title: Infertility associated with incomplete spermatogenic arrest and oligozoospermia in Egr4-deficient mice.
abstract: Male fertility is complex and depends upon endocrine/paracrine regulatory mechanisms and morphogenetic processes occurring during testicular development, spermatogenesis (mitosis and meiosis) and spermiogenesis (spermatid maturation). Egr4 (NGFI-C, pAT133), a member of the Egr family of zinc-finger transcription factors, is thought to be involved in cellular growth and differentiation, but its specific function has been previously unknown. We derived Egr4 null mice through targeted mutagenesis and found that they were phenotypically normal with the exception that males, but not females, were infertile. Egr4 is expressed at low levels within male germ cells during meiosis and is critical for germ cell maturation during the early-mid pachytene stage. While most Egr4 null male germ cells undergo apoptosis during early-mid pachytene, some are capable of maturing beyond an apparent Egr4-dependent developmental restriction point. Consequently, a limited degree of spermiogenesis occurs but this is accompanied by markedly abnormal spermatozoon morphology and severe oligozoospermia. Egr4 appears to regulate critical genes involved in early stages of meiosis and has a singularly important role in male murine fertility. These data raise the possibility that Egr4 may contribute to some forms of human idiopathic male infertility.
authors.affiliation: The Department of Pathology and Divisions of Neuropathology and Laboratory Medicine, and Department of Obstetrics and Gynecology, Washington University School of Medicine, St Louis, MO 63110, USA.
authors.forename: W G
authors.initials: WG
authors.lastname: Tourtellotte
authors.forename: R
authors.initials: R
authors.lastname: Nagarajan
authors.forename: A
authors.initials: A
authors.lastname: Auyeung
authors.forename: C
authors.initials: C
authors.lastname: Mueller
authors.forename: J
authors.initials: J
authors.lastname: Milbrandt
mesh_terms: D000818:Animals; D017209:Apoptosis; D004268:DNA-Binding Proteins / Q000235:genetics*; D051765:Early Growth Response Transcription Factors; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006801:Humans; D007248:Infertility, Male / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D051379:Mice; D016296:Mutagenesis; D009845:Oligospermia / Q000235:genetics*; D011003:Ploidies; D013079:Sperm Maturation; D013090:Spermatocytes / Q000378:metabolism / Q000473:pathology; D013091:Spermatogenesis / Q000235:genetics*; D013094:Spermatozoa / Q000002:abnormalities; D013737:Testis / Q000166:cytology / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C111028:EGR4 protein, human; D051765:Early Growth Response Transcription Factors; C486392:Egr4 protein, mouse; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53