Fate maps of ventral and dorsal pancreatic progenitor cells in early somite stage mouse embryos.
The origins of liver progenitor cells have been extensively studied, but evidence on the origin of pancreatic precursor cells is currently limited. Pancreatic and duodenal homeobox gene 1 (Pdx1) is one of the earliest known markers for the pancreas. A transgenic mouse line expressing green fluorescent protein (GFP) under the control of the Pdx1 promoter showed that Pdx1/GFP expression was first observed in the mid-region of the anterior intestinal portal (AIP) lip at embryonic day (E) 8.5 at the 5-6 somite stage (ss). The liver progenitors were confirmed to originate from separate domains at the lateral endoderm and the inner part of the medial AIP as previously reported (Tremblay and Zaret, 2005), which turned out to lie caudally to the Pdx1/GFP-expressing domain. To confirm if the early Pdx1/GFP-positive cells give rise to the pancreatic bud, we labeled the cells on the lip of the AIP using the carbocyanine dye CM-DiI and traced their fates in 1-4 ss, 5-6 ss and 7-9 ss E8.5 embryos using an ex utero whole embryo culture method. At 1 ss, the ventral pancreas progenitors were observed in the lateral endoderm, not yet being segregated from the liver or gut progenitors. Cells that contributed solely to the ventral pancreas first appeared at the AIP lip from 5 ss. At 5-6 ss, cells from the medial of the AIP lip contributed to the ventral pancreas. The pancreas fate region become narrower as development progresses. At 7-9 ss, the cells contributing to the ventral pancreas resided in a narrow region of the AIP lip. From 5 ss, the right flanking region contributes to the posterior gut, and the left flanking region contributes to the anterior gut. Dorsal pancreatic progenitors originate from the dorsal endoderm at the 3-6 somite level at 7-9 ss, though they have not yet diverged from the dorsal gut progenitors at this stage.
Department of Stem Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Kumamoto 860-0811, Japan.
Rika
R
Miki
Tetsu
T
Yoshida
Kazuya
K
Murata
Shinya
S
Oki
Kazuhiko
K
Kume
Shoen
S
Kume
D000818:Animals; D000071616:CDX2 Transcription Factor; D046149:Embryo Culture Techniques; D004622:Embryo, Mammalian / Q000166:cytology; D047108:Embryonic Development; D004707:Endoderm / Q000166:cytology / Q000502:physiology; D005260:Female; D041981:Gastrointestinal Tract / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000096:biosynthesis; D051542:Hepatocyte Nuclear Factor 3-beta / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D008297:Male; D051379:Mice / Q000196:embryology*; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D038081:Organogenesis; D010179:Pancreas / Q000166:cytology* / Q000196:embryology / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis; D019170:Somites / Q000166:cytology / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism
D000071616:CDX2 Transcription Factor; C487514:Cdx2 protein, mouse; C496503:Foxa2 protein, mouse; D018398:Homeodomain Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D051542:Hepatocyte Nuclear Factor 3-beta; D049452:Green Fluorescent Proteins