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Developmental biology of the Psammomys obesus pancreas: Cloning and expression of the Neurogenin-3 gene

Vedtofte, Louise; Bodvarsdottir, Thora B.; Karlsen, Allan LU and Heller, R. Scott (2007) In Journal of Histochemistry and Cytochemistry 55(1). p.97-104
Abstract
The desert gerbil Psammomys obesus, an established model of type 2 diabetes (M), has previously been shown to lack pancreatic and duodenal homeobox gene 1 (Pdx-1) expression. Pdx-1 deficiency leads to pancreas agenesis in both mice and humans. We have therefore further examined the pancreas of P. obesus during embryonic development. Using Pdx-1 antisera raised against evolutionary conserved epitopes, we failed to detect Pdx-1 immunoreactivity at any time points. However, at E14.5, Nkx6.1 immunoreactivity marks the nuclei of all epithelial cells of the ventral and dorsal pancreatic buds and the only endocrine cell types found at this time point are glucagon and PYY. At E18.5 the pancreas is well branched and both glucagon- and... (More)
The desert gerbil Psammomys obesus, an established model of type 2 diabetes (M), has previously been shown to lack pancreatic and duodenal homeobox gene 1 (Pdx-1) expression. Pdx-1 deficiency leads to pancreas agenesis in both mice and humans. We have therefore further examined the pancreas of P. obesus during embryonic development. Using Pdx-1 antisera raised against evolutionary conserved epitopes, we failed to detect Pdx-1 immunoreactivity at any time points. However, at E14.5, Nkx6.1 immunoreactivity marks the nuclei of all epithelial cells of the ventral and dorsal pancreatic buds and the only endocrine cell types found at this time point are glucagon and PYY. At E18.5 the pancreas is well branched and both glucagon- and ghrelin-positive cells are scattered or found in clusters, whereas insulin-positive cells are not found. At E22.5, the acini of the exocrine pancreas are starting to mature, and amylase and carboxypeptidase A immunoreactivity is found scattered and not in all acini. Ghrelin-, glucagon-, PYY-, gastrin-, somatostatin (SS)-, pancreatic poly-peptide (PP)-, and insulin-immunoreactive cells are found scattered or in small groups within or lining the developing ductal epithelium as marked by cytokeratin 19. Using degenerate PCR, the P. obesus Neurogenin-3 (Ngn-3) gene was cloned. Nucleotide and amino acid sequences show high homology with known Ngn-3 sequences. Using specific antiserum, we can observe that Ngn-3-immunoreactive cells are rare at E14.5 but readily detectable at E18.5 and E22.5. In conclusion, despite the lack of detection of Pdx-1, the P. obesus pancreas develops similarly to Muridae species, and the Ngn-3 sequence and expression pattern is highly conserved in P. obesus. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
glucagon, developmental biology, type 2 diabetes, Psammomys obesus, neurogenin-3, sand rat, pancreas, insulin
in
Journal of Histochemistry and Cytochemistry
volume
55
issue
1
pages
97 - 104
publisher
Histochemical Society
external identifiers
  • wos:000243018400010
  • scopus:33845941716
ISSN
0022-1554
DOI
10.1369/jhc.6A7073.2006
language
English
LU publication?
yes
id
07bbd467-feda-41b4-80c1-e9c8078c949f (old id 681581)
date added to LUP
2008-01-03 09:58:25
date last changed
2017-07-30 04:37:21
@article{07bbd467-feda-41b4-80c1-e9c8078c949f,
  abstract     = {The desert gerbil Psammomys obesus, an established model of type 2 diabetes (M), has previously been shown to lack pancreatic and duodenal homeobox gene 1 (Pdx-1) expression. Pdx-1 deficiency leads to pancreas agenesis in both mice and humans. We have therefore further examined the pancreas of P. obesus during embryonic development. Using Pdx-1 antisera raised against evolutionary conserved epitopes, we failed to detect Pdx-1 immunoreactivity at any time points. However, at E14.5, Nkx6.1 immunoreactivity marks the nuclei of all epithelial cells of the ventral and dorsal pancreatic buds and the only endocrine cell types found at this time point are glucagon and PYY. At E18.5 the pancreas is well branched and both glucagon- and ghrelin-positive cells are scattered or found in clusters, whereas insulin-positive cells are not found. At E22.5, the acini of the exocrine pancreas are starting to mature, and amylase and carboxypeptidase A immunoreactivity is found scattered and not in all acini. Ghrelin-, glucagon-, PYY-, gastrin-, somatostatin (SS)-, pancreatic poly-peptide (PP)-, and insulin-immunoreactive cells are found scattered or in small groups within or lining the developing ductal epithelium as marked by cytokeratin 19. Using degenerate PCR, the P. obesus Neurogenin-3 (Ngn-3) gene was cloned. Nucleotide and amino acid sequences show high homology with known Ngn-3 sequences. Using specific antiserum, we can observe that Ngn-3-immunoreactive cells are rare at E14.5 but readily detectable at E18.5 and E22.5. In conclusion, despite the lack of detection of Pdx-1, the P. obesus pancreas develops similarly to Muridae species, and the Ngn-3 sequence and expression pattern is highly conserved in P. obesus.},
  author       = {Vedtofte, Louise and Bodvarsdottir, Thora B. and Karlsen, Allan and Heller, R. Scott},
  issn         = {0022-1554},
  keyword      = {glucagon,developmental biology,type 2 diabetes,Psammomys obesus,neurogenin-3,sand rat,pancreas,insulin},
  language     = {eng},
  number       = {1},
  pages        = {97--104},
  publisher    = {Histochemical Society},
  series       = {Journal of Histochemistry and Cytochemistry},
  title        = {Developmental biology of the Psammomys obesus pancreas: Cloning and expression of the Neurogenin-3 gene},
  url          = {http://dx.doi.org/10.1369/jhc.6A7073.2006},
  volume       = {55},
  year         = {2007},
}