18. Syrzycka, M; Hallson, G; Fitzpatrick, KA; Kim, I; Cotsworth, S; Hollebakken, RE; Simonetto, K; Yang, LD; Luongo, S; Beja, K; Coulthard, AB; Hilliker, AJ; Sinclair, DA; Honda, BM. (2019) Genetic and Molecular Analysis of Essential Genes in Centromeric Heterochromatin of the Left Arm of Chromosome 3 in Drosophila melanogaster.G3-Genes Genomes Genet. 9: 1581-1595 Genetic and Molecular Analysis of Essential Genes in Centromeric Heterochromatin of the Left Arm of Chromosome 3 in Drosophila melanogaster
centromeric heterochromatin; essential genes; functional annotation
A large portion of the Drosophila melanogaster genome is contained within heterochromatic regions of chromosomes, predominantly at centromeres and telomeres. The remaining euchromatic portions of the genome have been extensively characterized with respect to gene organization, function and regulation. However, it has been difficult to derive similar data for sequences within centromeric (centric) heterochromatin because these regions have not been as amenable to analysis by standard genetic and molecular tools. Here we present an updated genetic and molecular analysis of chromosome 3L centric heterochromatin (3L Het). We have generated and characterized a number of new, overlapping deficiencies (Dfs) which remove regions of 3L Het. These Dfs were critically important reagents in our subsequent genetic analysis for the isolation and characterization of lethal point mutations in the region. The assignment of these mutations to genetically-defined essential loci was followed by matching them to gene models derived from genome sequence data: this was done by using molecular mapping plus sequence analysis of mutant alleles, thereby aligning genetic and physical maps of the region. We also identified putative essential gene sequences in 3L Het by using RNA interference to target candidate gene sequences. We report that at least 25, or just under 2/3 of loci in 3L Het, are essential for viability and/or fertility. This work contributes to the functional annotation of centric heterochromatin in Drosophila, and the genetic and molecular tools generated should help to provide important insights into the organization and functions of gene sequences in 3L Het. DOI PubMed
17. Hallson G, Hollebakken RE, Li T, Syrzycka M, Kim I, Cotsworth S, Fitzpatrick KA, Sinclair DA, Honda BM. (2012) dSet1 Is the Main H3K4 Di- and Tri-Methyltransferase Throughout Drosophila Development.Genetics 2012 Jan;190(1):91-100. Epub 2011 Nov 2. dSet1 Is the Main H3K4 Di- and Tri-Methyltransferase Throughout Drosophila Development
In eukaryotes, the post-translational addition of methyl groups to histone H3 lysine 4 (H3K4) plays key roles in maintenance and establishment of appropriate gene expression patterns and chromatin states. We report here that an essential locus within chromosome 3L centric heterochromatin encodes the previously uncharacterized Drosophila melanogaster ortholog (dSet1, CG40351) of the Set1 H3K4 histone methyltransferase (HMT). Our results suggest that dSet1 acts as a "global" or general H3K4 di- and trimethyl HMT in Drosophila. Levels of H3K4 di- and trimethylation are significantly reduced in dSet1 mutants during late larval and post-larval stages, but not in animals carrying mutations in genes encoding other well-characterized H3K4 HMTs such as trr, trx, and ash1. The latter results suggest that Trr, Trx, and Ash1 may play more specific roles in regulating key cellular targets and pathways and/or act as global H3K4 HMTs earlier in development. In yeast and mammalian cells, the HMT activity of Set1 proteins is mediated through an evolutionarily conserved protein complex known as Complex of Proteins Associated with Set1 (COMPASS). We present biochemical evidence that dSet1 interacts with members of a putative Drosophila COMPASS complex and genetic evidence that these members are functionally required for H3K4 methylation. Taken together, our results suggest that dSet1 is responsible for the bulk of H3K4 di- and trimethylation throughout Drosophila development, thus providing a model system for better understanding the requirements for and functions of these modifications in metazoans.
16. Hallson, G; Hollebakken, RE; Li, TS; Syrzycka, M; Kim, I; Cotsworth, S; Fitzpatrick, KA; Sinclair, DAR; Honda, BM. (2012) dSet1 Is the Main H3K4 Di- and Tri-Methyltransferase Throughout Drosophila Development.Genetics 190: 91-U516 dSet1 Is the Main H3K4 Di- and Tri-Methyltransferase Throughout Drosophila Development
In eukaryotes, the post-translational addition of methyl groups to histone H3 lysine 4 (H3K4) plays key roles in maintenance and establishment of appropriate gene expression patterns and chromatin states. We report here that an essential locus within chromosome 3L centric heterochromatin encodes the previously uncharacterized Drosophila melanogaster ortholog (dSet1, CG40351) of the Set1 H3K4 histone methyltransferase (HMT). Our results suggest that dSet1 acts as a "global" or general H3K4 di- and trimethyl HMT in Drosophila. Levels of H3K4 di- and trimethylation are significantly reduced in dSet1 mutants during late larval and post-larval stages, but not in animals carrying mutations in genes encoding other well-characterized H3K4 HMTs such as trr, trx, and ash1. The latter results suggest that Trr, Trx, and Ash1 may play more specific roles in regulating key cellular targets and pathways and/or act as global H3K4 HMTs earlier in development. In yeast and mammalian cells, the HMT activity of Set1 proteins is mediated through an evolutionarily conserved protein complex known as Complex of Proteins Associated with Set1 (COMPASS). We present biochemical evidence that dSet1 interacts with members of a putative Drosophila COMPASS complex and genetic evidence that these members are functionally required for H3K4 methylation. Taken together, our results suggest that dSet1 is responsible for the bulk of H3K4 di- and trimethylation throughout Drosophila development, thus providing a model system for better understanding the requirements for and functions of these modifications in metazoans. DOI PubMed
15. Lloyd, VK; Fitzpatrick, K. (2008) Genome and chromosome structure - Twelve dynamic and evolving genomes.Fly 2: 141-144 Genome and chromosome structure - Twelve dynamic and evolving genomes
Drosophila; chromosome; genome; heterochromatin; trans-silencing; chromosome pairing; DNA damage; hybrid incompatibility; novel genes; genome evolution
Chromosomes are not inert structures that haul the genome through cell division. The dynamic properties of chromosomes, during the cell cycle, the lifetime of the organism and across evolutionary time, featured prominently at the 49,h Annual Drosophila Research Conference. Platform presentations, workshops and posters focused on many aspects of chromosome structure and function including chromosome interactions such as trans-silencing and pairing between homologous and non-homologous chromosomes, specialized portions of the chromosome including the centromere and telomeres, the structure, function and evolution of the large heterochromatic domains such as the Y and 4(th) chromosomes, centric heterochromatin and subtelomeric heterochromatin. The speed of evolutionary changes in these regions, and the consequences for speciation and hybrid-incompatibility, were recurring themes. Finally, there was considerable new insight offered into the mechanics by which chromosomes are rearranged and changes in the types of alterations occurring over the lifetime of the organism, which can result in novel genes and gene flow between chromosomes. The availability of the twelve sequenced Drosophila genomes has allowed new insights into the structure, function and evolutionary transformation of chromosomes and genomes that will continue to transform our view of the chromosome as a dynamic and flexible entity that houses and regulates the genome.
14. Syrzycka M, McEachern LA, Kinneard J, Prabhu K, Fitzpatrick K, Schulze S, Rawls JM, Lloyd VK, Sinclair DA, Honda BM. (2007) The pink gene encodes the Drosophila orthologue of the human Hermansky-Pudlak syndrome 5 (HPS5) gene.Genome 50(6):548-56 The pink gene encodes the Drosophila orthologue of the human Hermansky-Pudlak syndrome 5 (HPS5) gene.
Hermansky-Pudlak syndrome (HPS) consists of a set of human autosomal recessive disorders, with symptoms resulting from defects in genes required for protein trafficking in lysosome-related organelles such as melanosomes and platelet dense granules. A number of human HPS genes and rodent orthologues have been identified whose protein products are key components of 1 of 4 different protein complexes (AP-3 or BLOC-1, -2, and -3) that are key participants in the process. Drosophila melanogaster has been a key model organism in demonstrating the in vivo significance of many genes involved in protein trafficking pathways; for example, mutations in the "granule group" genes lead to changes in eye colour arising from improper protein trafficking to pigment granules in the developing eye. An examination of the chromosomal positioning of Drosophila HPS gene orthologues suggested that CG9770, the Drosophila HPS5 orthologue, might correspond to the pink locus. Here we confirm this gene assignment, making pink the first eye colour gene in flies to be identified as a BLOC complex gene.PDF
13. Syrzycka, M; McEachern, LA; Kinneard, J; Prabhu, K; Fitzpatrick, K; Schulze, S; Rawls, JM; Lloyd, VK; Sinclair, DAR; Honda, BM. (2007) The pink gene encodes the Drosophila orthologue of the human Hermansky-Pudlak syndrome 5 (HPS5) gene.Genome 50: 548-556 The pink gene encodes the Drosophila orthologue of the human Hermansky-Pudlak syndrome 5 (HPS5) gene
Drosophila eye colour; protein trafficking; Hermansky-Pudlak syndrome
Hermansky-Pudlak syndrome (HPS) consists of a set of human autosomal recessive disorders, with symptoms resulting from defects in genes required for protein trafficking in lysosome-related organelles such as melanosomes and platelet dense granules. A number of human HPS genes and rodent orthologues have been identified whose protein products are key components of 1 of 4 different protein complexes (AP-3 or BLOC-1, -2, and -3) that are key participants in the process. Drosophila melanogaster has been a key model organism in demonstrating the in vivo significance of many genes involved in protein trafficking pathways; for example, mutations in the "granule group'' genes lead to changes in eye colour arising from improper protein trafficking to pigment granules in the developing eye. An examination of the chromosomal positioning of Drosophila HPS gene orthologues suggested that CG9770, the Drosophila HPS5 orthologue, might correspond to the pink locus. Here we confirm this gene assignment, making pink the first eye colour gene in flies to be identified as a BLOC complex gene. DOI PubMed
12. Schulze, SR; McAllister, BF; Sinclair, DAR; Fitzpatrick, KA; Marchetti, M; Pimpinelli, S; Honda, BM. (2006) Heterochromatic genes in Drosophila: A comparative analysis of two genes.Genetics 173: 1433-1445 Heterochromatic genes in Drosophila: A comparative analysis of two genes
Centromeric heterochromatin comprises similar to 30% of the Drosophila melanogaster genome, forming a transcriptionally repressive environment that silences euchromatic genes juxtaposed nearby. Surprisingly, there are genes naturally resident in heterochromatin, which appear to require this environment for optimal activity. Here we report an evolutionary analysis of two genes, Dbp80 and RpL15, which are adjacent in proximal 3L heterochromatin of D. melanogaster. DmDbp80 is typical of previously described heterochromatic genes: large, with repetitive sequences in its many introns. In contrast, DmRpL15 is uncharacteristically small. The orthologs of these genes were examined in D. pseudoobscura and D. virilis. In situ hybridization and whole-genome assembly analysis show that these genes are adjacent, but not centromeric in the genome of D. pseudoobscura, while they are located on different chromosomal elements in D. virilis. Dbp80 gene organization differs dramatically among these species, while RpL15 structure is conserved. A bioinformatic analysis in five additional Drosophila species demonstrates active repositioning of these genes both within and between chromosomal elements. This study shows that Dbp80 and RpL15 can function in contrasting chromatin contexts on an evolutionary timescale. The complex history of these genes also provides unique insight into the dynamic nature of genome evolution.
11. Schulze, SR; McAllister, BF; Sinclair, DAR; Fitzpatrick, KA; Marchetti, M; Pimpinelli, S; Honda, BM. (2006) Heterochromatic genes in Drosophila: A comparative analysis of two genes.Genetics 173: 1433-1445 Heterochromatic genes in Drosophila: A comparative analysis of two genes
Centromeric heterochromatin comprises similar to 30% of the Drosophila melanogaster genome, forming a transcriptionally repressive environment that silences euchromatic genes juxtaposed nearby. Surprisingly, there are genes naturally resident in heterochromatin, which appear to require this environment for optimal activity. Here we report an evolutionary analysis of two genes, Dbp80 and RpL15, which are adjacent in proximal 3L heterochromatin of D. melanogaster. DmDbp80 is typical of previously described heterochromatic genes: large, with repetitive sequences in its many introns. In contrast, DmRpL15 is uncharacteristically small. The orthologs of these genes were examined in D. pseudoobscura and D. virilis. In situ hybridization and whole-genome assembly analysis show that these genes are adjacent, but not centromeric in the genome of D. pseudoobscura, while they are located on different chromosomal elements in D. virilis. Dbp80 gene organization differs dramatically among these species, while RpL15 structure is conserved. A bioinformatic analysis in five additional Drosophila species demonstrates active repositioning of these genes both within and between chromosomal elements. This study shows that Dbp80 and RpL15 can function in contrasting chromatin contexts on an evolutionary timescale. The complex history of these genes also provides unique insight into the dynamic nature of genome evolution. DOI PubMed
10.Fitzpatrick, KA; Sinclair, DA; Schulze, SR; Syrzycka, M; Honda, BM. (2005) A genetic and molecular profile of third chromosome centric heterochromatin in Drosophila melanogaster.Genome 48: 571-584 A genetic and molecular profile of third chromosome centric heterochromatin in Drosophila melanogaster
heterochromatin; Drosophila; cytogenetics; genomics
In this review, we combine the results of our published and unpublished work with the published results of other laboratories to provide an updated map of the centromeric heterochromatin of chromosome 3 in Drosophila melanogaster. To date, we can identify more than 20 genes (defined DNA sequences with well-characterized functions and (or) defined genetic complementation groups), including at least 16 essential loci. With the ongoing emergence of data from genetic, cytological, and genome sequencing studies, we anticipate continued, substantial progress towards understanding the function, structure, and evolution of centric heterochromatin. DOI PubMed
9. Schulze, SR; Sinclair, DAR; Fitzpatrick, KA; Honda, BM. (2005) A genetic and molecular characterization of two proximal heterochromatic genes on chromosome 3 of Drosophila melanogaster.Genetics 169: 2165-2177 A genetic and molecular characterization of two proximal heterochromatic genes on chromosome 3 of Drosophila melanogaster
Heterochromatin comprises a transcription ally repressive chromosome compartment in the eukaryotic nucleus; this is exemplified by the silencing effect it has on euchromatic genes that have been relocated nearby, a phenomenon known as position-effect variegation (PEV), first demonstrated in Drosophila melanogaster. However, the expression of essential heterochromatic genes within these apparently repressive regions of the genome presents a paradox, an understanding of which Could provide key insights into the effects of chromatin structure on gene expression. To date, very few of these resident heterochromatic genes have been characterized to air), extent, and their expression and regulation remain poorly nuclei-stood. Here we report the cloning and characterization of two proximal heterochromatic genes in 1). melanogaster, located deep within the centric heterochromatin of the left arm of chromosome 3. One of these genes, RpL15, is uncharacteristically small, is highly expressed, and encodes an essential ribosomal protein. Its expression appears to be compromised in a genetic background deficient for heterochromatin protein I (HP1), a protein associated with gene silencing in these regions. The second gene in this Study, Dbp80, is very large and also appears to show a transcriptional dependence upon HP1; however, it does not correspond to any known lethal complementation group and is likely to be a nonessential gene. DOI PubMed
8. Schulze, S; Sinclair, DAR; Silva, E; Fitzpatrick, KA; Singh, M; Lloyd, VK; Morin, KA; Kim, J; Holm, DG; Kennison, JA; Honda, BM. (2001) Essential genes in proximal 3L heterochromatin of Drosophila melanogaster.Molecular and General Genetics 264: 782-789 Essential genes in proximal 3L heterochromatin of Drosophila melanogaster
essential heterochromatic genes; position-effect variegation; Drosophila melanogaster
We have further characterized essential loci within the centric heterochromatin of the left arm of chromosome 3 (3L) of Drosophila melanogaster, using EMS, radiation and P element mutagenesis. We failed to find any new essential genes, a result that suggests a lower-than-average gene density in this region. Mutations affecting expression of the most proximal gene [lethal 1, l1 or l(3)80Fj] act as dominant suppressors of Polycomb (Pc), behavior which is consistent with a putative trithorax group (trx-G) gene. The third gene to the left of the centromere [lethal 3, l3 or l(3)80Fh] is likely to correspond to verthandi (vtd), a known trx-G gene that plays a role in the regulation of hedgehog (hh) expression and signalling. The intervening gene [lethal 2, l2 or l(3)80Fi] is required throughout development, and mutant alleles have interesting phenotypes; in Various allelic combinations that survive, we observe fertility, bristle, wing, eye and cuticle defects.
7. Schulze, S; Sinclair, DAR; Silva, E; Fitzpatrick, KA; Singh, M; Lloyd, VK; Morin, KA; Kim, J; Holm, DG; Kennison, JA; Honda, BM. (2001) Essential genes in proximal 3L heterochromatin of Drosophila melanogaster.Mol. Gen. Genet. 264: 782-789 Essential genes in proximal 3L heterochromatin of Drosophila melanogaster
essential heterochromatic genes; position-effect variegation; Drosophila melanogaster
We have further characterized essential loci within the centric heterochromatin of the left arm of chromosome 3 (3L) of Drosophila melanogaster, using EMS, radiation and P element mutagenesis. We failed to find any new essential genes, a result that suggests a lower-than-average gene density in this region. Mutations affecting expression of the most proximal gene [lethal 1, l1 or l(3)80Fj] act as dominant suppressors of Polycomb (Pc), behavior which is consistent with a putative trithorax group (trx-G) gene. The third gene to the left of the centromere [lethal 3, l3 or l(3)80Fh] is likely to correspond to verthandi (vtd), a known trx-G gene that plays a role in the regulation of hedgehog (hh) expression and signalling. The intervening gene [lethal 2, l2 or l(3)80Fi] is required throughout development, and mutant alleles have interesting phenotypes; in Various allelic combinations that survive, we observe fertility, bristle, wing, eye and cuticle defects. DOI PubMed
6. Sinclair, DAR; Schulze, S; Silva, E; Fitzpatrick, KA; Honda, BM. (2000) Essential genes in autosomal heterochromatin of Drosophila melanogaster.Genetica 109: 9-18 Essential genes in autosomal heterochromatin of Drosophila melanogaster
Su(var); position-effect variegation; Trithorax group
We are taking two approaches to understanding the structure, function and regulation of essential genes within Drosophila heterochromatin. In the first, we have undertaken a genetic and molecular characterization of essential genes within proximal 3L heterochromatin. The expression of such 'resident' genes within a heterochromatic environment is paradoxical and poorly understood, given that the same environment can inactivate euchromatic sequences (position effect variegation, or PEV). A second approach involves the study of the local chromosomal environment of heterochromatic (het) genes, as assayed both biochemically, and via the effects of genetic modifiers of PEV, the latter being putative components important for het gene expression. Our results to date suggest that the three most proximal genes in 3L heterochromatin have key roles in development, and indicate strong effects of combinations of genetic modifiers of PEV on het gene expression.
5. Sinclair, DAR; Schulze, S; Silva, E; Fitzpatrick, KA; Honda, BM. (2000) Essential genes in autosomal heterochromatin of Drosophila melanogaster.Genetica 109: 9-18 Essential genes in autosomal heterochromatin of Drosophila melanogaster
Su(var); position-effect variegation; Trithorax group
We are taking two approaches to understanding the structure, function and regulation of essential genes within Drosophila heterochromatin. In the first, we have undertaken a genetic and molecular characterization of essential genes within proximal 3L heterochromatin. The expression of such 'resident' genes within a heterochromatic environment is paradoxical and poorly understood, given that the same environment can inactivate euchromatic sequences (position effect variegation, or PEV). A second approach involves the study of the local chromosomal environment of heterochromatic (het) genes, as assayed both biochemically, and via the effects of genetic modifiers of PEV, the latter being putative components important for het gene expression. Our results to date suggest that the three most proximal genes in 3L heterochromatin have key roles in development, and indicate strong effects of combinations of genetic modifiers of PEV on het gene expression. DOI PubMed
4. Singh, M; Silva, E; Schulze, S; Sinclair, DAR; Fitzpatrick, KA; Honda, BM. (2000) Cloning and characterization of a new theta-class glutathione-S-transferase (GST) gene, gst-3, from Drosophila melanogaster.Gene 247: 167-173 Cloning and characterization of a new theta-class glutathione-S-transferase (GST) gene, gst-3, from Drosophila melanogaster
insect; pesticide resistance; stress response
We report here on the cloning and characterization of a new theta-class glutathione-S-transferase (GST) gene, gst-3, from Drosophila melanogaster. Its sequence is distinct from previously characterized Drosophila GST genes, and Southern blotting shows no other closely related genes in the genome. In-situ hybridization localizes the gene to chromosome 2 (55D), near gst-2 (53F), and clearly separate from the gst-D cluster at 87B. The gene is intronless and appears to possess conventional 5' TATA, Cap and 3' polyadenylation signals. A single transcript, approximately 1 kb in size, appears to be expressed at high levels in all developmental stages examined. When this gene is overexpressed using various upstream GAL4 driver systems, no striking phenotypes are observed; however, we detect bristle morphology defects in some progeny. The gst-3 gene does not appear to be essential, based upon our observation that mutant flies homozygous for an EP element insertion 5' to the TATA box produce little or no detectable gst-3 mRNA; these flies are viable and fertile at 25 and 29 degrees C. Nevertheless, the gst-3 gene appears to be evolutionarily conserved in other Drosophila species, suggesting that it may be functionally important. (C) 2000 Elsevier Science B.V. All rights reserved.
3. Warner, TS; Sinclair, DAR; Fitzpatrick, KA; Singh, H; Devlin, RH; Honda, BM. (1998) The light gene of Drosophila melanogaster encodes a homologue of VPS41, a yeast gene involved in cellular-protein trafficking.Genome 41: 236-243 The light gene of Drosophila melanogaster encodes a homologue of VPS41, a yeast gene involved in cellular-protein trafficking
vesicle transport; eye-colour gene; heterochromatin
Mutations in a number of genes affect eye colour in Drosophila melanogaster; some of these "eye-colour" genes have been shown to be involved in various aspects of cellular transport processes. In addition, combinations of viable mutant alleles of some of these genes, such as carnation (car) combined with either light (It) or deep-orange (dor) mutants, show lethal interactions. Recently, dor was shown to be homologous to the yeast gene PEP3 (VPS18), which is known to be involved in intracellular trafficking. We have undertaken to extend our earlier work on the It gene, in order to examine in more detail its expression pattern and to characterize its gene product via sequencing of a cloned cDNA. The gene appears to be expressed at relatively high levels in all stages and tissues examined, and shows strong homology to VPS41, a gene involved in cellular-protein trafficking in yeast and higher eukaryotes. Further genetic experiments also point to a role for It in transport processes: we describe lethal interactions between viable alleles of It and dor, as well as phenotypic interactions (reductions in eye pigment) between alleles of It and another eye-colour gene, garnet (g), whose gene product has close homology to a subunit of the human adaptor complex, AP-3. DOI PubMed
2. FITZPATRICK, KA; GORSKI, SM; URSULIAK, Z; PRICE, JV. (1995) EXPRESSION OF PROTEIN-TYROSINE-PHOSPHATASE GENES DURING OOGENESIS IN DROSOPHILA-MELANOGASTER.Mechanisms of Development 53: 171-183 EXPRESSION OF PROTEIN-TYROSINE-PHOSPHATASE GENES DURING OOGENESIS IN DROSOPHILA-MELANOGASTER
DROSOPHILA; PROTEIN TYROSINE PHOSPHATASE; OOGENESIS; MESSENGER-RNA LOCALIZATION
The spatial and temporal expression of seven Drosophila protein tyrosine phosphatase genes during oogenesis was examined by whole mount in-situ hybridization of antisense RNA probes to ovaries. Our observations indicate diverse expression patterns consistent with multiple roles for protein tyrosine phosphatases in the ovary. DPTP99A and corkscrew transcripts are expressed in follicle cells, consistent with possible roles in the EGF receptor signaling pathway. Transcripts from corkscrew and DPTP10D are detected in the germline during oogenesis and localized to the oocyte during egg chamber development. Localization of the two transcripts is disrupted by mutations in egalitarian and Bicaudal D. DLAR and DPTP4E transcripts are found in the germline during the same developmental stages as DPTP10D transcripts, but their transcripts are not localized to the oocyte. DPTP61F transcription is detected only after stage 6 of oogenesis. After stage 10B these transcripts are transported to the oocyte; thus ovarian transcription of DPTP61F may reflect a maternal contribution of the mRNA for later use during embryogenesis. DPTP69D transcripts are sequestered in the nucleus from stage 7 to stage 10, and then released to the cytoplasm. Our observations suggest that the export of DPTP69D mRNA from the nucleus is temporally regulated during oogenesis.
1. FITZPATRICK, KA; GORSKI, SM; URSULIAK, Z; PRICE, JV. (1995) EXPRESSION OF PROTEIN-TYROSINE-PHOSPHATASE GENES DURING OOGENESIS IN DROSOPHILA-MELANOGASTER.Mech. Dev. 53: 171-183 EXPRESSION OF PROTEIN-TYROSINE-PHOSPHATASE GENES DURING OOGENESIS IN DROSOPHILA-MELANOGASTER
DROSOPHILA; PROTEIN TYROSINE PHOSPHATASE; OOGENESIS; MESSENGER-RNA LOCALIZATION
The spatial and temporal expression of seven Drosophila protein tyrosine phosphatase genes during oogenesis was examined by whole mount in-situ hybridization of antisense RNA probes to ovaries. Our observations indicate diverse expression patterns consistent with multiple roles for protein tyrosine phosphatases in the ovary. DPTP99A and corkscrew transcripts are expressed in follicle cells, consistent with possible roles in the EGF receptor signaling pathway. Transcripts from corkscrew and DPTP10D are detected in the germline during oogenesis and localized to the oocyte during egg chamber development. Localization of the two transcripts is disrupted by mutations in egalitarian and Bicaudal D. DLAR and DPTP4E transcripts are found in the germline during the same developmental stages as DPTP10D transcripts, but their transcripts are not localized to the oocyte. DPTP61F transcription is detected only after stage 6 of oogenesis. After stage 10B these transcripts are transported to the oocyte; thus ovarian transcription of DPTP61F may reflect a maternal contribution of the mRNA for later use during embryogenesis. DPTP69D transcripts are sequestered in the nucleus from stage 7 to stage 10, and then released to the cytoplasm. Our observations suggest that the export of DPTP69D mRNA from the nucleus is temporally regulated during oogenesis. DOI PubMed
