From kcook@XXXX Fri Mar 01 18:11:41 2002
To: flybase-updates@XXXX
Subject: Phenotypes and complementation of zf30C mutations
Phenotypes and complementation of zf30C mutations
Kevin Cook
Bloomington Drosophila Stock Center, Indiana University
This report explores the phenotypes associated with P element insertions at
the zf30C gene. When I began my analysis, the Berkeley Drosophila Genome
Project (Adams et al, 2000; Spradling et al., 1999) had documented the
following facts. (1) The P{lacW}zf30Ck02506, P{lacW}zf30Ck02510,
P{EP}zf30CEP518 and P{EP}zf30CEP2228 insertions all map to the zf30C
gene. (2) The P{lacW}zf30Ck02506 and P{lacW}zf30Ck02510 are
nonindependent insertions and the chromosomes carrying the insertions
failed to complement for lethality. (3) The chromosomes carrying
P{lacW}zf30Ck02506 and P{lacW}zf30Ck02510 complemented Df(2L)30A-C and
Df(2L)s1402 for lethality, but failed to complement Df(2L)N22-5. (4) The
chromosome carrying P{lacW}zf30Ck02506 complemented Df(2L)N22-3 for
lethality.
Df(2L)30A-C deletes the pelo (Castrillon et al., 1993) and und (Cutforth
and Gaul, 1999) genes flanking zf30C, but Df(2L)30A-C complements
P{lacW}zf30Ck02506 and P{lacW}zf30Ck02510 for lethality (Adams et al,
2000; Spradling et al., 1999). This, and the fact that P{EP}zf30CEP518
and P{EP}zf30CEP2228 are homozygous viable, led me to examine crosses
between zf30C alleles and deletions of 30C. I found that the zf30C
mutations cause wing and female fertility phenotypes, but not lethality. My
observations are detailed below.
1. The severity of the zf30C alleles could be ranked
zf30Ck02506<zf30CEP518<zf30CEP2228 in terms of wing phenotype.
zf30Ck02506 in combination with Df(2L)30A-C, Df(2L)gamma7, Df(2L)N22-3 or
Df(2L)s1402 gave incompletely penetrant shortening of the L5 wing vein and
posterior crossvein. L5 vein shortening was seen in a minority of flies and
PCV shortening was uncommon. zf30CEP518 in combination with Df(2L)30A-C,
Df(2L)gamma7, Df(2L)N22-3, Df(2L)s1402, Df(2L)N22-5 or Df(2L)N22-14 had
slightly more penetrant L5 and PCV shortening and occasional shortening of
L2. In addition, I observed an incompletely penetrant outspread wing
phenotype. zf30CEP2228 in combination with Df(2L)30A-C, Df(2L)gamma7,
Df(2L)N22-3, Df(2L)s1402, Df(2L)N22-5 or Df(2L)N22-14 gave highly penetrant
L5, PCV and L2 shortening. Wings were usually outspread and, in the
severest cases, dragged on the ground. I saw some nicking of the wing margins.
2. zf30C alleles showed the same allelic strength
(zf30Ck02506<zf30CEP518<zf30CEP2228) regarding female fertility.
Females carrying zf30Ck02506 in combination with Df(2L)30A-C,
Df(2L)gamma7, Df(2L)N22-3 or Df(2L)s1402 were all fertile. Females carrying
zf30CEP518 in combination with Df(2L)30A-C, Df(2L)gamma7, Df(2L)N22-3,
Df(2L)s1402, Df(2L)N22-5 or Df(2L)N22-14 were either sterile or weakly
fertile. Females carrying zf30CEP2228 in combination with Df(2L)30A-C,
Df(2L)gamma7, Df(2L)N22-3, Df(2L)s1402, Df(2L)N22-5 or Df(2L)N22-14 were
invariably sterile. Females with any of the sterile genotypes laid a few
nonhatching eggs and had ovaries of normal size with no overt morphological
defects.
3. No male sterility was seen with any zf30C genotypes.
4. The phenotypes of zf30CEP518 and zf30CEP2228 in combination with
zf30Ck02506 were less severe than phenotypes in combination with the
deletions. No wing defects or female sterility was seen in
zf30CEP518/zf30Ck02506 flies. zf30CEP2228/zf30Ck02506 flies showed
only weakly penetrant L5 shortening or thinning, and females were fertile.
Consistent with the BDGP results, the chromosome carrying
P{lacW}zf30Ck02506 was lethal in combination with Df(2L)N22-5. It was
also lethal with Df(2L)N22-14. This indicates the presence of at least one
lethal mutation linked to the P{lacW}zf30Ck02506 insertion. The l(2)DB2
locus is probably mutated, since l(2)DB21 failed to complement the
chromosome carrying P{lacW}zf30Ck02506.
Dp(2;Y)cb50 was capable of at least partially rescuing the wing phenotypes
of the zf30C alleles in combination with Df(2L)s1402. Dp(2;Y)cb50;
zf30Ck02506/Df(2L)s1402 males were normal. Dp(2;Y)cb50;
zf30CEP518/Df(2L)s1402 males had normal wing veins, but extremely
outspread wings. Dp(2;Y)cb50; zf30CEP2228/Df(2L)s1402 males showed a
weakly penetrant vein shortening phenotype, and outspread wings. Curiously,
the outspread wing phenotype was more penetrant and pronounced in the
presence of the duplication than in its absence.
Loss-of-function alleles in the nearby und locus show a L5 shortening
phenotype similar to that of zf30C alleles. Nevertheless, complementation
tests between zf30Ck02506, zf30CEP518 or zf30CEP2228 and unddelta34
showed no abnormal phenotypes.
References:
Adams et al., 2000. The genome sequence of Drosophila melanogaster. Science
287: 2185-2195 (FBrf0126983).
Castrillon et al., 1993. Toward a molecular genetic analysis of
spermatogenesis in Drosophila melanogaster: characterization of
male-sterile mutants generated by single P element mutagenesis. Genetics
135: 489-505 (FBrf0064394).
Cutforth and Gaul, 1999. A methionine aminopeptidase and putative regulator
of translation initiation is required for cell growth and patterning in
Drosophila. Mech. Dev. 82(1,2): 23--28 (FBrf0108434).
Spradling et al., 1999. The Berkeley Drosophila genome project gene
disruption project. Single P-element insertions mutating 25% of vital
Drosophila genes. Genetics 153: 135-177 (FBrf0111489)
__________________________________________________________
Kevin Cook, Ph.D. Bloomington Drosophila Stock Center
Department of Biology http://flystocks.bio.indiana.edu
Jordan Hall 142
Indiana University 812-855-5782
1001 E. Third St. 812-855-2577 (fax)
Bloomington, IN 47405-3700 kcook@XXXX
