Mutations in the escargot (esg) locus, which codes for a zinc-finger-containing protein with similarity to the product of the snail gene, cause a variety of defects in adult structures such as loss of abdominal cuticle and malformation of the wings and legs. esg RNA is expressed in wing, haltere, leg and genital imaginal discs and in abdominal histoblast nests in the embryo. Expression in imaginal tissues is also found in third instar larvae. In esg mutant larvae, normally diploid abdominal histoblasts replicate their DNA without cell division and become similar in appearance to the polytene larval epidermal cells. A similar phenotype was also found in imaginal discs of larvae mutant for both esg and the Drosophila raf gene. These results suggest that one of the normal functions of esg may be the maintenance of diploidy in imaginal cells.

Reference

Ashburner
M.
,
Thompson
P.
,
Roote
J.
,
Lasko
P. F.
,
Grau
Y.
,
El Messal
M.
,
Roth
S.
,
Simpson
P.
(
1990
)
The genetics of a small autosomal region of Drosophila melanogaster containing the structural gene for alcohol dehydrogenase. VII. Characterization of the region around the snail and the cactus loci.
Genetics
126
,
679
694
Bier
E.
,
Vaessin
H.
,
Shepherd
S.
,
Lee
K.
,
McCall
K.
,
Barbel
S.
,
Ackerman
L.
,
Carretto
R.
,
Uemara
T.
,
Grell
E.
,
Jan
L. Y.
,
Jan
Y. N.
(
1989
)
Searching for pattern and mutation in the Drosophila genome with a P-lacZ vector.
Genes Dev
3
,
1273
1287
Ephrussi
A.
,
Dickinson
L.
,
Lehman
R.
(
1991
)
oskar organizes the germ plasm and directs localization of the posterior determinant nanos.
Cell
66
,
37
50
Nishida
Y.
,
Hata
M.
,
Ayaki
T.
,
Ryo
H.
,
Yamagata
M.
,
Shimizu
K.
,
Nishizuka
Y.
(
1988
)
Proliferation of both somatic and germ cells is affected in the Drosophila mutant of the raf proto-oncogene.
EMBO J
7
,
775
781
Pearson
M. J.
(
1974
)
The abdominal epidermis of Calliphora erythrocephala (Diptera). I Polyteny and growth in the laval cells.
J. Cell Sci
16
,
113
131
Robertson
H. M.
,
Preston
C. R.
,
Phillis
R. W.
,
Johnson-Schlitz
D. M.
,
Benz
W. K.
,
Engels
W. R.
(
1988
)
A stable source of P element transposase in Drosophila melanogaster.
Genetics
118
,
461
470
Tautz
D.
,
Pfeifle
C.
(
1989
)
A non-radioactive in situ hybridization method for the localization of specific RNAs in Drosophila embryos reveals translational control of the segmentation gene hunchback.
Chromosoma
98
,
81
85
Tomlinson
A.
,
Ready
D. F.
(
1987
)
Neuronal differentiation in the Drosophila ommatidium.
Dev. Biol
120
,
366
376
Whiteley
M.
,
Noguchi
P. D.
,
Sensabaugh
S. M.
,
Odenwald
W. F.
,
Kassis
J. A.
(
1992
)
The Drosophila gene escargot encodes a zinc finger motif found in snail -related genes.
Mech. Dev
36
,
117
127
This content is only available via PDF.