ing this critical window of development by produc- 
ing two-dimensional gel electrophoresis protein 
profiles of embryos at half-day intervals (days 7 to 
10). This resource provides a basis of comparison 
for examination of effects of genetic mutation or 
mutagenic/teratogenic agents. Dr. Kurnit has shown 
that there is a unique protein pattern for each half- 
day time point, with a burst of novel protein syn- 
thesis on day 8. This database is being used to ex- 
amine proteins affected by the iv murine mutation, 
which are therefore potential candidates for play- 
ing a role in determination of laterality and spatial 
PUBLICATIONS 
interrelationships of the internal organs. The ef- 
fects of the mutagen retinoic acid, which produces 
situs inversus similar to the iv mutation as one of 
its effects, are also being examined with this 
database. Multiple quantitative alterations caused 
by the iv gene on day 8.5 have been documented, 
and several of these overlap alterations caused by a 
retinoic acid phenocopy of the iv gene. 
Dr. Kurnit is also Professor of Pediatrics and 
Human Genetics at the University of Michigan Med- 
ical School. 
Articles 
Buraczynska, M., Stewart, G.D., Sherman, S., Freeman, V, Grantham, M., Uchida, I., Hassold, T, and Kurnit, 
D.M. 1989. Studying nondisjunction of chromosome 21 with cytogenetic markers on the short arm and 
DNA markers encompassing the long arm. Prog Clin Biol Res 311:101-113. 
Gait, J., Boyd, E., Connor, J.M., and Ferguson-Smith, M.A. 1989. Isolation of chromosome 21-specific DNA 
probes and their use in the analysis of nondisjunction in Down syndrome. Hum Genet 81:113-119. 
Phelan, M.C., Morton, C.C., Stevenson, R.E., Tanzi, R.E., Stewart, G.D., Watkins, PC., Gusella, J.F., and Amos, 
J.A. 1988. Molecular and cytogenetic characterization of a de novo t(5p;21q) in a patient previously diag- 
nosed as monosomy 21. Am J Hum Genet 43:511-519. 
Tanzi, R.E., Haines, J. L., Watkins, PC, Stewart, G.D. , Wallace, M.R., Hallewell, R., Wong, C, Wexler, N.S., Con- 
nealy P.M., and Gusella, J. F. 1988. Genetic linkage map of human chromosome 21. Genomics ^-.129-1^6. 
Wong, C, Kazazian, H.H., Jr., Stetten, G., Earnshaw, WC, Van Keuren, M.L., and Antonarakis, S.E. 1989. Mo- 
lecular mechanism in the formation of a human ring chromosome 21. Proc Natl Acad Sci USA 86:1914- 
1918. 
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