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M F Wolfner

Publications and source records attributed to M F Wolfner.

At least 37 records · Page 2Linked to original sources
PubMed1998

Seminal fluid regulation of female sexual attractiveness in Drosophila melanogaster.

Finding a willing and suitable mate is critical for sexual reproduction. Visual, auditory, and chemical cues aid in locating and/or attracting partners. After mating, females from many insect species become less attractive. This is caused by changes in the quantity and/or quality of pheromones synthesized by the female and to changes in the female's behavior. For example, female insects may stop releasing pheromones, assume a mate refusal posture, or move less in response to males. Many postmating changes in female insects are triggered by seminal fluid proteins from the male's accessory gland proteins (Acps) and by sperm. To determine the role of seminal fluid components in mediating changes in attractiveness, we measured the attractiveness of Drosophila melanogaster females that had been mated to genetically altered males that lack sperm and/or Acps. We found that the drop in female attractiveness occurs in two phases. A short-term drop in attractiveness is triggered independent of the receipt of sperm and Acps. Maintenance of lowered attractiveness is dependent upon sperm.

Animals↗
PubMed1998

Functional dissection of YA, an essential, developmentally regulated nuclear lamina protein in Drosophila melanogaster.

The Drosophila YA protein is a nuclear lamina component whose function is essential to initiate embryonic development. To identify regions of YA required for its action in its normal cellular context, we made targeted mutations in the YA protein and tested their consequences in flies and embryos in vivo. We found that critical amino acids are distributed along the length of the YA molecule, with functionally important regions including the N- and the C-terminal ends, the cysteine residues in YA's two potential zinc fingers, a serine/threonine-rich region, and a potential maturation-promoting factor or mitogen-activated protein kinase phosphorylation target site, ITPIR. In addition, several Ya mutations showed intragenic complementation, with N-terminal mutations complementing C-terminal mutations, suggesting that YA proteins interact with one another. In support of this interaction, we demonstrated by immunoprecipitation that YA molecules are present in complexes with each other. Finally, we showed that the C-terminal 179 amino acids of YA are necessary to target, or retain, YA in the nuclear envelope.

Animals↗
PubMed1998

Interactions among Drosophila nuclear envelope proteins lamin, otefin, and YA.

The nuclear envelope plays many roles, including organizing nuclear structure and regulating nuclear events. Molecular associations of nuclear envelope proteins may contribute to the implementation of these functions. Lamin, otefin, and YA are the three Drosophila nuclear envelope proteins known in early embryos. We used the yeast two-hybrid system to explore the interactions between pairs of these proteins. The ubiquitous major lamina protein, lamin Dm, interacts with both otefin, a peripheral protein of the inner nuclear membrane, and YA, an essential, developmentally regulated protein of the nuclear lamina. In agreement with this interaction, lamin and otefin can be coimmunoprecipitated from the vesicle fraction of Drosophila embryos and colocalize in nuclear envelopes of Drosophila larval salivary gland nuclei. The two-hybrid system was further used to map the domains of interaction among lamin, otefin, and YA. Lamin's rod domain interacts with the complete otefin protein, with otefin's hydrophilic NH2-terminal domain, and with two different fragments derived from this domain. Analogous probing of the interaction between lamin and YA showed that the lamin rod and tail plus part of its head domain are needed for interaction with full-length YA in the two-hybrid system. YA's COOH-terminal region is necessary and sufficient for interaction with lamin. Our results suggest that interactions with lamin might mediate or stabilize the localization of otefin and YA in the nuclear lamina. They also suggest that the need for both otefin and lamin in mediating association of vesicles with chromatin might reflect the function of a protein complex that includes these two proteins.

Animals↗
PubMed1997

Formation of the male pronuclear lamina in Drosophila melanogaster.

Upon fertilization, a sperm nucleus reorganizes to become a male pronucleus. This reorganization includes breakdown and reformation of the nuclear envelope of the male pronucleus. In this study, we used a maternally encoded nuclear lamina protein, YA, in parallel with another lamina protein, lamin Dm, as probes to study the formation of the male pronuclear lamina in Drosophila melanogaster. Ectopically expressed YA is present in the nuclear envelopes of spermatocytes, but not in mature sperm, similar to endogenous lamin Dm. This suggests that the nuclear envelope of Drosophila sperm differs from that of somatic cells. Upon fertilization, YA and lamin Dm are recruited to the periphery of the male-derived nucleus before or during the early stages of migration by the male pronucleus. Using a paternal effect mutation, snky, we found that recruitment of lamina proteins to the male pronucleus requires, and probably accompanies, reorganization of the sperm nucleus. In order to identify factors that affect the recruitment of nuclear lamina proteins to the male pronucleus, we examined the subcellular localization of YA and lamin Dm in mutant embryos defective for the function of either the male pronucleus (mh, K81, and pal or both pronuclei (gnu, png, and plu). None of these mutations affect the recruitment of YA or lamin Dm to the male pronuclear envelope, suggesting that the mutations affect processes independent of, or after, reorganization of the nuclear envelope. Double mutant analyses between Ya and gnu suggest that YA plays a role in the nuclear envelope permissive for rounds of DNA replication.

Animals↗
PubMed1997

Tokens of love: functions and regulation of Drosophila male accessory gland products.

A male fruit fly influences the behavior and physiology of his mate via molecules that he transmits to her in his semen. The mated female fly has an elevated rate of egg laying, a decreased receptivity to mating and a shorter life span; she also stores sperm from the mating. Molecular genetic analyses possible in this insect model system permit the dissection of seminal fluid components that cause these mating responses in the female. Studies with transgenic and mutant flies have shown that products of the male's accessory gland cause short-term changes in the female's behavior and physiology; persistence of these changes requires the storage of sperm. Further dissection of accessory gland function has defined several molecules that cause these effects. A "sex peptide" and a prohormone-like molecule (Accessory gland protein 26Aa) stimulate the female's egg-laying rate; the sex peptide also depresses her receptivity to mating. A large glycoprotein (Acp36DE) appears to function in "corralling" sperm for storage. Studies of accessory gland products and the regulation of the genes that encode them will be important in understanding insect reproduction, behavior, and speciation and ultimately in designing ways to control the impressive fertility of unwanted insects. These studies also provide excellent models to address basic questions in cell biology such as the control of genes in response to sex-specific, mating-regulated and cell type-specific cues and the function and targeting of peptide hormones.

Animals↗
PubMed1997

New genes for male accessory gland proteins in Drosophila melanogaster.

The accessory gland of male insects produces components of the seminal fluid that alter the behavior, physiology and life span of the mated female, and contribute to her efficient storage and utilization of sperm. As a step towards understanding how this occurs, we have isolated genes encoding 12 previously unreported accessory gland-specific mRNAs from the fruit fly Drosophila melanogaster. We report here the restriction maps of the new genes, the chromosome positions--which are all autosomal--of the 11 non-repetitive genes, their expression patterns, and the sequences of the accessory gland proteins (Acps) encoded by nine of the genes. Eight of the proteins predicted from these sequences begin with putative secretion signals. Following their signal sequences, three of the predicted molecules are peptides and the other five are larger polypeptides with characteristics of cleavable prohormones. The ninth molecule, which has an N-terminal hydrophobic region but no consensus signal peptide cleavage site, is predicted to be a 716 amino acid glycoprotein. Of the nine proteins, two have intriguing similarities to sequences in protein databases. Acp76A is a 388 amino acid pro-protein which contains a signature sequence for the serpin class of protease inhibitors. The 115 amino acid Acp62F has a 28 amino acid region of high sequence similarity to a neurotoxin of the Brazilian armed spider Phoneutria nigriventer. Models are discussed in which Acp76A plays a role in the observed regulation of Acp proteolysis and/or in the coagulation of seminal fluid to form a mating plug, and in which Acp62F contributes to the reported toxicity of Drosophila seminal fluid.

Animals↗
PubMed1997

The developmentally regulated Drosophila embryonic nuclear lamina protein 'Young Arrest' (fs(1)Ya) is capable of associating with chromatin.

The Drosophila fs(1)Ya protein (YA) is an essential component of the early embryonic nuclear lamina. Mutant zygotes lacking functional YA arrest in the first division cycles following fertilization, hence having a 'Young Arrest' of their development. The nuclear lamina is thought to act as the structural backbone for the nucleus and to provide anchoring sites for interphase chromosomes. Here, we demonstrate in vitro that YA is not required for the de novo formation of nuclear structures. Since YA's sequence predicts potential DNA binding motifs, this protein may instead function to connect the lamina and chromosomes, and thus aid in organizing the nucleus. We ectopically expressed YA in polytene cells and demonstrated its association with polytene chromosomes, preferentially at interbands. Furthermore, our in vitro studies indicate that embryonic YA protein is capable of associating with decondensed chromatin. These observations suggest that YA may be required for the interaction between chromatin and the nuclear envelope during early embryogenesis.

Animals↗
PubMed1995

A Drosophila seminal fluid protein, Acp26Aa, stimulates egg laying in females for 1 day after mating.

Mating triggers behavioral and physiological changes in the Drosophila melanogaster female, including an elevation of egg laying. Seminal fluid molecules from the male accessory gland are responsible for initial behavioral changes, but persistence of these changes requires stored sperm. Using genetic analysis, we have identified a seminal fluid protein that is responsible for an initial elevation of egg laying. This molecule, Acp26Aa, has structural features of a prohormone and contains a region with amino acid similarity to the egg-laying hormone of Aplysia. Acp26Aa is transferred to the female during mating, where it undergoes processing. Here we report the generation and analysis of mutants, including a null, in Acp26Aa. Females mated to male flies that lack Acp26Aa lay fewer eggs than do mates of normal males. This effect is apparent only on the first day after mating. The null mutation has no other detectable physiological or behavioral effects on the male or the mated female.

Amino Acid Sequence↗
PubMed1995

Cost of mating in Drosophila melanogaster females is mediated by male accessory gland products.

Female Drosophila melanogaster with environmentally or genetically elevated rates of mating die younger than controls. This cost of mating is not attributable to receipt of sperm. We demonstrate here that seminal fluid products from the main cells of the male accessory gland are responsible for the cost of mating in females, and that increasing exposure to these products increases female death rate. Main-cell products are also involved in elevating the rate of female egg-laying, in reducing female receptivity to further matings and in removing or destroying sperm of previous mates. The cost of mating to females may therefore represent a side-effect of evolutionary conflict between males.

Animals↗
PubMed1995

Male and female cooperate in the prohormone-like processing of a Drosophila melanogaster seminal fluid protein.

Acp26Aa is a Drosophila seminal fluid protein that plays a role in the elevation of egg-laying by the mated female and has structural features of a prohormone. The protein, which has a region of sequence similarity to the egg-laying hormone of Aplysia, is transferred to the Drosophila female during mating. Acp26Aa is processed in the mated female's genital tract. We show here that the processing involves sequential proteolytic cleavages, and we map the position of these cleavages. Although Acp26Aa is not cleaved in the male, its processing in the mated female requires activities donated by the male. Acp26Aa ectopically expressed in unmated females is not processed. Processing of Acp26Aa in wild-type females mated to males with altered seminal fluid is dependent on the presence and amount of male accessory gland secretions. The need for molecular cooperation between the sexes for processing of Acp26Aa could restrict its activity to the mated female.

Amino Acid Sequence↗
PubMed1995

Mutational analyses of fs(1)Ya, an essential, developmentally regulated, nuclear envelope protein in Drosophila.

The fs(1)Ya protein (YA) is an essential, maternally encoded, nuclear lamina protein that is under both developmental and cell cycle control. A strong Ya mutation results in early arrest of embryos. To define the function of YA in the nuclear envelope during early embryonic development, we characterized the phenotypes of four Ya mutants alleles and determined their molecular lesions. Ya mutant embryos arrest with abnormal nuclear envelopes prior to the first mitotic division; a proportion of embryos from two leaky Ya mutants proceed beyond this but arrest after several abnormal divisions. Ya unfertilized eggs contain nuclei of different sizes and condensation states, apparently due to abnormal fusion of the meiotic products immediately after meiosis. Lamin is localized at the periphery of the uncondensed nuclei in these eggs. These results suggest that YA function is required during and after egg maturation to facilitate proper chromatin condensation, rather than to allow a lamin-containing nuclear envelope to form. Two leaky Ya alleles that partially complement have lesions at opposite ends of the YA protein, suggesting that the N- and C-termini are important for YA function and that YA might interact with itself either directly or indirectly.

Alleles↗
PubMed1994

The Drosophila fs(1)Ya protein, which is needed for the first mitotic division, is in the nuclear lamina and in the envelopes of cleavage nuclei, pronuclei, and nonmitotic nuclei.

The Drosophila melanogaster fs (1) Ya gene encodes a nuclear envelope protein needed to initiate embryonic cleavage divisions. In cleavage stage embryos the fs (1) Ya gene product is localized to the nuclear envelope in a cell cycle dependent manner. We show here that fs(1)Ya protein is also present in polar bodies of early cleavage stage embryos as well as in endoreplicating yolk nuclei. This observation suggests that the fs(1)Ya protein is necessary but not solely responsible for embryonic mitosis. Furthermore, cell cycle stage dependent nuclear localization is also seen for ectopically produced fs(1)Ya protein in tissue culture cells, neuroblasts, and male accessory glands, which are free of maternal products. We therefore conclude that cell cycle dependent nuclear localization does not require any exclusively maternal products. Finally, our immunoelectron microscopy shows that the fs(1)Ya protein distribution parallels that of lamin, indicating that it is a nuclear lamina protein.

Animals↗
PubMed1994

Two tightly-linked Drosophila male accessory gland transcripts with the same developmental expression derive from independent transcription units.

Acp26Aa and Acp26Ab are Drosophila male accessory gland transcripts that are tightly linked and transcribed from the same DNA strand. Despite their being separated by 20 base pairs, the transcripts show identical responses to several developmental signals. These observations make it important to determine whether the 26A region contains two separable genes with the same developmental expression or a single developmentally regulated transcription unit whose product is processed to yield Acp26Aa and Acp26Ab. We show that Acp26Aa and Acp26Ab are separate mRNAs using a reverse transcription-polymerase chain reaction assay and reporter gene fusions. We also show that the regulatory elements for Acp26Ab lie within a fragment containing the intergenic region and transcribed sequences of Acp26Aa and Acp26Ab.

Animals↗
PubMed1993

Probing the function of Drosophila melanogaster accessory glands by directed cell ablation.

The female Drosophila melanogaster fly undergoes behavioral changes after mating, including an increase in egg laying and an avoidance of remating. Accessory-gland products elicit these changes transiently when introduced into unmated female flies. We report here the generation and phenotype of flies that lack functional accessory-gland main cells as a consequence of genetically directed delivery of diphtheria toxin subunit A to those cells. Only main-cell secretions are essential for the short-term inhibition to remating; no other products of the genital tract can replace their function. Long-term inhibition to remating depends only on the storage of sperm in the female. Both sperm and main-cell secretions have roles in the increase of egg laying by the mated female. In addition to full-strength diphtheria toxin, we used low-activity toxins to kill only those cells that express toxin at high levels. These transgenic strains that express diphtheria toxins of different strengths in accessory-gland main cells will be useful in further defining the role of these cells.

Animals↗
PubMed1993

Structure, expression, and hormonal control of genes from the mosquito, Aedes aegypti, which encode proteins similar to the vitelline membrane proteins of Drosophila melanogaster.

Genomic and cDNA clones of a gene expressed after a blood meal in the mosquito, Aedes aegypti, were identified as having significant similarity to the vitelline membrane protein genes of Drosophila melanogaster. The predicted protein had unusually high contents of alanine, histidine, and proline and contained a region of hydrophobic amino acids that was highly conserved in the predicted protein of the D. melanogaster vitelline membrane protein genes. The 15a gene was expressed from 5 to 40 hr after a blood meal. It was expressed only in the follicle cells of the ovary, particularly in the cells surrounding the oocyte. The 15a gene was expressed in ovaries of the blood-fed, decapitated female in response to an injection of 20-hydroxyecdysone, and in ovaries from non-blood-fed females incubated with the hormone, even in the presence of cycloheximide. A second gene, with weaker homology to 15a, is presumably another member of a family of related genes, as is the case with D. melanogaster vitelline membrane protein genes. This second gene contained a coding sequence similar to a decapeptide recently isolated from mosquito ovaries as an "oostatic factor" (Borovsky et al., FASEB J. 4, 3015-3020, 1990).

Aedes↗
PubMed1992

Cell type-specific gene expression in the Drosophila melanogaster male accessory gland.

The accessory gland of the male Drosophila melanogaster plays a vital role in reproduction. This secretory organ synthesizes products that are transferred to the female and are necessary to elicit the proper physiological and behavioral responses in the female. The accessory gland is composed of two morphologically distinct secretory cell types, the main cells and the secondary cells. Previous studies identified some genes expressed in main cells or in all accessory gland cells. In this paper we use P-element mediated enhancer traps to examine gene expression in the accessory gland. We show that, in addition to genes expressed in main cells only or in all accessory gland secretory cells, there are genes expressed specifically in secondary cells. Each cell type is uniform in the expression of its genes. Our results demonstrate that the two cell types are not only morphologically distinct but also biochemically distinct. We also show that the two cell types differ in their regulation of gene expression in response to mating activity.

Aging↗