Xenopus insm1 is essential for gastrointestinal and pancreatic endocrine cell development.
In mammals, it has been well established that gastrointestinal and pancreatic endocrine cells are specified by a cascade of different transcription factors, but whether these same pathways (or linear relationships) operate in Xenopus is currently unknown. We recently identified the endocrine-specific zinc finger transcription factor insulinoma associated protein 1 (insm1) as a dorsal-enriched gene. We found that insm1 is expressed in the dorsal pancreas as early as NF28, making it one of the earliest markers to be localized to the dorsal pancreas. Through morpholino-mediated knockdown, we demonstrate that insm1 is essential for proper specification of both gastrointestinal and pancreatic endocrine cells. In addition, we place insm1 downstream of ngn3 and upstream of pax6 and neuroD in the endocrine cell transcription factor cascade. These are the first results showing that the endodermal endocrine cell development in Xenopus uses the same transcriptional cascade as in mammals.
Horb
Lori Dawn
LD
Laboratory of Molecular Organogenesis, Institut de Recherches Cliniques de Montréal, Montréal, QC Canada. marko.horb@ircm.qc.ca
Jarkji
Zeina H
ZH
Horb
Marko E
ME
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D019858:Enteroendocrine Cells / Q000166:cytology / Q000502:physiology; D041981:Gastrointestinal Tract / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D010179:Pancreas / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism*; D014982:Xenopus laevis / Q000033:anatomy & histology / Q000196:embryology / Q000378:metabolism
D015415:Biomarkers; C532313:INSM1 protein, Xenopus; D016376:Oligonucleotides, Antisense; D014157:Transcription Factors; D029867:Xenopus Proteins
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