CHROMOSOME BEHAVIOR UNDER THE INFLUENCE OF CLARET-NONDISJUNCTIONAL IN DROSOPHILA MELANOGASTER

Genetics ◽  
1969 ◽  
Vol 61 (3) ◽  
pp. 577-594
Author(s):  
D G Davis
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosome Behavior

scholarly journals Genetic analysis of the claret locus of Drosophila melanogaster.

Genetics ◽  
1989 ◽  
Vol 123 (3) ◽  
pp. 511-524 ◽  
Author(s):  
W Sequeira ◽  
C R Nelson ◽  
P Szauter
Keyword(s):  
Drosophila Melanogaster ◽  
Single Gene ◽  
Chromosome Rearrangement ◽  
Overlapping Genes ◽  
Early Cleavage ◽  
Chromosome Behavior ◽  
Eye Color ◽  
Single Target ◽  
Radiation Induced ◽  
New Alleles

Abstract The claret (ca) locus of Drosophila melanogaster comprises two separately mutable domains, one responsible for eye color and one responsible for proper disjunction of chromosomes in meiosis and early cleavage divisions. Previously isolated alleles are of three types: (1) alleles of the claret (ca) type that affect eye color only, (2) alleles of the claret-nondisjunctional (cand) type that affect eye color and chromosome behavior, and (3) a meiotic mutation, non-claret disjunctional (ncd), that affects chromosome behavior only. In order to investigate the genetic structure of the claret locus, we have isolated 19 radiation-induced alleles of claret on the basis of the eye color phenotype. Two of these 19 new alleles are of the cand type, while 17 are of the ca type, demonstrating that the two domains do not often act as a single target for mutagenesis. This suggests that the two separately mutable functions are likely to be encoded by separate or overlapping genes rather than by a single gene. One of the new alleles of the cand type is a chromosome rearrangement with a breakpoint at the position of the claret locus. If this breakpoint is the cause of the mutant phenotype and there are no other mutations associated with the rearrangement, the two functions must be encoded by overlapping genes.

Sister chromatid cohesiveness: Vital function, obscure mechanism

1990 ◽  
Vol 68 (11) ◽  
pp. 1231-1242 ◽  
Author(s):  
Marjorie P. Maguire
Keyword(s):  
Drosophila Melanogaster ◽  
Sister Chromatid ◽  
Topoisomerase Ii ◽  
Model Building ◽  
Vital Function ◽  
Chromosome Behavior ◽  
Alternative Means ◽  
Ploidy Changes ◽  
Experimental Treatments ◽  
Sister Centromere

Observations of chromosome behavior have suggested that it is sister chromatid cohesiveness which is primarily responsible for maintenance of chiasmate association between pachytene and anaphase of the first meiotic division and also for maintenance of sister centromere association until anaphase II. These associations seem essential for assurance of normal distribution of chromosomes into gametes (except in organisms in which alternative means have evolved, such as the male of Drosophila melanogaster). Sister chromatid cohesiveness is also found in varying degrees at mitosis. Reports of observations that are relevant to the nature of this cohesiveness are reviewed here with particular attention to behavior under a variety of conditions which include ploidy changes, presence of mutation effects, chromosome rearrangements, and experimental treatments. Attention is focused on constraints imposed upon model building by the observations, and also on directions for future study, which seem promising.Key words: sister chromatid cohesiveness, chiasmata, topoisomerase II, synaptonemal complex, meiosis.

Effects of Recombination-Deficient and Repair-Deficient Loci on Meiotic and Mitotic Chromosome Behavior in Drosophila Melanogaster

1980 ◽  
pp. 189-208 ◽  
Author(s):  
Bruce S. Baker ◽  
Maurizio Gatti ◽  
Adelaide T. C. Carpenter ◽  
Sergio Pimpinelli ◽  
David A. Smith
Keyword(s):  
Drosophila Melanogaster ◽  
Mitotic Chromosome ◽  
Chromosome Behavior

scholarly journals GENETICALLY INDUCED MITOTIC EXCHANGE IN THE HETEROCHROMATIN OF DROSOPHILA MELANOGASTER

Genetics ◽  
1981 ◽  
Vol 99 (3-4) ◽  
pp. 443-459
Author(s):  
Leonard G Robbins
Keyword(s):  
Drosophila Melanogaster ◽  
Temperature Sensitive ◽  
Chromosome Behavior ◽  
Ribosomal Cistrons ◽  
Y Chromosomes ◽  
Multiple Copies

ABSTRACT Multiple copies of the 18s and 28sribosomal RNA cistrons are present in both the Xand Y chromosomes of Drosophila melanogaster.Data are presented here that identify a locus, Rex,that causes exchange-like events between duplicated ribosomal complexes at the ends of an attached-XY chromosome. Rex:(1) is close to or in the basal heterochromatin of the Xchromosome; (2)is semidominant and (its effect) is temperature sensitive; (3) acts maternally; and (4) affects behavior of paternally derived attached-XY chromosomes shortly after fertilization. Though, at this point, the existence of Rexis known only from its effects on behavior of a particular compound chromosome, it presents intriguing possibilities for understanding regulation of chromosome behavior and organization of the ribosomal cistrons.

scholarly journals The Responding Site of the Rex Locus of Drosophila melanogaster

Genetics ◽  
1987 ◽  
Vol 115 (2) ◽  
pp. 271-276
Author(s):  
Ellen E Swanson
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Ribosomal Rna ◽  
Maternal Effect ◽  
Copy Number ◽  
Mitotic Chromosome ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Rrna Gene ◽  
Chromosome Behavior

ABSTRACT Rex is a dominant, maternal-effect locus in the heterochromatin of the X chromosome Drosophila melanogaster. It causes an early mitotic exchange-like event between heterochromatic elements of an attached- XY in X/attached-XY embryos of Rex mothers. Evidence is presented here that the site of Rex action is the ribosomal RNA gene cluster (the bb locus) only; no other heterochromatin is affected. The Rex locus may be useful in studying regulation of rRNA-gene copy number, mitotic chromosome behavior and heterochromatic function.

scholarly journals ZW10 Helps Recruit Dynactin and Dynein to the Kinetochore

1998 ◽  
Vol 142 (3) ◽  
pp. 763-774 ◽  
Author(s):  
Daniel A. Starr ◽  
Byron C. Williams ◽  
Thomas S. Hays ◽  
Michael L. Goldberg
Keyword(s):  
Drosophila Melanogaster ◽  
Metaphase Plate ◽  
Yeast Two Hybrid ◽  
Chromosome Behavior ◽  
Anaphase Onset ◽  
Chromosome Separation ◽  
Dynactin Complex ◽  
Two Hybrid ◽  
In Cells ◽  
Microtubule Capture

Mutations in the Drosophila melanogaster zw10 gene, which encodes a conserved, essential kinetochore component, abolish the ability of dynein to localize to kinetochores. Several similarities between the behavior of ZW10 protein and dynein further support a role for ZW10 in the recruitment of dynein to the kinetochore: (a) in response to bipolar tension across the chromosomes, both proteins mostly leave the kinetochore at metaphase, when their association with the spindle becomes apparent; (b) ZW10 and dynein both bind to functional neocentromeres of structurally acentric minichromosomes; and (c) the localization of both ZW10 and dynein to the kinetochore is abolished in cells mutant for the gene rough deal. ZW10's role in the recruitment of dynein to the kinetochore is likely to be reasonably direct, because dynamitin, the p50 subunit of the dynactin complex, interacts with ZW10 in a yeast two-hybrid screen. Since in zw10 mutants no defects in chromosome behavior are observed before anaphase onset, our results suggest that dynein at the kinetochore is essential for neither microtubule capture nor congression to the metaphase plate. Instead, dynein's role at the kinetochore is more likely to be involved in the coordination of chromosome separation and/or poleward movement at anaphase onset.

A New Smaller Sized Virus-Like Particle in Drosophila Melanogaster

2001 ◽  
Vol 7 (S2) ◽  
pp. 742-743
Author(s):  
Jeffrey G. Ault ◽  
Ellen Shimakawa
Keyword(s):  
Drosophila Melanogaster ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Freeze Substitution ◽  
Uranyl Acetate ◽  
High Pressure Freezing ◽  
Chromosome Behavior ◽  
Thin Sections ◽  
Behavior Study ◽  
Virus Like Particle

During a chromosome behavior study involving high-pressure freezing (HPF)/freeze substitution (FS) of Drosophila melanogaster testes, we discovered quasi-crystalline inclusions in the nuclei of adjacent gut epithelial cells (Fig. 1). The HPF and FS protocols were standard. The viscera of adult flies were packed in yeast paste for HPF. The tissue was fixed by FS with 1% osmium tetroxide in acetone for 72 hours at -90° C then 48 hours at -60° C. Afterwards, it was washed several times at room temperature in 100% acetone and embedded in Epon/Araldite. Thin sections were cut and stained with uranyl acetate and lead. As expected with HPF/FS, the material was well-preserved with straight microtubules, smooth membranes, dense mitochondria, and abundant ribosomes both on the rough endoplasmic reticulum and in the full cytoplasm (Fig. 1).The inclusions consisted of virus-like particles packed loosely together in orderly arrays. Particles were usually hexagonally packed with spaces disrupting the periodicity (Figs. 2 and 3).

scholarly journals MUTATIONS IN GENES ENCODING ESSENTIAL MITOTIC FUNCTIONS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1985 ◽  
Vol 110 (4) ◽  
pp. 647-670
Author(s):  
David A Smith ◽  
Bruce S Baker ◽  
Maurizio Gatti
Keyword(s):  
Drosophila Melanogaster ◽  
Mitotic Chromosome ◽  
Chromosome Instability ◽  
Temperature Sensitive ◽  
Chromosome Behavior ◽  
Chromosome Transmission ◽  
Genes Encoding ◽  
Genetic Techniques ◽  
Elevated Frequency ◽  
Chromosome Integrity

ABSTRACT Temperature-sensitive mutations at 15 loci that affect the fidelity of mitotic chromosome behavior have been isolated in Drosophila melanogaster. These mitotic mutants were detected in a collection of 168 EMS-induced X-linked temperature-sensitive (ts) lethal and semilethal mutants. Our screen for mutations with mitotic effects was based upon the reasoning that under semirestrictive conditions such mutations could cause an elevated frequency of mitotic chromosome misbehavior and that such events would be detectable with somatic cell genetic techniques. Males hemizygous for each ts lethal and heterozygous for the recessive autosomal cell marker mwh were reared under semirestrictive conditions, and the wings of those individuals surviving to adulthood were examined for an increased frequency of mwh clones. Those mutations producing elevated levels of chromosome instability during growth of the wing imaginal disc were also examined for their effects on chromosome behavior in the cell lineages producing the abdominal cuticle. Fifteen mutations affect chromosome behavior in both wing and abdominal cells and thus identify loci generally required for the fidelity of mitotic chromosome transmission. Mapping and complementation tests show that these mutations represent 15 loci. One mutant is an allele of a locus (mus-101) previously identified by mutagensensitive mutants and a second mutant is an allele of the lethal locus zw10.—The 15 mutants were also examined cytologically for their effects on chromosomes in larval neuroblasts. Taken together, the results of our cytological and genetical studies show that these mutants identify loci with wild-type functions necessary for either (1) maintenance of chromosome integrity or (2) regular disjunction of chromosomes or (3) chromosome condensation. Thus, these mutations define a broad spectrum of genes required for the normal execution of the mitotic chromosome cycle.

scholarly journals The genetic analysis of distributive segregation in Drosophila melanogaster. II. Further genetic analysis of the nod locus.

Genetics ◽  
1990 ◽  
Vol 125 (1) ◽  
pp. 115-127 ◽  
Author(s):  
P Zhang ◽  
R S Hawley
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
General Property ◽  
Mitotic Chromosome ◽  
Meiotic Chromosome ◽  
Complete Loss ◽  
Null Alleles ◽  
Chromosome Loss ◽  
Loss Of Function ◽  
Chromosome Behavior

Abstract In Drosophila melanogster females the segregation of nonexchange chromosomes is ensured by the distributive segregation system. The mutation noda specifically impairs distributive disjunction and induces nonexchange chromosomes to undergo nondisjunction, as well as both meiotic and mitotic chromosome loss. We report here the isolation of seven recessive X-linked mutations that are allelic to noda. As homozygotes, all of these mutations exhibit a phenotype that is similar to that exhibited by noda homozygotes. We have also used these mutations to demonstrate that nod mutations induce nonexchange chromosomes to nondisjoin at meiosis II. Our data demonstrate that the effects of noda on meiotic chromosome behavior are a general property of mutations at the nod locus. Several of these mutations exhibit identical phenotypes as homozygotes and as heterozygotes with a deficiency for the nod locus; these likely correspond to complete loss-of-function or null alleles. None of these mutations causes lethality, decreases the frequency of exchange, or impairs the disjunction of exchange chromosomes in females. Thus, either the nod locus defines a function that is specific to distributive segregation or exchange can fully compensate for the absence of the nod+ function.

Sign in / Sign up

Export Citation Format

Share Document