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.

scholarly journals Imprinting of the Y Chromosome Influences Dosage Compensation in roX1 roX2 Drosophila melanogaster

Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 811-820 ◽  
Author(s):  
Debashish U. Menon ◽  
Victoria H. Meller
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Dosage Compensation ◽  
Sex Chromosome ◽  
Germ Line ◽  
Chromatin Modification ◽  
Regulatory System ◽  
The Body ◽  
Autosomal Gene ◽  
Y Chromosomes

Drosophila melanogaster males have a well-characterized regulatory system that increases X-linked gene expression. This essential process restores the balance between X-linked and autosomal gene products in males. A complex composed of the male-specific lethal (MSL) proteins and RNA is recruited to the body of transcribed X-linked genes where it modifies chromatin to increase expression. The RNA components of this complex, roX1 and roX2 (RNA on the X1, RNA on the X2), are functionally redundant. Males mutated for both roX genes have dramatically reduced survival. We show that reversal of sex chromosome inheritance suppresses lethality in roX1 roX2 males. Genetic tests indicate that the effect on male survival depends upon the presence and source of the Y chromosome, revealing a germ line imprint that influences dosage compensation. Conventional paternal transmission of the Y chromosome enhances roX1 roX2 lethality, while maternal transmission of the Y chromosome suppresses lethality. roX1 roX2 males with both maternal and paternal Y chromosomes have very low survival, indicating dominance of the paternal imprint. In an otherwise wild-type male, the Y chromosome does not appreciably affect dosage compensation. The influence of the Y chromosome, clearly apparent in roX1 roX2 mutants, thus requires a sensitized genetic background. We believe that the Y chromosome is likely to act through modulation of a process that is defective in roX1 roX2 mutants: X chromosome recognition or chromatin modification by the MSL complex.

scholarly journals Birth of a new gene on the Y chromosome of Drosophila melanogaster

2015 ◽  
Vol 112 (40) ◽  
pp. 12450-12455 ◽  
Author(s):  
Antonio Bernardo Carvalho ◽  
Beatriz Vicoso ◽  
Claudia A. M. Russo ◽  
Bonnielin Swenor ◽  
Andrew G. Clark
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Sequence Divergence ◽  
Autosomal Gene ◽  
Specific Expression ◽  
Linked Gene ◽  
Y Chromosomes ◽  
New Gene ◽  
Recent Duplication ◽  
Testis Specific Expression

Contrary to the pattern seen in mammalian sex chromosomes, where most Y-linked genes have X-linked homologs, the Drosophila X and Y chromosomes appear to be unrelated. Most of the Y-linked genes have autosomal paralogs, so autosome-to-Y transposition must be the main source of Drosophila Y-linked genes. Here we show how these genes were acquired. We found a previously unidentified gene (flagrante delicto Y, FDY) that originated from a recent duplication of the autosomal gene vig2 to the Y chromosome of Drosophila melanogaster. Four contiguous genes were duplicated along with vig2, but they became pseudogenes through the accumulation of deletions and transposable element insertions, whereas FDY remained functional, acquired testis-specific expression, and now accounts for ∼20% of the vig2-like mRNA in testis. FDY is absent in the closest relatives of D. melanogaster, and DNA sequence divergence indicates that the duplication to the Y chromosome occurred ∼2 million years ago. Thus, FDY provides a snapshot of the early stages of the establishment of a Y-linked gene and demonstrates how the Drosophila Y has been accumulating autosomal genes.

scholarly journals Y-Linked Male Sterile Mutations Induced by P Element in Drosophila melanogaster

Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 735-744 ◽  
Author(s):  
Ping Zhang ◽  
Rebecca L Stankiewicz
Keyword(s):  
Drosophila Melanogaster ◽  
Y Chromosome ◽  
Insertional Mutagenesis ◽  
Germ Line ◽  
Position Effect ◽  
Repetitive Sequences ◽  
P Element ◽  
Dependent Manner ◽  
Male Sterile ◽  
Structural And Functional Properties

Abstract The Y chromosome in Drosophila melanogaster is composed of highly repetitive sequences and is essential only in the male germ line. We employed P-element insertional mutagenesis to induce male sterile mutations in the Y chromosome. By using a combination of two modifiers of position effect variegation, adding an extra Y chromosome and increasing temperature, we isolated 61 P(ry+) elements in the Y chromosome. Six of these Y-linked insertions (approximately 10%) induced male sterile mutations that are mapped to two genes on the long and one on the short arms of the Y chromosome. These mutations are revertible to the wild type in a cell-autonomous and germ-line-dependent manner, consistent with previously defined Y-linked gene functions. Phenotypes associated with these P-induced mutations are similar to those resulting from deletions of the Y chromosome regions corresponding to the male fertility genes. Three alleles of the kl-3 gene on the Y long arm result in loss of the axonemal outer dynein arms in the spermatid tail, while three ks-2 alleles on the Y short arm induce defects at early postmeiotic stages. The recovery of the ms(Y) mutations induced by single P-element insertions will facilitate our effort to understand the structural and functional properties of the Y chromosome.

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 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.

Delimiting regulatory sequences of the Drosophila melanogaster Ddc gene

1986 ◽  
Vol 6 (12) ◽  
pp. 4548-4557
Author(s):  
J Hirsh ◽  
B A Morgan ◽  
S B Scholnick
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Line ◽  
Regulatory Elements ◽  
P Element ◽  
Developmental Expression ◽  
Upstream Region ◽  
Regulatory Sequences ◽  
Flanking Sequences

We delimited sequences necessary for in vivo expression of the Drosophila melanogaster dopa decarboxylase gene Ddc. The expression of in vitro-altered genes was assayed following germ line integration via P-element vectors. Sequences between -209 and -24 were necessary for normally regulated expression, although genes lacking these sequences could be expressed at 10 to 50% of wild-type levels at specific developmental times. These genes showed components of normal developmental expression, which suggests that they retain some regulatory elements. All Ddc genes lacking the normal immediate 5'-flanking sequences were grossly deficient in larval central nervous system expression. Thus, this upstream region must contain at least one element necessary for this expression. A mutated Ddc gene without a normal TATA boxlike sequence used the normal RNA start points, indicating that this sequences is not required for start point specificity.

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 The Expression Level of the 3a Movement Protein Determines Differences in Severity of Symptoms Between Two Strains of Tomato Aspermy Cucumovirus

1997 ◽  
Vol 10 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Ignacio M. Moreno ◽  
Juan José Bernal ◽  
Blanca García de Blas ◽  
Emilio Rodriguez-Cerezo ◽  
Fernando García-Arenal
Keyword(s):  
Movement Protein ◽  
Stop Codon ◽  
Site Directed Mutagenesis ◽  
In Vitro Translation ◽  
Protein Accumulation ◽  
Cdna Clones ◽  
Post Inoculation ◽  
Mild Phenotype ◽  
Systemic Leaf ◽  
Chlorotic Mottle

Two strains of tomato aspermy cucumovirus, 1-TAV and V-TAV, differ in the severity of the symptoms induced in Nicotiana tabacum: 1-TAV induces a severe chlorotic mottle that appears 5 days post inoculation (d.p.i.) in the second systemic leaf, while V-TAV-infected plants show a mild chlorotic mottle, unevenly distributed in the leaf lamina, that appears 7 d.p.i. in the third or fourth systemic leaf. The manipulation of full-length cDNA clones giving infectious transcripts of V-TAV RNAs 1, 2, and 3 and 1-TAV RNA 3 revealed that the slow, mild phenotype of V-TAV maps to the movement protein (MP) gene. By site-directed mutagenesis it was further shown that this phenotype co-segregates with a single nucleotide substitution that introduces an in-frame UAA stop codon at the fourth position of the MP open reading frame of V-TAV. The presence of this stop codon results in a diminished expression of the MP in both tobacco protoplasts and leaves. Analyses of the progress of infection and of the time course of MP and coat protein accumulation show that the low level of MP in V-TAV-infected leaves limits the rate of cell-to-cell movement and leads to the mild phenotype. Data from the infectivity of RNA 3 transcripts with or without this stop codon, plus data from in vitro translation of virion or transcript RNA 3, suggest that the small amount of MP observed in V-TAV-infected leaves is expressed from a minor RNA 3 subpopulation lacking the stop codon.

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