In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell pr... more In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell proliferation during development [Martin et al. (1977) Dev Biol 55, 213-232; Mansfield et al. (1994) Dev Biol 165, 507-526]. Earlier, we demonstrated that the Drosophila tumour suppressor Merlin participates not only in imaginal discs proliferation control, but also performs a separate Nebenkern structural function in Drosophila spermatogenesis [Dorogova et al. (2008) BMC Cell Biol 9, 1. Here, we show that the hyd mutants also have spermatogenesis defects: chromosome condensation and attachment to the spindle, centrosome behaviour and cytokinesis in meiosis. The process of spermatid elongation was also greatly affected: nuclei were scattered along the cyst and had an abnormal shape, Nebenkern-axoneme angular relation and attachment was distorted, axonemes themselves lost correct structure. Since Hyd and pAbp protein families share a common PABC [poly(A)-binding protein C-terminal] protein domain, we also studied spermatogenesis in pAbp homozygotes and found defects in cytokinesis and spermatid elongation. However, our study of hyd and pAbp genetic interaction revealed only the phenotype of defective nuclei shape at the final stage of spermatid differentiation. So, the PABC domain is unlikely to be responsible for meiotic defects. Thus, our data document that, in addition to the tumour suppressor Merlin, another tumour suppressor, Hyd, also has a function in spermatogenesis.
In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell pr... more In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell proliferation during development [Martin et al. (1977) Dev Biol 55, 213-232; Mansfield et al. (1994) Dev Biol 165, 507-526]. Earlier, we demonstrated that the Drosophila tumour suppressor Merlin participates not only in imaginal discs proliferation control, but also performs a separate Nebenkern structural function in Drosophila spermatogenesis [Dorogova et al. (2008) BMC Cell Biol 9, 1. Here, we show that the hyd mutants also have spermatogenesis defects: chromosome condensation and attachment to the spindle, centrosome behaviour and cytokinesis in meiosis. The process of spermatid elongation was also greatly affected: nuclei were scattered along the cyst and had an abnormal shape, Nebenkern-axoneme angular relation and attachment was distorted, axonemes themselves lost correct structure. Since Hyd and pAbp protein families share a common PABC [poly(A)-binding protein C-terminal] protein domain, we also studied spermatogenesis in pAbp homozygotes and found defects in cytokinesis and spermatid elongation. However, our study of hyd and pAbp genetic interaction revealed only the phenotype of defective nuclei shape at the final stage of spermatid differentiation. So, the PABC domain is unlikely to be responsible for meiotic defects. Thus, our data document that, in addition to the tumour suppressor Merlin, another tumour suppressor, Hyd, also has a function in spermatogenesis.
Hsp67Bc in Drosophila melanogaster is a member of the small heat shock protein family, the main f... more Hsp67Bc in Drosophila melanogaster is a member of the small heat shock protein family, the main function of which is to prevent the aggregation of misfolded or damaged proteins. Hsp67Bc interacts with Starvin and Hsp23, which are known to be a part of the cold-stress response in the fly during the recovery phase. In this study, we investigated the role of the Hsp67Bc gene in the cold-stress response. We showed that in adult Drosophila, Hsp67Bc expression increases after cold stress and decreases after 1.5 h of recovery, indicating the involvement of Hsp67Bc in short-term stress recovery. We also implemented a deletion in the D. melanogaster Hsp67Bc gene using imprecise excision of a P-element and analyzed the cold tolerance of Hsp67Bc-null mutants at different developmental stages. We found that Hsp67Bc-null homozygous flies are viable and fertile but display varying cold-stress tolerance throughout the stages of ontogenesis: the survival after cold stress is slightly impaired in la...
Intraspecific hybrid dysgenesis (HD) appears after some strains of D. melanogaster are crossed. T... more Intraspecific hybrid dysgenesis (HD) appears after some strains of D. melanogaster are crossed. The predominant idea is that the movement of transposable P elements causes HD. It is believed that P elements appeared in the D. melanogaster genome in the middle of the last century by horizontal transfer, simultaneously with the appearance of HD determinants. A subsequent simultaneous expansion of HD determinants and P elements occurred. We analyzed the current distribution of HD determinants in natural populations of D. melanogaster and found no evidence of their further spread. However, full-sized P elements were identified in the genomes of all analyzed natural D. melanogaster strains independent of their cytotypes. Thus, the expansion of P elements does not correlate with the expansion of HD determinants. We found that the ovaries of dysgenic females did not contain germ cells despite the equal number of primordial germ cells in early stages in dysgenic and non-dysgenic embryos. We propose that HD does not result from DNA damage caused by P element transposition, but it would be the disruption in the regulation of dysgenic ovarian formation that causes the dysgenic phenotypes.
The Trithorax-like (Trl) gene of Drosophila melanogaster encodes the multifunctional protein GAGA... more The Trithorax-like (Trl) gene of Drosophila melanogaster encodes the multifunctional protein GAGA involved in many cellular processes. We have isolated and described a new hypomorphic mutation of the Trl gene--Trl(en82). The mutation is the insertion of a 1.4 kb P-element into the 5' untranslated region. Trl expression decreased in the ovaries of mutant flies by about 30%; however, it caused abnormalities. The Trl(en82) mutation combined with the null allele of Trl caused female sterility: the females laid a few small eggs with abnormal shape. Many egg chambers demonstrated abnormalities in the Trl(en82) mutants: the oocyte had a regular shape and intruded into the egg chamber region with nurse cells; the rapid transport of nurse cell cytoplasm into the oocyte was disturbed, which resulted in the "dumpless" phenotype of the chambers in mutants; follicular cells often did not completely cover the oocyte and concentrated on its posterior end; and the migration of centrip...
We generated and characterized a new hypomorphic mutation of Drosophila melanogaster Trithorax-li... more We generated and characterized a new hypomorphic mutation of Drosophila melanogaster Trithorax-like (Trl) gene named Trl362. The Trl362 homozygous females are sterile and lay a small number of eggs; most embryos die at the early developmental stages. The transcriptional Trl level of adult Trl362 females was markedly lowered. Little or no GAGA protein, encoded by Trl@, was detected in the nurse cell nuclei. The ovaries of Trl362 females showed impairments, such considerable changes in the structure of both ovarioles and individual egg chambers. We believe that the observed ovarian defects in Trl362 mutants are mostly due to a decreased amount of GAGA protein in the germline cells. An increase of GAGA-519 protein caused by introduction of hsp83:GAGA-519 transgene against Trl362 background rescued partially the female fertility. It may well be that a decrease of GAGA protein in Trl362 germline cells leads to a defective expression of the genes regulated by transcription factor GAGA, wh...
The effect of the mastv40 mutation was studied using neural ganglion cells of third-instar larvae... more The effect of the mastv40 mutation was studied using neural ganglion cells of third-instar larvae of Drosophila melanogaster. The distributions of the cells by the interphase nucleus diameter and by the distance between the sister chromosome sets in anaphase were analyzed. Three following types of defects induced by the mutation were described: (1) Monopolar mitosis or, in the case of bipolar mitosis, an abnormally short distance between the sister chromosome sets in anaphase and early telophase. We believe that these abnormalities are caused by damage of the start and (or) motor mechanisms of centrosome separation at the beginning and in the end of mitosis. (2) Lagging and bridging of chromosomes in anaphase and early telophase. These defects seem to be related to the disruption of functioning of mitotic spindle microtubules and (or) their defective attachment to the appropriate kinetochores. (3) Unlimited division of aneuploid and polyploid cells, which may be explained either by ...
The effect of mutation aarV158 on anaphase separation of chromatids was studied on fixed cells of... more The effect of mutation aarV158 on anaphase separation of chromatids was studied on fixed cells of neural ganglia of Drosophila melanogaster larvae. It was shown that mutation aarV158 causes three types of defective chromosome segregation manifested as (1) monopolar anaphase, (2) separation of chromatids to an abnormally short distance in anaphase, and (3) bridging and lagging of some chromatids or prolonged asynchronous separation of sister chromatid sets to the poles in anaphase. We believe that the former two types of defective segregation are caused by disturbed centrosome separation at the beginning of mitosis and the third type, by defects in chromatid separation during anaphase. During the two-year maintenance of the mutation in a heterozygous state, partial correction (adaptive modification) of the defects of type 1 and type 2 (but not type 3) occurred. The correction of type 1 and type 2 defects during adaptogenesis depended on the genotype: in heterozygotes and homozygotes,...
The effect of cell cycle mutation ff3 on chromosome segregation was studied on fixed cells of neu... more The effect of cell cycle mutation ff3 on chromosome segregation was studied on fixed cells of neural ganglia. The cell distributions by diameter of interphase nuclei and by distance between sister chromatid sets were compared at anaphase and telophase. In the control wild-type strain Lausenne, the cell distribution by distance between sister chromatids in anaphase was similar to their distribution by nuclear size. The mean distance between segregating chromatids at anaphase (lcp) coincided with the mean diameter of interphase nuclei (dcp) and was 8.3 microns. Cells passed to telophase when chromatids were at least 10 microns apart. The mutant ff3 strain differed from the control strain Lausenne in cell distribution by interphase nuclear diameter and distance between sister chromatids in anaphase; the mean nuclear diameter and mean distance between segregating chromatids similarly increased to 9.3 microns. A specific feature of mitosis in mutant strain ff3 was a premature beginning o...
A method of screening for meiotic mutations based on genetic analysis of chromosome disjunction i... more A method of screening for meiotic mutations based on genetic analysis of chromosome disjunction in germline mosaic clones of females homozygous for potential mutations is proposed. The clones are obtained at high frequency due to the use of the transgenic FLP/FRT system of mitotic recombination. This system permits obtaining homozygous clones in the first generation after mutagenesis, whereas the cultures are set up after selection for potential meiotic mutations. This significantly enhances, the efficiency of screening by the elimination of the limiting stage. Using this method, the following mutations were revealed in the 3L arm of Drosophila: ff6 leading to disturbed centriole disjunction, which results in appearance of multi-tail spermatids and three-pole spindles during male meiosis; ff3 leading to the formation of chromosome bridges in anaphase and telophase, chromosome nondisjunction, and premature chromatin condensation after metaphase; embryonic lethal ff29, with disturbed ...
A study was made of three insertional mutations (Trl13C, Trls2325, and TrlEP(3)3184) located in t... more A study was made of three insertional mutations (Trl13C, Trls2325, and TrlEP(3)3184) located in the second intron of the Trithorax-like (Trl) gene for the GAGA transcription factor (GAF). Their cytological effects were analyzed in oogenesis, early embryonic development, and in larval development (96-108 h) in cells of nervous ganglia and imaginal disks. Notwithstanding an interallelic difference in expression, all three P-element insertions proved to be dominant as far as the examined parameters were concerned. The most substantial defects were the formation of "granular" chromatin during the interphase and mitosis and high proportions of cells with hypercondensed chromatin (which were arrested at the G2/M boundary) and cells with abnormal chromosome segregation. A higher frequency of egg chambers with trophocytes defective in number and in chromatin condensation was observed in females carrying the mutant Trl gene. The defects were assumed to result from poor coordination...
Highly polyploid cells were detected in ganglia of Drosophila melanogaster larvae homozygous for ... more Highly polyploid cells were detected in ganglia of Drosophila melanogaster larvae homozygous for the chbv40 mutation (78D) resulting from insertion of the P[lArB] construction. Frequency distribution of metaphases differing in chromosome number showed that the primary defect caused by the mutation involved formation of the unipolar chromosome spindle. This was confirmed directly by cytological analysis. Circular mitotic figures (CMF), i.e., circles of chromosomes with centromeres pointing inward and chromatid arms pointing outward, were also observed in neuroblasts of the homozygotes. Such structures are characteristic of polo and mgr mutations that alter the functions of the centrosome.
Transpositions of the vector P[lArB] into the regions 78D, 61F, and 85F of chromosome 3, which re... more Transpositions of the vector P[lArB] into the regions 78D, 61F, and 85F of chromosome 3, which result in various anomalies of mitoses in neural ganglions of homozygous larvae, were obtained by insertion mutagenesis. The tissue specificity of regulatory elements controlling the reporter gene was studied by staining for the activity of beta-galactosidase reporter gene of the vector P[lArB]. These regulatory elements are suggested to be the enhancers of the genes carrying insertions. In all studied mutants, staining for beta-galactosidase was found in tissues containing actively proliferating cells. The staining of germarium in adult female ovaries was the most pronounced. The germarium staining pattern was used for the identification of novel insertions leading to mitosis abnormalities. The P1003 (99F) insertion was found, which according to preliminary data leads to an increase in the mitotic index and anomalies of chromosome structure in neuroblasts of homozygous larvae. In addition...
In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell pr... more In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell proliferation during development [Martin et al. (1977) Dev Biol 55, 213-232; Mansfield et al. (1994) Dev Biol 165, 507-526]. Earlier, we demonstrated that the Drosophila tumour suppressor Merlin participates not only in imaginal discs proliferation control, but also performs a separate Nebenkern structural function in Drosophila spermatogenesis [Dorogova et al. (2008) BMC Cell Biol 9, 1. Here, we show that the hyd mutants also have spermatogenesis defects: chromosome condensation and attachment to the spindle, centrosome behaviour and cytokinesis in meiosis. The process of spermatid elongation was also greatly affected: nuclei were scattered along the cyst and had an abnormal shape, Nebenkern-axoneme angular relation and attachment was distorted, axonemes themselves lost correct structure. Since Hyd and pAbp protein families share a common PABC [poly(A)-binding protein C-terminal] protein domain, we also studied spermatogenesis in pAbp homozygotes and found defects in cytokinesis and spermatid elongation. However, our study of hyd and pAbp genetic interaction revealed only the phenotype of defective nuclei shape at the final stage of spermatid differentiation. So, the PABC domain is unlikely to be responsible for meiotic defects. Thus, our data document that, in addition to the tumour suppressor Merlin, another tumour suppressor, Hyd, also has a function in spermatogenesis.
In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell pr... more In Drosophila, the ubiquitin ligase Hyd (hyperplastic disc) is required for regulation of cell proliferation during development [Martin et al. (1977) Dev Biol 55, 213-232; Mansfield et al. (1994) Dev Biol 165, 507-526]. Earlier, we demonstrated that the Drosophila tumour suppressor Merlin participates not only in imaginal discs proliferation control, but also performs a separate Nebenkern structural function in Drosophila spermatogenesis [Dorogova et al. (2008) BMC Cell Biol 9, 1. Here, we show that the hyd mutants also have spermatogenesis defects: chromosome condensation and attachment to the spindle, centrosome behaviour and cytokinesis in meiosis. The process of spermatid elongation was also greatly affected: nuclei were scattered along the cyst and had an abnormal shape, Nebenkern-axoneme angular relation and attachment was distorted, axonemes themselves lost correct structure. Since Hyd and pAbp protein families share a common PABC [poly(A)-binding protein C-terminal] protein domain, we also studied spermatogenesis in pAbp homozygotes and found defects in cytokinesis and spermatid elongation. However, our study of hyd and pAbp genetic interaction revealed only the phenotype of defective nuclei shape at the final stage of spermatid differentiation. So, the PABC domain is unlikely to be responsible for meiotic defects. Thus, our data document that, in addition to the tumour suppressor Merlin, another tumour suppressor, Hyd, also has a function in spermatogenesis.
Hsp67Bc in Drosophila melanogaster is a member of the small heat shock protein family, the main f... more Hsp67Bc in Drosophila melanogaster is a member of the small heat shock protein family, the main function of which is to prevent the aggregation of misfolded or damaged proteins. Hsp67Bc interacts with Starvin and Hsp23, which are known to be a part of the cold-stress response in the fly during the recovery phase. In this study, we investigated the role of the Hsp67Bc gene in the cold-stress response. We showed that in adult Drosophila, Hsp67Bc expression increases after cold stress and decreases after 1.5 h of recovery, indicating the involvement of Hsp67Bc in short-term stress recovery. We also implemented a deletion in the D. melanogaster Hsp67Bc gene using imprecise excision of a P-element and analyzed the cold tolerance of Hsp67Bc-null mutants at different developmental stages. We found that Hsp67Bc-null homozygous flies are viable and fertile but display varying cold-stress tolerance throughout the stages of ontogenesis: the survival after cold stress is slightly impaired in la...
Intraspecific hybrid dysgenesis (HD) appears after some strains of D. melanogaster are crossed. T... more Intraspecific hybrid dysgenesis (HD) appears after some strains of D. melanogaster are crossed. The predominant idea is that the movement of transposable P elements causes HD. It is believed that P elements appeared in the D. melanogaster genome in the middle of the last century by horizontal transfer, simultaneously with the appearance of HD determinants. A subsequent simultaneous expansion of HD determinants and P elements occurred. We analyzed the current distribution of HD determinants in natural populations of D. melanogaster and found no evidence of their further spread. However, full-sized P elements were identified in the genomes of all analyzed natural D. melanogaster strains independent of their cytotypes. Thus, the expansion of P elements does not correlate with the expansion of HD determinants. We found that the ovaries of dysgenic females did not contain germ cells despite the equal number of primordial germ cells in early stages in dysgenic and non-dysgenic embryos. We propose that HD does not result from DNA damage caused by P element transposition, but it would be the disruption in the regulation of dysgenic ovarian formation that causes the dysgenic phenotypes.
The Trithorax-like (Trl) gene of Drosophila melanogaster encodes the multifunctional protein GAGA... more The Trithorax-like (Trl) gene of Drosophila melanogaster encodes the multifunctional protein GAGA involved in many cellular processes. We have isolated and described a new hypomorphic mutation of the Trl gene--Trl(en82). The mutation is the insertion of a 1.4 kb P-element into the 5' untranslated region. Trl expression decreased in the ovaries of mutant flies by about 30%; however, it caused abnormalities. The Trl(en82) mutation combined with the null allele of Trl caused female sterility: the females laid a few small eggs with abnormal shape. Many egg chambers demonstrated abnormalities in the Trl(en82) mutants: the oocyte had a regular shape and intruded into the egg chamber region with nurse cells; the rapid transport of nurse cell cytoplasm into the oocyte was disturbed, which resulted in the "dumpless" phenotype of the chambers in mutants; follicular cells often did not completely cover the oocyte and concentrated on its posterior end; and the migration of centrip...
We generated and characterized a new hypomorphic mutation of Drosophila melanogaster Trithorax-li... more We generated and characterized a new hypomorphic mutation of Drosophila melanogaster Trithorax-like (Trl) gene named Trl362. The Trl362 homozygous females are sterile and lay a small number of eggs; most embryos die at the early developmental stages. The transcriptional Trl level of adult Trl362 females was markedly lowered. Little or no GAGA protein, encoded by Trl@, was detected in the nurse cell nuclei. The ovaries of Trl362 females showed impairments, such considerable changes in the structure of both ovarioles and individual egg chambers. We believe that the observed ovarian defects in Trl362 mutants are mostly due to a decreased amount of GAGA protein in the germline cells. An increase of GAGA-519 protein caused by introduction of hsp83:GAGA-519 transgene against Trl362 background rescued partially the female fertility. It may well be that a decrease of GAGA protein in Trl362 germline cells leads to a defective expression of the genes regulated by transcription factor GAGA, wh...
The effect of the mastv40 mutation was studied using neural ganglion cells of third-instar larvae... more The effect of the mastv40 mutation was studied using neural ganglion cells of third-instar larvae of Drosophila melanogaster. The distributions of the cells by the interphase nucleus diameter and by the distance between the sister chromosome sets in anaphase were analyzed. Three following types of defects induced by the mutation were described: (1) Monopolar mitosis or, in the case of bipolar mitosis, an abnormally short distance between the sister chromosome sets in anaphase and early telophase. We believe that these abnormalities are caused by damage of the start and (or) motor mechanisms of centrosome separation at the beginning and in the end of mitosis. (2) Lagging and bridging of chromosomes in anaphase and early telophase. These defects seem to be related to the disruption of functioning of mitotic spindle microtubules and (or) their defective attachment to the appropriate kinetochores. (3) Unlimited division of aneuploid and polyploid cells, which may be explained either by ...
The effect of mutation aarV158 on anaphase separation of chromatids was studied on fixed cells of... more The effect of mutation aarV158 on anaphase separation of chromatids was studied on fixed cells of neural ganglia of Drosophila melanogaster larvae. It was shown that mutation aarV158 causes three types of defective chromosome segregation manifested as (1) monopolar anaphase, (2) separation of chromatids to an abnormally short distance in anaphase, and (3) bridging and lagging of some chromatids or prolonged asynchronous separation of sister chromatid sets to the poles in anaphase. We believe that the former two types of defective segregation are caused by disturbed centrosome separation at the beginning of mitosis and the third type, by defects in chromatid separation during anaphase. During the two-year maintenance of the mutation in a heterozygous state, partial correction (adaptive modification) of the defects of type 1 and type 2 (but not type 3) occurred. The correction of type 1 and type 2 defects during adaptogenesis depended on the genotype: in heterozygotes and homozygotes,...
The effect of cell cycle mutation ff3 on chromosome segregation was studied on fixed cells of neu... more The effect of cell cycle mutation ff3 on chromosome segregation was studied on fixed cells of neural ganglia. The cell distributions by diameter of interphase nuclei and by distance between sister chromatid sets were compared at anaphase and telophase. In the control wild-type strain Lausenne, the cell distribution by distance between sister chromatids in anaphase was similar to their distribution by nuclear size. The mean distance between segregating chromatids at anaphase (lcp) coincided with the mean diameter of interphase nuclei (dcp) and was 8.3 microns. Cells passed to telophase when chromatids were at least 10 microns apart. The mutant ff3 strain differed from the control strain Lausenne in cell distribution by interphase nuclear diameter and distance between sister chromatids in anaphase; the mean nuclear diameter and mean distance between segregating chromatids similarly increased to 9.3 microns. A specific feature of mitosis in mutant strain ff3 was a premature beginning o...
A method of screening for meiotic mutations based on genetic analysis of chromosome disjunction i... more A method of screening for meiotic mutations based on genetic analysis of chromosome disjunction in germline mosaic clones of females homozygous for potential mutations is proposed. The clones are obtained at high frequency due to the use of the transgenic FLP/FRT system of mitotic recombination. This system permits obtaining homozygous clones in the first generation after mutagenesis, whereas the cultures are set up after selection for potential meiotic mutations. This significantly enhances, the efficiency of screening by the elimination of the limiting stage. Using this method, the following mutations were revealed in the 3L arm of Drosophila: ff6 leading to disturbed centriole disjunction, which results in appearance of multi-tail spermatids and three-pole spindles during male meiosis; ff3 leading to the formation of chromosome bridges in anaphase and telophase, chromosome nondisjunction, and premature chromatin condensation after metaphase; embryonic lethal ff29, with disturbed ...
A study was made of three insertional mutations (Trl13C, Trls2325, and TrlEP(3)3184) located in t... more A study was made of three insertional mutations (Trl13C, Trls2325, and TrlEP(3)3184) located in the second intron of the Trithorax-like (Trl) gene for the GAGA transcription factor (GAF). Their cytological effects were analyzed in oogenesis, early embryonic development, and in larval development (96-108 h) in cells of nervous ganglia and imaginal disks. Notwithstanding an interallelic difference in expression, all three P-element insertions proved to be dominant as far as the examined parameters were concerned. The most substantial defects were the formation of "granular" chromatin during the interphase and mitosis and high proportions of cells with hypercondensed chromatin (which were arrested at the G2/M boundary) and cells with abnormal chromosome segregation. A higher frequency of egg chambers with trophocytes defective in number and in chromatin condensation was observed in females carrying the mutant Trl gene. The defects were assumed to result from poor coordination...
Highly polyploid cells were detected in ganglia of Drosophila melanogaster larvae homozygous for ... more Highly polyploid cells were detected in ganglia of Drosophila melanogaster larvae homozygous for the chbv40 mutation (78D) resulting from insertion of the P[lArB] construction. Frequency distribution of metaphases differing in chromosome number showed that the primary defect caused by the mutation involved formation of the unipolar chromosome spindle. This was confirmed directly by cytological analysis. Circular mitotic figures (CMF), i.e., circles of chromosomes with centromeres pointing inward and chromatid arms pointing outward, were also observed in neuroblasts of the homozygotes. Such structures are characteristic of polo and mgr mutations that alter the functions of the centrosome.
Transpositions of the vector P[lArB] into the regions 78D, 61F, and 85F of chromosome 3, which re... more Transpositions of the vector P[lArB] into the regions 78D, 61F, and 85F of chromosome 3, which result in various anomalies of mitoses in neural ganglions of homozygous larvae, were obtained by insertion mutagenesis. The tissue specificity of regulatory elements controlling the reporter gene was studied by staining for the activity of beta-galactosidase reporter gene of the vector P[lArB]. These regulatory elements are suggested to be the enhancers of the genes carrying insertions. In all studied mutants, staining for beta-galactosidase was found in tissues containing actively proliferating cells. The staining of germarium in adult female ovaries was the most pronounced. The germarium staining pattern was used for the identification of novel insertions leading to mitosis abnormalities. The P1003 (99F) insertion was found, which according to preliminary data leads to an increase in the mitotic index and anomalies of chromosome structure in neuroblasts of homozygous larvae. In addition...
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Papers by Svetlana Fedorova