HYBRID DYSGENESIS IN DROSOPHILA MELANOGASTER: MORPHOLOGICAL AND CYTOLOGICAL STUDIES OF OVARIAN DYSGENESIS

Genetics ◽  
1979 ◽  
Vol 92 (4) ◽  
pp. 1141-1152 ◽  
Author(s):  
Ruth E Schaefer ◽  
Margaret G Kidwell ◽  
Anne Fausto-Sterling

ABSTRACT A type of intraspecific hybrid sterility, between two strains of Drosophila melanogaster, referred to as GD (gonadal dysgenesis) sterility, is observed when females from a type of strain called M are crossed with males from a second type called P. Absence of egg-laying is characteristic of female GD sterility and its manifestation is conditional on high developmental temperatures. Morphological and cytological studies of GD sterile females are described. These individuals were normal in body size and external appearance. No defects in sperm storage were observed. Both adult and larval ovaries were drastically reduced in size in comparison with control ovaries. This ovarian dysgenesis was sometimes unilateral, but more frequently it was bilateral, particularly in females developing at the highest test temperature. The ovarioles of dysgenic ovaries contained no vitellaria; the germaria lacked any cells resembling the cystocyte clusters of normal ovaries. I t is concluded that sterility results from an early blockage in ovarian development, rather than from atrophy of previously developed structures. Possible mechanisms for this developmental arrest are discussed.

Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 845-857 ◽  
Author(s):  
Deborah M Neubaum ◽  
Mariana F Wolfner

Abstract Mated females of many animal species store sperm. Sperm storage profoundly influences the number, timing, and paternity of the female’s progeny. To investigate mechanisms for sperm storage in Drosophila melanogaster, we generated and analyzed mutations in Acp36DE. Acp36DE is a male seminal fluid protein whose localization in mated females suggested a role in sperm storage. We report that male-derived Acp36DE is essential for efficient sperm storage by females. Acp36DE1 (null) mutant males produced and transferred normal amounts of sperm and seminal fluid proteins. However, mates of Acp36DE1 males stored only 15% as many sperm and produced 10% as many adult progeny as control-mated females. Moreover, without Acp36DE, mated females failed to maintain an elevated egg-laying rate and decreased receptivity, behaviors whose persistence (but not initiation) normally depends on the presence of stored sperm. Previous studies suggested that a barrier in the oviduct confines sperm and Acp36DE to a limited area near the storage organs. We show that Acp36DE is not required for barrier formation, but both Acp36DE and the barrier are required for maximal sperm storage. Acp36DE associates tightly with sperm. Our results indicate that Acp36DE is essential for the initial storage of sperm, and that it may also influence the arrangement and retention of stored sperm.


Genetics ◽  
2002 ◽  
Vol 160 (1) ◽  
pp. 211-224
Author(s):  
Oliver Lung ◽  
Uyen Tram ◽  
Casey M Finnerty ◽  
Marcie A Eipper-Mains ◽  
John M Kalb ◽  
...  

Abstract Drosophila melanogaster seminal fluid proteins stimulate sperm storage and egg laying in the mated female but also cause a reduction in her life span. We report here that of eight Drosophila seminal fluid proteins (Acps) and one non-Acp tested, only Acp62F is toxic when ectopically expressed. Toxicity to preadult male or female Drosophila occurs upon one exposure, whereas multiple exposures are needed for toxicity to adult female flies. Of the Acp62F received by females during mating, ~10% enters the circulatory system while ~90% remains in the reproductive tract. We show that in the reproductive tract, Acp62F localizes to the lumen of the uterus and the female's sperm storage organs. Analysis of Acp62F's sequence, and biochemical assays, reveals that it encodes a trypsin inhibitor with sequence and structural similarities to extracellular serine protease inhibitors from the nematode Ascaris. In light of previous results demonstrating entry of Acp62F into the mated female's hemolymph, we propose that Acp62F is a candidate for a molecule to contribute to the Acp-dependent decrease in female life span. We propose that Acp62F's protease inhibitor activity exerts positive protective functions in the mated female's reproductive tract but that entry of a small amount of this protein into the female's hemolymph could contribute to the cost of mating.


Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 195-204 ◽  
Author(s):  
Michael J Simmons ◽  
Kevin J Haley ◽  
Craig D Grimes ◽  
John D Raymond ◽  
Jarad B Niemi

Abstract Drosophila were genetically transformed with a hobo transgene that contains a terminally truncated but otherwise complete P element fused to the promoter from the Drosophila hsp70 gene. Insertions of this H(hsp/CP) transgene on either of the major autosomes produced the P transposase in both the male and female germlines, but not in the soma. Heat-shock treatments significantly increased transposase activity in the female germline; in the male germline, these treatments had little effect. The transposase activity of two insertions of the H(hsp/CP) transgene was not significantly greater than their separate activities, and one insertion of this transgene reduced the transposase activity of P(ry+, Δ2-3)99B, a stable P transgene, in the germline as well as in the soma. These observations suggest that, through alternate splicing, the H(hsp/CP) transgene produces a repressor that feeds back negatively to regulate transposase expression or function in both the somatic and germline tissues. The H(hsp/CP) transgenes are able to induce gonadal dysgenesis when the transposase they encode has P-element targets to attack. However, this ability and the ability to induce P-element excisions are repressed by the P cytotype, a chromosomal/cytoplasmic state that regulates P elements in the germline.


1998 ◽  
Vol 71 (1) ◽  
pp. 21-30 ◽  
Author(s):  
RICHARD M. BADGE ◽  
JOHN F. Y. BROOKFIELD

We have discovered, in an inbred line (Loua) of Drosophila melanogaster from Zaïre, a third chromosome showing unusual P element repression. Repression of P element transposition by this chromosome, named Loua3, is dominant zygotic and has three unusual properties. Firstly, its repression of the gonadal dysgenesis caused by a strong P haplotype is strongly temperature-dependent, being most evident at higher rearing temperatures. Secondly, subdivision of Loua3 by recombination abolishes repression: the effect is apparently a function of the intact chromosome. Finally, Loua3 also diminishes somatic lethality when chromosomes carrying many ‘ammunition’ elements (Birmingham2) are exposed to the constitutive transposase source Δ2-3(99B). The chromosome has 17 P elements, none full-length, located in at least 12 dispersed positions.


Genetics ◽  
1995 ◽  
Vol 140 (1) ◽  
pp. 219-229 ◽  
Author(s):  
G K Yasuda ◽  
G Schubiger ◽  
B T Wakimoto

Abstract The vast majority of known male sterile mutants of Drosophila melanogaster fail to produce mature sperm or mate properly. The ms(3) K81(1) mutation is one of a rare class of male sterile mutations in which sterility is caused by developmental arrest after sperm entry into the egg. Previous studies showed that males homozygous for the K81(1) mutation produce progeny that arrest at either of two developmental stages. Most embryos arrest during early nuclear cycles, whereas the remainder are haploid embryos that arrest at a later stage. This description of the mutant phenotype was based on the analysis of a single allele isolated from a natural population. It was therefore unclear whether this unique paternal effect phenotype reflected the normal function of the gene. The genetic analysis and initial molecular characterization of five new K81 mutations are described here. Hemizygous conditions and heteroallelic combinations of the alleles were associated with male sterility caused by defects in embryogenesis. No other mutant phenotypes were observed. Thus, the K81 gene acted as a strict paternal effect gene. Moreover, the biphasic pattern of developmental arrest was common to all the alleles. These findings strongly suggested that the unusual embryonic phenotype caused by all five new alleles was due to loss of function of the K81+ gene. The K81 gene is therefore the first clear example of a strict paternal effect gene in Drosophila. Based on the embryonic lethal phenotypes, we suggest that the K81+ gene encodes a sperm-specific product that is essential for the male pronucleus to participate in the first few embryonic nuclear divisions.


1989 ◽  
Vol 78 (2) ◽  
pp. 243-248 ◽  
Author(s):  
E. Santiago ◽  
A. Dom�nguez ◽  
J. Albornoz ◽  
R. Pi�eiro ◽  
J. I. Izquierdo

2021 ◽  
Author(s):  
Bailly Tiphaine ◽  
Philip Kohlmeier ◽  
Rampal Etienne ◽  
Bregje Wertheim ◽  
Jean-Christophe Billeter

Being part of a group facilitates cooperation between group members, but also creates competition for limited resources. This conundrum is problematic for gravid females who benefit from being in a group, but whose future offspring may struggle for access to nutrition in larger groups. Females should thus modulate their reproductive output depending on their social context. Although social-context dependent modulation of reproduction is documented in a broad range of species, its underlying mechanisms and functions are poorly understood. In the fruit fly Drosophila melanogaster, females actively attract conspecifics to lay eggs on the same resources, generating groups in which individuals may cooperate or compete. The tractability of the genetics of this species allows dissecting the mechanisms underlying physiological adaptation to their social context. Here, we show that females produce eggs increasingly faster as group size increases. By laying eggs faster in group than alone, females appear to reduce competition between offspring and increase their likelihood of survival. In addition, females in a group lay their eggs during the light phase of the day, while isolated females lay them during the night. We show that responses to the presence of others are determined by vision through the motion detection pathway and that flies from any sex, mating status or species can trigger these responses. The mechanisms of this modulation of egg-laying by group is connected to a lifting of the inhibition of light on oogenesis and egg-laying by stimulating hormonal pathways involving juvenile hormone. Because modulation of reproduction by social context is a hallmark of animals with higher levels of sociality, our findings represent a protosocial mechanism in a species considered solitary that may have been the target of selection for the evolution of more complex social systems.


2020 ◽  
Author(s):  
Yongzhuo Chen ◽  
Min Zhang ◽  
Wei Hu ◽  
Jing Li ◽  
Pengcheng Liu ◽  
...  

Abstract Background Drosophila suzukii is widely distributed. Research has revealed that the presence of Drosophila melanogaster can reduce the emergence and egg laying of D. suzukii. However, the reasons for these phenomena have not yet been reported. To investigate this issue, we sought to answer three questions: Can the presence of D. melanogaster reduce the longevity of D. suzukii? Does D. melanogaster dominate in larval interspecific competition with D. suzukii? Does reproductive interference occur between these species; i.e., do individuals of one species (e.g., D. suzukii) engage in reproductive activities with individuals of the other (e.g., D. melanogaster) such that the fitness of one or both species is reduced? Results The results showed that the adult offspring number of Drosophila suzukii was significantly reduced when this species was reared with Drosophila melanogaster. The larval interspecific competition had no significant effects on Drosophila suzukii longevity or population size. Surprisingly, Drosophila melanogaster imposed reproductive interference on males of Drosophila suzukii, which led to a significant decline in the rate of successful mating of the latter species. Conclusions The presence of Drosophila melanogaster causes the population size of Drosophila suzukii to decrease through reproductive interference, and the rate of successful mating in Drosophila suzukii is significantly reduced in the presence of Drosophila melanogaster.


Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 45-57
Author(s):  
F. Giorgi ◽  
J. Jacob

The role played by the vitellogenic oocytes of Drosophila melanogaster in relation to the elaboration of material taken from the haemolymph is examined by ultrastructural cytochemistry. As revealed by the Gomori procedure, acid phosphatase occurs widely over the forming yolk platelets of the cortical and central ooplasm. A number of Golgi apparatuses in thecortical ooplasm are also positively stained with lead precipitates. With the proceeding of the ovarian development it becomes progressively more difficult to demonstrate cytochemically the enzyme over the yolk platelets. In stage 9–10 chambers the acid phosphatase is restricted to the so-called associated body, while the rest of the yolk platelet appears devoid of lead deposits. By using a osmium zinc iodide (OZ1) complex as a preferential staining method for the Golgi apparatus, it has been shown that, apart from the apparatus itself, a number of OZI deposits occur over the superficial layer of the forming yolk platelets. When mature yolk platelets are formed at later stages, the OZI deposits in the yolk platelets come to be restricted to the cap-like region of the superficial layer which contains the associated body. In vitellogenic oocytes, both the internal lining of the limiting membrane of the forming yolk platelets and the associated body of the mature yolk platelets react positively, to cytochemical methods to demonstrate carbohydrates. The present findings are interpreted as indicating the involvement of lysosomal enzymes in the process of maturation of the yolk material. The suggestion is also made that such an involvement is required to accomplish a selective hydrolysis of those blood proteins which have been taken in by vitellogenic oocytes along with yolk precursors.


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