title: Bovine Lhx8, a Germ Cell-Specific Nuclear Factor, Interacts with Figla.
abstract: LIM homeobox 8 (Lhx8) is a germ cell-specific transcription factor essential for the development of oocytes during early oogenesis. In mice, Lhx8 deficiency causes postnatal oocyte loss and affects the expression of many oocyte-specific genes. The aims of this study were to characterize the bovine Lhx8 gene, determine its mRNA expression during oocyte development and early embryogenesis, and evaluate its interactions with other oocyte-specific transcription factors. The bovine Lhx8 gene encodes a protein of 377 amino acids. A splice variant of Lhx8 (Lhx8_v1) was also identified. The predicted bovine Lhx8 protein contains two LIM domains and one homeobox domain. However, one of the LIM domains in Lhx8_v1 is incomplete due to deletion of 83 amino acids near the N terminus. Both Lhx8 and Lhx8_v1 transcripts were only detected in the gonads but none of the somatic tissues examined. The expression of Lhx8 and Lhx8_v1 appears to be restricted to oocytes as none of the transcripts was detectable in granulosa or theca cells. The maternal Lhx8 transcript is abundant in GV and MII stage oocytes as well as in early embryos but disappear by morula stage. A nuclear localization signal that is required for the import of Lhx8 into nucleus was identified, and Lhx8 is predominantly localized in the nucleus when ectopically expressed in mammalian cells. Finally, a novel interaction between Lhx8 and Figla, another transcription factor essential for oogenesis, was detected. The results provide new information for studying the mechanisms of action for Lhx8 in oocyte development and early embryogenesis.
authors.affiliation: Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, West Virginia, United States of America.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Fu
authors.affiliation: Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, West Virginia, United States of America.
authors.forename: Mingxiang
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, West Virginia, United States of America.
authors.forename: Kristen
authors.initials: K
authors.lastname: Mastrantoni
authors.affiliation: Department of Biology, West Virginia University, Morgantown, West Virginia, United States of America.
authors.forename: Mark
authors.initials: M
authors.lastname: Perfetto
authors.affiliation: Department of Biology, West Virginia University, Morgantown, West Virginia, United States of America.
authors.forename: Shuo
authors.initials: S
authors.lastname: Wei
authors.affiliation: Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, West Virginia, United States of America.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Yao
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002417:Cattle; D002460:Cell Line; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D005854:Germ Cells / Q000378:metabolism*; D006066:Gonads / Q000378:metabolism; D057809:HEK293 Cells; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D060850:LIM-Homeodomain Proteins / Q000378:metabolism*; D057136:Nuclear Receptor Subfamily 6, Group A, Member 1 / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism; D009866:Oogenesis / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D013799:Theca Cells / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D057136:Nuclear Receptor Subfamily 6, Group A, Member 1; D012333:RNA, Messenger; D014157:Transcription Factors; C112960:LIM homeobox protein 8