Germ-line sex determination in Drosophila melanogaster

1990 ◽  
Vol 6 ◽  
pp. 259-263 ◽  
Author(s):  
Daniel Pauli ◽  
Anthony P. Mahowald
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Determination ◽  
Germ Line

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.

Sex-lethal, master and slave: a hierarchy of germ-line sex determination in Drosophila

Development ◽  
1993 ◽  
Vol 119 (3) ◽  
pp. 897-908 ◽  
Author(s):  
B. Oliver ◽  
Y.J. Kim ◽  
B.S. Baker
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Determination ◽  
Ovarian Tumor ◽  
Germ Line ◽  
Female Sex ◽  
Somatic Signal ◽  
Female Germ Line ◽  
Sex Lethal ◽  
Female Specific ◽  
Genetic Hierarchy

Female sex determination in the germ line of Drosophila melanogaster is regulated by genes functioning in the soma as well as genes that function within the germ line. Genes known or suspected to be involved in germ-line sex determination in Drosophila melanogaster have been examined to determine if they are required upstream or downstream of Sex-lethal+, a known germ-line sex determination gene. Seven genes required for female-specific splicing of germ-line Sex-lethal+ pre-mRNA are identified. These results together with information about the tissues in which these genes function and whether they control sex determination and viability or just sex determination in the germ line have been used to deduce the genetic hierarchy regulating female germ-line sex determination. This hierarchy includes the somatic sex determination genes transformer+, transformer-2+ and doublesex+ (and by inference Sex-lethal+), which control a somatic signal required for female germ-line sex determination, and the germ-line ovarian tumor genes fused+, ovarian tumor+, ovo+, sans fille+, and Sex-lethal+, which are involved in either the reception or interpretation of this somatic sex determination signal. The fused+, ovarian tumor+, ovo+ and sans fille+ genes function upstream of Sex-lethal+ in the germ line.

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 spenito is required for sex determination in Drosophila melanogaster

2015 ◽  
Vol 112 (37) ◽  
pp. 11606-11611 ◽  
Author(s):  
Dong Yan ◽  
Norbert Perrimon
Keyword(s):  
Drosophila Melanogaster ◽  
Stem Cell ◽  
Alternative Splicing ◽  
Sex Determination ◽  
Nuclear Protein ◽  
Germ Line ◽  
Splicing Regulation ◽  
Protein Loss ◽  
Family Protein ◽  
Female Germ Line

Sex-lethal (Sxl) encodes the master regulator of the sex determination pathway in Drosophila and acts by controlling sex identity in both soma and germ line. In females Sxl maintains its own expression by controlling the alternative splicing of its own mRNA. Here, we identify a novel sex determination gene, spenito (nito) that encodes a SPEN family protein. Loss of nito activity results in stem cell tumors in the female germ line as well as female-to-male somatic transformations. We show that Nito is a ubiquitous nuclear protein that controls the alternative splicing of the Sxl mRNA by interacting with Sxl protein and pre-mRNA, suggesting that it is directly involved in Sxl auto-regulation. Given that SPEN family proteins are frequently mutated in cancers, our results suggest that these factors might be implicated in tumorigenesis through splicing regulation.

scholarly journals Expression of a gene duplication encoding conserved sperm tail proteins is translationally regulated in Drosophila melanogaster.

1993 ◽  
Vol 13 (3) ◽  
pp. 1708-1718 ◽  
Author(s):  
M Schäfer ◽  
D Börsch ◽  
A Hülster ◽  
U Schäfer
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Family ◽  
Translational Control ◽  
Germ Line ◽  
Gene Families ◽  
Homologous Gene ◽  
Male Sterile ◽  
Sperm Tail ◽  
Repetitive Motif ◽  
Carboxy Terminal

We have analyzed a locus of Drosophila melanogaster located at 98C on chromosome 3, which contains two tandemly arranged genes, named Mst98Ca and Mst98Cb. They are two additional members of the Mst(3)CGP gene family by three criteria. (i) Both genes are exclusively transcribed in the male germ line. (ii) Both transcripts encode a protein with a high proportion of the repetitive motif Cys-Gly-Pro. (iii) Their expression is translationally controlled; while transcripts can be detected in diploid stages of spermatogenesis, association with polysomes can be shown only in haploid stages of sperm development. The genes differ markedly from the other members of the gene family in structure; they do not contain introns, they are of much larger size, and they have the Cys-Gly-Pro motifs clustered at the carboxy-terminal end of the encoded proteins. An antibody generated against the Mst98Ca protein recognizes both Mst98C proteins in D. melanogaster. In a male-sterile mutation in which spermiogenesis is blocked before individualization of sperm, both of these proteins are no longer synthesized. This finding provides proof of late translation for the Mst98C proteins and thereby independent proof of translational control of expression. Northern (RNA) and Western immunoblot analyses indicate the presence of homologous gene families in many other Drosophila species. The Mst98C proteins share sequence homology with proteins of the outer dense fibers in mammalian spermatozoa and can be localized to the sperm tail by immunofluorescence with an anti-Mst98Ca antibody.

scholarly journals Evolution of Sex Determination in Caenorhabditis: Unusually High Divergence of tra-1 and Its Functional Consequences

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 587-595 ◽  
Author(s):  
Mario de Bono ◽  
Jonathan Hodgkin
Keyword(s):  
Sex Determination ◽  
Germ Line ◽  
Amino Acid Identity ◽  
Evolution Of Sex ◽  
Phenotypic Differences ◽  
C Elegans ◽  
Functional Studies ◽  
Somatic Gonad ◽  
Functional Consequences ◽  
Significant Divergence

Abstract The tra-1 gene is a terminal regulator of somatic sex in Caenorhabditis elegans: high tra-1 activity elicits female development, low tra-1 activity elicits male development. To investigate the function and evolution of tra-1, we examined the tra-1 gene from the closely related nematode C. briggsae. Ce-tra-1 and Cb-tra-1 are unusually divergent. Each gene generates two transcripts, but only one of these is present in both species. This common transcript encodes TRA-1A, which shows only 44% amino acid identity between the species, a figure much lower than that for previously compared genes. A Cb-tra-1 transgene rescues many tissues of tra-1(nul1) mutants of C. elegans but not the somatic gonad or germ line. This transgene also causes nongonadal feminization of XO animals, indicating incorrect sexual regulation. Alignment of Ce-TRA-1A and Cb-TRA-1A defines several conserved regions likely to be important for tra-1 function. The phenotypic differences between Ce-tra-1(null) mutants rescued by Cb-tra-1 transgenes and wild-type C. elegans indicate significant divergence of regulatory regions. These molecular and functional studies suggest that evolution of sex determination in nematodes is rapid and genetically complex.

scholarly journals Extended Reproductive Roles of the fruitless Gene in Drosophila melanogaster Revealed by Behavioral Analysis of New fru Mutants

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1107-1130 ◽  
Author(s):  
Adriana Villella ◽  
Donald A Gailey ◽  
Barbra Berwald ◽  
Saiyou Ohshima ◽  
Phillip T Barnes ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Determination ◽  
Molecular Genetics ◽  
Behavioral Analysis ◽  
Behavioral Phenotypes ◽  
New Mutations

The fruitless mutants fru3 and fru4 were assessed for sex-specific reproductive-behavioral phenotypes and compared to the previously reported fru mutants. Among the several behavioral anomalies exhibited by males expressing these relatively new mutations, some are unique. fru3 and fru4 males are less stimulated to court females than and fru1 and fru2. No courtship pulse song is generated by either fru3 or fru4 males, even though they perform brief wing extensions. fru3 and fru4 males display significantly less chaining behavior than do fru1 males. The hierarchy of courtship responses by fru males directed toward females vs. males, when presented with both sexes simultaneously, is that fru1 males perform vigorous and indiscriminant courtship directed at either sex; fru4 males are similarly indiscriminant, but courtship levels were lower than fru1; fru2 males prefer females; fru3 males show a courtship bias toward males. fru3 and fru4 males essentially lack the Muscle of Lawrence (MOL). On several reproductive criteria, there was no difference between fru-variant females and fru  +. The increases in phenotypic severity measured for the new mutants are discussed in the context of the emerging molecular genetics of fru and with regard to the gene's position within the sex-determination pathway.

scholarly journals Genetic and Molecular Characterization of sting, a Gene Involved in Crystal Formation and Meiotic Drive in the Male Germ Line of Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 749-760 ◽  
Author(s):  
Armin Schmidt ◽  
Gioacchino Palumbo ◽  
Maria P Bozzetti ◽  
Patrizia Tritto ◽  
Sergio Pimpinelli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Drosophila Melanogaster ◽  
Null Allele ◽  
Germ Line ◽  
Meiotic Drive ◽  
P Element ◽  
Crystal Formation ◽  
Male Sterile ◽  
Male Sterile Mutation

Abstract The sting mutation, caused by a P element inserted into polytene region 32D, was isolated by a screen for male sterile insertions in Drosophila melanogaster. This sterility is correlated with the presence of crystals in spermatocytes and spermatids that are structurally indistinguishable from those produced in males carrying a deficiency of the Y-linked crystal (cry) locus. In addition, their morphology is needle-like in Ste+ flies and star-shaped in Ste flies, once again as observed in cry– males. The sti mutation leads to meiotic drive of the sex chromosomes, and the strength of the phenomenon is correlated with the copy number of the repetitive Ste locus. The same correlation is also true for the penetrance of the male sterile mutation. A presumptive sti null allele results in male sterility and lethal maternal effect. The gene was cloned and shown to code for a putative protein that is 866 amino acids long. A C-terminal domain of 82 amino acids is identified that is well conserved in proteins from different organisms. The gene is expressed only in the germline of both sexes. The interaction of sting with the Ste locus can also be demonstrated at the molecular level. While an unprocessed 8-kb Ste primary transcript is expressed in wild-type males, in X/Y homozygous sti males, as in X/Y cry– males, a 0.7-kb mRNA is produced.

scholarly journals Drosophila melanogaster male germ line-specific transcripts with autosomal and Y-linked genes.

Genetics ◽  
1993 ◽  
Vol 134 (1) ◽  
pp. 293-308 ◽  
Author(s):  
S R Russell ◽  
K Kaiser
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Germ Line ◽  
Stop Codon ◽  
Chromatin Condensation ◽  
Sperm Chromatin ◽  
Autosomal Gene ◽  
Cdna Clones ◽  
Autosomal Locus ◽  
Functional Protein

Abstract We have identified of set of related transcripts expressed in the germ line of male Drosophila melanogaster. Surprisingly, while one of the corresponding genes is autosomal the remainder are located on the Y chromosome. The autosomal locus, at 77F on chromosome arm 3L, corresponds to the previously described transcription unit 18c, located in the first intron of the gene for an RI subunit of cAMP-dependent protein kinase. The Y chromosome copies have been mapped to region h18-h19 on the cytogenetic map of the Y outside of any of the regions required for male fertility. In contrast to D. melanogaster, where Y-linked copies were found in nine different wild-type strains, no Y-linked copies were found in sibling species. Several apparently Y-derived cDNA clones and one Y-linked genomic clone have been sequenced. The Y-derived genomic DNA shares the same intron/exon structure as the autosomal copy as well as related flanking sequences suggesting that it transposed to the Y from the autosomal locus. However, this particular Y-linked copy cannot encode a functional polypeptide due to a stop codon at amino acid position 72. Divergence among five different cDNA clones ranges from 1.5 to 6% and includes a large number of third position substitutions. We have not yet obtained a full-length cDNA from a Y-linked gene and therefore cannot conclude that the D. melanogaster Y chromosome contains functional protein-coding genes. The autosomal gene encodes a predicted polypeptide with 45% similarity to histones of the H5 class and more limited similarity to cysteine-rich protamines. This protein may be a distant relative of the histone H1 family perhaps involved in sperm chromatin condensation.

Major sex-determining genes and the control of sexual dimorphism in Caenorhabditis elegans

Genome ◽  
1989 ◽  
Vol 31 (2) ◽  
pp. 625-637 ◽  
Author(s):  
Jonathan Hodgkin ◽  
Andrew D. Chisholm ◽  
Michael M. Shen
Keyword(s):  
Caenorhabditis Elegans ◽  
Sex Determination ◽  
X Chromosome ◽  
Germ Line ◽  
Cell Lineage ◽  
Regulatory Genes ◽  
Nematode Caenorhabditis Elegans ◽  
X Chromosomes ◽  
The Many ◽  
Lineage Analysis

Sex determination in Caenorhabditis elegans involves a cascade of major regulatory genes connecting the primary sex determining signal, X chromosome dosage, to key switch genes, which in turn direct development along either male or female pathways. Animals with one X chromosome (XO) are male, while animals with two X chromosomes (XX) are hermaphrodite: hermaphrodite development occurs because the action of the regulatory genes is modified in the germ line so that both sperm and oocytes are made inside a completely female soma. The regulatory genes are being examined by both genetic and molecular means. We discuss how these major genes, in particular the last switch gene in the cascade, tra-1, might regulate the many different sex-specific events that occur during the development of the hermaphrodite and of the male.Key words: nematode, Caenorhabditis elegans, sex determination, sexual differentiation, cell lineage analysis.

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