Gamete Biology

Nuclear Origin of Aging-Associated Meiotic Defects in Senescence-Accelerated Mice

Abstract
Factors of both cytoplasmic and nuclear origin regulate metaphase chromosome alignment and spindle checkpoint during mitosis. Most aneuploidies associated with maternal aging are believed to derive from non-disjunction and meiotic errors, such as aberrations in spindle formation and chromosome alignment at meiosis I. Senescence-accelerated mice (SAM) exhibit aging-associated meiotic defects, specifically chromosome misalignment at meiosis I and II that resemble those found in human female aging. How maternal aging disrupts meiosis remains largely unexplained. Using germinal vesicle (GV) nuclear transfer, we found that aging-associated misalignment of metaphase chromosomes is predominately associated with the nuclear factors in the SAM model. Cytoplasm of young hybrid B6C3F1 mouse oocytes could partly rescue aging-associated meiotic chromosome misalignment, whereas cytoplasm of young SAM was ineffective in preventing the meiotic defects of old SAM oocytes, indicative of deficiency of SAM oocyte cytoplasm. Our results demonstrate that both nuclear and cytoplasmic factors contribute to the meiotic defects of the old SAM oocytes, and that the nuclear compartment plays the predominant role in the etiology of aging-related meiotic defects.

Key words: Gamete Biology • Aging • Developmental biology • Meiosis

This article has been cited by other articles:

				V.J. Hall, D. Compton, P. Stojkovic, M. Nesbitt, M. Herbert, A. Murdoch, and M. Stojkovic Developmental competence of human in vitro aged oocytes as host cells for nuclear transfer Hum. Reprod., January 1, 2007; 22(1): 52 - 62. [Abstract] [Full Text] [PDF]

				C. Tatone, M. C. Carbone, R. Gallo, S. Delle Monache, M. Di Cola, E. Alesse, and F. Amicarelli Age-Associated Changes in Mouse Oocytes During Postovulatory In Vitro Culture: Possible Role for Meiotic Kinases and Survival Factor BCL2 Biol Reprod, February 1, 2006; 74(2): 395 - 402. [Abstract] [Full Text] [PDF]

				M. A Morelli and P. E Cohen Not all germ cells are created equal: Aspects of sexual dimorphism in mammalian meiosis Reproduction, December 1, 2005; 130(6): 761 - 781. [Abstract] [Full Text] [PDF]

				L.-B. Cui, X.-Y. Huang, and F.-Z. Sun Transfer of germinal vesicle to ooplasm of young mice could not rescue ageing-associated chromosome misalignment in meiosis of oocytes from aged mice Hum. Reprod., June 1, 2005; 20(6): 1624 - 1631. [Abstract] [Full Text] [PDF]