title: Spermidine, but not spermine, is essential for pigment pattern formation in zebrafish.
abstract: Polyamines are small poly-cations essential for all cellular life. The main polyamines present in metazoans are putrescine, spermidine and spermine. Their exact functions are still largely unclear; however, they are involved in a wide variety of processes affecting cell growth, proliferation, apoptosis and aging. Here we identify idefix, a mutation in the zebrafish gene encoding the enzyme spermidine synthase, leading to a severe reduction in spermidine levels as shown by capillary electrophoresis-mass spectrometry. We show that spermidine, but not spermine, is essential for early development, organogenesis and colour pattern formation. Whereas in other vertebrates spermidine deficiency leads to very early embryonic lethality, maternally provided spermidine synthase in zebrafish is sufficient to rescue the early developmental defects. This allows us to uncouple them from events occurring later during colour patterning. Factors involved in the cellular interactions essential for colour patterning, likely targets for spermidine, are the gap junction components Cx41.8, Cx39.4, and Kir7.1, an inwardly rectifying potassium channel, all known to be regulated by polyamines. Thus, zebrafish provide a vertebrate model to study the in vivo effects of polyamines.
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abteilung 3, Spemannstrasse 35, Tübingen 72076, Germany.
authors.forename: Hans Georg
authors.initials: HG
authors.lastname: Frohnhöfer
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abteilung 3, Spemannstrasse 35, Tübingen 72076, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Geiger-Rudolph
authors.affiliation: Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Pattky
authors.affiliation: Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Meixner
authors.affiliation: Institut für Physikalische und Theoretische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, Tübingen 72076, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Huhn
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abteilung 3, Spemannstrasse 35, Tübingen 72076, Germany.
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Maischein
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abteilung 3, Spemannstrasse 35, Tübingen 72076, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Geisler
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abteilung 3, Spemannstrasse 35, Tübingen 72076, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Gehring
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abteilung 3, Spemannstrasse 35, Tübingen 72076, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Maderspacher
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abteilung 3, Spemannstrasse 35, Tübingen 72076, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Nüsslein-Volhard
authors.affiliation: Max-Planck-Institut für Entwicklungsbiologie, Abteilung 3, Spemannstrasse 35, Tübingen 72076, Germany uwe.irion@tuebingen.mpg.de.
authors.forename: Uwe
authors.identifier: http://orcid.org/0000-0003-2823-5840
authors.initials: U
authors.lastname: Irion
keywords: Pattern formation; Pigmentation; Polyamine; Spermidine synthase; Spermine synthase; Zebrafish