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At least 991 records · Page 55Linked to original sources
PubMed2002

Evolutionary optimality applied to Drosophila experiments: hypothesis of constrained reproductive efficiency.

The general purpose of the paper is to test evolutionary optimality theories with experimental data on reproduction, energy consumption, and longevity in a particular Drosophila genotype. We describe the resource allocation in Drosophila females in terms of the oxygen consumption rates devoted to reproduction and to maintenance. The maximum ratio of the component spent on reproduction to the total rate of oxygen consumption, which can be realized by the female reproductive machinery, is called metabolic reproductive efficiency (MRE). We regard MRE as an evolutionary constraint. We demonstrate that MRE may be evaluated for a particular Drosophila phenotype given the fecundity pattern, the age-related pattern of oxygen consumption rate, and the longevity. We use a homeostatic model of aging to simulate a life history of a representative female fly, which describes the control strain in the long-term experiments with the Wayne State Drosophila genotype. We evaluate the theoretically optimal trade-offs in this genotype. Then we apply the Van Noordwijk-de Jong resource acquisition and allocation model, Kirkwood's disposable soma theory. and the Partridge-Barton optimality approach to test if the experimentally observed trade-offs may be regarded as close to the theoretically optimal ones. We demonstrate that the two approaches by Partridge-Barton and Kirkwood allow a positive answer to the question, whereas the Van Noordwijk-de Jong approach may be used to illustrate the optimality. We discuss the prospects of applying the proposed technique to various Drosophila experiments, in particular those including manipulations affecting fecundity.

Aging↗
PubMed2004

Insulin reduces apoptosis and increases DNA synthesis and cell size via distinct signalling pathways in Drosophila Kc cells.

During development of Drosophila, cell proliferation and size are known to be regulated by insulin. Here we use Drosophila Kc cells to examine the molecular basis for the control of cell growth by insulin. Growing cells in the presence of insulin increased cell number above control levels at 16, 24, 48 and 72 h. We have demonstrated a novel anti-apoptotic effect of insulin (approximately 50%) in these cells, measured by caspase 3-like activity, which contributed to the increase in cell number. The anti-apoptotic effect was observed both in control cells and those in which apoptosis was induced by ultraviolet irradiation. An approximately 2-fold stimulation of bromodeoxyuridine incorporation demonstrated that insulin also increased Kc cell proliferation by stimulating new DNA synthesis. The ability of insulin to increase cell number, stimulate bromodeoxyuridine incorporation and reduce caspase 3-like activity was prevented by PD98059, which inhibits activation of the Drosophila extracellular signal regulated kinase (DERK) pathway, and was unaffected by wortmannin, an inhibitor of Drosophila phosphatidylinositol 3-kinase (DPI3K). Insulin also increased cell size approximately 2-fold and this was prevented by wortmannin and rapamycin, an inhibitor of Drosphilia target of rapamycin (DTOR). In summary, we show that DERK plays an important role in mediating the effect of insulin to reduce apoptosis and increase DNA synthesis whereas the DPI3K/DTOR/Dp70S6 kinase pathway mediates effects of insulin on cell size in Drosophila Kc cells.

Androstadienes↗
PubMed2006

Biochemical characterization of Drosophila gamma-glutamyl carboxylase and its role in fly development.

To investigate structure-function relationships in gamma-glutamyl carboxylases, the enzyme from Drosophila melanogaster was characterized. Four cysteine residues were shown to be important determinants for enzymatic activity. Native Drosophila substrates have not yet been identified, but propeptides of human prothrombin and factor IX are recognized by the Drosophila enzyme. The presence of the propeptide region increased apparent affinity by approximately 200-fold, and mutation of a hydrophobic residue of factor IX propeptide (F-16A) decreased carboxylation by 90%, as in the human enzyme. Substrate recognition appears to be highly conserved between the human and Drosophila gamma-glutamyl carboxylases. Inactivation of Drosophila gamma-glutamyl carboxylase by non-sense mutations or insertional mutagenesis by P-element insertion have no apparent effects on growth and fertility under laboratory conditions.

Alanine↗
PubMed1991

Role of aspartic acid 38 in the cofactor specificity of Drosophila alcohol dehydrogenase.

Drosophila alcohol dehydrogenase (ADH), an NAD(+)-dependent dehydrogenase, shares little sequence similarity with horse liver ADH. However, these two enzymes do have substantial similarity in their secondary structure at the NAD(+)-binding domain [Benyajati, C., Place, A. P., Powers, D. A. & Sofer, W. (1981) Proc. Natl Acad. Sci. USA 78, 2717-2721]. Asp38, a conserved residue between Drosophila and horse liver ADH, appears to interact with the hydroxyl groups of the ribose moiety in the AMP portion of NAD+. A secondary-structure comparison between the nucleotide-binding domain of NAD(+)-dependent enzymes and that of NADP(+)-dependent enzymes also suggests that Asp38 could play an important role in cofactor specificity. Mutating Asp38 of Drosophila ADH into Asn38 decreases Km(app)NADP 62-fold and increases kcat/Km(app)NADP 590-fold at pH 9.8, when compared with wild-type ADH. These results suggest that Asp38 is in the NAD(+)-binding domain and its substituent, Asn38, allows Drosophila ADH to use both NAD+ and NADP+ as its cofactor. The observations from the experiments of thermal denaturation and kinetic measurement with pH also confirm that the repulsion between the negative charges of Asp38 and 2'-phosphate of NADP+ is the major energy barrier for NADP+ to serve as a cofactor for Drosophila ADH.

Alcohol Dehydrogenase↗
PubMed1995

A putative digestive cysteine proteinase from Drosophila melanogaster is predominantly expressed in the embryonic and larval midgut.

Plant seeds have biodefense systems for protection against insects. One of these systems may be based on the occurrence of phytocystatins, cysteine proteinase inhibitors of plant origin, that probably inhibit insect cysteine proteinases involved in digestive functions. To elucidate a molecular mechanism for this biodefense phenomenon, we isolated a gene encoding a putative digestive cysteine proteinase from Drosophila melanogaster, a suitable model species. The cloned genomic DNA fragment contained a sequence encoding a cysteine proteinase. The mature enzyme from the encoded protein, termed Drosophila cysteine proteinase-1, consisted of 218 amino acid residues. Drosophila cysteine proteinase-1 showed 67% similarity in its amino acid sequence to a lobster cysteine proteinase-3 contained in the digestive juice. This enzyme also showed significant similarities to cysteine proteinases of animal origin such as cathepsins H and L, and to proteinases of plant origin such as rice oryzains alpha and beta. In situ hybridization studies for the embryo showed that the mRNA for Drosophila cysteine proteinase-1 was predominantly expressed in the midgut. Larval alimentary organs, such as the salivary gland and the midgut including the gastric caeca, also expressed the mRNA at significant levels. These observations, suggesting that Drosophila cysteine proteinase-1 is a digestive cysteine proteinase which can be used as a model target of phytocystatins, will hopefully lead to new strategies for the regulation of pest insects.

Amino Acid Sequence↗
PubMed2006

Rap-GEF/Rap signaling restricts the formation of supernumerary spermathecae in Drosophila melanogaster.

Sperm storage in the female is a key factor for reproductive success in a variety of organisms, including Drosophila melanogaster. The spermathecae (SP) are the Drosophila organs for long-term storage. While wild-type female flies have two SP, occasionally, three or four SP have been observed in mutant flies. However, the molecular mechanism of SP formation is unknown. Here we show that loss of function of a Drosophila Rap-GEF (GEF26) result in an occurrence of the supernumerary SP; females have three SP (varies from 11 to 62% in different allele combinations) instead of the normal two SP. In addition, the Gef26 mutant flies also have ectopic wing veins and extra mechanosensory organs. The supernumerary SP phenotype of the Gef26 mutation can be enhanced by the Drosophila Rap mutations and rescued by overexpressing the cell adhesion molecule DE-cadherin. These data suggest that the Rap-GEF/Rap signaling controls the formation of supernumerary spermathecae through modulating cell adhesion in Drosophila.

Animals↗
PubMed1991

Genomic organization of Drosophila choline acetyltransferase.

Choline acetyltransferase (ChAT; acetyl-CoA:choline-O-acetyltransferase; EC 2.3.1.6) is the enzyme responsible for the synthesis of the neurotransmitter acetylcholine and is thus the genetic determinant of neurons with a cholinergic phenotype. We have screened a Drosophila genomic library using a cRNA probe, transcribed from Drosophila ChAT cDNA, and isolated three independent clones representing all the exons of this gene. The gene spans more than 26 kb of DNA and is organized into eight exons containing 594, 80, 192, 759, 408, 147, 201, and 1,612 nucleotides. All inserts that hybridized with a cRNA probe have been subcloned and the sequence of intron/exon boundaries determined. The only part of the ChAT gene not represented in our clones is a part of the first intron. A minimum size for this uncloned DNA has been deduced from Southern analysis of Drosophila genomic DNA. We also have probed the transcripts of the ChAT gene by northern analysis of total Drosophila RNA using two different exon-specific antisense RNA probes. An exon I probe detected two bands of RNA whereas an exon VIII probe hybridized with only the smaller band, previously identified as ChAT mRNA. These results indicate a complex transcription pattern for the ChAT locus in Drosophila.

Amino Acid Sequence↗
PubMed2005

Behavioral, physical, and demographic changes in Drosophila populations through dietary restriction.

Dietary restriction (DR) is a valuable experimental tool for studying the aging process. Primary advancement of research in this area has relied on rodent models, but attention has recently turned toward Drosophila melanogaster. However, little is known about the baseline effects of DR on wild-type Drosophila and continued experimentation requires such information. The findings described here survey the effects of DR on inbred, wild-type populations of Canton-S fruit flies and demonstrate a robust effect of diet on longevity. Over a circumscribed range of dietary conditions, healthy lifespan varies by as much as 121% for wild-type Drosophila females. Significant differences are also observed for male flies, but the magnitude of the DR effect is less robust. Mortality analyses of the survivorship data reveal that this variation in lifespan can be attributed to a modulation of the rate parameter for the mortality function - a change in the demographic rate of aging. Since the feeding of fruit flies is less easily controlled than that of rodents, this research also addresses the validity of applying a DR model to Drosophila populations. Feeding and body weight data for flies given the various dietary conditions surveyed indicate that Drosophila on higher-calorie diets consume a similar volume of food to those on a low-calorie diet, resulting in different levels of calorie intake. Fertility and activity levels demonstrate that the diets surveyed are comparable, and that increasing the calorie content of laboratory food up to twice the normal concentration is not pathologic for experimental fly populations.

Aging↗
PubMed1991

Very high affinity interaction of DPI 201-106 and BDF 8784 enantiomers with the phenylalkylamine-sensitive Ca2(+)-channel in Drosophila head membranes.

1. Piperazinylindoles (DPI 201-106, BDF 8784), drugs known to act on voltage-dependent Na(+)-channels, bind with very high affinity to a Ca2(+)-channel-associated phenylalkylamine receptor in Drosophila melanogaster head membranes. These compounds and (+)-tetrandrine, a naturally occurring Ca2(+)-antagonist, were the most selective inhibitors for phenylalkylamine-labelled Drosophila Ca2(+)-channels compared to mammalian L-type Ca2(+)-channels. 2. Replacement of the cyano group by a methyl group in (+)-DPI 201-106 ((+)-BDF 8784) increases the IC50 value for inhibition of phenylalkylamine labelling of Drosophila Ca2(+)-channels from 0.29 to 2.1 nM but decreases the IC50 value for inhibition of phenylalkylamine labelling of mammalian skeletal muscle Ca2(+)-channels from 3480 to 49 nM. 3. DPI 201-106 enantiomers completely block (at 0.1 microM) phenylalkylamine photolabelling of a 136 K polypeptide in Drosophila head membranes whereas 10 microM aconitine or lidocaine are without effect. 4. Assessment of the Ca2(+)-antagonist effects of the substituted DPI 201-106 enantiomers in K(+)-depolarized taenia strips from guinea-pig caecum yielded pA2 values of 6.33 +/- 0.07 for (-)-BDF 8784 and 6.99 +/- 0.17 for (+)-BDF 8784, respectively. 5. Piperazinylindoles, previously believed to act nonspecifically on voltage-dependent mammalian L-type Ca2(+)-channels, therefore have stereoselectivity for a novel binding site and chemical selectivity unrelated to local anaesthetic activity. 6. It is proposed that a very high affinity piperazinylindole-selective site is coupled to the phenylalkylamine receptor of Drosophila Ca2(+)-channels. These sites are still present on mammalian L-type Ca2(+)-channels but have lower affinity and/or are less tightly coupled to phenylalkylamine receptors on the alpha 1-subunit.

Affinity Labels↗
PubMed1999

Structure, function, and expression of Drosophila melanogaster FMRFamide-related peptides.

In 1977, Price and Greenberg identified the tetrapeptide FMRFamide as a cardioexcitatory molecule from mollusc. Subsequent to this discovery, FMRFamide-related peptides (FaRPs) have been identified in both invertebrates and vertebrates. Peptides in the FaRP family contain a common RFamide C-terminus and act as modulators and messengers of neural and gastrointestinal functions. Like other organisms, Drosophila melanogaster contains several genes that encode for numerous FaRPs. Elucidating the processing and activities of multiple FaRPs encoded in a single precursor is critical to establishing their roles in physiology. In this manuscript, we describe the distribution of FMRFamide immunoreactive materials in the Drosophila central nervous system and gut, and correlate it with the expression of specific FaRPs and their activities. The unique distributions and biological activities of Drosophila FaRPs suggest that the precursors are highly processed and the structurally related peptides are not functionally redundant. The complete distribution of FaRPs in the central nervous system and gut as detected by FMRFamide antisera is not accounted for by the sum of the individual expression patterns of the known Drosophila peptides. Thus, these data suggest that one or more Drosophila FaRPs or structurally related peptides remain to be discovered.

Amino Acid Sequence↗
PubMed1986

Characterization and expression of collagen-like genes in Drosophila melanogaster.

We have used a cloned chicken collagen cDNA sequence to help identify hypothetic members of the collagen gene family from Drosophila melanogaster. Several experimental evidences have been obtained which indicate that the Drosophila genome contains numerous collagen-like sequences. We have characterized in more detail ten distinct DNA sequences that hybridized strongly to the heterologous collagen probe. By in situ hybridization we have shown that these sequences are dispersed throughout the Drosophila genome. Two of them are shown to originate from the previously described DCg 1 and DCg 2 collagen genes. In other respects, we show that in addition to DCg 1 and DCg 2, at least five putative collagen genes are expressed during the Drosophila lifetime. These genes are unique, and some of them are seen to be transcribed into different size classes of mRNAs. Additionally, the data presented so far demonstrate that the expression of these genes is regulated temporally and/or quantitatively during the Drosophila life cycle.

Animals↗
PubMed1990

Regulated splicing of the Drosophila P transposable element third intron in vitro: somatic repression.

In eukaryotic cells alternative splicing of messenger RNA precursors (pre-mRNA's) is a means of regulating gene expression. Although a number of the components that participate in regulating some alternative splicing events have been identified by molecular genetic procedures, the elucidation of the biochemical mechanisms governing alternative splicing requires in vitro reaction systems. The tissue specificity of P element transposition in Drosophila depends on the germline restriction of pre-mRNA splicing of the P element third intron (IVS3). Drosophila P element IVS3 pre-mRNA substrates were spliced accurately in vitro in heterologous human cell extracts but not in Drosophila somatic cell splicing extracts. Components in Drosophila somatic cell extracts that specifically inhibited IVS3 splicing in vitro were detected by a complementation assay. Biochemical assays for Drosophila RNA binding proteins were then used to detect a 97-kilodalton protein that interacts specifically with 5' exon sequences previously implicated in the control of IVS3 splicing in vivo. Inhibition of IVS3 splicing in vitro could be correlated with binding of the 97-kD protein to 5' exon sequences, suggesting that one aspect of IVS3 tissue-specific splicing involves somatic repression by specific RNA-protein interactions.

Animals↗
PubMed1991

Expression of bovine superoxide dismutase in Drosophila melanogaster augments resistance of oxidative stress.

Superoxide dismutases (SOD) play a major role in the intracellular defense against oxygen radical damage to aerobic cells. In eucaryotes, the cytoplasmic form of the enzyme is a 32-kDa dimer containing two copper and two zinc atoms (CuZn SOD) that catalyzes the dismutation of the superoxide anion (O2-) to H2O2 and O2. Superoxide-mediated damage has been implicated in a number of biological processes, including aging and cancer; however, it is not certain whether endogenously elevated levels of SOD will reduce the pathological events resulting from such damage. To understand the in vivo relationship between an efficient dismutation of O2- and oxidative injury to biological structures, we generated transgenic strains of Drosophila melanogaster overproducing CuZn SOD. This was achieved by microinjecting Drosophila embryos with P-elements containing bovine CuZn SOD cDNA under the control of the Drosophila actin 5c gene promoter. Adult flies of the resulting transformed lines which expressed both mammalian and Drosophila CuZn SOD were then used as a novel model for evaluating the role of oxygen radicals in aging. Our data show that expression of enzymatically active bovine SOD in Drosophila flies confers resistance to paraquat, an O2(-)-generating compound. This is consistent with data on adult mortality, because there was a slight but significant increase in the mean lifespan of several of the transgenic lines. The highest level of expression of the active enzyme in adults was 1.60 times the normal value. Higher levels may have led to the formation of toxic levels of H2O2 during development, since flies that died during the process of eclosion showed an unusual accumulation of lipofuscin (age pigment) in some of their cells. In conclusion, our data show that free-radical detoxification has a minor by positive effect on mean longevity for several strains.

Animals↗
PubMed1992

Heterogeneous nuclear ribonucleoprotein complexes and proteins in Drosophila melanogaster.

Pre-mRNAs cotranscriptionally associate with a small group of proteins to form heterogeneous nuclear ribonucleoprotein (hnRNP) complexes. We have previously identified two genes in Drosophila melanogaster, Hrb98DE and Hrb87F (i.e., genes at 98DE and 87F encoding putative hnRNA binding proteins), which encode five protein species homologous to the mammalian A-B hnRNP proteins. The studies presented herein show that antibodies against the RNP domains of Hrb98DE reacted with 10 to 15 distinct spots of 38 to 40 kDa in the basic region of two-dimensional gels. These nuclear proteins bound single-stranded nucleic acids and were extracted from Drosophila tissue culture cells as 40 to 80S hnRNP complexes in association with 300 to 800 nucleotide fragments of RNA. The peak of poly(A)+ RNA sequences was coincident with the peak of HRB proteins in sucrose gradients, strongly suggesting that the HRB complexes identified are Drosophila hnRNP complexes. The repertoire of HRB proteins did not change significantly during embryogenesis and was similar to that observed in Drosophila tissue culture cells. Analyses with peptide-specific antisera demonstrated that the major proteins in the hnRNP complex were encoded by the two genes previously identified. Although the Drosophila HRB proteins are only approximately 60% identical throughout the RNP domains to the mammalian A-B hnRNP proteins, features of the basic pre-mRNA packaging mechanism appear to be highly conserved between D. melanogaster and mammals.

Amino Acid Sequence↗
PubMed1993

AU-rich intronic elements affect pre-mRNA 5' splice site selection in Drosophila melanogaster.

cis-spliced nuclear pre-mRNA introns found in a variety of organisms, including Tetrahymena thermophila, Drosophila melanogaster, Caenorhabditis elegans, and plants, are significantly richer in adenosine and uridine residues than their flanking exons are. The functional significance of this intronic AU richness, however, has been demonstrated only in plant nuclei. In these nuclei, 5' and 3' splice sites are selected in part by their positions relative to AU-rich elements spread throughout the length of an intron. Because of this position-dependent selection scheme, a 5' splice site at the normal (+1) exon-intron boundary having only three contiguous consensus nucleotides can compete effectively with an enhanced exonic site (-57E) having nine consensus nucleotides and outcompete an enhanced site (+106E) embedded within the AU-rich intron. To determine whether transitions from AU-poor exonic sequences to AU-rich intronic sequences influence 5' splice site selection in other organisms, alleles of the pea rbcS3A1 intron were expressed in Drosophila Schneider 2 cells, and their splicing patterns were compared with those in tobacco nuclei. We demonstrate that this heterologous transcript can be accurately spliced in transfected Drosophila nuclei and that a +1 G-to-A knockout mutation at the normal splice site activates the same three cryptic 5' splice sites as in tobacco. Enhancement of the exonic (-57) and intronic (+106) sites to consensus splice sites indicates that potential splice sites located in the upstream exon or at the 5' exon-intron boundary are preferred in Drosophila cells over those embedded within AU-rich intronic sequences. In contrast to tobacco, in which the activities of two competing 5' splice sites upstream of the AU-rich intron are modulated by their proximity to the AU transition point, D. melanogaster utilizes the upstream site which has a higher proportion of consensus nucleotides. The enhanced version of the cryptic intronic site is efficiently selected in D. melanogaster when the normal +1 site is weakened or discrete AU-rich elements upstream of the +106E site are disrupted. Selection of this internal site in tobacco requires more drastic disruption of these motifs. We conclude that 5' splice site selection in Drosophila nuclei is influenced by the intrinsic strengths of competing sites and by the presence of AU-rich intronic elements but to a different extent than in tobacco.

Animals↗
PubMed1997

Interactions of Drosophila Cbl with epidermal growth factor receptors and role of Cbl in R7 photoreceptor cell development.

The human proto-oncogene product c-Cbl and a similar protein in Caenorhabditis elegans (Sli-1) contain a proline-rich COOH-terminal region that binds Src homology 3 (SH3) domains of proteins such as the adapter Grb2. Cb1-Grb2 complexes can be recruited to tyrosine-phosphorylated epidermal growth factor (EGF) receptors through the SH2 domain of Grb2. Here we identify by molecular cloning a Drosophila cDNA encoding a protein (Drosophila Cbl [D-Cbl]) that shows high sequence similarity to the N-terminal region of human c-Cbl but lacks proline-rich sequences and fails to bind Grb2. Nonetheless, in COS-1 cells, expression of hemagglutinin epitope-tagged D-Cbl results in its coimmunoprecipitation with EGF receptors in response to EGF. EGF also caused tyrosine phosphorylation of D-Cbl in such cells, but no association of phosphatidylinositol 3-kinase was detected in assays using anti-p85 antibody. A point mutation in D-Cbl (G305E) that suppresses the negative regulation of LET-23 by the Cbl homolog Sli-1 in C. elegans prevented tyrosine phosphorylation of D-Cbl as well as binding to the liganded EGF receptor in COS-1 cells. Colocalization of EGF receptors with both endogenous c-Cbl or expressed D-Cbl in endosomes of EGF-treated COS-1 cells is also demonstrated by immunofluorescence microscopy. In lysates of adult transgenic Drosophila melanogaster, GST-DCbl binds to the tyrosine-phosphorylated 150-kDa torso-DER chimeric receptor. Expression of D-Cbl directed by the sevenless enhancer in intact Drosophila compromises severely the development of the R7 photoreceptor neuron. These data suggest that despite the lack of Grb2 binding sites, D-Cbl functions as a negative regulator of receptor tyrosine kinase signaling in the Drosophila eye by a mechanism that involves its association with EGF receptors or other tyrosine kinases.

Adaptor Proteins, Signal Transducing↗
PubMed1989

Nonrandom distribution of long mono- and dinucleotide repeats in Drosophila chromosomes: correlations with dosage compensation, heterochromatin, and recombination.

Long stretches of (dC-dA)n.(dT-dG)n, abbreviated CA/TG, have a distinctive distribution on Drosophila chromosomes (M.L. Pardue, K. Lowenhaupt, A. Rich, and A. Nordheim, EMBO J. 6:1781-1789, 1987). The distribution of CA/TG suggests a correlation with the overall transcriptional activity of chromosomal regions and with the ability to undergo meiotic recombination. These correlations are conserved among Drosophila species and may indicate one or more chromosomal functions. To test the generality of these findings, we analyzed the distribution of the rest of the six possible mono- and dinucleotide repeats (A/T, C/G, AT/AT, CA/TG, CT/AG, and CG/CG). All but CG/CG were present at significant levels in the genomes of the six Drosophila species studied; however, A/T levels were an order of magnitude lower than those of the other sequences. Data base analyses suggested that the same sequences are present in other eucaryotes. Like CA/TG, both CT/AG and C/G showed increased levels on dosage-compensating chromosomes; however, the individual sites clearly differed for each sequence. In contrast, A/T and AT/AT, although present in Drosophila DNA, could not be detected in situ in polytene chromosomes. We also used in situ hybridization to analyze the neo-Y chromosome of Drosophila miranda, an ancestral autosome that has become attached to the Y chromosome and is now partially heterochromatic. The neo-Y has acquired repeated DNA sequences; we found that the added sequences are as devoid of mono- and dinucleotide repeats as other heterochromatin. The distribution and function of these sequences are likely to result from both their repetitious nature and base contents.

Animals↗
PubMed2003

Construction of a cDNA-based microarray for Drosophila melanogaster: a comparison of gene transcription profiles from SL2 and Kc167 cells.

We have constructed a DNA microarray that represents approximately 6900 of the estimated 13,598 genes in the Drosophila melanogaster genome. The microarray contains 5756 target cDNAs from the Berkeley Drosophila Genome Project, 1078 cDNAs from the National Institutes of Health Drosophila testis cDNA library, and 546 gene fragments that were amplified from genomic DNA. The methods for DNA amplification and microarray manufacture are presented. Academic researchers can obtain the microarray from the Canadian Drosophila Microarray Centre. To evaluate the utility of these arrays, we compared the gene transcription profiles of two commonly used Drosophila cell lines. Analysis revealed that 5412 spot pairs gave signals consistently above the average background in Kc167 cells, whereas 5636 spot pairs met this criterion in SL2 cells. When the expression profiles of the cell lines were compared, 1437 genes displayed at least a 1.5-fold difference, and 170 genes had a threefold or greater difference between the two cell lines. In each case, with respect to Kc167 when compared with SL2 cells, the number of genes that were upregulated was nearly equal to the number of downregulated genes. This result demonstrates that despite the similar embryonic derivation of both cell lines, their transcriptional profiles are very different.

Animals↗