IAP genes partake weighty roles in the astogeny and whole body regeneration in the colonial urochordate Botryllus schlosseri

Amalia Rosner, Olha Kravchenko, Baruch Rinkevich

Research output: Contribution to journalArticlepeer-review


Inhibitors of Apoptosis Protein (IAP) genes participate in processes like apoptosis, proliferation, innate immunity, inflammation, cell motility, differentiation and in malignancies. Here we reveal 25 IAP genes in the tunicate Botryllus schlosseri's genome and their functions in two developmental biology phenomena, a new mode of whole body regeneration (WBR) induced by budectomy, and blastogenesis, the four-staged cycles of botryllid ascidian astogeny. IAP genes that were specifically upregulated during these developmental phenomena were identified, and protein expression patterns of one of these genes, IAP28, were followed. Most of the IAP genes upregulation recorded at blastogenetic stages C/D was in concert with the upregulation at 100 μM H 2 O 2 apoptotic-induced treatment and in parallel to expressions of AIF1, Bax, Mcl1, caspase 2 and two orthologues of caspase 7. Wnt agonist altered the takeover duration along with reduced IAP expressions, and displacement of IAP28 + phagocytes. WBR was initiated solely at blastogenetic stage D, where zooidal absorption was attenuated and regeneration centers were formed either from remains of partially absorbed zooids or from deformed ampullae. Subsequently, bud-bearing zooids developed, in concert with a massive IAP28-dependent phagocytic wave that eliminated the old zooids, then proceeded with the establishment of morphologically normal-looking colonies. IAP4, IAP14 and IAP28 were also involved in WBR, in conjunction with the expression of the pro-survival PI3K-Akt pathway. IAPs function deregulation by Smac mimetics resulted in severe morphological damages, attenuation in bud growth and differentiation, and in destabilization of colonial coordination. Longtime knockdown of IAP functions prior to the budectomy, resulted in colonial death.

Original languageEnglish
Pages (from-to)320-341
Number of pages22
JournalDevelopmental Biology
Issue number2
StatePublished - 15 Apr 2019
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2018 Elsevier Inc.


  • Apoptosis
  • Blastogenesis
  • Botryllus schlosseri
  • Brinapant
  • Budectomy
  • GDC-0152
  • IAP
  • Regeneration
  • Smac mimetics
  • Wnt agonist
  • Zooidectomy

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology
  • Cell Biology


Dive into the research topics of 'IAP genes partake weighty roles in the astogeny and whole body regeneration in the colonial urochordate Botryllus schlosseri'. Together they form a unique fingerprint.

Cite this