CORRELATIONS BETWEEN CHROMOSOME SEGMENTS AND FITNESS IN DROSOPHILA MELANOGASTER. IV. FECUNDITY, VIABILITY AND THE THIRD CHROMOSOME

1980 ◽  
Vol 22 (3) ◽  
pp. 405-410 ◽  
Author(s):  
William Chapco
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Genetic Background ◽  
Egg Production ◽  
Adjacent Segment ◽  
Egg Viability ◽  
Clear Pattern ◽  
The Third ◽  
Chromosome Segments ◽  
Agricultural Implications

Unmarked segments within the third chromosomes of three different Drosophila melanogaster lines were assessed for their effects on egg production and egg viability. By making a series of crosses among original and derived recombinant lines, it was possible to estimate parameters representing additive, dominance (for egg production), and interaction effects of the segments. Each segment influences both traits, but to extents which are dependent on the genetic background provided by an adjacent segment. There is no clear pattern, however, with respect to the segments' joint effects on the two characters. Unlike in the previous study involving the X chromosome, the majority of the derived recombinant lines were superior in fitness to their original lines. The agricultural implications of this result with respect to the manipulation of chromosomal segments in order to achieve higher yields are discussed.

scholarly journals CORRELATIONS BETWEEN CHROMOSOME SEGMENTS AND FITNESS IN DROSOPHILA MELANOGASTER. II. THE X CHROMOSOME AND EGG VIABILITY

Genetics ◽  
1979 ◽  
Vol 92 (2) ◽  
pp. 595-601
Author(s):  
William Chapco
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Egg Production ◽  
Egg Viability ◽  
X Chromosomes ◽  
Isogenic Lines ◽  
Chromosome Segments

ABSTRACT Unmarked segments within the X chromosomes of four different Drosophila melanogaster isogenic lines were assessed with respect to egg-to-adult viability. The results were compared with those of an earlier study involving egg production. All segments influence both traits, but to extents that are dependent upon the strains being compared. Segmental effects are also a function of the genetical background, which, in this case, constitutes material within the same chromowme. With respect to both traits, the segments are not necessarily parallel in their effects. A segment that increases fecundity, for example, may or may not augment viability. The possibility of manipulating chromosomal segments to improve "yield" in organisms is explored.

scholarly journals Studies of esterase 6 in Drosophila melanogaster: XIV. Variation of esterase 6 levels controlled by unlinked genes in natural populations

1984 ◽  
Vol 43 (2) ◽  
pp. 181-190 ◽  
Author(s):  
Craig S. Tepper ◽  
Anne L. Terry ◽  
James E. Holmes ◽  
Rollin C. Richmond
Keyword(s):  
Drosophila Melanogaster ◽  
Structural Gene ◽  
X Chromosome ◽  
Genetic Background ◽  
Natural Populations ◽  
Regulatory Elements ◽  
Regulatory Locus ◽  
The Third ◽  
Esterase 6 ◽  
Activity Modifiers

SUMMARYThe esterase 6 (Est-6) locus in Drosophila melanogaster is located on the third chromosome and is the structural gene for a carboxylesterase (E.C.3.1.1.1) and is polymorphic for two major electromorphs (slow and fast). Isogenic lines containing X chromosomes extracted from natural populations and substituted into a common genetic background were used to detect unlinked factors that affect the activity of the Est-6 locus. Twofold activity differences of esterase 6 (EST 6) were found among males from these derived lines, which differ only in their X chromosome. These unlinked activity modifiers identify possible regulatory elements. Immunoelectrophoresis was used to estimate quantitatively the levels of specific cross-reacting material in the derived lines. The results show that the variation in activity is due to differences in the amount of EST 6 present. The data are consistent with the hypothesis that there is at least one locus on the X chromosome that regulates the synthesis of EST 6 and that this regulatory locus may be polymorphic in natural populations.

scholarly journals CORRELATIONS BETWEEN CHROMOSOME SEGMENTS AND FITNESS IN DROSOPHILA MELANOGASTER. I. THE X CHROMOSOME AND EGG PRODUCTION

Genetics ◽  
1977 ◽  
Vol 85 (4) ◽  
pp. 721-732
Author(s):  
William Chapco
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Egg Production ◽  
Position Effect ◽  
X Chromosomes ◽  
Heterozygous Condition ◽  
Coupling Phase ◽  
Isogenic Lines ◽  
Apparent Relationship ◽  
Chromosome Segments

ABSTRACT Unmarked segments within the X chromosomes of four different Drosophila melanogaster isogenic lines were assessed with respect to egg production. By making a series of crosses among original and derived recombinant lines, it was possible to estimate parameters representing additive, dominance and interaction effects of the segments. It was shown that whereas most of the segments were additive for egg production when homozygous, they all displayed dominance in the heterozygous condition. Two of the strains were characterized by intersegmental interaction. A possible position effect was detected for these same two strains, with flies in the coupling phase laying more eggs than those in the repulsion configuration. There was no apparent relationship between the number of eggs laid and the amount of heterozygosity within the X chromosome.

scholarly journals THE EFFECTS OF HETEROZYGOSITY CHANGES ON VIABILITY IN DROSOPHILA MELANOGASTER

Genetics ◽  
1972 ◽  
Vol 70 (4) ◽  
pp. 595-610
Author(s):  
Ray Moree
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Background ◽  
Laboratory Strain ◽  
Theoretical Expectation ◽  
Wild Type ◽  
Small Deviations ◽  
The Third ◽  
The Difference

ABSTRACT The viability effects of chromosomes from an old and from a new laboratory strain of D. melanogaster were studied in eight factorial combinations and at two heterozygosity levels. The combinations were so constructed that heterozygosity level could be varied in the third chromosomes of the carriers of a homozygous lethal marker, in the third chromosomes of their wild-type segregants, and in the genetic backgrounds of both. Excluding the effect of the marker and the exceptional outcomes of two of the combinations, and taking into account both large and small deviations from theoretical expectation, the following summary is given as the simplest consistent explanation of the results: 1) If total heterozygosities of two segregant types tend toward equality their viabilities tend toward equality also, whether background heterozygosity is high or low; if background heterozygosities is higher the tendency toward equality is slightly greater. 2) If total heterozygosity of two segregant types are unequal the less heterozygous type has the lower viability; the difference is more pronounced when background heterozygosity is low, less when it is high. 3) Differences between segregant viabilities are correlated with differences between the total heterozygosities of the two segregants; genetic background is effective to the extent, and only to the extent, that it contributes to the magnitude of this difference. This in turn appears to underlie, at least partly, the expression of a pronounced interchromosomal epistasis. Thus in this study viability is seen to depend upon both the quantity and distribution of heterozygosity, not only among the chromosomes of an individual but among the individuals of a given combination as well.

scholarly journals Interactions and developmental effects of mutations in the Broad-Complex of Drosophila melanogaster.

Genetics ◽  
1988 ◽  
Vol 118 (2) ◽  
pp. 247-259
Author(s):  
I Kiss ◽  
A H Beaton ◽  
J Tardiff ◽  
D Fristrom ◽  
J W Fristrom
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Genetic Locus ◽  
Larval Instar ◽  
Imaginal Discs ◽  
Functional Domains ◽  
Developmental Processes ◽  
The Third ◽  
Developmental Effects ◽  
Broad Complex

Abstract The 2B5 region on the X chromosome of Drosophila melanogaster forms an early ecdysone puff at the end of the third larval instar. The region contains a complex genetic locus, the Broad-Complex (BR-C) composed of four groups of fully complementing (br, rbp, l(1)2Bc, and l(1)2Bd) alleles, and classes of noncomplementing (npr 1) and partially noncomplementing l(1)2Bab alleles. BR-C mutants prevent metamorphosis, including the morphogenesis of imaginal discs. Results are presented that indicate that the BR-C contains two major functional domains. One, the br domain is primarily, if not exclusively, involved in the elongation and eversion of appendages by imaginal discs. The second, the l(1)2Bc domain, is primarily involved in the fusion of discs to form a continuous adult epidermis. Nonetheless, the two domains may encode products with related functions because in some situations mutants in both domains appear to affect similar developmental processes.

Requirements for autosomal gene activity during precellular stages of Drosophila melanogaster

Development ◽  
1988 ◽  
Vol 104 (3) ◽  
pp. 495-509 ◽  
Author(s):  
P.T. Merrill ◽  
D. Sweeton ◽  
E. Wieschaus
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Single Cells ◽  
Gene Activity ◽  
Autosomal Gene ◽  
The Third ◽  
Specific Effects ◽  
Morphological Defects ◽  
Zygotic Gene

To identify early requirements for zygotic gene activity in Drosophila, we used compound autosomes and autosome-Y translocations to generate embryos deficient for cytologically defined portions of the genome. No obvious gross morphological defects were observed in any deficiency class until the beginning of cycle 14. Only seven autosomal regions were identified with discrete effects visible prior to the onset of gastrulation. These regions include genes with locus-specific effects on the clearing of the cortical cytoplasm during early cycle 14, (22AB), the initiation of the slow and fast phases of cellularization (26BF and 40AC, respectively), the apical-basal distribution of nuclei during cycle 14 (71C-75C) and the closing off of furrow canals during cellularization (100AC). The distal tip of the third chromosome also contains two loci (99DF and 100AC) whose deletion causes multiple nuclei to be cellularized into single cells, a phenotype similar to that produced in embryos totally lacking the X-chromosome.

MALELESS, A RECESSIVE AUTOSOMAL MUTANT OF DROSOPHILA MELANOGASTER THAT SPECIFICALLY KILLS MALE ZYGOTES

Genetics ◽  
1975 ◽  
Vol 81 (1) ◽  
pp. 135-141
Author(s):  
Akihiro Fukunaga ◽  
Atsumi Tanaka ◽  
Kugao Oishi
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Larval Stage ◽  
Lethal Gene ◽  
Homozygous Condition ◽  
The Third ◽  
Male Specific Lethal ◽  
Male Specific ◽  
Transforming Genes

ABSTRACT A second chromosome male-specific lethal gene, maleless (mle), in D. melanogaster is described. It kills males but not females in homozygous condition, regardless of whether female parents are heterozygous or homozygous for mle. Many, if not most, homozygous males survive up to the third instar larval stage, but cannot pupate and die eventually as larvae. No interactions with sex-transforming genes, tra and dsx, were observed. It is proposed that mle interacts with a gene(s) on the X chromosome, which is not dosage compensated.

scholarly journals A CYTOGENETIC ANALYSIS OF CYCLIC NUCLEOTIDE PHOSPHODIESTERASE ACTIVITIES IN DROSOPHILA

Genetics ◽  
1977 ◽  
Vol 85 (4) ◽  
pp. 609-622
Author(s):  
John A Kiger ◽  
Eric Golanty
Keyword(s):  
Drosophila Melanogaster ◽  
Structural Gene ◽  
X Chromosome ◽  
Cyclic Nucleotide ◽  
Phosphodiesterase Activity ◽  
Structural Genes ◽  
Camp Phosphodiesterase ◽  
Cgmp Phosphodiesterase ◽  
The Third ◽  
Segmental Aneuploidy

ABSTRACT The genome of Drosophila melanogaster has been surveyed for chromosomal regions which exert a dosage effect on the activities of cAMP phosphodiesterase or cGMP phosphodiesterase. Two regions increase cAMP phosphodiesterase activity when present as duplications. A region of the X chromosome increases cAMP phosphodiesterase activity when duplicated and decreases that activity when deficient. This region has been delimited to chromomeres 3D3 and 3D4, with 3D4 being the most probable locus, and may contain a structural gene for cAMP phosphodiesterase. A region on the third chromosome, 90E-91B, increase cAMP phosphodiesterase activity when duplicated but has no affect on the activity when deficient. Two regions increase cGMP phosphodiesterase activity when present as duplications. A region of the X chromosome, 5D-9C, increases cGMP phosphodiesterase activity when duplicated, but smaller duplications covering this region fail to show such an increase, indicating that a single locus is not responsible for the increase observed for the larger duplication. A region of the third chromosome, 88C-91B, also increases cGMP phosphodiesterase activity when duplicated. Smaller duplications covering this region show smaller increases than that observed for the larger duplication, suggesting that at least three loci between 88C and 91B contribute to the observed increase by that region. Deficiencies covering region 88C-91B do not affect cGMP phosphodiesterase activity. No locus for a presumptive structural gene for cGMP phosphodiesterase has been found. Limitations of the use of segmental aneuploidy in locating structural genes for enzymes are discussed.

scholarly journals Suppression of a lethal trisomic phenotype in Drosophila melanogaster by increased dosage of an unlinked locus.

Genetics ◽  
1993 ◽  
Vol 134 (1) ◽  
pp. 243-249 ◽  
Author(s):  
D R Dorer ◽  
M A Cadden ◽  
B Gordesky-Gold ◽  
G Harries ◽  
A C Christensen
Keyword(s):  
Drosophila Melanogaster ◽  
X Chromosome ◽  
Gene Dosage ◽  
Chromosome Region ◽  
Dosage Effect ◽  
Gene Dosage Effect ◽  
Unlinked Locus ◽  
Lethal Phenotype ◽  
The Third ◽  
Dosage Sensitivity

Abstract One of the most extreme examples of gene dosage sensitivity is the Triplo-lethal locus (Tpl) on the third chromosome of Drosophila melanogaster, which is lethal when present in either one or three copies. Increased dosage of an unlinked locus, Isis, suppresses the triplo-lethal phenotype of Tpl, but not the haplo-lethal phenotype. We have mapped Isis to the X chromosome region 7E3-8A5, and shown that the suppression is a gene dosage effect. Altered dosage of Isis in the presence of two copies of Tpl has no obvious effects. By examining the interactions between Isis dosage and Tpl we suggest that Isis does not directly repress Tpl expression, but acts downstream on the triplo-lethal phenotype of Tpl.

scholarly journals Structure, frequency and distribution of P elements in relation to P—M hybrid dysgenic male recombination in Drosophila melanogaster

1989 ◽  
Vol 53 (3) ◽  
pp. 163-171 ◽  
Author(s):  
K. A. Exley ◽  
P. Eggleston
Keyword(s):  
Drosophila Melanogaster ◽  
Egg Production ◽  
Polytene Chromosomes ◽  
Element Distribution ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
Male Recombination ◽  
P Elements ◽  
Egg Hatchability ◽  
The Third

SummaryThe frequency and distribution of P elements were investigated in the third chromosomes of two wild-type strains of Drosophila melanogaster using in situ hybridization of biotinylated probes to the polytene chromosomes. The relationship between these data and the extent of hybrid dysgenesis was determined through assays of egg production, egg hatchability (F2 embryo lethality), snw destabilization and male recombination along the third chromosome. The results suggest that P-element distribution, frequency and structure are all contributory factors in the regulation of hybrid dysgenesis. Texas 6 was shown consistently to be a stronger P strain than Texas 1, eliciting greater reductions in fertility, more extensive snw destabilization and higher frequencies of male recombination. Clustering of male recombination events, arising from pre-meiotic crossing over, was evident among the dysgenic progeny of each strain. Male recombination and snw destabilization were independently distributed among the dysgenic males studied, suggesting that these traits represent separate P-mediated functions. The third chromosome male recombination maps produced by the two strains differed significantly from each other and from the published female meiotic and polytene chromosome maps. Male recombination breakpoints were associated with the original distribution of P sequences in the two strains and the results suggest that this relationship may be closer for potentially complete P factors than for P sequences in general. An analysis of sub-lines derived from individual recombinant males revealed that chromosomal breakpoints could also be associated with novel insertions following P-element transposition.

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