primate-specific β-tubulin isotype whose expression is confined to oocytes and the early embryo. We previously found that mutations in TUBB8 caused oocyte maturation arrest. The objective was to describe newly discovered mutations in TUBB8 and to characterise the accompanying spectrum of phenotypes and modes of inheritance. METHODS AND RESULTS:Patients with oocyte maturation arrest were sequenced with respect to TUBB8. We investigated the effects of identified mutations in vitro, in cultured cells and in mouse oocytes. Seven heterozygous missense and two homozygous mutations were identified. These mutations cause a range of folding defects in vitro, different degrees of microtubule disruption upon expression in cultured cells and interfere to varying extents in the proper assembly of the meiotic spindle in mouse oocytes. Several of the newly discovered TUBB8 mutations result in phenotypic variability. For example, oocytes harbouring any of three missense mutations (I210V, T238M and N348S) could extrude the first polar body. Moreover, they could be fertilised, although the ensuing embryos became developmentally arrested. Surprisingly, oocytes from patients harbouring homozygous TUBB8 mutations that in either case preclude the expression of a functional TUBB8 polypeptide nonetheless contained identifiable spindles. CONCLUSIONS: Our data substantially expand the range of dysfunctional oocyte phenotypes incurred by mutation in TUBB8, underscore the independent nature of human oocyte meiosis and differentiation, extend the class of genetic diseases known as the tubulinopathies and provide new criteria for the qualitative evaluation of meiosis II (MII) oocytes for in vitro fertilization (IVF). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Authors: Bora Lee; Elke Vermassen; Sook-Young Yoon; Veerle Vanderheyden; Junya Ito; Dominique Alfandari; Humbert De Smedt; Jan B Parys; Rafael A Fissore Journal: Development Date: 2006-11 Impact factor: 6.868
Authors: Martin W Breuss; Thai Nguyen; Anjana Srivatsan; Ines Leca; Guoling Tian; Tanja Fritz; Andi H Hansen; Damir Musaev; Jennifer McEvoy-Venneri; Kiely N James; Rasim O Rosti; Eric Scott; Uner Tan; Richard D Kolodner; Nicholas J Cowan; David A Keays; Joseph G Gleeson Journal: Hum Mol Genet Date: 2017-01-15 Impact factor: 6.150