An ultrastructural analysis of the ecdysoneless ((l(3)ecd 1ts) ring gland during the third larval instar of Drosophila melanogaster

1991 ◽  
Vol 265 (3) ◽  
pp. 435-445 ◽  
Author(s):  
Ji-da Dai ◽  
Vincent C. Henrich ◽  
Lawrence I. Gilbert
Keyword(s):  
Drosophila Melanogaster ◽  
Larval Instar ◽  
Ultrastructural Analysis ◽  
The Third ◽  
Ring Gland

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

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.

scholarly journals Experimental modification of the dominance relations of a melanotic tumour gene in Drosophila melanogaster

1972 ◽  
Vol 20 (1) ◽  
pp. 115-135 ◽  
Author(s):  
Ann Louise Belt ◽  
Barrie Burnet
Keyword(s):  
Drosophila Melanogaster ◽  
Larval Instar ◽  
Environment Interaction ◽  
Larval Food ◽  
Dominance Relations ◽  
The Third ◽  
Genotype Environment Interaction ◽  
Tumour Formation ◽  
Food Medium ◽  
Melanotic Tumour

SUMMARYThe melanotic tumour gene tu-C4 in Drosophila melanogaster shows incomplete dominance, together with variable penetrance and expressivity. It is tentatively located in the region of locus 52–53 on the third chromosome. Tumour formation in mutant homozygotes involves a precocious haemocyte transformation leading to the appearance of lamellocytes at the beginning of the third larval instar. These aggregate to form tumour-like masses which subsequently melanize. The process of tumour formation is in broad outline similar to that found in other tumour strains. Melanotic tumour formation is treated as a dichotomous threshold character, assuming an underlying normal distribution of liability relative to a fixed threshold. The expression of the tumour gene can be influenced by the levels of protein, phospholipid, nucleic acid and carbohydrate in the larval food medium, and changes in dominance and penetrance induced by sub-optimal environments deficient in these nutrients are positively correlated. Reinforcement by selection of the dominance relations of tu-C4 was accompanied by correlated changes in penetrance. Conversely, selection for increased penetrance was accompanied by correlated changes in dominance. Dominance and penetrance, it is concluded, are fundamentally related aspects of tumour gene expression. Recruitment of dominance modifiers linked to the tumour gene was excluded by the mating scheme employed, and the observed changes in dominance relations in response to selection were due largely to modifiers located on the second chromosome. Changes in dominance relations produced by selection could be significantly reinforced, or reversed, by environmental factors and consequently show a substantial genotype – environment interaction effect. These facts are relevant to current theories of dominance evolution.

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.

scholarly journals Drosophila Med6 Is Required for Elevated Expression of a Large but Distinct Set of Developmentally Regulated Genes

2001 ◽  
Vol 21 (15) ◽  
pp. 5242-5255 ◽  
Author(s):  
Byung Soo Gim ◽  
Jin Mo Park ◽  
Jeong Ho Yoon ◽  
Changwon Kang ◽  
Young-Joon Kim
Keyword(s):  
Cell Proliferation ◽  
Drosophila Melanogaster ◽  
Transcriptional Activation ◽  
Larval Instar ◽  
Developmentally Regulated ◽  
The Third ◽  
Reverse Transcription Pcr ◽  
Evolutionarily Conserved ◽  
Elevated Expression

ABSTRACT Mediator is the evolutionarily conserved coactivator required for the integration and recruitment of diverse regulatory signals to basal transcription machinery. To elucidate the functions of metazoan Mediator, we isolated Drosophila melanogaster Med6mutants. dMed6 is essential for viability and/or proliferation of most cells. dMed6 mutants failed to pupate and died in the third larval instar with severe proliferation defects in imaginal discs and other larval mitotic cells. cDNA microarray, quantitative reverse transcription-PCR, and in situ expression analyses of developmentally regulated genes indMed6 mutants showed that transcriptional activation of many, but not all, genes was affected. Among the genes found to be affected were some that play a role in cell proliferation and metabolism. Therefore, dMed6 is required in most cells for transcriptional regulation of many genes important for diverse aspects of Drosophila development.

Ecdysteroids during the third larval instar in I(3)ecd-1ts, a temperature-sensitive mutant of Drosophila melanogaster

1984 ◽  
Vol 54 (1) ◽  
pp. 76-84 ◽  
Author(s):  
P. Berreur ◽  
P. Porcheron ◽  
M. Moriniere ◽  
J. Berreur-Bonnenfant ◽  
S. Belinski-Deutsch ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Larval Instar ◽  
Temperature Sensitive ◽  
Sensitive Mutant ◽  
Temperature Sensitive Mutant ◽  
The Third

scholarly journals THE INTERACTION OF TWO COMPLEX LOCI, ZESTE AND BITHORAX IN DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 75 (2) ◽  
pp. 299-321
Author(s):  
T C Kaufman ◽  
S E Tasaka ◽  
D T Suzuki
Keyword(s):  
Drosophila Melanogaster ◽  
Heterocyclic Compounds ◽  
Larval Instar ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Extreme Form ◽  
The Third ◽  
Specific Allele ◽  
Pigment Change

ABSTRACT It has been found that certain alleles of the zeste locus (za 1-1.0) have no phenotype of their own, but interact with certain alleles at the bithorax locus (bx 3-58.8). This interaction takes the form of an enhancement of the homeotic bx phenotype to a more extreme form—i.e., the metathorax is transformed into mesothorax in varying degrees depending on the bx allele used. This enhancement is somewhat reminiscent of the transvection effect described by Lewis (1954). The characterization of the interaction thus far has shown that the enhancement only effects bx alleles which arise spontaneously, whereas the origin of the za allele is unimportant. The gene claret nondisjunctional was used for the production of gynandromorphs which showed that the enhancing ability of za, like the eye pigment change caused by z, is autonomous. The enhancement of one specific allele (bx34e), which is temperature-sensitive, has allowed a delineation of the temperature-sensitive period of the bithorax locus to a period extending from the middle of the second larval instar to the middle of the third larval instar. These results, as well as those of other enhancer and suppressor systems in Drosophila, have revealed the possibility of the involvement of heterocyclic compounds in the control of cell determination and fate in Drosophila melanogaster.

scholarly journals A Cluster of Cuticle Protein Genes of Drosophila melanogaster at 65A: Sequence, Structure and Evolution

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1213-1224
Author(s):  
Jean-Philippe Charles ◽  
Carol Chihara ◽  
Shamim Nejad ◽  
Lynn M Riddiford
Keyword(s):  
Drosophila Melanogaster ◽  
Genomic Dna ◽  
Multiple Copy ◽  
Sequence Structure ◽  
Coding Regions ◽  
The Third ◽  
Genetic Complexity ◽  
Genes Encoding ◽  
Cuticle Protein ◽  
Cuticle Proteins

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.

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

Genetics ◽  
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.

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

Gene ◽  
2000 ◽  
Vol 246 (1-2) ◽  
pp. 157-167 ◽  
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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