Mouse Chromosome 16
Roger H. Reeves,
* Deborah E. Cabin
Department of Physiology, P203, Johns Hopkins School of Medicine, 725 N. Wolfe St., Baltimore, MD 21205 USA
Laboratory of Genetic Disease Research, National Human Genome Research Institute, 49 Convent Dr., 49B67, MSC 4472,
Bethesda, MD 20892-4472, USA
Submitted: 1 December 1998
The eighth report for mouse Chromosome 16 (Chr 16) includes
706 markers, of which 102 are new this year. All but two of these
markers are localized on the chromosome, and several markers
listed as syntenic last year are localized on this year’s map (for
example, Hlcs and Hgd). The major change from previous years is
that 56 of the new markers, more than half, have been localized on
physical maps. This reflects efforts to physically map two regions
of the chromosome, the region with shared linkage on human Chr
22 (the D16Ais markers) and the distal part of the chromosome
with shared linkage on human Chr 21 (the D16Jhu markers). These
projects have also mapped a number of existing markers to higher
precision on physical maps, for example Comt and Erg.
The positions assigned here to the physically mapped markers
show order and approximate physical distances, but are not to
precise scale. The regions being physically mapped reflect interest
in using the mouse for models of human disease; in these cases, the
diseases of interest being the DiGeorge and Down syndromes.
Fifteen new genes have been mapped on Chr 16 in the past
year as well as 31 new expressed sequence tags, most from the
ERATO Doi effort in Japan (the D16Ertd markers). The availabil-
ity of radiation hybrid mapping panels for mouse should allow
more rapid mapping of molecular markers in the future. New genes
found in regions with physical coverage can also be very easily
and accurately mapped.
The rationale for marker localization and confidence assign-
ments on the Committee Report map has been explained at length
in previous reports. Briefly, it is challenging to integrate markers
from different crosses that have few markers in common. Markers
that are placed with reasonable certainty in relation to flanking
markers, or are non-recombinant with such markers, are indicated
by a confidence rating of 1. Markers mapped on well-characterized
physical maps are precisely ordered and received a confidence
rating of 1. Markers mapped on crosses with fewer commonly used
markers lie in the general region around the given position, but
order with respect to all flanking markers cannot be determined.
These are given a rating of 2. The lowest confidence rating of 3 is
given to markers localized only to a broad area by methods such as
QTL analysis, in situ hybridization, somatic cell hybrid analysis, or
markers mapped on crosses with few markers in common with
other crosses. Markers with a confidence of 3 are assigned a spe-
cific position due to constraints in presentation, but should be
assumed only to fall in the general region where they are posi-
One hundred eleven of the markers on mouse Chr16 now have
known human homologues. The regions of conserved synteny with
human chromosomes have been extended slightly in two cases.
STCH, the proximal-most known gene on human Chr 21, extends
the shared homology with mouse Chr 16 proximally, and
D16Xrf306, though not well-localized, is now the proximal-most
gene in the human Chr 16 region. Physical mapping demonstrates
that D16Mit28 and 29, distal to Dv13 by recombinational mapping,
lie proximal to Thpo, making Dvl3 the proximal-most gene in the
human Chr 3 region. Eif4b at position 14.2 has a supposed human
homologue on 18p11.2, but until the human mapping is confirmed
and other genes from human Chr 18 mapped on mouse Chr 16, this
cannot be considered a new region of shared linkage with Chr 16.
The regions of shared homologies are: a) human Chr 16p13: from
D16Xrf306 at 1.7 to Ntan at 8.7; b) human Chr 8q11: Cebpd at 9
to Slugh at 9.4; c) human Chr 22q11.2: Vpreb1 at 9.8 to Igl-C1 at
13; d) human Chr 3q28q-13.3: Dvl3 at 13.1 to Pit1 at 43.5; and e)
human Chr 21q11.2-q22.3: Stch at 47.2 to Mx2 at 69.7. In addi-
tion, the first marker from rat, D16R11Mgh5, appears on the Chr
16 map at position 43. Six new traits appear on the map for a total
of 21: Tlsr5, Epd1, wsnp, nct, Cplaq2, and lpd1 and lpd2, which
are counted as a single trait as they define the ends of a rearrange-
ment producing the lipid defect. This number will likely increase
in the future as loci identified in large-scale ENU mutagenesis
projects are mapped.
The Chr 16 map has been expanded this year from 70 to 72
map units. This is to better resolve orders of markers mapped on
high density physical maps.
Acknowledgments. This work was supported in part by PHS awards
HD24605 and HG00405.
* Committee Chair
Correspondence to: R.H. Reeves
Mammalian Genome 10, 957 (1999).
© Springer-Verlag New York Inc. 1999