title: Detection and quantification of maternal-effect gene transcripts in mouse second polar bodies: potential markers of embryo developmental competence.
abstract: OBJECTIVE
  To test the hypothesis that quantification of messenger RNAs originating from the second polar body (PB(2)) provides a noninvasive tool for assessing embryo quality.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Hospital-based academic research laboratory.
  
  
  METHODS
  CD1 female mice.
  
  
  METHODS
  Metaphase II oocytes obtained from 7- to 8-week-old mice after pregnant mare's serum gonadotropin and hCG priming. After in vitro fertilization, the PB(2) was biopsied from zygote, followed by reverse transcription. Real-time polymerase chain reaction was performed to quantify gene expression levels in single PB(2). The sibling zygotes were continuously cultured to blastocyst stage.
  
  
  METHODS
  Embryo developmental competence and six maternal-effect gene (Dnmt1, Mater, Nobox, Npm2, Tcl1, and Zar1) transcripts in the PB(2).
  
  
  RESULTS
  Second polar body messenger RNA was detected in all candidate genes. Transcripts that were present in greater abundance in the zygote were more likely to be detected in quantitative polymerase chain reaction replicates from single PB(2). Four candidate genes (Dnmt1, Nobox, Npm2, and Tcl1) expression levels in PB(2) between two groups (two-cell embryo vs. blastocyts) approached statistical significance.
  
  
  CONCLUSIONS
  Second polar bodies may contain a representative transcript profile to that of the zygote after fertilization. Differences in gene expression in PB(2) may be potential biomarkers of embryo quality.
authors: Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.
authors: Ze-Xu
authors: ZX
authors: Jiao
authors: Teresa K
authors: TK
authors: Woodruff
mesh_terms: D000818:Animals; D000941:Antigens / Q000235:genetics; D001755:Blastocyst / Q000378:metabolism* / Q000473:pathology; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics; D004527:Egg Proteins / Q000235:genetics; D046149:Embryo Culture Techniques; D047108:Embryonic Development / Q000235:genetics; D005260:Female; D005307:Fertilization in Vitro; D018507:Gene Expression Regulation, Developmental; D005819:Genetic Markers; D018398:Homeodomain Proteins / Q000235:genetics; D008677:Metaphase; D051379:Mice; D056489:Nucleoplasmins / Q000235:genetics; D054315:Oocyte Retrieval; D010062:Ovulation Induction; D059705:Polar Bodies / Q000378:metabolism* / Q000473:pathology; D011247:Pregnancy; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D015053:Zygote / Q000378:metabolism* / Q000473:pathology
chemical_list: D000941:Antigens; D004527:Egg Proteins; D005819:Genetic Markers; D018398:Homeodomain Proteins; C416503:Nalp5 protein, mouse; C533552:Npm2 protein, mouse; D056489:Nucleoplasmins; C456265:Og2x protein, mouse; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C490393:Tcl1 protein, mouse; D014157:Transcription Factors; C471630:Zar1 protein, mouse; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619381:Dnmt1 protein, mouse