Transcriptional profiling of fetal hypothalamic TRH neurons
1 Departamento de Genética y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
2 Laboratory of Molecular Biology, Medical Research Council, Hills Road, Cambridge CB2 0QH, UK
3 Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
4 Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
5 Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
6 Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, 61801, USA
BMC Genomics 2011, 12:222 doi:10.1186/1471-2164-12-222Published: 10 May 2011
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.
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.
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.