Sex Determination Signals Control ovo-B Transcription in Drosophila melanogaster Germ Cells

Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 537-545
Author(s):  
Justen Andrews ◽  
Brian Oliver
Keyword(s):  
Transcription Factor ◽  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Sex Determination ◽  
Sexual Identity ◽  
Germ Cells ◽  
Female Germline ◽  
Chromosome Karyotype ◽  
Inductive Signals

Abstract Nonautonomous inductive signals from the soma and autonomous signals due to a 2X karyotype determine the sex of Drosophila melanogaster germ cells. These two signals have partially overlapping influences on downstream sex determination genes. The upstream OVO-B transcription factor is required for the viability of 2X germ cells, regardless of sexual identity, and for female germline sexual identity. The influence of inductive and autonomous signals on ovo expression has been controversial. We show that ovo-B is strongly expressed in the 2X germ cells in either a male or a female soma. This indicates that a 2X karyotype controls ovo-B expression in the absence of inductive signals from the female soma. However, we also show that female inductive signals positively regulate ovo-B transcription in the 1X germ cells that do not require ovo-B function. Genetic analysis clearly indicates that inductive signals from the soma are not required for ovo-B function in 2X germ cells. Thus, while somatic inductive signals and chromosome karyotype have overlapping regulatory influences, a 2X karyotype is a critical germline autonomous determinant of ovo-B function in the germline.

scholarly journals Germline Sex Determination regulates sex-specific signaling between germline stem cells and their niche

2021 ◽  
Author(s):  
Pradeep Kumar Bhaskar ◽  
Sheryl Southard ◽  
Kelly Baxter ◽  
Mark Van Doren
Keyword(s):  
Stem Cells ◽  
Sex Determination ◽  
Sexual Identity ◽  
Germ Cells ◽  
Sex Chromosome ◽  
Germline Stem Cells ◽  
Somatic Gonad ◽  
Stat Signaling ◽  
Female Germline ◽  
Germline Sex Determination

SummaryThe establishment of sexual identity in germ cells is critical for the development of male and female germline stem cells (GSCs) and production of sperm vs. eggs. Thus, this process is essential for sexual reproduction and human fertility. Germ cells depend on signals from the somatic gonad to determine their sex, but in organisms such as flies, mice and humans, the sex chromosome genotype of the germ cells is also important for germline sexual development. How somatic signals and germ cell-intrinsic cues act together to regulate germline sex determination is a key question about which little is known. We have found that JAK/STAT signaling in the GSC niche promotes male identity in germ cells and GSCs, in part by activating expression of the epigenetic reader Phf7. We have also found that JAK/STAT signaling is blocked in XX (female) germ cells through the intrinsic action of the sex determination gene Sex lethal, which preserves female identity. Thus, an important function of germline sexual identity is to control how GSCs respond to signals in their niche environment.

scholarly journals Genetic evidence that the ovo locus is involved in Drosophila germ line sex determination.

Genetics ◽  
1990 ◽  
Vol 125 (3) ◽  
pp. 535-550 ◽  
Author(s):  
B Oliver ◽  
D Pauli ◽  
A P Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Determination ◽  
Sexual Identity ◽  
Gene Product ◽  
Germ Cells ◽  
Germ Line ◽  
Partial Transformation ◽  
Loss Of Function ◽  
Lethal Allele ◽  
Sex Lethal

Abstract Zygotically contributed ovo gene product is required for the survival of female germ cells in Drosophila melanogaster. Trans-allelic combinations of weak and dominant ovo mutations (ovoD) result in viable germ cells that appear to be partially transformed from female to male sexual identity. The ovoD2 mutation is partially suppressed by many Sex-lethal alleles that affect the soma, while those that affect only the germ line fail to interact with ovoD2. One of two loss-of-function ovo alleles is suppressed by a loss-of-function Sex-lethal allele. Because ovo mutations are germ line dependent, it is likely that ovo is suppressed by way of communication between the somatic and germ lines. A loss-of-function allele of ovo is epistatic to germ line dependent mutations in Sex-lethal. The germ line dependent sex determination mutation, sans fille, and ovoD mutations show a dominant synergistic interaction resulting in partial transformation of germ line sexual identity. The ovo locus appears to be involved in germ line sex determination and is linked in some manner to sex determination in the soma.

scholarly journals Genetic analysis of an intersex allele (ix5) that regulates sexual phenotype of both female and male Drosophila melanogaster

2002 ◽  
Vol 80 (1) ◽  
pp. 7-14 ◽  
Author(s):  
M. ACHARYYA ◽  
R. N. CHATTERJEE
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Sex Determination ◽  
Male Genitalia ◽  
Point Mutations ◽  
Normal Male ◽  
Sexual Phenotype ◽  
Sex Comb ◽  
Male Sex ◽  
Courtship Activity

An allele of intersex (ix5) of Drosophila melanogaster has been characterized. The genetic analysis of the allele demonstrated that like other point mutations of ix, the ix5 allele also transformed diplo-X individuals into intersexes. The ix5 mutation also affects the arrangement of sex comb bristles on the forelegs of males, although they had morphologically nearly normal male genitalia. They often fail to display a sustained pattern of courtship activity when tested. Orcein-stained squash preparations of testes from ix5 males revealed a defect in spermatogenesis. Our results, taken together with those of McRobert & Tompkins (1985), indicate that the ix+ gene also functions in male sex determination.

scholarly journals iPLA2-VIA is required for healthy aging of neurons, muscle, and the female germline in Drosophila melanogaster

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256738
Author(s):  
Surya Jyoti Banerjee ◽  
Adina Schonbrun ◽  
Sogol Eizadshenass ◽  
Shimshon Benji ◽  
Yaakov Tzvi Cantor ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cells ◽  
Healthy Aging ◽  
Phospholipase Activity ◽  
Mitochondrial Potential ◽  
Age Related ◽  
Functional Aspects ◽  
Mutant Female ◽  
Neuronal Tissues ◽  
Female Germline

Neurodegenerative disease (ND) is a growing health burden worldwide, but its causes and treatments remain elusive. Although most cases of ND are sporadic, rare familial cases have been attributed to single genes, which can be investigated in animal models. We have generated a new mutation in the calcium-independent phospholipase A2 (iPLA2) VIA gene CG6718, the Drosophila melanogaster ortholog of human PLA2G6/PARK14, mutations in which cause a suite of NDs collectively called PLA2G6-associated neurodegeneration (PLAN). Our mutants display age-related loss of climbing ability, a symptom of neurodegeneration in flies. Although phospholipase activity commonly is presumed to underlie iPLA2-VIA function, locomotor decline in our mutants is rescued by a transgene carrying a serine-to-alanine mutation in the catalytic residue, suggesting that important functional aspects are independent of phospholipase activity. Additionally, we find that iPLA2-VIA knockdown in either muscle or neurons phenocopies locomotor decline with age, demonstrating its necessity in both neuronal and non-neuronal tissues. Furthermore, RNA in situ hybridization shows high endogenous iPLA2-VIA mRNA expression in adult germ cells, and transgenic HA-tagged iPLA2-VIA colocalizes with mitochondria there. Mutant males are fertile with normal spermatogenesis, while fertility is reduced in mutant females. Mutant female germ cells display age-related mitochondrial aggregation, loss of mitochondrial potential, and elevated cell death. These results suggest that iPLA2-VIA is critical for mitochondrial integrity in the Drosophila female germline, which may provide a novel context to investigate its functions with parallels to PLAN.

scholarly journals Molecular genetics of the Drosophila melanogaster ovo locus, a gene required for sex determination of germline cells.

Genetics ◽  
1992 ◽  
Vol 130 (4) ◽  
pp. 791-803
Author(s):  
M D Garfinkel ◽  
A R Lohe ◽  
A P Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Determination ◽  
Genomic Dna ◽  
Transcription Unit ◽  
Complementation Group ◽  
P Element ◽  
Female Sterility ◽  
Germline Cells ◽  
Female Specific ◽  
Female Germline

Abstract The Drosophila melanogaster ovo gene is required for survival and differentiation of female germline cells, apparently playing a role in germline sex determination. We recovered 60 kb of genomic DNA from its genetic location at 4E1,2 on the X chromosome. A transcription unit coding for an apparently female-specific germline-dependent 5-kb poly(A)+ RNA size class is located substantially in a 7-kb region, within which three DNA-detectable lesions for mutations that inactivate the ovo function are located at two sites approximately 4 kb apart. The breakpoint of a deficiency that removes the neighboring lethal complementation group shavenbaby (svb) but leaves the ovo function intact maps approximately 5 kb to the molecular left of the leftmost ovo mutant site. A class of mutations that inactivates both the svb function and the ovo function affects genomic DNA between the two ovo sites. Sequences required for the two genetic functions are partly overlapping. In spite of this overlap, P element-mediated gene transfer of a 10-kb genomic DNA segment containing the 5-kb poly(A)+ RNA transcription unit rescues the female sterility phenotypes of ovo mutations, but not the svb lethality.

scholarly journals Identification and Genetic Analysis of wunen, a Gene Guiding Drosophila melanogaster Germ Cell Migration

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1231-1241 ◽  
Author(s):  
Nian Zhang ◽  
Jiaping Zhang ◽  
Yan Cheng ◽  
Ken Howard
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Migration ◽  
Genetic Analysis ◽  
Germ Cell ◽  
Germ Cells ◽  
Germ Line ◽  
Genetic Locus ◽  
Somatic Gonad ◽  
Germ Cell Migration ◽  
Oriented Movement

Abstract We describe a novel genetic locus, wunen (wun), required for guidance of germ cell migration in early Drosophila development. Loss of wun function does not abolish movement but disrupts the orientation of the motion causing the germ cells to disperse even though their normal target, the somatic gonad, is well formed. We demonstrate that the product of this gene enables a signal to pass from the soma to the germ line and propose that the function of this signal is to selectively stabilize certain cytoplasmic extensions resulting in oriented movement. To characterize this guidance factor, we have mapped wun to within 100 kb of cloned DNA.

scholarly journals iPLA2-VIA is required for healthy aging in neurons, muscle, and female germline in Drosophila melanogaster

2021 ◽  
Author(s):  
Surya Banerjee ◽  
Adina Schonbrun ◽  
Sogol Eizadshenass ◽  
Shimshon Benji ◽  
Yaakov Tzvi Cantor ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cells ◽  
Healthy Aging ◽  
Phospholipase Activity ◽  
Mitochondrial Potential ◽  
Age Related ◽  
Functional Aspects ◽  
Mutant Female ◽  
Neuronal Tissues ◽  
Female Germline

AbstractNeurodegenerative disease (ND) is a growing health burden worldwide, but its causes and treatments remain elusive. Although most cases of ND are sporadic, rare familial cases have been attributed to single genes, which can be investigated in animal models. We have generated a new mutation in the calcium-independent phospholipase A2 (iPLA2) VIA gene CG6718, the Drosophila melanogaster ortholog of human PLA2G6/PARK14, mutations in which cause a suite of NDs collectively called PLA2G6-associated neurodegeneration (PLAN). Our mutants display age-related loss of climbing ability, a symptom of neurodegeneration in flies. Although phospholipase activity commonly is presumed to underlie iPLA2-VIA function, locomotor decline in our mutants is rescued by a transgene carrying a serine-to-alanine mutation in the catalytic residue, suggesting that important functional aspects are independent of phospholipase activity. Additionally, we find that iPLA2-VIA knockdown in either muscle or neurons phenocopies locomotor decline with age, demonstrating its necessity in both neuronal and non-neuronal tissues. Furthermore, RNA in situ hybridization shows high endogenous iPLA2-VIA mRNA expression in adult germ cells, and transgenic HA-tagged iPLA2-VIA colocalizes with mitochondria there. Mutant males are fertile with normal spermatogenesis, while fertility is reduced in mutant females. Mutant female germ cells display age-related mitochondrial aggregation, loss of mitochondrial potential, and elevated cell death. These results suggest that iPLA2-VIA is important for germline mitochondrial integrity in Drosophila, which may be relevant for understanding how PLAN develops.

scholarly journals An autoregulatory switch in sex-specific phf7 transcription causes loss of sexual identity and tumors in the Drosophila female germline

2020 ◽  
Author(s):  
Anne E. Smolko ◽  
Laura Shapiro-Kulnane ◽  
Helen K. Salz
Keyword(s):  
Germ Cell ◽  
Sexual Identity ◽  
Germ Cells ◽  
Transcriptional Repression ◽  
Feedback Mechanism ◽  
Phd Finger ◽  
Transcriptional Reprogramming ◽  
Male Germline ◽  
Regulatory Circuit ◽  
Female Germline

ABSTRACTMaintenance of germ cell sexual identity is essential for reproduction. Entry into the spermatogenesis or oogenesis pathway requires that the appropriate gene network is activated and the antagonist network is silenced. For example, in Drosophila female germ cells, forced expression of the testis-specific PHD finger protein 7 (PHF7) disrupts oogenesis leading to either an agametic or germ cell tumor phenotype. Here we show that PHF7 expressing ovarian germ cells inappropriately express hundreds of genes, many of which are male germline genes. We find that the majority of genes under PHF7 control in female germ cells are not under PHF7 control in male germ cells, suggesting that PHF7 is acting in a tissue-specific manner. Remarkably, transcriptional reprogramming includes a positive autoregulatory feedback mechanism in which ectopic PHF7 overcomes its own transcriptional repression through promoter switching. Furthermore, we find that tumorigenic capacity is dependent on the dosage of phf7. This study reveals that high levels of ectopic PHF7 in female germ cells leads to a loss of sexual identity and promotion of a regulatory circuit beneficial for tumor initiation and progression.

scholarly journals Germline masculinization by Phf7 in D. melanogaster requires its evolutionarily novel C-terminus and the HP1-family protein HP1D3csd

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shu Yuan Yang
Keyword(s):  
Sex Determination ◽  
Germ Cells ◽  
Transcriptome Profiling ◽  
Phd Finger ◽  
Intrinsic Factors ◽  
Male Germline ◽  
C Terminus ◽  
Family Protein ◽  
Key Factor ◽  
Female Germline

AbstractGerm cells inDrosophila melanogasterneed intrinsic factors along with somatic signals to activate proper sexual programs. A key factor for male germline sex determination is PHD finger protein 7 (Phf7), a histone reader expressed in the male germline that can trigger sex reversal in female germ cells and is also important for efficient spermatogenesis. Here we find that the evolutionarily novel C-terminus in Phf7 is necessary to turn on the complete male program in the early germline ofD. melanogaster, suggesting that this domain may have been uniquely acquired to regulate sexual differentiation. We further looked for genes regulated byPhf7related to sex determination in the embryonic germline by transcriptome profiling of FACS-purified embryonic gonads. One of the genes positively-regulated by Phf7 in the embryonic germline was anHP1family member,Heterochromatin Protein 1D3 chromoshadow domain (HP1D3csd).We find that this gene is needed for Phf7 to induce male-like development in the female germline, indicating that HP1D3csd is an important factor acting downstream of Phf7 to regulate germline masculinization.

scholarly journals Sex Determination in the Drosophila Germline Is Dictated by the Sexual Identity of the Surrounding Soma

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1741-1756 ◽  
Author(s):  
J A Waterbury ◽  
J I Horabin ◽  
D Bopp ◽  
P Schedl
Keyword(s):  
Sex Determination ◽  
Sexual Identity ◽  
Signaling Pathway ◽  
X Chromosome ◽  
Germ Cells ◽  
Chromosome Counting ◽  
Counting System ◽  
Germline Expression ◽  
Female Specific ◽  
Male Specific

Abstract It has been suggested that sexual identity in the germline depends upon the combination of a nonautonomous somatic signaling pathway and an autonomous X chromosome counting system. In the studies reported here, we have examined the role of the sexual differentiation genes transformer (tra) and doublesex (dsx) in regulating the activity of the somatic signaling pathway. We asked whether ectopic somatic expression of the female products of the tra and dsx genes could feminize the germline of XY animals. We find that TraF is sufficient to feminize XY germ cells, shutting off the expression of male-specific markers and activating the expression of female-specific markers. Feminization of the germline depends upon the constitutively expressed transformer-2 (tra-2) gene, but does not seem to require a functional dsx gene. However, feminization of XY germ cells by TraF can be blocked by the male form of the Dsx protein (DsxM). Expression of the female form of dsx, DsxF, in XY animals also induced germline expression of female markers. Taken together with a previous analysis of the effects of mutations in tra, tra-2, and dsx on the feminization of XX germ cells in XX animals, our findings indicate that the somatic signaling pathway is redundant at the level tra and dsx. Finally, our studies call into question the idea that a cell-autonomous X chromosome counting system plays a central role in germline sex determination.

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