scholarly journals Evidence of a dual function in fl(2)d, a gene needed for Sex-lethal expression in Drosophila melanogaster.

Genetics ◽  
1992 ◽  
Vol 130 (3) ◽  
pp. 597-612 ◽  
Author(s):  
B Granadino ◽  
A San Juán ◽  
P Santamaria ◽  
L Sánchez
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cells ◽  
Sensitive Period ◽  
Dual Function ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Loss Of Function ◽  
Germline Development ◽  
Suppression Effect ◽  
Pole Cells

Abstract In Drosophila melanogaster, the female sexual development of the soma and the germline requires the activity of the gene Sxl. The somatic cells need the function of the gene fl(2)d to follow the female developmental pathway, due to its involvement in the female-specific splicing of Sxl RNA. Here we report the analysis of both fl(2)d1 and fl(2)d2 mutations: (1) fl(2)d1 is a temperature-sensitive mutation lethal in females and semilethal in males; (2) fl(2)d2 is lethal in both sexes; (3) the fl(2)d1/fl(2)d2 constitution is temperature-sensitive and lethal in females, while semilethal in males. The temperature-sensitive period of fl(2)d1 in females expands the whole development. SxlM1 partially suppresses the lethality of fl(2)d1 homozygous females and that of fl(2)d1/fl(2)d2 constitution, whereas it does not suppress the lethality of fl(2)d2 homozygous females. The addition of extra Sxl+ copies does not increase the suppression effect of SxlM1. The fl(2)d1 mutation in homozygosis and the fl(2)d1/fl(2)d2 constitution, but not the fl(2)d2 in homozygosis, partially suppress the lethality of SxlM1 males. This suppression is not prevented by the addition of extra Sxl+ copies. The semilethality of both fl(2)d1 and fl(2)d1/fl(2)d2 males, and the lethality of fl(2)d2 males, is independent of Sxl function. There is no female synergistic lethality between mutations at fl(2)d and neither at sc or da. However, the female synergistic lethality between mutations at Sxl and either sc or da is increased by fl(2)d mutations. We have analyzed the effect of the fl(2)d mutations on the germline development of both females and males. For that purpose, we carried out the clonal analysis of fl(2)d1 in the germline. In addition, pole cells homozygous for fl(2)d2 were transplanted into wild-type host embryos, and we checked whether the mutant pole cells were capable of forming functional gametes. The results indicated that fl(2)d mutant germ cells cannot give rise to functional oocytes, while they can form functional sperm. Moreover, SxlM1 suppresses the sterility of the fl(2)d1 homozygous females developing at the permissive temperature. Thus, with respect to the development of the germline the fl(2)d mutations mimic the behavior of loss-of-function mutations at the gene Sxl. Females double heterozygous for fl(2)d and snf1621 are fully viable and fertile. fl(2)d2 in heterozygosis partially suppresses the phenotype of female germ cells homozygous for snf1621; however, this is not the case with the fl(2)d1 mutation. The fl(2)d mutations partially suppress the phenotype of the female germ cells homozygous for ovoDIrSI.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Studies on male recombination in a Southern Greek Drosophila melanogaster population: (a) Effect of temperature. (b) Suppression of male recombination in reciprocal crosses

1977 ◽  
Vol 29 (3) ◽  
pp. 231-238 ◽  
Author(s):  
George Yannopoulos ◽  
Michael Pelecanos
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cells ◽  
Larval Stage ◽  
Effect Of Temperature ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Cytoplasmic Factor ◽  
Male Recombination ◽  
The City ◽  
North Western

SUMMARYA second chromosome of Drosophila melanogaster (symbol 31.1) isolated from a natural population of North-Western Peloponnesus (at a distance of 8 km from the city of Patras) was found to induce recombination in heterozygous males, both in the second and third chromosomes. The present study also revealed the following points. (1) The phenomenon is temperature-sensitive with higher male recombination at 29 °C than at 25 or 15 °C. (2) The temperature-sensitive period is during the larval stage where premeiotic divisions of germ cells take place. (3) Suppression of male recombination in both the second and third chromosomes occurred when 31.1/CyL4 females were used in the matings, and (4) the suppression of male recombination is caused by a cytoplasmic factor of the CyL4/Pm stock.

scholarly journals Hybrid dysgenesis in Drosophila melanogaster: partial sterility associated with embryo lethality in the P-M system

1984 ◽  
Vol 44 (1) ◽  
pp. 11-28 ◽  
Author(s):  
Margaret G. Kidwell
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
Gonadal Development ◽  
Hybrid Dysgenesis ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Hybrid Progeny ◽  
Partial Sterility ◽  
Embryo Lethality ◽  
Response To Temperature

SummaryVariable frequencies of unhatched eggs were observed to be produced by a number of F1 interstrain hybrids. This type of partial sterility resulting from F2 embryo death was found to be associated with the P-M system of hybrid dysgenesis. Dysgenic hybrid progeny of crosses between M strain females and P strain males may therefore have reduced fertility due to the disruption of development at two different stages: early F1 gonadal development and early F2 embryo development. These disruptions result in the previously described F1 gonadal dysgenesis (GD sterility) and F2 embryo lethality (EL sterility) respectively. The two morphologically distinct types of P-M-associated sterility differ in their patterns of response to F1 developmental temperature, and the temperature-sensitive period for EL sterility occurs considerably later in F1 development than for GD sterility. EL sterility is similar to SF sterility, which is associated with the I–R system of hybrid dysgenesis in that both result from death during early F2 embryogenesis. However, EL sterility differs from SF sterility in not being restricted to hybrids of the female sex and in showing different patterns of response to temperature and ageing in the F1 generation. Some implications of the existence of EL sterility for methods of strain classification in the I–R system are explored.

scholarly journals Genetic analysis of the enhancer of zeste locus and its role in gene regulation in Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 185-199 ◽  
Author(s):  
R S Jones ◽  
W M Gelbart
Keyword(s):  
Gene Regulation ◽  
Drosophila Melanogaster ◽  
Ectopic Expression ◽  
Polycomb Group ◽  
Temperature Sensitive ◽  
Loss Of Function ◽  
Eye Color ◽  
Polycomb Group Genes ◽  
Enhancer Of Zeste ◽  
Gene Complexes

Abstract The Enhancer of zeste [E(z)] locus of Drosophila melanogaster is implicated in multiple examples of gene regulation during development. First identified as dominant gain-of-function modifiers of the zeste1-white (z-w) interaction, mutant E(z) alleles also produce homeotic transformations. Reduction of E(z)+ activity leads to both suppression of the z-w interaction and ectopic expression of segment identity genes of the Antennapedia and bithorax gene complexes. This latter effect defines E(z) as a member of the Polycomb-group of genes. Analysis of E(z)S2, a temperature-sensitive E(z) allele, reveals that both maternally and zygotically produced E(z)+ activity is required to correctly regulate the segment identity genes during embryonic and imaginal development. As has been shown for other Polycomb-group genes, E(z)+ is required not to initiate the pattern of these genes, but rather to maintain their repressed state. We propose that the E(z) loss-of-function eye color and homeotic phenotypes may both be due to gene derepression, and that the E(z)+ product may be a general repressing factor required for both examples of negative gene regulation.

THE DEVELOPMENTAL GENETICS OF THE TEMPERATURE-SENSITIVE LETHAL ALLELE OF THE SUPPRESSOR OF FORKED, l(1)su(f)ts67g, IN DROSOPHILA MELANOGASTER

Genetics ◽  
1974 ◽  
Vol 76 (3) ◽  
pp. 487-510
Author(s):  
Marianne E Dudick ◽  
Theodore R F Wright ◽  
Lynda Lee Brothers
Keyword(s):  
Drosophila Melanogaster ◽  
Ribosomal Protein ◽  
Sensitive Period ◽  
Developmental Genetics ◽  
Temperature Sensitive ◽  
Wild Type Allele ◽  
Wild Type ◽  
Type Allele ◽  
Lethal Allele

ABSTRACT A temperature-sensitive lethal allele of suppressor of forked, l(1)su(f)ts67g (ts67), has been discovered and characterized as follows: Flies which are hemizygous for ts67 live at 18° and 25° but die at 30° primarily as larvae. The temperature-sensitive period for ts67 homozygotes or hemizygotes begins in second instar and ends at pupation. ts67 is lethal at 30° when heterozygous with suppressor of forked (su(f)), a deficiency for suppressor of forked (su(f)  -), and a non-conditional lethal allele of suppressor of forked (3DES). It is viable at 30° when heterozygous with the wild-type allele of suppressor of forked. At 25° but not at 18° forked bristles are suppressed in flies of the following genotypes: fsts67/Y, fsts67/fsts67, fsts67/fssu(f), futs67/fs3DES, futs67/fssu(f)  -, futs67/fssu(f). There is some suppression of forked bristles at 25° in the heterozygote, fsts67/fs+su(f). The forked bristle phenotype is not suppressed at either temperature in flies of the genotypes futs67/Y, futs67/futs67/ (fs and fu indicating suppressible and unsuppressible alleles of forked). The temperature-sensitive period for suppression of forked bristles begins at pupation and extends through the period of bristle synthesis. The deficiency phenotype (bristles reduced in size or absent, wing wrinkled or blistered, eyes rough) typical of flies of the genotype fssu(f)/fssu(f)  - at 18° and 25°, is exhibited by flies of the genotypes fsts67/fssu(f)  - at 25° and futs67/fssu(f) at 29°. An allele of lozenge (lz1) which can be suppressed by su(f) is suppressed at 25° but not at 18° in lz1ts67/Y males. ts67 homozygous females are fertile at 25° but sterile at 30°. The hypothesis is discussed that the su(f) locus codes for a ribosomal protein and that suppression and enhancement are affected by mutations at the locus by mutant ribosome-induced misreading. The possibility is presented that ts67 may be used to determine the translation time in development of any gene.

scholarly journals Temperature sensitivity of negative segregation distortion in Drosophila melanogaster.

Genetics ◽  
1993 ◽  
Vol 135 (3) ◽  
pp. 831-841 ◽  
Author(s):  
Y Hiraizumi
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Segregation Distortion ◽  
Current Model ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Absolute Increase ◽  
Negative Segregation ◽  
Absolute Reduction ◽  
Radical Revision

Abstract Previous work has shown that the direction of segregation distortion in the SD (Segregation Distorter) system in Drosophila melanogaster can sometimes be reversed, but this was found only with rather weak distorters and the effect was not large. The present study reports large negative segregation distortion in a strong distorter, SD-72 chromosome. In the presence of a specific X chromosome, supp-X(SD), the proportion, k, of SD-72 chromosomes recovered from the SD-72/cn bw males ranges from 0.99 at 20 degrees to 0.11 at 28.5 degrees, whereas with a standard-X chromosome, k ranges from 0.99 to 0.95 for the same temperature range. The temperature-sensitive period is during spermiogenesis. Using a mating system in which the sperm supply is nearly exhausted, it was shown that the negative distortion at high temperatures is due to an absolute reduction in the number of SD-72 chromosomes and an absolute increase in the number of cn bw chromosomes recovered. After adjusting for non-SD-related temperature effects, the amount of decrease in the number of SD-72 progeny is nearly the same as the amount of increase in the number of cn bw progeny, suggesting that the dysfunction switches from a spermatid carrying one homolog to one carrying the other. Negative distortion requires a radical revision of current hypotheses for the mechanism of segregation distortion and a possible modification of the current model is suggested, based on differential recovery of dysfunction in the two homologs during spermiogenesis.

Temperature-sensitive periods of mutations affecting cell division in Tetrahymena thermophila

1980 ◽  
Vol 43 (1) ◽  
pp. 59-74 ◽  
Author(s):  
J. Frankel ◽  
J. Mohler ◽  
A.K. Frankel
Keyword(s):  
Cell Division ◽  
Tetrahymena Thermophila ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Physiological Effects ◽  
Sensitive Periods ◽  
Phenotypic Abnormality ◽  
Mutant Cells

Temperature-sensitive periods were determined by application of temperature shifts and shocks to 3 temperature-sensitive cell division arrest (cda) mutants of Tetrahymena thermophila. A restrictive temperature, 36 degrees C, was found at which all 3 mutants are fully penetrant, yet other physiological effects are minimal. At this temperature, the temperature-sensitive period of cdaC2 is a unique 5-min period in mid-division, that of cdaA1 is a similarly brief period situated about 0.5 h prior to cell division, while the temperature-sensitive period of cdaH1 is 20 to 30 min long and immediately precedes cell division. These periods either coincide with (cdaC2, cdaH1) or immediately precede (cdaA1) the onset of phenotypic abnormality at the restrictive temperature. Brief exposure to 36 degrees C during the temperature-sensitive period in any of these mutants brings about irreversible arrest of division furrows in progress or preparation. Mutant cells suffering such arrest can, however, divide again at a permissive temperature by forming new furrows at different sites.

Induction of indora expression in pole cells by the mesoderm is required for female germ-line development in Drosophila melanogaster

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 1023-1029 ◽  
Author(s):  
M. Mukai ◽  
M. Kashikawa ◽  
S. Kobayashi
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cells ◽  
Germ Line ◽  
Animal Groups ◽  
Novel Transcript ◽  
Expression Of Genes ◽  
Female Germ Line ◽  
Pole Cells

In many animal groups, the interaction between germ and somatic line is required for germ-line development. In Drosophila, the germ-line precursors (pole cells) formed at the posterior tip of the embryos migrate toward the mesodermal layer where they adhere to the dorsolateral mesoderm, which ensheaths the pole cells to form the embryonic gonads. These mesodermal cells may control the expression of genes that function in pole cells for their development into germ cells. However, such downstream genes have not been isolated. In this study, we identify a novel transcript, indora (idr), which is expressed only in pole cells within the gonads. Reduction of idr transcripts by an antisense idr expression caused the failure of pole cells to produce functional germ cells in females. Furthermore, we demonstrate that idr expression depends on the presence of the dorsolateral mesoderm, but it does not necessarily require its specification as the gonadal mesoderm. Our findings suggest that the induction of idr in pole cells by the mesodermal cells is required for germ-line development.

scholarly journals The recovery and preliminary examination of a temperature sensitive suppressor of the cryptocephal mutant of Drosophila melanogaster

1981 ◽  
Vol 38 (3) ◽  
pp. 297-314 ◽  
Author(s):  
John C. Sparrow
Keyword(s):  
Drosophila Melanogaster ◽  
Temperature Shift ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Induced Mutations ◽  
Chitin Synthesis ◽  
Preliminary Examination

SUMMARYThe recovery of two EMS induced mutations which are dominant suppressors of the lethality of cryptocephal in Drosophila melanogaster are described. One of these mutations Su(crc)1 is described in detail. It maps very close to cryptocephal at 54·7 on the second chromosome and its suppression of cryptocephal is temperature-sensitive. Temperature shift experiments show that the temperature-sensitive period is from before the pupariation until 12 h post pupariation. The temperature-sensitive period of Su(crc)1 is discussed in relation to the expression of l(2)crc, head eversion and the timing of pupal chitin synthesis.

scholarly journals Experimental Studies on Pole Cells and Midgut Differentiation in Diptera

1960 ◽  
Vol 13 (4) ◽  
pp. 541 ◽  
Author(s):  
DF Poulson ◽  
DF Waterhouse
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cells ◽  
Polar Region ◽  
Experimental Studies ◽  
Cell Formation ◽  
Lucilia Cuprina ◽  
Pole Cell ◽  
Gonad Size ◽  
The Common ◽  
Pole Cells

Highly localized irradiation with ultraviolet of the posterior polar region of eggs of Drosophila melanogaster and Lucilia cuprina in pre.pole cell and pole cell stages results in reduction in numbers of the cuprophilic cells of the middle midgut as well as in reduction of gonad size and number. Carefully timed eggs were exposed to dosages of ultraviolet (from a source giving about 90 per cent. at wavelength 2536 A) ranging from 1200 to 2400 I-' W sec/cm2 over periods of 2-4 min. Treatments at the time of active pole cell formation were found to be most effective in producing defects of both gut and gonads, thus demon� strating the common origin of the cuprophilic cells of the middle midgut and the germ cells of the gonads.

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