Chromosomal localization of Celsr2 and Celsr3 in the mouse; Celsr3 is
a candidate for the tippy (tip) lethal mutant on Chromosome 9
Caroline J. Formstone,
* Jane Barclay,
Peter F.R. Little
Department of Biochemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London, SW7 2AZ, UK
Department of Paediatrics, University College, The Rayne Institute, 5 University Street, London, WC1E 6JJ, UK
Received: 19 November 1999 / Accepted: 26 January 2000
An exciting new and unique class of developmentally regulated
adhesion-based signaling molecules has been identified recently
with the isolation of a number of related cadherin containing
seven-pass transmembrane proteins in vertebrates (in the mouse
Celsr1 and flamingo, and in the rat MEGF2 (Hadjantonakis et al.
1997, 1998; Nakayama et al. 1998; Usui et al. 1999) and inverte-
brates (Hadjantonakis et al. 1998; Usui et al. 1999). Analysis of the
gene isolated from Drosophila, flamingo (fmi), has demonstrated
an important role in regulating the structurally related 7TM recep-
tor, frizzled (fz), to establish polar cell polarity within the Dro-
sophila wing and has indicated that this gene is essential for em-
bryogenesis via its role in neural development (Barnes et al. 1998).
In the mouse, we have identified a three-member gene family
(Celsr1, 2, and 3; Hadjantonakis et al. 1997; Formstone and Little,
manuscript in preparation). Studies on their spatial and temporal
patterns of mRNA expression have implicated them in a number of
developmental processes such as compartmentation of the central
nervous system (CNS) and in facial development (Hadjantonakis
et al. 1998; Formstone and Little, manuscript in preparation).
Celsr1 has been shown previously to map to mouse Chromosome
(Chr) 15 (Hadjantonakis et al. 1997) and is considered a candidate
for the now extinct gastrulation mutant, Blind (Bld; Watson 1968).
The human ortholog, CELSR1, is located on Chr 22q13 close to a
series of deletions that are associated with phenotypic defects such
as developmental delay, hypotonia, and dysmorphic facial features
(Hadjantonakis et al. 1997).
As an initial step towards defining a function for Celsr2 and
Celsr3, we sought to compare the expression of the Celsr family in
various adult tissues by RT-PCR analysis and to determine the
map position of both mouse and human orthologs.
Expression. Previous analyses of expression of the Celsr gene
family have concentrated primarily on embryonic tissues (Hadjan-
tonakis et al. 1997, 1998; Formstone and Little, manuscript in
preparation). Northern blot analyses of Celsr2 and Celsr3 or-
thologs in the adult rat (MEGF3 and MEGF2 respectively) have
been reported and demonstrate the existence of large mRNA spe-
cies of approximately 12 and 13 kb within the rat brain (Nakayama
et al. 1998). Here we have used RT-PCR for the expression analy-
sis of Celsr family members within the adult mouse (Table 1).
These data are consistent with data obtained from studies on their
expression during embryonic development by in situ hybridization
of whole embryos and sectioned tissue (Formstone and Little,
manuscript in preparation). Celsr1 and Celsr2 expression is found
in both the nervous system and within tissues undergoing epithe-
lial-mesenchymal interaction, whereas Celsr3 transcripts are re-
stricted to sites of active neurogenesis within the developing
mouse embryo (Formstone and Little, manuscript in preparation).
Chromosomal mapping of Celsr2 and Celsr3. The mouse Celsr2
and Celsr3 genes were mapped with the EUCIB (European
Interspecific Backcross) panel (www.hgmp.mrc.ac.uk./Mbx/
MbxHomepage.html). Their orthologs in human, CELSR2 and
CELSR3, were mapped with somatic cell and Genebridge 4 hybrid
panels (Kelsall et al. 1998; Gyapay et al. 1996).
Celsr2. In the interspecific backcross, analysis of 68 progeny po-
sitioned Celsr2 between D3Mit13 and D3Mit145 on mouse Chr 3
(lod > 6, Fig. 1a). No mouse mutations have, as yet, been identified
within this region.
CELSR2. Mapping in the human was performed initially with so-
matic cell hybrids assigning CELSR2 to Chr 1. High-resolution
mapping was subsequently performed with the Genebridge 4 ra-
diation hybrid panel. Radiation hybrid mapping places CELSR2 at
1p21-13, 3.05cR from CHLC.GCT8C07 (lod > 3, Fig. 1a). A break
in conserved linkage with the mouse within this region of human
Chr 1 enabled us to finely map CELSR2 to 1p21 (Fig. 1a).
*Present address: Department of Developmental Neurobiology, Hodgkin
Building, Guy’s Campus, Kings College, London, SE1 9RT, UK.
Correspondence to: P.F.R. Little; e-mail: firstname.lastname@example.org
Table 1. RT-PCR analysis of the Celsr family within embryonic and adult
Celsr1 Celsr2 Celsr3
Mouse embryo + + +
Brain + + +
Spinal cord + + +
Eye + + +
Heart − ± −
Lung + + −
Kidney + + −
Liver − − −
Spleen + + −
To avoid PCR amplification of contaminating DNA from RNA samples, primers were
designed to span a number of exons. HPRT was used as a control for contaminating
DNA and to standardize the quantity of initial RNA amounts. RT-PCR data are a
result of three separate experiments with three different samples of RNA from each
tissue; (+) high levels of PCR product; (±) low levels of PCR product; (−) no PCR
product detected. Celsr1 primers were as reported previously (Hadjantonakis et al.
1997). PCR conditions for Celsr1 and HPRT were as described (Hadjantonakis et al.
1997). Celsr2 and Celsr3 primers are forward: agtgtcttcctgtacatcc; reverse: cactctg-
gtcatcttccaggg (approximately 600 bp fragment) and forward: ctgacttctgctggatctcc;
reverse; cactgaagagacggtagagg (approximately 480-bp fragment) respectively, de-
rived from the cytoplasmic domain of each gene. Forty cycles of PCR were performed
under standard conditions for all analyses performed; annealing temperatures for
Celsr2 and Celsr3 were 56°C with 1 m
© Springer-Verlag New York Inc. 2000Mammalian Genome 11, 392–394 (2000).