Genetic control of sex determination in the germ line and soma of the housefly, Musca domestica

Development ◽  
1994 ◽  
Vol 120 (9) ◽  
pp. 2531-2538 ◽  
Author(s):  
D. Hilfiker-Kleiner ◽  
A. Dubendorfer ◽  
A. Hilfiker ◽  
R. Nothiger
Keyword(s):  
Sex Determination ◽  
Musca Domestica ◽  
Germ Cells ◽  
Maternal Effect ◽  
Germ Line ◽  
M Cells ◽  
Female Genotype ◽  
Female Germ Line ◽  
Pole Cells

In Musca domestica, sex in the soma is cell autonomously determined by the male-determiner M, or by the female-determiner FD. Transplanted pole cells (precursors of the germ line) show that sex determination of germ cells is non-autonomous genotypically male pole cells form functional eggs in female hosts, and genotypically female pole cells form functional sperm in male hosts. When M/+ cells undergo oogenesis, a male-determining maternal effect predetermines offspring without M, i.e. of female genotype, to develop as fertile males. FD is epistatic to M in the female germ line, as it is in the soma, overruling the masculinizing effect of M. The results suggest that maternal F product is needed for activation of the zygotic F gene.

Induction of indora expression in pole cells by the mesoderm is required for female germ-line development in Drosophila melanogaster

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 1023-1029 ◽  
Author(s):  
M. Mukai ◽  
M. Kashikawa ◽  
S. Kobayashi
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cells ◽  
Germ Line ◽  
Animal Groups ◽  
Novel Transcript ◽  
Expression Of Genes ◽  
Female Germ Line ◽  
Pole Cells

In many animal groups, the interaction between germ and somatic line is required for germ-line development. In Drosophila, the germ-line precursors (pole cells) formed at the posterior tip of the embryos migrate toward the mesodermal layer where they adhere to the dorsolateral mesoderm, which ensheaths the pole cells to form the embryonic gonads. These mesodermal cells may control the expression of genes that function in pole cells for their development into germ cells. However, such downstream genes have not been isolated. In this study, we identify a novel transcript, indora (idr), which is expressed only in pole cells within the gonads. Reduction of idr transcripts by an antisense idr expression caused the failure of pole cells to produce functional germ cells in females. Furthermore, we demonstrate that idr expression depends on the presence of the dorsolateral mesoderm, but it does not necessarily require its specification as the gonadal mesoderm. Our findings suggest that the induction of idr in pole cells by the mesodermal cells is required for germ-line development.

scholarly journals The Male-Determining Activity on the Y Chromosome of the Housefly (Musca domestica L.) Consists of Separable Elements

Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 651-661
Author(s):  
Monika Hediger ◽  
Ariane Denise Minet ◽  
Markus Niessen ◽  
Regula Schmidt ◽  
Denise Hilfiker-Kleiner ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Maternal Effect ◽  
Germ Line ◽  
C Banding ◽  
Female Germ Line ◽  
The Common ◽  
Pole Cells ◽  
Different Strains ◽  
Autosomal Translocation ◽  
Determining Factor

Abstract In the common housefly, the presence or absence of a male-determining factor, M, is responsible for sex determination. In different strains, M has been found on the Y, on the X, or on any of the five autosomes. By analyzing a Y-autosomal translocation and a ring-shaped, truncated Y chromosome, we could show that M on the Y consists of at least two regions with M activity: One of them can be assigned to the short arm of the Y chromosome (MYS), which is largely C-banding negative, the other region lies on the C-banding positive long arm of the Y, including the centromeric part (MYL). Each region alone behaves as a hypomorphic M factor, causing many carriers to develop as intersexes of the mosaic type instead of as males. When introduced into the female germ line by transplantation of progenitor germ cells (pole cells), the MYS shows an almost complete maternal effect that predetermines 96% of the genotypic female (NoM) animals to develop as males. In contrast, the MYL has largely lost its maternal effect, and most of the NoM animals develop as females. Increasing the amount of product made by either of the two hypomorphic M factors (by combining the MYS and MYL or two MYS) leads to complete male development in almost every case. We thus assume that the Y chromosome carries at least two copies of M, and that these are functionally equivalent.

scholarly journals The Y-Chromosomal and Autosomal Male-Determining M Factors of Musca domestica Are Equivalent

Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 271-280
Author(s):  
R Schmidt ◽  
M Hediger ◽  
S Roth ◽  
R Nöthiger ◽  
A Dubendorfer
Keyword(s):  
Musca Domestica ◽  
Germ Line ◽  
Dominant Factor ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Female Development ◽  
Dominant Female ◽  
Female Germ Line ◽  
Pole Cells ◽  
Determining Factor

Abstract In Musca domestica, male sex is determined by a dominant factor, M, located either on the Y, the X or on an autosome. M prevents the activity of the female-determining gene F. In the absence of M, F becomes active and dictates female development. The various M factors may represent translocated copies of an ancestral Y-chromosomal M. Double mutants and germ line chimeras show that MY, MI, MII, MIII and MV perform equivalent functions. When brought into the female germ line, they predetermine male development of the offspring. This maternal effect is overruled by the dominant female-determining factor FD. MI and MII are weak M factors, as demonstrated by the presence of yolk proteins in MI/+ males and by the occurrence of some intersexes among the offspring that developed from transplanted MI/+ and MII/+ pole cells. The arrhenogenic mutation Ag has its focus in the female germ line and its temperature-sensitive period during oogenesis. We propose that MI and Ag represent allelic M factors that are affected in their expression. Analysis of mosaic gonads showed that in M. domsticu the sex of the germ line is determined by inductive signals from the surrounding soma. We present a model to account for the observed phenomena.

scholarly journals The role of the ovarian tumor locus in Drosophila melanogaster germ line sex determination

Development ◽  
1993 ◽  
Vol 119 (1) ◽  
pp. 123-134 ◽  
Author(s):  
D. Pauli ◽  
B. Oliver ◽  
A.P. Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Determination ◽  
Germ Cells ◽  
Ovarian Tumor ◽  
Germ Line ◽  
Gene Dosage ◽  
Constitutive Expression ◽  
Regulatory Cascade

The locus ovarian tumor (otu) is involved in several aspects of oogenesis in Drosophila melanogaster. The possible role of otu in the determination of the sexual identity of germ cells has not been extensively explored. Some otu alleles produce a phenotype known as ovarian tumors: ovarioles are filled with numerous poorly differentiated germ cells. We show that these mutant germ cells have a morphology similar to primary spermatocytes and that they express male germ line-specific reporter genes. This indicates that they are engaged along the male pathway of germ line differentiation. Consistent with this conclusion, we found that the splicing of Sex-lethal (Sxl) pre-mRNAs occurs in the male-specific mode in otu-transformed germ cells. The position of the otu locus in the regulatory cascade of germ line sex determination has been studied by using mutations that constitutively express the feminizing activity of the Sxl gene. The sexual transformation of the germ cells observed with several combinations of otu alleles can be reversed by constitutive expression of Sxl. This shows that otu acts upstream of Sxl in the process of germ line sex determination. Other phenotypes of otu mutations were not rescued by constitutive expression of Sxl, suggesting that several functions of otu are likely to be independent of sex determination. Finally, we show that the gene dosage of otu modifies the phenotype of ovaries heterozygous for the dominant alleles of ovo, another gene involved in germ line sex determination. One dose of otu+ enhances the ovoD ovarian phenotypes, while three doses partially suppress these phenotypes. Synergistic interaction between ovoD1 and otu alleles leads to the occasional transformation of chromosomally female germ cells into early spermatocytes. These interactions are similar to those observed between ovoD and one allele of the sans fille (snf) locus. Altogether, our results imply that the otu locus acts, along with ovo, snf, and Sxl, in a pathway (or parallel pathways) required for proper sex determination of the female germ line.

scholarly journals The Female-Determining Gene F of the Housefly, Musca domestica, Acts Maternally to Regulate Its Own Zygotic Activity

Genetics ◽  
1998 ◽  
Vol 150 (1) ◽  
pp. 221-226 ◽  
Author(s):  
Andreas Dübendorfer ◽  
Monika Hediger
Keyword(s):  
Musca Domestica ◽  
Germ Line ◽  
Wild Type ◽  
Female Development ◽  
Continuous Activity ◽  
In The Wild ◽  
Female Germ Line ◽  
The Common ◽  
Pole Cells ◽  
Zygotic Genome

AbstractIn Musca domestica, the common housefly, female development requires the continuous activity of the sex-determining gene F from early embryogenesis until metamorphosis. To activate F in embryogenesis, two conditions must be met: There must be no male-determining M factor in the zygotic genome, and the egg must be preconditioned by F activity in the maternal germ line. This maternal activity can be suppressed by introducing an M factor into the maternal germ line, which causes all offspring, including those that do not carry M, to develop as males. By transplantation of pole cells (germline progenitor cells) we have constructed such females with a genetically male germ line and, simultaneously, males with a genetically female germ line carrying a constitutive allele of F [FDominant (FD)]. Crosses between these animals yielded offspring that, despite the presence of M in the maternal germ line, were of female sex, solely due to zygotic FD brought in via the sperm. This shows that zygotic F function alone is sufficient to promote female development and that in the wild-type situation, maternal F product serves no other function but to activate the zygotic F gene.

scholarly journals The Mutation masculinizer (man) Defines a Sex-Determining Gene With Maternal and Zygotic Functions in Musca domestica L.

Genetics ◽  
1997 ◽  
Vol 145 (1) ◽  
pp. 173-183 ◽  
Author(s):  
R Schmidt ◽  
M Hediger ◽  
R Nöthiger ◽  
A Dübendorfer
Keyword(s):  
Musca Domestica ◽  
Maternal Effect ◽  
Dominant Factor ◽  
Loss Of Function ◽  
New Mutation ◽  
Yolk Proteins ◽  
Hypomorphic Allele ◽  
Internal Structures ◽  
Primary Signal ◽  
Pole Cells

In Musca domestica, the primary signal for sex determination is the dominant factor M, which is assumed to regulate a postulated female-determining gene F. Presence of M prevents expression of F so that male development ensues. In the absence of M, F can become active, which dictates the female pathway. The existence of F is inferred from FD, a dominant factor that is epistatic to M. We describe a new mutation masculinizer, which has all the properties expected for a null or strongly hypomorphic allele of F: (1) it maps to the same chromosomal location as FD, (2) homozygous man/man animals develop as males, (3) homozygous man/man clones generated in man/+ female larvae differentiate male structures, (4) man has a sex-determining maternal effect. About a third of the morphological males synthesize yolk proteins, which indicates that they are intersexual in internal structures. The maternal effect of man is complete in offspring that derive from homozygous man/man pole cells transplanted into female hosts. In this case, all man/+ progeny become fertile males that do not produce yolk proteins. A sex-determining maternal effect has previously been demonstrated for FD. Like F, maternal man  + is needed for zygotic man  + to become active, providing further evidence that man is a loss-of-function allele of F.

Multiple products from the shavenbaby-ovo gene region of Drosophila melanogaster: relationship to genetic complexity

1994 ◽  
Vol 14 (10) ◽  
pp. 6809-6818
Author(s):  
M D Garfinkel ◽  
J Wang ◽  
Y Liang ◽  
A P Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Gene Region ◽  
Multiple Products ◽  
Zinc Finger Motifs ◽  
Genetic Complexity ◽  
Complex Locus ◽  
Female Germ Line ◽  
Sensory Structures ◽  
Pole Cells

The Drosophila melanogaster shavenbaby (svb)-ovo gene region is a complex locus, containing two distinct but comutable genetic functions. ovo is required for survival and differentiation of female germ line cells and plays a role in germ line sex determination. In contrast, svb is required in both male and female embryos for the production of epidermal locomotor and sensory structures. Sequences required for the two genetic functions are partially overlapping. ovo corresponds to a previously described germ line-dependent 5.0-kb poly(A)+ mRNA that first appears in the germarium and accumulates in nurse cells during oogenesis. The 5.0-kb mRNA is stored in the egg, but it is rapidly lost in the embryos except for its continued presence in the germ line precursor pole cells. The ovo mRNA predicts a 1,028-amino-acid 110.6-kDa protein homologous with transcription factors. We have identified an embryonic mRNA, 7.1 kb in length, that contains exons partially overlapping those of the 5.0-kb poly(A)+ mRNA. The spatial distribution of this newly discovered transcript during midembryogenesis suggests that it corresponds to the svb function. The arrangement of exons common to the 5.0- and 7.1-kb mRNAs suggests that the Ovo and Svb proteins share DNA-binding specificity conferred by four Cys2-His2 zinc finger motifs but differ functionally in their capacity to interact with other components of the transcription machinery.

scholarly journals Sex determination in Drosophila: sis-b, a major numerator element of the X:A ratio in the soma, does not contribute to the X:A ratio in the germ line

Development ◽  
1993 ◽  
Vol 117 (2) ◽  
pp. 763-767 ◽  
Author(s):  
M. Steinmann-Zwicky
Keyword(s):  
Sex Determination ◽  
Germ Cells ◽  
Germ Line ◽  
Somatic Cells ◽  
Present Evidence ◽  
Primary Signal ◽  
Sex Lethal

In soma and germ cells of Drosophila, the X:A ratio builds a primary signal for sex determination, and in both tissues Sex-lethal (Sxl) function is required for cells to enter the female pathway. In somatic cells of XX animals, the products of X-chromosomal elements of the X:A ratio activate Sxl. Here I show that sisterless-b (sis-b), which is the X-chromosomal element of the somatic X:A ratio that has best been analysed, is not required for oogenesis. I also present evidence that Sxl function might not be sufficient to direct germ cells into the female pathway. These results show that the elements forming the X:A ratio in the germ line are different from the elements forming the X:A ratio in the soma and they suggest that, in the germ line, Sxl might not be regulated by the X:A ratio.

scholarly journals Mitochondrial functionality in female reproduction

2017 ◽  
Vol 71 (1) ◽  
pp. 0-0
Author(s):  
Łukasz Gąsior ◽  
Regina Daszkiewicz ◽  
Mateusz Ogórek ◽  
Zbigniew Polański
Keyword(s):  
Mitochondrial Genome ◽  
Germ Cells ◽  
Germ Line ◽  
Whole Body ◽  
Female Reproduction ◽  
Normal Number ◽  
Female Germ Line ◽  
And Function ◽  
Role And Function

In most animal species female germ cells are the source of mitochondrial genome for the whole body of individuals. As a source of mitochondrial DNA for future generations the mitochondria in the female germ line undergo dynamic quantitative and qualitative changes. In addition to maintaining the intact template of mitochondrial genome from one generation to another, mitochondrial role in oocytes is much more complex and pleiotropic. The quality of mitochondria determines the ability of meiotic divisions, fertilization ability, and activation after fertilization or sustaining development of a new embryo. The presence of normal number of functional mitochondria is also crucial for proper implantation and pregnancy maintaining. This article addresses issues of mitochondrial role and function in mammalian oocyte and presents new approaches in studies of mitochondrial function in female germ cells.

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