A CLOSELY LINKED GROUP OF DOMINANT MUTATIONS IN THE THIRD CHROMOSOME OF DROSOPHILA MELANOGASTER

A 36-kb genomic DNA segment of the Drosophila melanogaster genome containing 12 clustered cuticle genes has been mapped and partially sequenced. The cluster maps at 65A 5-6 on the left arm of the third chromosome, in agreement with the previously determined location of a putative cluster encompassing the genes for the third instar larval cuticle proteins LCP5, LCP6 and LCP8. This cluster is the largest cuticle gene cluster discovered to date and shows a number of surprising features that explain in part the genetic complexity of the LCP5, LCP6 and LCP8 loci. The genes encoding LCP5 and LCP8 are multiple copy genes and the presence of extensive similarity in their coding regions gives the first evidence for gene conversion in cuticle genes. In addition, five genes in the cluster are intronless. Four of these five have arisen by retroposition. The other genes in the cluster have a single intron located at an unusual location for insect cuticle genes.

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GENETIC AND BIOCHEMICAL BASIS OF ENZYME ACTIVITY VARIATION IN NATURAL POPULATIONS. I. ALCOHOL DEHYDROGENASE IN DROSOPHILA MELANOGASTER

Genetics ◽

10.1093/genetics/89.2.371 ◽

1978 ◽

Vol 89 (2) ◽

pp. 371-388

Author(s):

John F McDonald ◽

Francisco J Ayala

Keyword(s):

Gene Regulation ◽

Drosophila Melanogaster ◽

Alcohol Dehydrogenase ◽

Natural Populations ◽

Difficult Problem ◽

Regulatory Genes ◽

Biochemical Basis ◽

Evolutionary Consequence ◽

The Third ◽

Adh Activity

ABSTRACT Recent studies by various authors suggest that variation in gene regulation may be common in nature, and might be of great evolutionary consequence; but the ascertainment of variation in gene regulation has proven to be a difficult problem. In this study, we explore this problem by measuring alcohol dehydrogenase (ADH) activity in Drosophila melanogaster strains homozygous for various combinations of given second and third chromosomes sampled from a natural population. The structural locus (Adh) coding for ADH is on the second chromosome. The results show that: (1) there are genes, other than Adh, that affect the levels of ADH activity; (2) at least some of these "regulatory" genes are located on the third chromosome, and thus are not adjacent to the Adh locus; (3) variation exists in natural populations for such regulatory genes; (4) the effect of these regulatory genes varies as they interact with different second chromosomes; (5) third chromosomes with high-activity genes are either partially or completely dominant over chromosomes with low-activity genes; (6) the effects of the regulatory genes are pervasive throughout development; and (7) the third chromosome genes regulate the levels of ADH activity by affecting the number of ADH molecules in the flies. The results are consistent with the view that the evolution of regulatory genes may play an important role in adaptation.

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Genetic and molecular analysis in the 70CD region of the third chromosome of Drosophila melanogaster

Gene ◽

10.1016/s0378-1119(00)00066-4 ◽

2000 ◽

Vol 246 (1-2) ◽

pp. 157-167 ◽

Cited By ~ 4

Author(s):

Thorsten Burmester ◽

Mátyás Mink ◽

Margit Pál ◽

Zsolt Lászlóffy ◽

Jean-Antoine Lepesant ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Molecular Analysis ◽

The Third

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Genetics of Differences in Pheromonal Hydrocarbons Between Drosophila melanogaster and D. simulans

Genetics ◽

10.1093/genetics/143.1.353 ◽

1996 ◽

Vol 143 (1) ◽

pp. 353-364 ◽

Cited By ~ 3

Author(s):

Jerry A Coyne

Keyword(s):

Drosophila Melanogaster ◽

Sexual Dimorphism ◽

Genetic Analysis ◽

Species Difference ◽

The Other ◽

Chromosome 3 ◽

Apparent Effect ◽

The Third ◽

Hydrocarbon Profile ◽

The Right

Abstract Females of Drosophila melanogaster and its sibling species D. simulans have very different cuticular hydrocarbons, with the former bearing predominantly 7,11-heptacosadiene and the latter 7-tricosene. This difference contributes to reproductive isolation between the species. Genetic analysis shows that this difference maps to only the third chromosome, with the other three chromosomes having no apparent effect. The D. simulans alleles on the left arm of chromosome 3 are largely recessive, allowing us to search for the relevant regions using D. melanogaster deficiencies. At least four nonoverlapping regions of this arm have large effects on the hydrocarbon profile, implying that several genes on this arm are responsible for the species difference. Because the right arm of chromosome 3 also affects the hydrocarbon profile, a minimum of five genes appear to be involved. The large effect of the third chromosome on hydrocarbons has also been reported in the hybridization between D. simulans and its closer relative D. sechellia, implying either an evolutionaly convergence or the retention in D. sechllia of an ancestral sexual dimorphism.

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The Post-embryonic Development of the Tracheal System in Drosophila melanogaster

Journal of Cell Science ◽

10.1242/jcs.s3-98.41.123 ◽

1957 ◽

Vol s3-98 (41) ◽

pp. 123-150

Author(s):

JOAN M. WHITTEN

Keyword(s):

Drosophila Melanogaster ◽

Adult Stage ◽

Larval Instar ◽

Pupal Stage ◽

Tracheal System ◽

True Nature ◽

The Third ◽

Air Sacs ◽

Abdominal Region ◽

Pupal Cuticle

The fate of the tracheal system is traced from the first larval instar to the adult stage. The basic larval pattern conforms to that shown for other Diptera Cyclorrhapha (Whitten, 1955), and is identical in all three instars. According to previous accounts the adult system directly replaces the larval: the larval system is partly shed, partly histolysed, and the adult system arises from imaginal cell clusters independently of the preceding larval system. In contrast, it is shown here that in the cephalic, thoracic, and anterior abdominal region there is a definite continuity in the tracheal system, from larval, through pupal to the adult stage, whereas in the posterior abdominal region the larval system is histolysed, and the adult system is independent of it in origin. Moreover, in the pupal stage this region is tracheated by tracheae arising from the anterior abdominal region and belonging to a distinct pupal system. Moulting of the tracheal linings is complete at the first and second larval ecdyses, but incomplete at the third larval-pupal and pupal-adult ecdyses. In consequence, in both pupal and adult systems there are tracheae which are secreted around preexisting tracheae, others formed as new ‘branch’ tracheae, and those which have been carried over from the previous instar. In the adult the newly formed tracheae of the posterior abdominal region fall into a fourth category. Most of the adult thoracic air sacs correspond to new ‘branch’ tracheae of other instars. The pre-pupal moult and instar are discussed with reference to the tracheal system and tentative suggestions are made concerning the true nature of the pre-pupal cuticle. There is no pre-pupal tracheal system. Events traced for Drosophila would seem to be general for Cyclorrhapha, both Acalypterae and Calypterae. The separate fates of the anterior and posterior abdom inal systems, in contrast with the straightforward development in Dipterc Nematocera, would appear to mark a distinct step in the evolution of the system in Diptera.

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The ash-1, ash-2 and trithorax genes of Drosophila melanogaster are functionally related.

Genetics ◽

10.1093/genetics/121.3.517 ◽

1989 ◽

Vol 121 (3) ◽

pp. 517-525 ◽

Cited By ~ 8

Author(s):

A Shearn

Keyword(s):

Drosophila Melanogaster ◽

Null Allele ◽

Homeotic Gene ◽

Bithorax Complex ◽

Substantial Evidence ◽

Genetic Tests ◽

Recessive Lethal ◽

The Third ◽

Sex Combs

Abstract Mutations in the ash-1 and ash-2 genes of Drosophila melanogaster cause a wide variety of homeotic transformations that are similar to the transformations caused by mutations in the trithorax gene. Based on this similar variety of transformations, it was hypothesized that these genes are members of a functionally related set. Three genetic tests were employed here to evaluate that hypothesis. The first test was to examine interactions of ash-1, ash-2 and trithorax mutations with each other. Double and triple heterozygotes of recessive lethal alleles express characteristic homeotic transformations. For example, double heterozygotes of a null allele of ash-1 and a deletion of trithorax have partial transformations of their first and third legs to second legs and of their halteres to wings. The penetrance of these transformations is reduced by a duplication of the bithorax complex. The second test was to examine interactions with a mutation in the female sterile (1) homeotic gene. The penetrance of the homeotic phenotype in progeny from mutant mothers is increased by heterozygosis for alleles of ash-1 or ash-2 as well as for trithorax alleles. The third test was to examine the interaction with a mutation of the Polycomb gene. The extra sex combs phenotype caused by heterozygosis for a deletion of Polycomb is suppressed by heterozygosis for ash-1, ash-2 or trithorax alleles. The fact that mutations in each of the three genes gave rise to similar results in all three tests represents substantial evidence that ash-1, ash-2 and trithorax are members of a functionally related set of genes.

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THE EFFECTS OF HETEROZYGOSITY CHANGES ON VIABILITY IN DROSOPHILA MELANOGASTER

Genetics ◽

10.1093/genetics/70.4.595 ◽

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.

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

Genetics Research ◽

10.1017/s0016672300025891 ◽

1984 ◽

Vol 43 (2) ◽

pp. 181-190 ◽

Cited By ~ 7

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.

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Relationships within the melanogaster species subgroup of the genus Drosophila ( Sophophora ). I. Inversion polymorphisms in Drosophila melanogaster and Drosophila simulans

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1976.0036 ◽

1976 ◽

Vol 193 (1111) ◽

pp. 137-157 ◽

Cited By ~ 49

Keyword(s):

Drosophila Melanogaster ◽

Drosophila Simulans ◽

Fourth Chromosome ◽

The Third ◽

Chromosome Inversions

Drosophila melanogaster from 67 collections have been analysed for their polymorphic inversions. Of the 53 inversions now known in this species 7 are widespread and 43 are endemic. The remaining 3 inversions may be widespread, but if so they are usually very rare. No X or fourth chromosome inversions were found. All the third chromosome inversions were paracentric, while six of the second chromosome inversions were pericentric. No inversions were found in D. simulans , of which 27 collections, from Africa, Europe, Australia and S. America, were studied.

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