scholarly journals SEX CHROMOSOME MEIOTIC DRIVE SYSTEMS IN DROSOPHILA MELANOGASTER I. ABNORMAL SPERMATID DEVELOPMENT IN MALES WITH A HETEROCHROMATIN-DEFICIENT X CHROMOSOME (sc  4  sc  8)

Genetics ◽  
1975 ◽  
Vol 79 (4) ◽  
pp. 613-634
Author(s):  
W J Peacock ◽  
George L Gabor Miklos ◽  
D J Goodchild
Keyword(s):  
Electron Microscopy ◽  
Drosophila Melanogaster ◽  
Sex Chromosome ◽  
Light And Electron Microscopy ◽  
Temperature Shift ◽  
Meiotic Drive ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Electron Microscopes ◽  
Drive Systems

ABSTRACT The meiotic drive characteristics of the In(1)sc4Lsc8R/Y system have been examined by genetic analysis and by light and electron microscopy. sc4sc8/Y males show a direct correlation between nondisjunction frequency and meiotic drive. Temperature-shift experiments reveal that the temperature-sensitive period for nondisjunction is at meiosis, whereas that for meiotic drive has both meiotic and post-meiotic components. Cytological analyses in the light and electron microscopes reveal failures in spermiogenesis in the testes of sc  4  sc  8 males. The extent of abnormal spermatid development increases as nondisjunction becomes more extreme.

scholarly journals MULTIPLE MEIOTIC DRIVE SYSTEMS IN THE DROSOPHILA MELANOGASTER MALE

Genetics ◽  
1972 ◽  
Vol 72 (1) ◽  
pp. 105-115
Author(s):  
George L Gabor Miklos ◽  
Armon F Yanders ◽  
W J Peacock
Keyword(s):  
Drosophila Melanogaster ◽  
Survival Probability ◽  
Sex Chromosome ◽  
Meiotic Drive ◽  
The Other ◽  
Segregation Distorter ◽  
Two Systems ◽  
Combined Action ◽  
Drive Systems

ABSTRACT The behaviour of two "meiotic drive" systems, Segregation-Distorter (SD) and the sex chromosome sc4sc8 has been examined in the same meiocyte. It has been found that the two systems interact in a specific way. When the distorting effects of SD and sc4sc8 are against each other, there is no detectable interaction. Each system is apparently oblivious to the presence of the other, gametes being produced according to independence expectations. However when the affected chromosomes are at the same meiotic pole an interaction occurs; the survival probability of the gamete containing both distorted chromosomal products is increased, rather than being decreased by the combined action of two systems.

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.

TEMPERATURE-DEPENDENT EXPRESSION OF THE APTEROUS PHENOTYPE IN DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 112 (2) ◽  
pp. 217-228
Author(s):  
Mary E Stevens ◽  
Peter J Bryant
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
Gene Product ◽  
Constant Temperature ◽  
Temperature Shift ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Temperature Dependent ◽  
Developmental Defects ◽  
Per Se

ABSTRACT Mutations at the apterous (ap) locus in Drosophila melanogaster produce a variety of developmental defects, including several classes of wing abnormalities. We describe the wing phenotype produced by homozygotes and hemizygotes of three different temperature-sensitive apterous alleles grown at 16, 18, 20, 22, 25, and 29°. We also describe the phenotype produced by each of these three alleles when heteroallelic with the non-temperature-sensitive apc allele. Constant-temperature and temperature-shift experiments show that each of the heteroallelic genotypes can produce several of the previously described apterous phenotypes and that the length of the temperature-sensitive period for a given phenotype depends on the allelic combinations used to measure it. We suggest that the stage-specific requirements of the tissue for gene product, rather than the time of gene expression per se, determine the temperature-sensitive periods for apterous and other loci. The results support the hypothesis that the various wing phenotypes produced by apterous mutations are due to quantitative reductions in the activity of gene product and that failure to meet specific threshold requirements for gene product can lead to qualitatively different phenotypes.

Mutations in a newly identified Drosophila melanogaster gene, mago nashi, disrupt germ cell formation and result in the formation of mirror-image symmetrical double abdomen embryos

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 373-384 ◽  
Author(s):  
R.E. Boswell ◽  
M.E. Prout ◽  
J.C. Steichen
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cell ◽  
Cell Formation ◽  
Temperature Shift ◽  
Longitudinal Axis ◽  
Posterior Pole ◽  
Mirror Image ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Mago Nashi

The mago nashi (mago) locus is a newly identified strict maternal effect, grandchildless-like, gene in Drosophila melanogaster. In homozygous mutant mago females reared at 17 degrees C, mago+ function is reduced, the inviable embryos lack abdominal segments and 84–98% of the embryos die. In contrast, at 25 degrees C, some mago alleles produce a novel gene product capable of inducing the formation of symmetrical double abdomen embryos. Reciprocal temperature-shift experiments indicate that the temperature-sensitive period is during oogenetic stages 7–14. Furthermore, embryos collected from mago1 homozygous females contain no apparent functional posterior determinants in the posterior pole. In viable F1 progeny from mago mutant females, regardless of genotype and temperature, polar granules are reduced or absent and germ cells fail to form (the grandchildless-like phenotype). Thus, we propose that the mago+ product is a component of the posterior determinative system, required during oogenesis, both for germ cell determination and delineation of the longitudinal axis of the embryo.

MEIOSIS IN COPRINUS: VI. THE CONTROL OF THE INITIATION OF MEIOSIS

1974 ◽  
Vol 16 (1) ◽  
pp. 155-164 ◽  
Author(s):  
B. C. Lu
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Mycelial Growth ◽  
Dark Period ◽  
Continuous Light ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Light Cycle ◽  
Sensitive Stage ◽  
Dark Regime

Meiosis in Coprinus lagopus is normally initiated at night under normal diurnal conditions. This timing can be shifted to 0900-1000 h by using a 16h light-8h dark regime with the light cycle commencing at 1600 h. For the initiation of meiosis, C. lagopus is temperature sensitive (35 C) under continuous light. The temperature sensitivity can be overcome by a dark period. The sensitive period occurs within 7 h of karyogmay. Only the first 2 h, however, are sensitive to light and high temperature. A shift-up to restrictive conditions before the sensitive stage effectively arrests the process leading to karyogamy. The arrest is reversible within 20 h. Upon returning to a 25 C chamber, karyogamy begins in 6 h in all basidiocarps. Thus using this technique accurate control of the initiation of meiosis can be achieved. Howeevr, prolonged arrest beyond 16 h causes the basidia to revert to mitosis and mycelial growth. The nucleolus is reduced in size and exhibits a large vacuole and a lack of granular components as shown by electron microscopy.

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 AND DEVELOPMENTAL ANALYSIS OF A TEMPERATURE-SENSITIVE MINUTE MUTATION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1981 ◽  
Vol 97 (3-4) ◽  
pp. 581-606 ◽  
Author(s):  
Donald A R Sinclair ◽  
David T Suzuki ◽  
Thomas A Grigliatti
Keyword(s):  
Larval Instar ◽  
Temperature Shift ◽  
Heat Pulse ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Direct Effects ◽  
First Instar ◽  
Reciprocal Temperature ◽  
Morphological Defects ◽  
Developmental Analysis

ABSTRACT A temperature-sensitive (ts) third chromosome Minute (M) mutation, designated Q-III, has been recovered and characterized. Q-III heterozygotes raised at 29" exhibit all of the dominant traits of M mutants including small bristles, rough eyes, prolonged development, reduced viability 2nd interactions with several unrelated mutations. Q-III homozygotes raised at 29° are lethal; death occurs primarily during the first larval instar. When raised at 22°, Q-Ill heterozygotes are phenotypically normal and Q-III homozygotes display moderate Mtraits. In addition, Q-IIIelicits ts sterility and maternal-effect lethality. As it true of Mlesions, the dominant traits of Q-111 are not expressed in triploid females raised at 29°. Complementation tests suggest that Q-III is a ts allele of M(3)LS4, which is located in 3L near the centromere.——Reciprocal temperature-shift experiments revealed that the temperature-sensitive period (TSP) of Q-111 lethality is polyphasic, extending from the first instar to the latter half of pupation. Heat-pulse experiments further resolved this into two post-embryonic TSPs: one occurring during the latter half of the second larval instar, and the other extending from the larval/pupal boundary to the second half of pupation. In addition, heat pulses elicited a large number of striking adult phenotypes in Q-III individuals. These included pattern alterations such as deficiencies and duplications and cther morphological defects in structures produced by the eye-antennal, leg, wing and genital imaginal discs and the abdominal histoblasts. Each defect or pattern alteration is associated with a specific TSP during development.——We favor the interpretation that most of the major Q-III defects, particularly the structural duplications and deficiencies, result from temperature-induced cell death in mitotically active imaginal anlagen, while the small macrochaete phene probably results from the direct effects of Q-III on bristle synthesis. The hypothesis that the Q-III locus specifices a component required for protein synthesis is discussed, and it is concluded that this hypothesis can account for the pleiotropy of Q-III, and that perhaps it can be extended to M loci in general.

scholarly journals A Caenorhabditis elegans RNA polymerase II gene, ama-1 IV, and nearby essential genes.

Genetics ◽  
1988 ◽  
Vol 118 (1) ◽  
pp. 61-74
Author(s):  
T M Rogalski ◽  
D L Riddle
Keyword(s):  
Caenorhabditis Elegans ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Gamma Ray ◽  
Temperature Shift ◽  
Developmental Rate ◽  
Egg Laying ◽  
Essential Genes ◽  
Sensitive Period ◽  
Temperature Sensitive

Abstract The amanitin-binding subunit of RNA polymerase II in Caenorhabditis elegans is encoded by the ama-1 gene, located approximately 0.05 map unit to the right of dpy-13 IV. Using the amanitin-resistant ama-1(m118) strain as a parent, we have isolated amanitin-sensitive mutants that carry recessive-lethal ama-1 alleles. Of the six ethyl methanesulfonate-induced mutants examined, two are arrested late in embryogenesis. One of these is a large deficiency, mDf9, but the second may be a novel point mutation. The four other mutants are hypomorphs, and presumably produce altered RNA polymerase II enzymes with some residual function. Two of these mutants develop into sterile adults at 20 degrees but are arrested as larvae at 25 degrees, and two others are fertile at 20 degrees and sterile at 25 degrees. Temperature-shift experiments performed with the adult sterile mutant, ama-1(m118m238ts), have revealed a temperature-sensitive period that begins late in gonadogenesis and is centered around the initiation of egg-laying. Postembryonic development at 25 degrees is slowed by 30%. By contrast, the amanitin-resistant allele of ama-1 has very little effect on developmental rate or fertility. We have identified 15 essential genes in an interval of 4.5 map units surrounding ama-1, as well as four gamma-ray-induced deficiencies and two duplications that include the ama-1 gene. The larger duplication, mDp1, may include the entire left arm of chromosome IV, and it recombines with the normal homologue at a low frequency. The smallest deficiency, mDf10, complements all but three identified genes: let-278, dpy-13 and ama-1, which define an interval of only 0.1 map unit. The terminal phenotype of mDf10 homozygotes is developmental arrest during the first larval stage, suggesting that there is sufficient maternal RNA polymerase II to complete embryonic development.

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.

SPERMATOCYTE GRANULES IN DROSOPHILA MELANOGASTER

1969 ◽  
Vol 11 (1) ◽  
pp. 153-168 ◽  
Author(s):  
John Erickson ◽  
A. B. Acton
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Drosophila Melanogaster ◽  
Host Cell ◽  
Acridine Orange ◽  
Meiotic Drive ◽  
Adult Males ◽  
Unit Membrane ◽  
The Third ◽  
The Individual

Granular inclusions are found in testes from a cn bw stock of Drosophila melanogaster, and maternally derived lines, such as SD. In late larval and early pupal stages, these granules show a polarized distribution within primary spermatocytes corresponding to the polarity basic to the type of meiotic drive where certain homologues reach that pole of the spermatocyte leading to functional sperm. In adult males, the granules are found in intercellular patches in the testes. Electron microscopy shows the spermatocyte granules to be spheroids of about 0.7 μ; dividing, or double forms resulting from division, are about 1.8 μ long. They contain numbers of ribosome-like particles and fine strands presumed to be DNA. The acridine orange test for nucleic acids was positive. Each granule is surrounded by two layers of unit membrane and a third such membrane envelopes the individual or the pair of granules, as the case may be. The third membrane layer (and additional membranes sometimes seen) is thought to be due to entrance of the granules into the host cell through the cisternae of the endoplasmic reticulum. Transmission of the granules is strictly maternal and independent of chromosome constitution. Transmission by contagion was not found. Spermatocyte granules are not requisite to the effectiveness of the SD meiotic drive system, which regularly carries them. A slightly lowered fertility of females carrying the granules was found but no similar effect is produced in males. The evidence suggests that they are parasitic organisms, probably Rickettsiae.

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