title: Pregnancy-specific {beta}-1-glycoprotein 1 and human leukocyte antigen-E mRNA in human sperm: differential expression in fertile and infertile men and evidence of a possible functional role during early development.
abstract: BACKGROUND
  Mature spermatozoa contain thousands of mRNA transcripts. It has been recently shown that human sperm can deliver RNA into the oocyte, suggesting that mRNAs might have a role before or after fertilization. Human embryos express PSG1 (pregnancy-specific beta-1-glycoprotein 1) and HLA-E (human leukocyte antigen-E), molecules playing a role in implantation and early development. We compared PSG1 and HLA-E sperm mRNA levels in fertile and infertile men and we tested the hypothesis that these transcripts are selectively retained in the newly formed zygote.
  
  
  METHODS
  Real-time RT-PCR was used to analyze sperm mRNA levels (n = 11 fertile, n = 31 infertile patients) of PSG1, HLA-E and PRM2 (protamine 2). The presence of PSG1 and HLA-E proteins was evaluated by western blot in sperm protein extracts (n = 3). Using ICSI of human sperm into hamster oocytes we evaluated the permanence of these mRNAs at different time points (n = 10 for each time) after fertilization.
  
  
  RESULTS
  PSG1, HLA-E and PRM2 transcripts were demonstrated in ejaculated sperm. The fertile group showed significantly higher levels of PSG1 and HLA-E mRNA (both P < 0.05) than the infertile group, whereas PRM2 levels were not significantly different. However, PSG1 and HLA-E proteins were not found in ejaculated sperm. Following ICSI, PRM2 was undetectable after fertilization; conversely, PSG1 and HLA-E transcripts remained detectable for at least 24 h of zygotic development.
  
  
  CONCLUSIONS
  We provide new evidence that indicates that human sperm deliver transcripts that may have a role in early embryo development and decreased levels of these transcripts may be associated with infertility.
authors.affiliation: Department of Obstetrics and Gynecology, The Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, 601 Colley Avenue, Norfolk, Virginia 23507, USA.
authors.forename: Conrado
authors.initials: C
authors.lastname: Avendaño
authors.forename: Anahí
authors.initials: A
authors.lastname: Franchi
authors.forename: Estella
authors.initials: E
authors.lastname: Jones
authors.forename: Sergio
authors.initials: S
authors.lastname: Oehninger
mesh_terms: D000818:Animals; D015153:Blotting, Western; D006224:Cricetinae; D047108:Embryonic Development / Q000235:genetics*; D005306:Fertilization; D006680:HLA Antigens / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007248:Infertility, Male / Q000378:metabolism*; D008297:Male; D009865:Oocytes / Q000378:metabolism; D011268:Pregnancy-Specific beta 1-Glycoproteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011479:Protamines / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012661:Semen / Q000166:cytology / Q000378:metabolism; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000378:metabolism*; D000097625:HLA-E Antigens
chemical_list: D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D011268:Pregnancy-Specific beta 1-Glycoproteins; D011479:Protamines; D012333:RNA, Messenger; D000097625:HLA-E Antigens; C068621:protamine 2