title: RASD1 Knockdown Results in Failure of Oocyte Maturation.
abstract: BACKGROUND
  Ras dexamethasone-induced protein (RASD1) is a member of Ras superfamily of small GTPases. RASD1 regulates various signaling pathways involved in iron homeostasis, growth hormone secretion, and circadian rhythm. However, RASD1 function in oocyte remains unknown.
  
  
  METHODS
  Using immunohistochemistry, immunofluorescence, and quantitative real-time RT-PCR, RASD1 expression in mouse ovary and RASD1 role in oocyte maturation-related gene expression, spindle formation, and chromosome alignment were analyzed. RNAi microinjection and time-lapse video microscopy were used to examine the effect of Rasd1 knockdown on oocyte maturation.
  
  
  RESULTS
  RASD1 was highly detected in oocytes transitioning from primordial to secondary follicles. Rasd1 was highly expressed in germinal vesicle (GV), during GV breakdown, and in metaphase I (MI) stage as oocytes mature, and its expression was significantly downregulated in MII stage. With knockdown of Rasd1, maturation in GV oocytes was arrested at MI stage, showing disrupted meiotic spindling and chromosomal misalignment. In addition, Obox4 and Arp2/3, engaged in MI-MII transition and cytokinesis, respectively, were misregulated in GV oocytes by Rasd1 knockdown.
  
  
  CONCLUSIONS
  These findings suggest that RASD1 is a novel factor in MI-MII oocyte transition and may be involved in regulating the progression of cytokinesis and spindle formation, controlling related signaling pathways during oocyte maturation.
authors.affiliation: Department of Biomedical Science, CHA University, Seongnam-si, Gyeonggi-do, Republic of Korea.
authors.forename: Youngeun
authors.initials: Y
authors.lastname: Lee
authors.forename: Kyeoung-Hwa
authors.initials: KH
authors.lastname: Kim
authors.forename: Hyemin
authors.initials: H
authors.lastname: Yoon
authors.forename: Ok-Hee
authors.initials: OH
authors.lastname: Lee
authors.forename: Eunyoung
authors.initials: E
authors.lastname: Kim
authors.forename: Miseon
authors.initials: M
authors.lastname: Park
authors.forename: Hoon
authors.initials: H
authors.lastname: Jang
authors.forename: Kwonho
authors.initials: K
authors.lastname: Hong
authors.forename: Hyuk
authors.initials: H
authors.lastname: Song
authors.forename: Jung Jae
authors.initials: JJ
authors.lastname: Ko
authors.forename: Woo Sik
authors.initials: WS
authors.lastname: Lee
authors.forename: Kyung-Ah
authors.initials: KA
authors.lastname: Lee
authors.forename: Eun Mi
authors.initials: EM
authors.lastname: Chang
authors.forename: Youngsok
authors.initials: Y
authors.lastname: Choi
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D033481:Chromosomes, Mammalian / Q000378:metabolism; D048749:Cytokinesis; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D008677:Metaphase / Q000235:genetics; D008813:Mice, Inbred ICR; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism*; D009928:Organ Specificity / Q000235:genetics; D034622:RNA Interference; D008941:Spindle Apparatus; D018631:ras Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C498511:Rasd1 protein, mouse; D018631:ras Proteins