View larger version (81K):
[in a new window]
|
Fig. 1. NKX6.2 expression in the developing mouse pancreas. (A,F) lacZ
expression, identified by X-gal staining in Nkx6.2tlz/+
embryos. Immunofluorescence detection of NKX6.2 (B-E, G-J; confocal images) or
ß-galactosidase (ß-gal) (K-M) together with various pancreatic
markers. (N) Amylase only. (A) At E9.5, lacZ expression is detectable
in the dorsal (dp) and ventral (vp) pancreatic anlagen. (B) Anti-ß-gal
and anti-NKX6.2 staining show complete overlap in the stomach (s) and dorsal
pancreas (dp) in Nkx6.2tlz/+ embryos. In the pancreas,
NKX6.2 is detected in a subset of PDX1+ cells (yellow cells in C),
but not in glucagon+ (Glc) cells at E10.5 (arrowhead in D). NKX6.2
is also found in the stomach epithelium (C). At E12.5, NKX6.2 expression is
largely restricted to the glucagon+ cells (E). At E15.5,
lacZ expression is predominantly detected in the dorsal, but also in
cells of the ventral pancreas (vp) (F), but also found in the distal stomach
and duodenum (d) (F). (G,H) NKX6.2 is absent from both NGN3+ (G)
and insulin+ (Ins) cells (arrowhead in H). By contrast, NKX6.2
colocalizes with glucagon and amylase (Amy) (I). Not all glucagon+
and amylase+ cells express NKX6.2 (arrowheads in I). At E15.5, the
majority of NKX6.2+ cells co-express PDX1 (J). In contrast to
NKX6.2, ß-gal occasionally colocalizes with NGN3 (open arrowhead in K)
and insulin (open arrowhead in L) in Nkx6.2tlz/+ embryos.
However, the majority of NGN3+ or insulin+ cells are
ß-gal negative (K, and arrowhead in L). Like NKX6.2, ß-gal is
expressed in a subset of glucagon+ cells (open arrowhead indicates
co-expressing cell; arrowhead indicates non-co-expressing cell in M) and in
exocrine cells, as shown by co-localization of ß-gal and amylase on
adjacent sections (arrow in M and N). Scale bar: 20 µm.
|
- and ß-cell development in the pancreas
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
- and ß-cell
development. Confocal images showing immunofluorescence detection of glucagon
(Glc) and insulin (Ins) in pancreas from wild-type, Nkx6.2-/-,
Nkx6.1-/- and
Nkx6.1-/-;Nkx6.2-/- embryos at E18.5 (A-D) and
E14.5 (G-J). Nkx6.2-/- (B,H) and wild-type (A,G) embryos
show similar numbers and organization of insulin+ and
glucagon+ cells in the pancreas. In Nkx6.1-/-
(I) and Nkx6.1-/-;Nkx6.2-/- (J) embryos,
glucagon+ cells are normal, but insulin+ cells are
reduced in number at E14.5. At E18.5,
Nkx6.1-/-;Nkx6.2-/- embryos (D) show a further
reduction in insulin+ cells as well as a reduction in
glucagon+ cells compared with Nkx6.1-/- embryos
(C). (E) Quantification of hormone+ cells in wild type and
Nkx6 compound mutants at E18.5. The average number of
glucagon+ and insulin+ cells per section was determined
by counting immunofluorescence-labeled cells. Five independent pancreata were
evaluated for each genotype and the average number of cells in wild type
arbitrarily set to 100. (F,K) Quantitative RT-PCR analysis of insulin and
glucagon in pancreata from Nkx6 compound mutants at E18.5 (F) and
E15.5 (K). Hormone expression levels are shown relative to the levels for
-actin mRNA from two independent measurements of four pancreata for
each genotype. For comparison, values are shown as a % of wild type, which was
arbitrarily set to 100%. At E18.5, insulin mRNA levels were 6.2±0.78%
of wild type in Nkx6.1-/- and 1.7±0.30% of wild
type in Nkx6.1-/-;Nkx6.2-/- embryos (F),
compared with 2.2±0.16% of wild type in Nkx6.1-/-
and 2.0±0.84% of wild type in
Nkx6.1-/-;Nkx6.2-/- embryos at E15.5 (K). The
values shown represent mean±s.e.m. *P<0.01, as
determined by Student's t-test. Scale bar: 50 µm.
