Teneurin-2 is expressed in tissues that regulate limb and somite pattern formation and is induced in vitro and in situ by FGF8.
Teneurin-2 is a member of a novel family of transmembrane proteins characterized to date in fish, birds, mammals, and Drosophila (e.g., the pair-rule gene product Ten-m). We have shown that teneurin-2 is expressed by neurons in the developing avian visual system in a pattern complementary to the expression of teneurin-1 and that recombinant teneurin-2 induces morphologic changes in neuronal cells in culture (Rubin et al., 1999). Here we have used cRNA probes to two newly identified splice variants and a teneurin-2-specific antibody to determine whether teneurin-2 is also expressed outside the nervous system. Both reverse transcriptase-polymerase chain reaction and in situ hybridization indicate that the three splice variants known so far are coexpressed at sites of pattern formation during development. Teneurin-2 mRNAs and protein are found in the developing limbs, somites, and craniofacial mesenchyme. In addition to expression of teneurin-2 by the apical ectodermal ridge, teneurin-2 transcripts also appear transiently at sites of tendon development. Teneurin-2 expression patterns were strikingly similar to those of fibroblast growth factor 8 (FGF8). In agreement with the overlapping expression pattern, FGF8-coated beads implanted into chicken limb buds induced the ectopic expression of teneurin-2 and soluble FGF8 induced teneurin-2 in limb explant cultures. Thus, teneurin-2 could act downstream of FGF8 during morphogenesis.
Tucker
R P
RP
Department of Cell Biology and Human Anatomy, University of California at Davis, Davis, California.
Chiquet-Ehrismann
R
R
Chevron
M P
MP
Martin
D
D
Hall
R J
RJ
Rubin
B P
BP
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D002642:Chick Embryo; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005121:Extremities / Q000196:embryology; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D015723:Gene Library; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D018878:Limb Buds / Q000378:metabolism; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D008648:Mesoderm / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009420:Nervous System / Q000378:metabolism; D009924:Organ Culture Techniques; D018075:RNA, Complementary / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D019170:Somites / Q000378:metabolism; D013710:Tendons / Q000378:metabolism; D013997:Time Factors
D030161:Avian Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D018075:RNA, Complementary; D012333:RNA, Messenger; D017468:Receptors, Fibroblast Growth Factor; C402591:teneurin-2 protein, chicken; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors