title: A thymosin beta15-like peptide promotes intersegmental myotome extension in the chicken embryo.
abstract: Beta-thymosins constitute a group of small actin-sequestering peptides. These highly conserved peptides are involved in cytoskeleton dynamics and can influence different cell properties such as motility, substrate adhesion, shape and chemotaxis. As a marker for tumour metastasis, the mammalian thymosin beta15 is believed to have an important diagnostic relevance in cancer prognosis, although little is known about its physiological function. In order to study the role of thymosin beta15(avian) in embryogenesis, we cloned the chicken and quail orthologues of thymosin beta15 and used the chicken as a model for vertebrate development. Avian thymosin beta15, the first known non-mammalian thymosin beta15-like gene, encodes a peptide that possesses a cysteine at position one after the methionine which is a significant difference compared to its mammalian counterparts. Thymosin beta15(avian) expression starts at an early stage of development. The expression pattern changes rapidly with development and differs from that of the related thymosin beta4 gene. The most prominent expression domain is seen in developing muscles of limbs and trunk. Gain-of-function experiments revealed that thymosin beta15(avian) has a function in normal myotome development. Ectopic over-expression of thymosin beta15(avian) leads to premature elongation of myotome cells trespassing segment borders. We conclude that thymosin beta15(avian) has a still undescribed function in promoting myocyte elongation.
authors.affiliation: Institute of Anatomy and Molecular Embryology, Ruhr-University Bochum, Universitätsstrasse 150, 44780, Bochum, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Chankiewitz
authors.forename: Gabriela
authors.initials: G
authors.lastname: Morosan-Puopolo
authors.forename: Faisal
authors.initials: F
authors.lastname: Yusuf
authors.forename: Stefan
authors.initials: S
authors.lastname: Rudloff
authors.forename: Felicitas
authors.initials: F
authors.lastname: Pröls
authors.forename: Veronika
authors.initials: V
authors.lastname: Kleff
authors.forename: Dietrich Kurt
authors.initials: DK
authors.lastname: Hofmann
authors.forename: Beate
authors.initials: B
authors.lastname: Brand-Saberi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002642:Chick Embryo; D003001:Cloning, Molecular; D018274:Electroporation; D008969:Molecular Sequence Data; D032342:Muscle Cells / Q000502:physiology*; D024510:Muscle Development / Q000235:genetics*; D018482:Muscle, Skeletal / Q000196:embryology* / Q000378:metabolism; D009362:Neoplasm Metastasis; D012190:Retroviridae / Q000235:genetics; D013947:Thymosin / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000235:genetics*; D000099201:Thymosin beta(4)
chemical_list: D013947:Thymosin; D000099201:Thymosin beta(4)