title: FOXL2 modulates cartilage, skeletal development and IGF1-dependent growth in mice.
abstract: BACKGROUND
  Haploinsufficiency of the FOXL2 transcription factor in humans causes Blepharophimosis/Ptosis/Epicanthus Inversus syndrome (BPES), characterized by eyelid anomalies and premature ovarian failure. Mice lacking Foxl2 recapitulate human eyelid/forehead defects and undergo female gonadal dysgenesis. We report here that mice lacking Foxl2 also show defects in postnatal growth and embryonic bone and cartilage formation.
  
  
  METHODS
  Foxl2 (-/-) male mice at different stages of development have been characterized and compared to wild type. Body length and weight were measured and growth curves were created. Skeletons were stained with alcian blue and/or alizarin red. Bone and cartilage formation was analyzed by Von Kossa staining and immunofluorescence using anti-FOXL2 and anti-SOX9 antibodies followed by confocal microscopy. Genes differentially expressed in skull vaults were evaluated by microarray analysis. Analysis of the GH/IGF1 pathway was done evaluating the expression of several hypothalamic-pituitary-bone axis markers by RT-qPCR.
  
  
  RESULTS
  Compared to wild-type, Foxl2 null mice are smaller and show skeletal abnormalities and defects in cartilage and bone mineralization, with down-regulation of the GH/IGF1 axis. Consistent with these effects, we find FOXL2 expressed in embryos at 9.5 dpc in neural tube epithelium, in head mesenchyme near the neural tube, and within the first branchial arch; then, starting at 12.5 dpc, expressed in cartilaginous tissue; and at PO and P7, in hypothalamus.
  
  
  CONCLUSIONS
  Our results support FOXL2 as a master transcription factor in a spectrum of developmental processes, including growth, cartilage and bone formation. Its action overlaps that of SOX9, though they are antagonistic in female vs male gonadal sex determination but conjoint in cartilage and skeletal development.
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cittadella Universitaria di Monserrato, SS 554 km 4500, Monserrato, 09042, Italy. mara.marongiu@irgb.cnr.it.
authors.forename: Mara
authors.initials: M
authors.lastname: Marongiu
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cittadella Universitaria di Monserrato, SS 554 km 4500, Monserrato, 09042, Italy. loredana.marcia@irgb.cnr.it.|Università degli Studi di Sassari, Sassari, Italy. loredana.marcia@irgb.cnr.it.
authors.forename: Loredana
authors.initials: L
authors.lastname: Marcia
authors.affiliation: Laboratory of Genetics, NIA-IRP, NIH, Baltimore, MD, USA. pelosie@grc.nia.nih.gov.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Pelosi
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cittadella Universitaria di Monserrato, SS 554 km 4500, Monserrato, 09042, Italy. mario.lovicu@irgb.cnr.it.
authors.forename: Mario
authors.initials: M
authors.lastname: Lovicu
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cittadella Universitaria di Monserrato, SS 554 km 4500, Monserrato, 09042, Italy. manila.deiana@irgb.cnr.it.
authors.forename: Manila
authors.initials: M
authors.lastname: Deiana
authors.affiliation: Laboratory of Genetics, NIA-IRP, NIH, Baltimore, MD, USA. zhangyon@mail.nih.gov.
authors.forename: Yonqing
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cittadella Universitaria di Monserrato, SS 554 km 4500, Monserrato, 09042, Italy. alepud@gmail.com.|Università degli Studi di Cagliari, Cagliari, Italy. alepud@gmail.com.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Puddu
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cittadella Universitaria di Monserrato, SS 554 km 4500, Monserrato, 09042, Italy. angela.loi@irgb.cnr.it.
authors.forename: Angela
authors.initials: A
authors.lastname: Loi
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cittadella Universitaria di Monserrato, SS 554 km 4500, Monserrato, 09042, Italy. manuela.uda@irgb.cnr.it.
authors.forename: Manuela
authors.initials: M
authors.lastname: Uda
authors.affiliation: Cante di Montevecchio Association, Genomic Research Center, Fano, Italy. bordiga34@gmail.com.
authors.forename: Antonino
authors.initials: A
authors.lastname: Forabosco
authors.affiliation: Laboratory of Genetics, NIA-IRP, NIH, Baltimore, MD, USA. SchlessingerD@grc.nia.nih.gov.
authors.forename: David
authors.initials: D
authors.lastname: Schlessinger
authors.affiliation: Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cittadella Universitaria di Monserrato, SS 554 km 4500, Monserrato, 09042, Italy. laura.crisponi@irgb.cnr.it.
authors.forename: Laura
authors.initials: L
authors.lastname: Crisponi
mesh_terms: D000818:Animals; D016569:Blepharophimosis / Q000378:metabolism; D001846:Bone Development; D002356:Cartilage / Q000254:growth & development* / Q000378:metabolism; D005260:Female; D000074842:Forkhead Box Protein L2; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D051379:Mice; D015398:Signal Transduction; D012868:Skin Abnormalities / Q000378:metabolism; D014564:Urogenital Abnormalities / Q000378:metabolism
chemical_list: D000074842:Forkhead Box Protein L2; D051858:Forkhead Transcription Factors; C498893:Foxl2 protein, mouse; C519530:insulin-like growth factor-1, mouse; D007334:Insulin-Like Growth Factor I