ALADIN is Required for the Production of Fertile Mouse Oocytes

Abstract

Asymmetric cell divisions depend on the precise placement of the spindle apparatus. In mammalian oocytes, spindles assemble close to the cell's center, but chromosome segregation takes place at the cell periphery where half of the chromosomes are expelled into small, nondeveloping polar bodies at anaphase. By dividing so asymmetrically, most of the cytoplasmic content within the oocyte is preserved, which is critical for successful fertilization and early development. Recently we determined that the nucleoporin ALADIN participates in spindle assembly in somatic cells, and we have also shown that female mice homozygously null for ALADIN are sterile. In this study we show that this protein is involved in specific meiotic stages, including meiotic resumption, spindle assembly, and spindle positioning. In the absence of ALADIN, polar body extrusion is compromised due to problems in spindle orientation and anchoring at the first meiotic anaphase. ALADIN null oocytes that mature far enough to be fertilized in vitro are unable to support embryonic development beyond the two-cell stage. Overall, we find that ALADIN is critical for oocyte maturation and appears to be far more essential for this process than for somatic cell divisions.

Identification of a novel putative interaction partner of the nucleoporin ALADIN

“…Our group reported that female mice homozygous deficient for Aaas are infertile (Huebner et al, 2006). Carvalhal et al recently presented that ALADIN is involved in mitotic and meiotic spindle assembly, chromosome segregation and production of fertile mouse oocytes (Carvalhal et al, 2015, 2016 preprint). Interestingly, both PGRMC1 and PGRMC2 seem to be involved in regulation of ovarian follicle development and therefore seem to have neuroendocrine functions (Wendler and Wehling, 2013).…”

The Effect of Lysophosphatidic Acid-supplemented Culture Medium on Human Immature Oocytes Matured in Vitro

“…The present results suggested that PLEK and PRKG1 were important for the maturation and development of oocytes in the culture medium supplemented with LPA, but there have not been any reports on these two genes regarding human oocyte maturation. We found that 47 downregulated genes enriched CC items related to the cell periphery; it is interesting to note that chromosomes separate during cell division at the cell periphery (37). Thus, our results indicated that LPA might affect cell division.…”

Identification of a novel putative interaction partner of the nucleoporin ALADIN

“…Our group reported that female mice homozygous deficient for Aaas are infertile (Huebner et al, 2006). Carvalhal et al recently presented that ALADIN is involved in mitotic and meiotic spindle assembly, chromosome segregation and production of fertile mouse oocytes (Carvalhal et al, 2015;Carvalhal et al, 2016). Interestingly, both PGRMC1 and 2 were shown to be involved in regulation of ovarian follicle development and therefore imply a neuroendocrine function (Wendler and Wehling, 2013).…”