title: Epab and Pabpc1 are differentially expressed in the postnatal mouse ovaries.
abstract: OBJECTIVE
  Embryonic poly(A)-binding protein (EPAB) and poly(A)-binding protein, cytoplasmic 1 (PABPC1) bind poly(A) tails of mRNAs and mediate their translational regulation in germ cells and early preimplantation embryos. Although expression patterns and possible functions of the Epab and Pabpc1 genes have been examined in vertebrate germ cells and early embryos, their expression levels and cellular localizations in the postnatal mouse ovaries remained elusive.
  
  
  METHODS
  In the present study, we first aimed to characterize expression levels of the Epab and Pabpc1 genes in the prepubertal (1-, 2-, and 3-week old), pubertal (4-, 5-, and 6-week old), postpubertal (16-week and 18-week old), and aged (52-, 60-, and 72-week old) mouse ovaries by using quantitative real-time polymerase chain reaction (qRT-PCR).
  
  
  RESULTS
  Epab mRNA was predominantly expressed in the prepubertal ovaries when compared to later developmental periods. However, Pabpc1 transcript was highly generated in the prepubertal and pubertal mouse ovaries except for 1-week old ovary than those of other developmental terms. In the prepubertal mouse ovaries, RNA in situ hybridization localized both Epab and Pabpc1 transcripts in the cytoplasm of oocytes and granulosa cells of all follicular stages. Consistently, Epab and Pabpc1 gene expression were detected in the cumulus cells and MII oocytes obtained from cumulus oocyte complexes (COCs). Ovarian follicle counting in the postnatal ovaries revealed that total number of follicles was higher in the prepubertal ovaries in comparison with later stages of development.
  
  
  CONCLUSIONS
  As a result, Epab and Pabpc1 expression exhibit differences at postnatal ovary development stages and both genes are transcribed in the granulosa cells and oocytes. These findings suggest that EPAB may predominantly play roles in translational regulation of the mRNAs during early oogenesis and folliculogenesis, but PABPC1 most likely perform these roles in the later terms of ovarian development along with EPAB protein.
authors.affiliation: Department of Histology and Embryology, School of Medicine, Akdeniz University, Campus, 07070, Antalya, Turkey.
authors.forename: Saffet
authors.initials: S
authors.lastname: Ozturk
authors.forename: Berna
authors.initials: B
authors.lastname: Sozen
authors.forename: Necdet
authors.initials: N
authors.lastname: Demir
mesh_terms: D000818:Animals; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D051379:Mice; D009865:Oocytes / Q000254:growth & development; D009866:Oogenesis / Q000235:genetics*; D006080:Ovarian Follicle / Q000254:growth & development; D039122:Poly(A)-Binding Protein I / Q000096:biosynthesis* / Q000235:genetics; D039102:Poly(A)-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C575837:EPAB protein, mouse; D039122:Poly(A)-Binding Protein I; D039102:Poly(A)-Binding Proteins