scholarly journals Epigenetic regulation affects fertility in Drosophila: toward the production of infertile models

2018 ◽  
Author(s):  
Hidetsugu Kohzaki ◽  
Maki Asano ◽  
Yota Murakami ◽  
Alexander Mazo
Keyword(s):  
Dna Replication ◽  
Gene Amplification ◽  
Epigenetic Regulation ◽  
Origin Recognition Complex ◽  
Ovarian Follicle ◽  
Gene Clusters ◽  
Follicle Cells ◽  
Female Sterility ◽  
Ovary Development ◽  
Replication Machinery

AbstractWe have revealed that the chorion gene clusters amplify by repeatedly initiating DNA replication from chorion gene amplification origins in the response to developmental signals, through the transcription factors in Drosophila ovarian follicle cells. Orc1, Orc2, and Cdc6 are forms of DNA replication machinery, which are conserved from yeast to humans; and Orc1 and Orc2 mutants are lethal. Overexpression of Orc1 or Orc2 (subunits of the origin recognition complex) led to female sterility, but overexpression of Cdc6 (an Orc family member) or GFP did not. We propose that DNA replication machinery contributes to development.Recently, we found that H3K4 was trimethylated at chorion gene amplification origins, but not at the Act1 locus. Overexpression of Lsd1H3K4 dimethylase and Lid H3K4 trimethylase are female sterile but not a Lid mutant. These results showed that epigenetic regulation affected fertility. Screening strategies using Drosophila flies could also lead to the development of drugs that reduce sterility and epigenetic effects related histone modification.Summary statementThere are approximately 470,000 infertile individuals in Japan. We knockowned the prereplicative complex components and demethlases during Drosophila ovary development. In these drospohila, we could be the model of infertile.

The Drosophila chiffon gene is required for chorion gene amplification, and is related to the yeast Dbf4 regulator of DNA replication and cell cycle

Development ◽  
1999 ◽  
Vol 126 (19) ◽  
pp. 4281-4293 ◽  
Author(s):  
G. Landis ◽  
J. Tower
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Gene Amplification ◽  
Cell Cycle Progression ◽  
Gene Clusters ◽  
Follicle Cells ◽  
Null Alleles ◽  
Female Sterility ◽  
Major Protein ◽  
Origin Firing

The Drosophila chorion genes encode the major protein components of the chorion (eggshell) and are arranged in two clusters in the genome. To meet the demand for rapid chorion synthesis, Drosophila ovary follicle cells amplify the chorion gene clusters approximately 80-fold. Amplification proceeds through repeated firing of one or more DNA replication origins located near the center of each gene cluster. Hypomorphic mutant alleles of the chiffon gene cause thin, fragile chorions and female sterility, and were found to eliminate chorion gene amplification. Null alleles of chiffon had the additional phenotypes of rough eyes and thin thoracic bristles: phenotypes often associated with disruption of normal cell cycle. The chiffon locus was cloned by chromosomal walking from the nearby cactus locus. A 6.5 kb transcript was identified and confirmed to be chiffon by sequencing of mutant alleles and by phenotypic rescue with genomic transformation constructs. The protein predicted by translation of the 5.1 kb chiffon ORF contains two domains related to the S. cerevisiae Dbf4 regulator of DNA replication origin firing and cell cycle progression: a 44 residue domain designated CDDN1 (43% identical) and a 41 residue domain designated CDDN2 (12% identical). The CDDN domains were also found in the S. pombe homolog of Dbf4, Dfp1, as well as in the proteins predicted by translation of the Aspergillus nimO gene and specific human and mouse clones. The data suggest a family of eukaryotic proteins related to Dbf4 and involved in initiation of DNA replication.

scholarly journals Drosophila E2f2 promotes the conversion from genomic DNA replication to gene amplification in ovarian follicle cells

Development ◽  
2001 ◽  
Vol 128 (24) ◽  
pp. 5085-5098 ◽  
Author(s):  
Pelin Cayirlioglu ◽  
Peter C. Bonnette ◽  
M. Ryan Dickson ◽  
Robert J. Duronio
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Gene Amplification ◽  
Genomic Dna ◽  
Essential Gene ◽  
Ovarian Follicle ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Female Sterility ◽  
Wild Type

Drosophila contains two members of the E2F transcription factor family (E2f and E2f2), which controls the expression of genes that regulate the G1-S transition of the cell cycle. Previous genetic analyses have indicated that E2f is an essential gene that stimulates DNA replication. We show that loss of E2f2 is viable, but causes partial female sterility associated with changes in the mode of DNA replication in the follicle cells that surround the developing oocyte. Late in wild-type oogenesis, polyploid follicle cells terminate a program of asynchronous endocycles in which the euchromatin is entirely replicated, and then confine DNA synthesis to the synchronous amplification of specific loci, including two clusters of chorion genes that encode eggshell proteins. E2f2 mutant follicle cells terminate endocycles on schedule, but then fail to confine DNA synthesis to sites of gene amplification and inappropriately begin genomic DNA replication. This ectopic DNA synthesis does not represent a continuation of the endocycle program, as the cells do not complete an entire additional S phase. E2f2 mutant females display a 50% reduction in chorion gene amplification, and lay poorly viable eggs with a defective chorion. The replication proteins ORC2, CDC45L and ORC5, which in wild-type follicle cell nuclei localize to sites of gene amplification, are distributed throughout the entire follicle cell nucleus in E2f2 mutants, consistent with their use at many genomic replication origins rather than only at sites of gene amplification. RT-PCR analyses of RNA purified from E2f2 mutant follicle cells indicate an increase in the level of Orc5 mRNA relative to wild type. These data indicate that E2f2 functions to inhibit widespread genomic DNA synthesis in late stage follicle cells, and may do so by repressing the expression of specific components of the replication machinery.

scholarly journals Drosophila Double parked: a conserved, essential replication protein that colocalizes with the origin recognition complex and links DNA replication with mitosis and the down-regulation of S phase transcripts

2000 ◽  
Vol 14 (14) ◽  
pp. 1765-1776 ◽  
Author(s):  
Allyson J. Whittaker ◽  
Irena Royzman ◽  
Terry L. Orr-Weaver
Keyword(s):  
Dna Replication ◽  
Origin Recognition Complex ◽  
Ovarian Follicle ◽  
S Phase ◽  
Follicle Cells ◽  
Replication Proteins ◽  
Direct Role ◽  
New Family ◽  
Adult Ovary ◽  
Origin Recognition

We identified a Drosophila gene, double parked(dup), that is essential for DNA replication and belongs to a new family of replication proteins conserved fromSchizosaccharomyces pombe to humans. Strong mutations indup cause embryonic lethality, preceded by a failure to undergo S phase during the postblastoderm divisions. dup is required also for DNA replication in the adult ovary, establishing thatdup is needed for DNA replication at multiple stages of development. Strikingly, DUP protein colocalizes with the origin recognition complex to specific sites in the ovarian follicle cells. This suggests that DUP plays a direct role in DNA replication. Thedup transcript is cell cycle regulated and is under the control of E2F and Cyclin E. Interestingly, dup mutant embryos fail both to downregulate S phase genes and to engage a checkpoint preventing mitosis until completion of S phase. This could be either because these events depend on progression of S phase beyond the point blocked in the dup mutants or because DUP is needed directly for these feedback mechanisms.

scholarly journals Drosophila insulin-like peptide 8 (DILP8) in ovarian follicle cells regulates ovulation and metabolism

2020 ◽  
Author(s):  
Sifang Liao ◽  
Dick R. Nässel
Keyword(s):  
Adult Female ◽  
Developmental Stages ◽  
Ovarian Follicle ◽  
Expression Patterns ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Ovary Development ◽  
Peripheral Neurons ◽  
Efferent Neurons

AbstractIn Drosophila eight insulin-like peptides (DILP1-8) are encoded on separate genes. These DILPs are characterized by unique spatial and temporal expression patterns during the lifecycle. Whereas functions of several of the DILPs have been extensively investigated at different developmental stages, the role of DILP8 signaling is primarily known from larvae and pupae where it couples organ growth and developmental transitions. In adult female flies, a study showed that a specific set of neurons that express the DILP8 receptor, Lgr3, is involved in regulation of reproductive behavior. Here, we further investigated the expression of dilp8/DILP8 and Lgr3 in adult female flies and the functional role of DILP8 signaling. The only site where we found both dilp8 expression and DILP8 immunolabeling was in follicle cells of mature ovaries. Lgr3 expression was detected in numerous neurons in the brain and ventral nerve cord, a small set of peripheral neurons innervating the abdominal heart, as well as in a set of follicle cells close to the oviduct. Ovulation was affected in dilp8 mutants as well as after dilp8-RNAi using dilp8 and follicle cell Gal4 drivers. More eggs were retained in the ovaries and fewer were laid, indicating that DILP8 is important for ovulation. Our data suggest that DILP8 signals locally to Lgr3 expressing follicle cells as well as systemically to Lgr3 expressing efferent neurons in abdominal ganglia that innervate oviduct muscle. Thus, DILP8 may act at two targets to regulate ovulation: follicle cell rupture and oviduct contractions. Furthermore, we could show that manipulations of dilp8 expression affect food intake and starvation resistance. Possibly this reflects a feedback signaling between ovaries and the CNS that ensures nutrients for ovary development. In summary, it seems that DILP8 signaling in regulation of reproduction is an ancient function, conserved in relaxin signaling in mammals.

scholarly journals The Saccharomyces cerevisiae MUM2 Gene Interacts With the DNA Replication Machinery and Is Required for Meiotic Levels of Double Strand Breaks

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1179-1189 ◽  
Author(s):  
Luther Davis ◽  
Maria Barbera ◽  
Amanda McDonnell ◽  
Katherine McIntyre ◽  
Rolf Sternglanz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Origin Recognition Complex ◽  
Wild Type ◽  
Replication Machinery ◽  
Synthesis Inhibitor ◽  
Strand Breaks ◽  
Meiotic Gene

Abstract The Saccharomyces cerevisiae MUM2 gene is essential for meiotic, but not mitotic, DNA replication and thus sporulation. Genetic interactions between MUM2 and a component of the origin recognition complex and polymerase α-primase suggest that MUM2 influences the function of the DNA replication machinery. Early meiotic gene expression is induced to a much greater extent in mum2 cells than in meiotic cells treated with the DNA synthesis inhibitor hydroxyurea. This result indicates that the mum2 meiotic arrest is downstream of the arrest induced by hydroxyurea and suggests that DNA synthesis is initiated in the mutant. Genetic analyses indicate that the recombination that occurs in mum2 mutants is dependent on the normal recombination machinery and on synaptonemal complex components and therefore is not a consequence of lesions created by incompletely replicated DNA. Both meiotic ectopic and allelic recombination are similarly reduced in the mum2 mutant, and the levels are consistent with the levels of meiosis-specific DSBs that are generated. Cytological analyses of mum2 mutants show that chromosome pairing and synapsis occur, although at reduced levels compared to wild type. Given the near-wild-type levels of meiotic gene expression, pairing, and synapsis, we suggest that the reduction in DNA replication is directly responsible for the reduced level of DSBs and meiotic recombination.

scholarly journals Transcriptional Repressor Functions of Drosophila E2F1 and E2F2 Cooperate To Inhibit Genomic DNA Synthesis in Ovarian Follicle Cells

2003 ◽  
Vol 23 (6) ◽  
pp. 2123-2134 ◽  
Author(s):  
Pelin Cayirlioglu ◽  
William O. Ward ◽  
S. Catherine Silver Key ◽  
Robert J. Duronio
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Dna Synthesis ◽  
Gene Amplification ◽  
Cell Cycle Progression ◽  
Ovarian Follicle ◽  
Cell Cycle Control ◽  
Control Cell ◽  
Follicle Cell ◽  
Follicle Cells

ABSTRACT Individual members of the E2F/DP protein family control cell cycle progression by acting predominantly as an activator or repressor of transcription. In Drosophila melanogaster the E2f1, E2f2, Dp, and Rbf1 genes all contribute to replication control in ovarian follicle cells, which become 16C polyploid and subsequently undergo chorion gene amplification late in oogenesis. Mutation of E2f2, Dp, or Rbf1 causes ectopic DNA replication throughout the follicle cell genome during gene amplification cycles. Here we show by both reverse transcription-PCR and DNA microarray analysis that the transcripts of prereplication complex (pre-RC) genes are elevated compared to the wild type in E2f2, Dp, and Rbf1 mutant follicle cells. For some genes the magnitude of this transcriptional derepression is greater in Rbf1 than in E2f2 mutants. These differences correlate with differences in the magnitude of the replication defects in follicle cells, which attain an inappropriate 32C DNA content in both Rbf1 and Dp mutants but not in E2f2 mutants. The ectopic genomic replication of E2f2 mutant follicle cells can be suppressed by reducing the Orc2, Orc5, or Mcm2 gene dose by half, indicating that small changes in pre-RC gene expression can affect DNA synthesis in these cells. We conclude that RBF1 forms complexes with both E2F1/DP and E2F2/DP that cooperate to repress the expression of pre-RC genes, which helps confine DNA synthesis to sites of gene amplification. In contrast, E2F1 and E2F2 repressors function redundantly for some genes in the embryo. Thus, the relative functional contributions of E2F1 and E2F2 to gene expression and cell cycle control depends on the developmental context.

scholarly journals fs (1) Yb is required for ovary follicle cell differentiation in Drosophila melanogaster and has genetic interactions with the Notch group of neurogenic genes.

Genetics ◽  
1995 ◽  
Vol 140 (1) ◽  
pp. 207-217 ◽  
Author(s):  
E Johnson ◽  
S Wayne ◽  
R Nagoshi
Keyword(s):  
Cell Fate ◽  
Ovarian Follicle ◽  
Follicle Cell ◽  
Follicle Cells ◽  
Female Sterility ◽  
Specific Factor ◽  
Temperature Sensitive ◽  
Egg Maturation ◽  
Egg Chambers ◽  
Mutant Phenotypes

Abstract Phenotypic and genetic analyses demonstrate that fs (1) Yb activity is required in the soma for the development of a subset of ovarian follicle cells and to support later stages of egg maturation. Mutations in fs (1) Yb cause a range of ovarian phenotypes, from the improper segregation of egg chambers to abnormal dorsal appendage formation. The mutant phenotypes associated with fs (1) Yb are very similar to the ovarian aberrations produced by temperature-sensitive alleles of Notch and Delta. Possible functional or regulatory interactions between fs (1) Yb and Notch are suggested by genetic studies. A duplication of the Notch locus partially suppresses the female-sterility caused by fs (1) Yb mutations, while reducing Notch dosage makes the fs (1) Yb mutant phenotype more severe. In addition, fs (1) Yb alleles also interact with genes that are known to act with or regulate Notch activity, including Delta, daughterless, and mastermind. However, differences between the mutant ovarian phenotype of fs (1) Yb and that of Notch or Delta indicate that the genes do not have completely overlapping functions in the ovary. We propose that fs (1) Yb acts as an ovary-specific factor that determines follicle cell fate.

Drosophila chorion gene amplification: a model system for the study of chromosome replication

1984 ◽  
Vol 307 (1132) ◽  
pp. 239-245
Keyword(s):  
Dna Replication ◽  
Dna Sequences ◽  
Ovarian Follicle ◽  
Model System ◽  
P Element ◽  
Follicle Cells ◽  
Tissue Specific ◽  
Chorion Genes ◽  
Specific Amplification

Two chromosomal domains of 80-100 kilobases containing Drosophila chorion genes undergo tissue-specific amplification in ovarian follicle cells during oogenesis. We have investigated the ability of small segments of DNA from within these regions to induce amplification after insertion into new chromosomal sites by P element-mediated transformation. Certain transduced chorion DNA sequences initiated a pattern of tissue-specific differential replication that was identical to norm al chorion amplification. Both the transformed chorion DNA as well as flanking rosy DNA sequences underw ent amplification. O ur results suggest that differential chorion DNA replication is mediated by specific origin-containing sequences located near the centre of the amplified domains. The possible role of such sequences in normal programmes of replication is discussed.

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