A differential display strategy identifies Cryptic, a novel EGF-related gene expressed in the axial and lateral mesoderm during mouse gastrulation.
We have developed a differential display screening approach to identify mesoderm-specific genes, relying upon the differentiation of embryonic stem (ES) cells in vitro. Using this strategy, we have isolated a novel murine gene that encodes a secreted molecule containing a variant epidermal growth factor-like (EGF) motif. We named this gene Cryptic, based on its predicted protein sequence similarity with Cripto, which encodes an EGF-related growth factor. Based on their strong sequence similarities, we propose that Cryptic, Cripto, and the Xenopus FRL-1 gene define a new family of growth factor-like molecules, which we name the 'CFC' (Cripto, Frl-1, and Cryptic) family. Analysis of Cryptic expression by in situ hybridization shows that it is expressed during gastrulation in two spatial domains that correspond to the axial and lateral mesoderm. In the first domain of expression, Cryptic expression is progressively localized to the anterior primitive streak, the head process, and the node and notochordal plate. In the second domain, Cryptic expression is initially concentrated in the lateral region of the egg cylinder, and is later found circumferentially in the intermediate and lateral plate mesoderm. Furthermore, Cryptic expression can also be detected at the early head-fold stage in the midline neuroectoderm, and consequently is an early marker for the prospective floor plate of the neural tube. Expression of Cryptic ceases at the end of gastrulation, and has not been observed in later embryonic stages or in adult tissues. Thus, Cryptic encodes a putative signaling molecule whose expression suggests potential roles in mesoderm and/or neural patterning during gastrulation.
Shen
M M
MM
Department of Genetics, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA. mshen@mbcl.rutgers.edu
Wang
H
H
Leder
P
P
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002478:Cells, Cultured; D017931:DNA Primers; D005314:Embryonic and Fetal Development; D004815:Epidermal Growth Factor / Q000737:chemistry; D058851:GPI-Linked Proteins; D005775:Gastrula / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D006133:Growth Substances / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D018398:Homeodomain Proteins; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D008648:Mesoderm / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000737:chemistry; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013234:Stem Cells / Q000166:cytology / Q000502:physiology; D014157:Transcription Factors; D014981:Xenopus; D029867:Xenopus Proteins
C491268:CFC1 protein, human; C104433:Cfc1 protein, mouse; D017931:DNA Primers; D058851:GPI-Linked Proteins; D006133:Growth Substances; D018398:Homeodomain Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C070636:TDGF1 protein, human; C489450:Tdgf1 protein, mouse; D014157:Transcription Factors; D029867:Xenopus Proteins; C096788:tdgf1.3 protein, Xenopus; D004815:Epidermal Growth Factor