scholarly journals A reevaluation of data from competitive tests shows high levels of heterosis in Drosophila melanogaster.

Genetics ◽  
1994 ◽  
Vol 137 (2) ◽  
pp. 509-511 ◽  
Author(s):  
B D Latter ◽  
J A Sved
Keyword(s):  
Drosophila Melanogaster ◽  
Substantial Reduction ◽  
Inbred Strains ◽  
Chromosome 2 ◽  
Comparable Amount ◽  
Single Generation ◽  
Multiple Generation ◽  
Population Cage ◽  
Sister Mating

Abstract We have analyzed the results from a range of procedures designed to measure the fitness under competitive conditions of inbred strains of Drosophila melanogaster, specifically strains which are homozygous for chromosome 2. All methods show a substantial reduction in fitness, ranging from an estimated 70-80% for single generation competition tests to 80-90% for a multiple generation population cage procedure. Furthermore, inbreeding through brother-sister mating reduces fitness by a comparable amount when allowance is made for the expected degree of homozygosity.

The productivity of four inbred strains of Drosophila melanogaster

1969 ◽  
Vol 47 (3) ◽  
pp. 313-321
Author(s):  
L. Butler
Keyword(s):  
Drosophila Melanogaster ◽  
Phenotypic Selection ◽  
Inbred Strains ◽  
No Production ◽  
Small Populations ◽  
Next Generation ◽  
Poisson Series ◽  
Sister Mating

Four inbred strains of flies have been maintained by brother × sister mating since November, 1963. Counts of production per vial were made at 14 days, and the flies from the most productive vial were used as the parents of the next generation. For analysis the data were separated into three groups: vials with no production (blanks), vials with less than 20 flies (low production), and those with over 20 flies. The number of blanks did not change significantly in strain A but did show significant decreases in strains B and D. Until generation 60 the number of blanks per generation was not distributed in a Poisson series, but after this generation it was. The number of vials with low production was high in all strains for the first 20 generations and then decreased in widely different generations for each strain.Changes took place in all four strains but by different mechanisms. In strain A there was no increase in range, but the mode moved from 40 to 150 flies per vial and the proportion of low productive vials fell from 15% to 2% per generation. In strain D the low production vials fell from 22% to 6% and there was an extension of the range. Each of the strains shows definite trends of increase and decrease which last from 3 to 30 generations, and vary in slope from 0.3 to 13.8 flies per vial per generation. While we cannot determine how much or how many of these slopes are environmental, it can be argued that since many of the slopes of the four strains are not correlated, part of the cause is genetic. The changes in the direction of the trends show that phenotypic selection in small populations was not effective in accumulating and exploiting mutations for greater productivity.

Studies on Inbred Strains of Drosophila melanogaster

1965 ◽  
Vol 99 (909) ◽  
pp. 495-510 ◽  
Author(s):  
Bruce Wallace ◽  
Carol Madden
Keyword(s):  
Drosophila Melanogaster ◽  
Inbred Strains

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.

A cDNA from Drosophila melanogaster encodes a lamin C-like intermediate filament protein

1993 ◽  
Vol 104 (4) ◽  
pp. 1263-1272 ◽  
Author(s):  
C.A. Bossie ◽  
M.M. Sanders
Keyword(s):  
Drosophila Melanogaster ◽  
Intermediate Filament ◽  
Blot Analysis ◽  
Polytene Chromosomes ◽  
Intermediate Filament Protein ◽  
Chromosome 2 ◽  
Cross Hybridization ◽  
Intermediate Filament Proteins ◽  
Nuclear Lamins ◽  
Filament Protein

A novel intermediate filament cDNA, pG-IF, has been isolated from a Drosophila melanogaster embryonic expression library screened with a polyclonal antiserum produced against a 46 kDa cytoskeletal protein isolated from Kc cells. This 46 kDa protein is known to be immunologically related to vertebrate intermediate filament proteins. The screen resulted in the isolation of four different cDNA groups. Of these, one has been identified as the previously characterized Drosophila nuclear lamin cDNA, Dm0, and a second, pG-IF, demonstrates homology to Dm0 by cross hybridization on Southern blots. DNA sequence analysis reveals that pG-IF encodes a newly identified intermediate filament protein in Drosophila. Its nucleotide sequence is highly homologous to nuclear lamins with lower homology to cytoplasmic intermediate filament proteins. pG-IF predicts a protein of 621 amino acids with a predicted molecular mass of 69,855 daltons. In vitro transcription and translation of pG-IF yielded a protein with a SDS-PAGE estimated molecular weight of approximately 70 kDa. It contains sequence principles characteristic of class V intermediate filament proteins. Its near neutral pI (6.83) and the lack of a terminal CaaX motif suggests that it may represent a lamin C subtype in Drosophila. In situ hybridization to polytene chromosomes detects one band of hybridization on the right arm of chromosome 2 at or near 51A. This in conjunction with Southern blot analysis of various genomic digests suggests one or more closely placed genes while Northern blot analysis detects two messages in Kc cells.

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.

An Analysis of Polygenes Affecting Wing Shape on Chromosome 2 inDrosophila melanogaster

Genetics ◽  
2001 ◽  
Vol 159 (3) ◽  
pp. 1045-1057 ◽  
Author(s):  
Kenneth Weber ◽  
Robert Eisman ◽  
Shawn Higgins ◽  
Lisa Morey ◽  
April Patty ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Element ◽  
Genetic Effects ◽  
Wing Shape ◽  
Pleiotropic Effects ◽  
Phenotypic Variance ◽  
Chromosome 2 ◽  
Additive Effects ◽  
Chromosome Segments ◽  
Small Additive

AbstractGenetic effects on an index of wing shape on chromosome 2 of Drosophila melanogaster were mapped using isogenic recombinants with transposable element markers. At least 10 genes with small additive effects are dispersed evenly along the chromosome. Many interactions exist, with only small net effects in homozygous recombinants and little effect on phenotypic variance. Heterozygous chromosome segments show almost no dominance. Pleiotropic effects on leg shape are only minor. At first view, wing shape genes form a rather homogeneous class, but certain complexities remain unresolved.

The effects of chromosome rearrangements on the expression of heterochromatic genes in chromosome 2L of Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 125 (1) ◽  
pp. 141-154 ◽  
Author(s):  
B T Wakimoto ◽  
M G Hearn
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosome Rearrangements ◽  
Centromeric Heterochromatin ◽  
Chromosome 2 ◽  
Regulatory Requirement ◽  
Position Effects ◽  
Heterochromatic Genes

Abstract The light (lt) gene of Drosophila melanogaster is located at the base of the left arm of chromosome 2, within or very near centromeric heterochromatin (2Lh). Chromosome rearrangements that move the lt+ gene from its normal proximal position and place the gene in distal euchromatin result in mosaic or variegated expression of the gene. The cytogenetic and genetic properties of 17 lt-variegated rearrangements are described in this report. We show that five of the heterochromatic genes adjacent to lt are subject to inactivation by these rearrangements and that the euchromatic loci in proximal 2L are not detectably affected. The properties of the rearrangements suggest that proximity to heterochromatin is an important regulatory requirement for at least six 2Lh genes. We discuss how the properties of the position effects on heterochromatic genes relate to other proximity-dependent phenomena such as transvection.

A CYTOGENETIC ANALYSIS OF THE CHROMOSOMAL REGION SURROUNDING THE α-GLYCEROPHOSPHATE DEHYDROGENASE LOCUS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1983 ◽  
Vol 105 (2) ◽  
pp. 371-386
Author(s):  
Michael A Kotarski ◽  
Sally Pickert ◽  
Ross J MacIntyre
Keyword(s):  
Drosophila Melanogaster ◽  
Polytene Chromosome ◽  
Cytogenetic Analysis ◽  
Chromosomal Region ◽  
Chromosome Band ◽  
Recombination Analysis ◽  
Chromosome 2 ◽  
Recessive Lethal ◽  
Lethal Mutations ◽  
Glycerophosphate Dehydrogenase

ABSTRACT The chromosomal region surrounding the structural gene for α-glycerophosphate dehydrogenase (αGpdh, 2-20.5) of Drosophila melanogaster has been studied in detail. Forty-three EMS-induced recessive lethal mutations and five previously identified visible mutations have been localized within the 25A-27D region of chromosome 2 by deficiency mapping and in some cases by a recombination analysis. The 43 lethal mutations specify 17 lethal loci. ?Gpdh has been localized to a single polytene chromosome band, 25F5, and there apparently are no lethals that map to the αGpdh locus.

scholarly journals Chromosomal mapping of murine c-fes and c-src genes.

1984 ◽  
Vol 4 (5) ◽  
pp. 978-981 ◽  
Author(s):  
C Blatt ◽  
M E Harper ◽  
G Franchini ◽  
M N Nesbitt ◽  
M I Simon
Keyword(s):  
Kinase Activity ◽  
Restriction Site ◽  
Mouse Genome ◽  
Inbred Strains ◽  
Chromosomal Mapping ◽  
Chromosome 2 ◽  
Distal Half ◽  
Viral Oncogenes ◽  
Tyrosine Specific Kinase ◽  
Restriction Site Polymorphisms

The murine homologs of two viral oncogenes associated with tyrosine-specific kinase activity have been assigned to different loci in the mouse genome. The segregation of restriction site polymorphisms, as detected by probes that are specific for endogenous c-fes and c-src sequences, was followed in the DNA of recombinant inbred strains. The c-fes gene was mapped to the proximal portion of chromosome 7, very close to the Gpi-1 locus, whereas c-src was linked to the Psp locus on the distal half of chromosome 2.

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