title: Transcriptional profiling of fetal hypothalamic TRH neurons.
abstract: BACKGROUND
  During murine hypothalamic development, different neuroendocrine cell phenotypes are generated in overlapping periods; this suggests that cell-type specific developmental programs operate to achieve complete maturation. A balance between programs that include cell proliferation, cell cycle withdrawal as well as epigenetic regulation of gene expression characterizes neurogenesis. Thyrotropin releasing hormone (TRH) is a peptide that regulates energy homeostasis and autonomic responses. To better understand the molecular mechanisms underlying TRH neuron development, we performed a genome wide study of its transcriptome during fetal hypothalamic development.
  
  
  RESULTS
  In primary cultures, TRH cells constitute 2% of the total fetal hypothalamic cell population. To purify these cells, we took advantage of the fact that the segment spanning -774 to +84 bp of the Trh gene regulatory region confers specific expression of the green fluorescent protein (GFP) in the TRH cells. Transfected TRH cells were purified by fluorescence activated cell sorting, various cell preparations pooled, and their transcriptome compared to that of GFP- hypothalamic cells. TRH cells undergoing the terminal phase of differentiation, expressed genes implicated in protein biosynthesis, intracellular signaling and transcriptional control. Among the transcription-associated transcripts, we identified the transcription factors Klf4, Klf10 and Atf3, which were previously uncharacterized within the hypothalamus.
  
  
  CONCLUSIONS
  To our knowledge, this is one of the first reports identifying transcripts with a potentially important role during the development of a specific hypothalamic neuronal phenotype. This genome-scale study forms a rational foundation for identifying genes that might participate in the development and function of hypothalamic TRH neurons.
authors.affiliation: Departamento de Genética y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Guerra-Crespo
authors.forename: Carlos
authors.initials: C
authors.lastname: Pérez-Monter
authors.forename: Sarath Chandra
authors.initials: SC
authors.lastname: Janga
authors.forename: Santiago
authors.initials: S
authors.lastname: Castillo-Ramírez
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Gutiérrez-Rios
authors.forename: Patricia
authors.initials: P
authors.lastname: Joseph-Bravo
authors.forename: Leonor
authors.initials: L
authors.lastname: Pérez-Martínez
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Charli
mesh_terms: D000818:Animals; D004622:Embryo, Mammalian; D005333:Fetus / Q000166:cytology* / Q000378:metabolism*; D020869:Gene Expression Profiling; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism*; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013973:Thyrotropin-Releasing Hormone / Q000235:genetics*
chemical_list: C000715469:Klf4 protein, rat; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D012333:RNA, Messenger; D013973:Thyrotropin-Releasing Hormone