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) All Versions of this Article: 72/1/58    most recent biolreprod.104.032987v1 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 Zhang, D. Articles by Wang, W.-H. Search for Related Content PubMed PubMed Citation Articles by Zhang, D. Articles by Wang, W.-H. Agricola Articles by Zhang, D. Articles by Wang, W.-H.

Localization of Mitotic Arrest Deficient 1 (MAD1) in Mouse Oocytes During the First Meiosis and Its Functions as a Spindle Checkpoint Protein¹

State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China

The present study was designed to investigate the localization of mitotic arrest deficient 1 (MAD1) in mouse oocytes during meiotic maturation and its relationship with kinetochores, chromosomes, and microtubules. Oocytes at various stages during the first meiosis were fixed and immunostained for MAD1, kinetochores, microtubules, and chromosomes. The stained oocytes were examined by confocal microscopy. Some oocytes were treated with nocodazole or Taxol before examination. The anti-MAD1 antibody was injected into the oocytes at the germinal vesicle (GV) stage for examination of chromosome alignment and spindle formation. It was found that MAD1 was present in the oocytes from the GV to prometaphase I stages around the nuclei. When the oocytes reached the metaphase I (M-I) to metaphase II (M-II) stages, MAD1 was mainly localized at the spindle poles. However, MAD1 relocated to the vicinity of the chromosomes when spindles were disassembled by nocodazole or cooling, and the relocated MAD1 moved back to the spindle poles during spindle recovery. Taxol treatment did not affect the MAD1 localization. Although anti-MAD1 antibody injection did not affect nuclear maturation, significantly higher proportions of injected oocytes had misaligned chromosomes when the oocytes reached the M-I to M-II stages. The results of the present study indicate that MAD1 is present in mouse oocytes at all stages during the first meiosis and that it participates in spindle checkpoint during meiosis. However, MAD1 could not check misaligned chromosomes during spindle recovery after the spindles were destroyed by drug or cooling, which caused some chromosomes to scatter in the oocytes.

¹ Supported by grants from the National Natural Science Foundation of China (30170385, 30125007, and 30170385).

² Correspondence: Wei-Hua Wang, State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 25 BeiSiHuanXi Road, Haidian, Beijing 100080, China. FAX: 86 106 265 0042; wangweihua11{at}yahoo.com

This article has been cited by other articles:

				D. Zhang, S. Yin, M.-X. Jiang, W. Ma, Y. Hou, C.-G. Liang, L.-Z. Yu, W.-H. Wang, and Q.-Y. Sun Cytoplasmic dynein participates in meiotic checkpoint inactivation in mouse oocytes by transporting cytoplasmic mitotic arrest-deficient (Mad) proteins from kinetochores to spindle poles Reproduction, April 1, 2007; 133(4): 685 - 695. [Abstract] [Full Text] [PDF]

				N. M. Steuerwald, M. D. Steuerwald, and J. B. Mailhes Post-ovulatory aging of mouse oocytes leads to decreased MAD2 transcripts and increased frequencies of premature centromere separation and anaphase Mol. Hum. Reprod., September 1, 2005; 11(9): 623 - 630. [Abstract] [Full Text] [PDF]