scholarly journals GENETIC ANALYSIS OF THE PROXIMAL REGION OF CHROMOSOME 2 OF DROSOPHILA MELANOGASTER. I. DETACHMENT PRODUCTS OF COMPOUND AUTOSOMES

Genetics ◽  
1975 ◽  
Vol 81 (4) ◽  
pp. 705-721
Author(s):  
A J Hilliker ◽  
D G Holm
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Gamma Radiation ◽  
Proximal Region ◽  
Promising Method ◽  
Low Density ◽  
Chromosome 2 ◽  
Genetic Composition ◽  
Allelism Tests ◽  
Dominance Tests

ABSTRACT To examine the genetic composition of proximal heterochromain in chromosome 2, the detachment of compound second autosomes, for generating proximal deficiencies, appeared a promising method. Compound seconds were detached by gamma radiation. A fraction of the detachment products were recessive lethals owing to proximal deficiencies. Analysis by inter se complementation, pseudo-dominance tests with proximal mutations and allelism tests with known deficiencies provided evidence for at least two loci between the centromere and the light locus in 2L and one locus in 2R between the rolled locus and the centromere. The data further demonstrate that rolled, and probably light, are located within the proximal heterochromatin. Thus, functional genetic loci are found in heterochromatin, albeit at low density.

scholarly journals GENETIC ANALYSIS OF THE CENTROMERIC HETEROCHROMATIN OF CHROMOSOME 2 OF DROSOPHILA MELANOGASTER: DEFICIENCY MAPPING OF EMS-INDUCED LETHAL COMPLEMENTATION GROUPS

Genetics ◽  
1976 ◽  
Vol 83 (4) ◽  
pp. 765-782
Author(s):  
Arthur J Hilliker
Keyword(s):  
Drosophila Melanogaster ◽  
Present Report ◽  
Heterochromatic Region ◽  
Centromeric Heterochromatin ◽  
Genetic Constitution ◽  
Genetic Dissection ◽  
Chromosome 2 ◽  
Multiple Alleles ◽  
Products Analysis ◽  
Dominance Tests

ABSTRACT Until recently, little was known of the genetic constitution of the heterochromatic segments of the major autosomes of Drosophila melanogaster. Our previous report described the genetic dissection of the proximal, heterochromatic region of chromosome 2 of Drosophila melanogasterby means of a series of overlapping deficiencies generated by the detachment of compound second autosomes (Hilliker and Holm 1975). Analysis of these deficiencies by inter se complementation, pseudo-dominance tests with proximal mutations and allelism tests with known deficiencies provided evidence for the existence of at least two loci between the centromere and the light locus in 2L and one locus in 2R between the rolled locus and the centromere. These data in conjunction with cytological observations demonstrated that light and rolled and three loci lying between them are located within the proximal heterochromatin of the second chromosome.——The present report describes the further analysis of this region through the induction with ethyl methanesulphonate (EMS) of recessive lethals allelic to the 2L and 2R proximal deficiencies associated with the detachment products. Analysis of the 118 EMS-induced recessive lethals and visible mutations recovered provided evidence for seven loci in the 2L heterochromatin and six loci in the 2R heterochromatin, with multiple alleles being obtained for most sites. Of these loci, one in 2L and two in 2R fall near the heterochromatic-euchromatic junctions of 2L and 2R respectively. None of the 113 EMS lethals behaved as a deficiency, implying that the heterochromatic loci uncovered in this study represent nonrepetitive cistrons. Thus functional genetic loci are found in heterochromatin, albeit at a very low density relative to euchromatin.

scholarly journals Persistent one-way walking in a circular arena in Drosophila melanogaster Canton-S strain

2017 ◽  
Author(s):  
Chengfeng Xiao ◽  
Shuang Qiu ◽  
R Meldrum Robertson
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Y Chromosome ◽  
Genetic Background ◽  
Chromosome 2 ◽  
Wild Type ◽  
Promoting Effect ◽  
Directional Change ◽  
Pleiotropic Function

AbstractWe describe persistent one-way walking of Drosophila melanogaster in a circular arena. Wild-type Canton-S adult flies walked in one direction, counter-clockwise or clockwise, for minutes, whereas white-eyed mutant w1118 changed directions frequently. Locomotion in the circular arena could be classified into four components: counter-clockwise walking, clockwise walking, nondirectional walking and pausing. Genetic analysis revealed that while wild-type genetic background was associated with reduced directional change and reduced numbers of one-way (including counterclockwise and clockwise) and nondirectional walks, the white (w+) locus promoted persistent oneway walking by increasing the maximal duration of one-way episodes. The promoting effect of w+ was further supported by the observations that (1) w+ duplicated to the Y chromosome, (2) four genomic copies of mini-white inserted on the autosomes, and (3) pan-neuronal overexpression of the White protein increased the maximal duration of one-way episodes, and that RNAi knockdown of w+ in the neurons decreased the maximal duration of one-way episodes. These results suggested a pleiotropic function of w+ in promoting persistent one-way walking in the circular arena.

Genetic analysis of the second chromosome centromeric heterochromatin of Drosophila melanogaster

Genome ◽  
2003 ◽  
Vol 46 (3) ◽  
pp. 343-352 ◽  
Author(s):  
Alistair B Coulthard ◽  
Daniel F Eberl ◽  
Cecil B Sharp ◽  
Arthur J Hilliker
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Centromeric Heterochromatin ◽  
Chromosome 2 ◽  
Lethal Mutant ◽  
Genetic Elements ◽  
Unpublished Work ◽  
Segregation Distorter ◽  
Mutant Phenotypes

Here we bring together our published and unpublished work with recent published findings of other laboratories to provide a revised map of the centromeric heterochromatin of chromosome 2 and descriptions of the 21 genetic elements therein. These elements consist of 16 vital loci, one male and one female sterile loci, one Minute locus, and two components of the Segregation Distorter system. Based on our latest analysis of the lethal mutant phenotypes of the vital genes, we have provided names for several genes that were previously known by their lethal number assignments.Key words: heterochromatin, Drosophila, cytogenetics.

scholarly journals GENETIC AND CYTOGENETIC ANALYSIS OF THE ADH REGION IN DROSOPHILA MELANOGASTER

Genetics ◽  
1977 ◽  
Vol 86 (3) ◽  
pp. 553-566
Author(s):  
Janis O'Donnell ◽  
Howard C Mandel ◽  
Marc Krauss ◽  
William Sofer
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Cytogenetic Analysis ◽  
Chromosome 2 ◽  
Cytological Examination ◽  
Lethal Mutations ◽  
Adh Gene ◽  
Complementation Groups

ABSTRACT Eighteen Adh-negative mutations were selected with 1-pentyn-3-ol after feeding of formaldehyde. Twelve of the 18 were shown by cytological and genetic analysis to be deletions. Cytological examination of the deletions allowed us to localize the Adh gene to a region including bands 35B3-5 on the left arm of chromosome 2. The deletions were also used to order known visible loci located near Adh.—The vital loci near Adh were also investigated. A total of 109 lethal mutations were generated with EMS and 33 of these, localized within a region defined by the overlap of two of the deletions, were found to belong to 13 complementation groups. If one includes three other loci known to belong there (el, Adh and Sco), a total of 16 complementation groups have been identified in the region close to Adh.

scholarly journals Genetic Analysis of the Heterochromatin of Chromosome 3 in Drosophila Melanogaster. II. Vital Loci Identified through Ems Mutagenesis.

Genetics ◽  
1988 ◽  
Vol 120 (2) ◽  
pp. 519-532
Author(s):  
G E Marchant ◽  
D G Holm
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Single Copy ◽  
Chromosome 3 ◽  
Temperature Sensitive ◽  
Chromosome 2 ◽  
Complementation Groups ◽  
Sensitive Allele ◽  
Interallelic Complementation ◽  
The Right

Abstract Chromosome 3 of Drosophila melanogaster contains the last major blocks of heterochromatin in this species to be genetically analyzed. Deficiencies of heterochromatin generated through the detachment of compound-3 chromosomes revealed the presence of vital loci in the heterochromatin of chromosome 3, but an extensive complementation analysis with various combinations of lethal and nonlethal detachment products gave no evidence of tandemly repeated vital genes in this region. These findings indicate that the heterochromatin of chromosome 3 is genetically similar to that of chromosome 2. A more thorough genetic analysis of the heterochromatic regions has been carried out using the chemical mutagen ethyl methanesulfonate (EMS). Seventy-five EMS-induced lethals allelic to loci uncovered by detachment-product deficiencies were recovered and tested for complementation. In total, 12 complementation groups were identified, ten in the heterochromatin to the left of the centromere and two to the right. All but two complementation groups in the left heterochromatic block could be identified as separate loci through deficiency mapping. The interallelic complementation observed between some EMS-induced lethals, as well as the recovery of a temperature-sensitive allele for each of the two loci, provided further evidence that single-copy, transcribed vital genes reside in the heterochromatin of chromosome 3. Cytological analysis of three detachment-product deficiencies provided evidence that at least some of the genes uncovered in this study are located in the most distal segments of the heterochromatin in both arms. This study provides a detailed genetic analysis of chromosome 3 heterochromatin and offers further information on the genetic nature and heterogeneity of Drosophila heterochromatin.

scholarly journals A GENETIC ANALYSIS OF THE KILLER-PRUNE (K-pn) LOCUS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1969 ◽  
Vol 62 (2) ◽  
pp. 353-358
Author(s):  
Eliezer Lifschytz ◽  
Raphael Falk
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis

scholarly journals A NOTE ON THE MATERNAL EFFECT MUTANTS DAUGHTERLESS AND ABNORMAL OOCYTE IN DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 73 (1) ◽  
pp. 73-86
Author(s):  
Arthur P Mange ◽  
L Sandler
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effect ◽  
Sex Chromosome ◽  
Chromosome 2 ◽  
Dominant Marker ◽  
Enhancing Effect ◽  
X Irradiation ◽  
The Right ◽  
Chromosome Breakpoint ◽  
Special Region

ABSTRACT Two deficiencies for, and a dominant enhancer of, the second chromosome maternal effect mutant, "daughterless" (da), were induced with X-irradiation. Their properties were studied with respect to both da and the linked maternal effect mutant, "abnormal oocyte" (abo), with the following conclusions. (1) The most probable map positions of da and abo are: J–½–da–2½–abo, where J is a dominant marker located at 41 on the standard map. (2) The da locus is in bands 31CD-F on the polytene chromosome map; abo is to the right of 32A. (3) Because homozygous da individuals survive while individuals carrying da and a deficiency for da are lethal, it is concluded that da is hypomorphic. (4) From a weak da-like maternal effect in heterozygous da females induced by an "Enhancer of da," we have confirmed a previous report that (a) the amount of sex chromosome heterochromatin contributed by the father can influence the severity of the da maternal effect, and (b) the sex chromosome heterochromatin which influences the da effect is different from that which influences the abo effect. (5) The possibility that da and abo are in a special region of chromosome 2 concerned with the regulation of sex chromosome heterochromatin is strengthened by the observation that the Enhancer of da appears to rescue abnormal eggs produced by homozygous abo mothers. (6) The Enhancer of da is a translocation between chromosomes 2 and 3 with the second chromosome breakpoint in the basal heterochromatin; because the enhancing effect maps in this region of chromosome 2, it is possible that autosomal, as well as sex chromosomal, heterochromatin interacts with da and abo.

scholarly journals Molecular Evolution of Duplicated Amylase Gene Regions in Drosophila melanogaster: Evidence of Positive Selection in the Coding Regions and Selective Constraints in the cis-Regulatory Regions

Genetics ◽  
2001 ◽  
Vol 157 (2) ◽  
pp. 667-677
Author(s):  
Hitoshi Araki ◽  
Nobuyuki Inomata ◽  
Tsuneyuki Yamazaki
Keyword(s):  
Drosophila Melanogaster ◽  
Molecular Evolution ◽  
Positive Selection ◽  
Natural Populations ◽  
Sliding Window ◽  
Selective Constraint ◽  
Proximal Region ◽  
Coding Regions ◽  
Asian Populations ◽  
Flanking Region

Abstract In this study, we randomly sampled Drosophila melanogaster from Japanese and Kenyan natural populations. We sequenced duplicated (proximal and distal) Amy gene regions to test whether the patterns of polymorphism were consistent with neutral molecular evolution. Fst between the two geographically distant populations, estimated from Amy gene regions, was 0.084, smaller than reported values for other loci, comparing African and Asian populations. Furthermore, little genetic differentiation was found at a microsatellite locus (DROYANETSB) in these samples (Gst′=−0.018). The results of several tests (Tajima's, Fu and Li's, and Wall's tests) were not significantly different from neutrality. However, a significantly higher level of fixed replacement substitutions was detected by a modified McDonald and Kreitman test for both populations. This indicates that positive selection occurred during or immediately after the speciation of D. melanogaster. Sliding-window analysis showed that the proximal region 1, a part of the proximal 5′ flanking region, was conserved between D. melanogaster and its sibling species, D. simulans. An HKA test was significant when the proximal region 1 was compared with the 5′ flanking region of Alcohol dehydrogenase (Adh), indicating a severe selective constraint on the Amy proximal region 1. These results suggest that natural selection has played an important role in the molecular evolution of Amy gene regions in D. melanogaster.

scholarly journals Transvection at the End of the Truncated Chromosome in Drosophila melanogaster

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1375-1387
Author(s):  
Mikhail Savitsky ◽  
Tatyana Kahn ◽  
Ekaterina Pomerantseva ◽  
Pavel Georgiev
Keyword(s):  
Drosophila Melanogaster ◽  
Homologous Chromosome ◽  
Regulatory Region ◽  
Proximal Region ◽  
The Other ◽  
Upstream Region ◽  
Upstream Sequence ◽  
Transcription Start ◽  
Promoter Proximal Region

Abstract The phenomenon of transvection is well known for the Drosophila yellow locus. Thus enhancers of a promoterless yellow locus in one homologous chromosome can activate the yellow promoter in the other chromosome where the enhancers are inactive or deleted. In this report, we examined the requirements for trans-activation of the yellow promoter at the end of the deficient chromosome. A number of truncated chromosomes ending in different areas of the yellow regulatory region were examined in combination with the promoterless y alleles. We found that trans-activation of the yellow promoter at the end of a deficient chromosome required ∼6 kb of an additional upstream sequence. The nature of upstream sequences affected the strength of transvection: addition of gypsy sequences induced stronger trans-activation than addition of HeT-A or yellow sequences. Only the promoter proximal region (within -158 bp of the yellow transcription start) was essential for trans-activation; i.e., transvection did not require extensive homology in the yellow upstream region. Finally, the yellow enhancers located on the two pairing chromosomes could cooperatively activate one yellow promoter.

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