logjam Encodes a Predicted EMP24/GP25 Protein That Is Required for Drosophila Oviposition Behavior

Genetics ◽  
2003 ◽  
Vol 164 (1) ◽  
pp. 173-186
Author(s):  
Ginger E Carney ◽  
Barbara J Taylor
Keyword(s):  
Intracellular Trafficking ◽  
Oviposition Behavior ◽  
Egg Laying ◽  
P Element ◽  
Female Reproduction ◽  
Multiple Functions ◽  
Cytoplasmic Vesicles ◽  
Egg Chambers ◽  
Low Levels ◽  
Overlapping Transcripts

Abstract A newly characterized Drosophila melanogaster gene, logjam (loj), functions in female reproduction by modulating oviposition behavior. The locus encodes at least six overlapping transcripts with unique 5′ ends. P-element mutants that express very low levels of loj transcripts are unable to oviposit mature eggs. This phenotype can be rescued by the introduction of a transgene expressing the most abundant loj transcript. As for many genes that specify behavioral outputs, loj is present in the adult central nervous system (CNS). Interestingly, it is also observed in vitellogenic egg chambers, suggesting that there may be multiple functions for this gene in egg-laying behavior. loj encodes a predicted protein with homology to the EMP24/GP25 transmembrane components of cytoplasmic vesicles and likely functions in intracellular trafficking.

scholarly journals Germline Cell Death Is Inhibited byP-Element Insertions Disrupting thedcp-1/pitaNested Gene Pair in Drosophila

Genetics ◽  
2003 ◽  
Vol 165 (4) ◽  
pp. 1881-1888 ◽  
Author(s):  
Bonni Laundrie ◽  
Jeanne S Peterson ◽  
Jason S Baum ◽  
Jeffrey C Chang ◽  
Dana Fileppo ◽  
...  
Keyword(s):  
Cell Death ◽  
Nurse Cell ◽  
Zinc Finger Protein ◽  
P Element ◽  
Germline Cell ◽  
Developmentally Regulated ◽  
Developmental Abnormalities ◽  
Egg Chambers ◽  
Caspase Gene ◽  
Active Caspase

AbstractGermline cell death in Drosophila oogenesis is controlled by distinct signals. The death of nurse cells in late oogenesis is developmentally regulated, whereas the death of egg chambers during mid-oogenesis is induced by environmental stress or developmental abnormalities. P-element insertions in the caspase gene dcp-1 disrupt both dcp-1 and the outlying gene, pita, leading to lethality and defective nurse cell death in late oogenesis. By isolating single mutations in the two genes, we have found that the loss of both genes contributes to this ovary phenotype. Mutants of pita, which encodes a C2H2 zinc-finger protein, are homozygous lethal and show dumpless egg chambers and premature nurse cell death in germline clones. Early nurse cell death is not observed in the dcp-1/pita double mutants, suggesting that dcp-1+ activity is required for the mid-oogenesis cell death seen in pita mutants. dcp-1 mutants are viable and nurse cell death in late oogenesis occurs normally. However, starvation-induced germline cell death during mid-oogenesis is blocked, leading to a reduction and inappropriate nuclear localization of the active caspase Drice. These findings suggest that the combinatorial loss of pita and dcp-1 leads to the increased survival of abnormal egg chambers in mutants bearing the P-element alleles and that dcp-1 is essential for cell death during mid-oogenesis.

scholarly journals Identifying the Biological Characteristics Associated with Oviposition Behavior of Tea Leafhopper Empoasca onukii Matsuda Using the Blue Light Detection Method

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 707
Author(s):  
Qi Yao ◽  
Huining Zhang ◽  
Long Jiao ◽  
Xiaoming Cai ◽  
Manqun Wang ◽  
...  
Keyword(s):  
Blue Light ◽  
Detection Method ◽  
Oviposition Behavior ◽  
Egg Laying ◽  
Biological Characteristics ◽  
Light Detection ◽  
Tea Plantations ◽  
Egg Density ◽  
Theoretical Evidence ◽  
Proven Method

Tea leafhopper (Empoasca onukii Matsuda) is amongst the key pests in tea plantations around the East Asian region. Stereomicroscopy is a conventional method used for detecting tea leafhopper eggs by dissecting the tender tissues. However, there is a need for a faster and more efficient method to directly observe and investigate intact eggs within tea shoots. The absence of a proven method limits research efforts for determining the oviposition behavior of E. onukii. Herein, we applied the blue light detection method (BLDM), a technique recently developed for other species, in order to detect E. onukii eggs directly and non-destructively within the tender shoot. In addition, we compared BLDM against the traditional stereomicroscope detection method (SMDM) for four tea cultivars. Notably, our results revealed that BLDM was precise and effective in measuring the egg laying quantity of E. onukii on intact tea shoots. Neither tea cultivars nor egg density in the tender shoot significantly affected the accuracy of BLDM. Furthermore, biological characteristics that have rarely been reported previously for E. onukii were investigated using the BLDM, including zygote duration, ovipositional rhythm, egg distribution within the tender shoot, and in different leaf positions, numbers of eggs laid by a single female daily, and laid by the entire generation. Therefore, these findings provide insights into the basic and theoretical evidence for the strategy and mechanism associated with the oviposition behavior of E. onukii.

Autosomal P[ovoD1] dominant female-sterile insertions in Drosophila and their use in generating germ-line chimeras

Development ◽  
1993 ◽  
Vol 119 (4) ◽  
pp. 1359-1369 ◽  
Author(s):  
T.B. Chou ◽  
E. Noll ◽  
N. Perrimon
Keyword(s):  
Tissue Specificity ◽  
Germ Line ◽  
Egg Laying ◽  
P Element ◽  
Follicle Cells ◽  
Gtpase Activating Protein ◽  
Lethal Mutations ◽  
Sterile Technique ◽  
Dominant Female ◽  
Polarity Determination

The ‘dominant female-sterile’ technique used to generate germ-line mosaics in Drosophila is a powerful tool to determine the tissue specificity (germ line versus somatic) of recessive female-sterile mutations as well as to analyze the maternal effect of recessive zygotic lethal mutations. This technique requires the availability of germ-line-dependent, dominant female-sterile (DFS) mutations that block egg laying but do not affect viability. To date only one X-linked mutation, ovoD1 has been isolated that completely fulfills these criteria. Thus the ‘DFS technique’ has been largely limited to the X-chromosome. To extend this technique to the autosomes, we have cloned the ovoD1 mutation into a P-element vector and recovered fully expressed P[ovoD1] insertions on each autosomal arm. We describe the generation of these P[ovoD1] strains as well as demonstrate their use in generating germ-line chimeras. Specifically, we show that the Gap1 gene, which encodes a Drosophila homologue of mammalian GTPase-activating protein, is required in somatic follicle cells for embryonic dorsoventral polarity determination.

scholarly journals The Drosophila tctex-1 Light Chain Is Dispensable for Essential Cytoplasmic Dynein Functions but Is Required during Spermatid Differentiation

2004 ◽  
Vol 15 (7) ◽  
pp. 3005-3014 ◽  
Author(s):  
Min-gang Li ◽  
Madeline Serr ◽  
Eric A. Newman ◽  
Thomas S. Hays
Keyword(s):  
Light Chain ◽  
Cytoplasmic Dynein ◽  
Sperm Nucleus ◽  
P Element ◽  
Dynein Light Chain ◽  
Null Mutant ◽  
Multiple Functions ◽  
Bona Fide ◽  
Adult Organism

Variations in subunit composition and modification have been proposed to regulate the multiple functions of cytoplasmic dynein. Here, we examine the role of the Drosophila ortholog of tctex-1, the 14-kDa dynein light chain. We show that the 14-kDa light chain is a bona fide component of Drosophila cytoplasmic dynein and use P element excision to generate flies that completely lack this dynein subunit. Remarkably, the null mutant is viable and the only observed defect is complete male sterility. During spermatid differentiation, the 14-kDa light chain is required for the localization of a nuclear “cap” of cytoplasmic dynein and for proper attachment between the sperm nucleus and flagellar basal body. Our results provide evidence that the function of the 14-kDa light chain in Drosophila is distinct from other dynein subunits and is not required for any essential functions in early development or in the adult organism.

Singly laid mole salamander (Ambystoma talpoideum) eggs resist mortality from water mold infection

Behaviour ◽  
2014 ◽  
Vol 151 (1) ◽  
pp. 125-136
Author(s):  
Dean A. Croshaw
Keyword(s):  
Population Biology ◽  
Oviposition Behavior ◽  
Positive Association ◽  
Egg Laying ◽  
Physical Contact ◽  
Embryo Viability ◽  
Egg Survival ◽  
Significant Positive Association ◽  
Water Mold ◽  
Mole Salamander

Parasites and pathogens are noteworthy forces in evolutionary and population biology. Water molds are known to infect and kill amphibian eggs, and masses placed in clusters sometimes suffer greater losses. Thus, selection may favor single oviposition behavior in which females scatter individual eggs to avoid contact with dead eggs, thereby lowering the chances of hyphal spread. I tested the hypothesis that eggs in physical contact with dead eggs are more susceptible to death via pathogen infection using a singly laying urodele, the mole salamander, whose congeners mostly lay eggs in masses. Focal eggs were placed in replicated containers with variable egg contact (physically touching or separated) by treatment eggs that varied in status (dead or alive). The effect of egg arrangement was significant, with focal eggs surviving better to hatching when not contacting treatment eggs. Although treatment egg status (dead vs. alive) was not influential on its own, the interaction between egg contact and status was an important determinant of focal egg survival. Only when eggs were physically touching was it important whether they were dead or alive. Moreover, when eggs were touching there was a significant positive association between focal egg survival and the number of surviving treatment eggs. Water mold infected most dead eggs in all treatment groups. This study shows that mole salamander eggs are more likely to die when touching other eggs that have perished, most likely because of a greater chance of water mold infection. Such mortality may have contributed to diversification of egg-laying behavior in amphibians and shows a potentially compounding fitness cost of diminished fertilization success and embryo viability.

Reproduction in the curly-tailed lizard Leiocephalus psammodromus from the Caicos Islands

1993 ◽  
Vol 71 (11) ◽  
pp. 2147-2151 ◽  
Author(s):  
Geoffrey R. Smith ◽  
John B. Iverson
Keyword(s):  
West Indies ◽  
Fat Body ◽  
Size Structure ◽  
Egg Laying ◽  
Egg Mass ◽  
British West Indies ◽  
Female Reproduction ◽  
Wet Season ◽  
Males And Females ◽  
Fat Body Mass

Reproduction and population structure were examined for the curly-tailed lizard Leiocephalus psammodromus from the Caicos Islands, British West Indies, from 1973 to 1978. Females and males mature at about 65–70 and 75–80 mm snout–vent length, respectively, and at about 1.5–2 years of age. Both male and female reproduction were seasonal, with egg-laying beginning late in the dry season (late April) and ending well into the wet season (September), with hatching during the wet season (late June to December). Multiple annual clutches are probably produced. Clutch size was typically two eggs (mean = 1.72 for 42 clutches). Eggs (preserved) averaged 19.9 × 9.2 mm, and mean preserved egg mass was 1.04 g. Fat-body mass in both males and females decreases with the onset of the reproductive season. The age/size structure of the population varied from month to month, depending on recruitment of hatchlings. Reproduction in Leiocephalus psammodromus is similar to that of other tropical lizards in seasonal environments.

scholarly journals Collective cell sorting requires contractile cortical waves in germline cells

2020 ◽  
Author(s):  
Soline Chanet ◽  
Jean-René Huynh
Keyword(s):  
Germ Cells ◽  
Somatic Cells ◽  
Active Role ◽  
Basic Unit ◽  
Female Reproduction ◽  
Primordial Follicles ◽  
Genetic Perturbations ◽  
Egg Chambers ◽  
Germline Cells ◽  
Cortical Contractility

ABSTRACTEncapsulation of germline cells by layers of somatic cells forms the basic unit of female reproduction called primordial follicles in mammals and egg chambers in Drosophila. How germline and somatic tissues are coordinated for the morphogenesis of each separated unit remains poorly understood. Here, using improved live-imaging of Drosophila ovaries, we uncovered periodic actomyosin waves at the cortex of germ cells. These contractile waves are associated with pressure release blebs, which project from germ cells into somatic cells. We demonstrate that these cortical activities, together with cadherin-based adhesion, are required to sort each germline cyst as one collective unit. Genetic perturbations of cortical contractility, blebs protrusion or adhesion between germline and somatic cells induced failures to encapsulate any germ cells or the inclusion of too many germ cells or even the mechanical split of germline cysts. Our results reveal that germ cells play an active role in the physical coupling with somatic cells to produce the female gamete.

scholarly journals Structure and expression of hybrid dysgenesis-induced alleles of the ovarian tumor (otu) gene in Drosophila melanogaster.

Genetics ◽  
1993 ◽  
Vol 133 (2) ◽  
pp. 253-263
Author(s):  
G L Sass ◽  
J D Mohler ◽  
R C Walsh ◽  
L J Kalfayan ◽  
L L Searles
Keyword(s):  
Drosophila Melanogaster ◽  
Ovarian Tumor ◽  
P Element ◽  
Female Sterility ◽  
Protein Coding ◽  
Transcription Start Sites ◽  
Insertion And Deletion ◽  
Undifferentiated Cells ◽  
Egg Chambers ◽  
Mutant Phenotypes

Abstract Mutations at the ovarian tumor (otu) gene of Drosophila melanogaster cause female sterility and generate a range of ovarian phenotypes. Quiescent (QUI) mutants exhibit reduced germ cell proliferation; in oncogenic (ONC) mutants germ cells undergo uncontrolled proliferation generating excessive numbers of undifferentiated cells; the egg chambers of differentiated (DIF) mutants differentiate to variable degrees but fail to complete oogenesis. We have examined mutations caused by insertion and deletion of P elements at the otu gene. The P element insertion sites are upstream of the major otu transcription start sites. In deletion derivatives, the P element, regulatory regions and/or protein coding sequences have been removed. In both insertion and deletion mutants, the level of otu expression correlates directly with the severity of the phenotype: the absence of otu function produces the most severe QUI phenotype while the ONC mutants express lower levels of otu than those which are DIF. The results of this study demonstrate that the diverse mutant phenotypes of otu are the consequence of different levels of otu function.

scholarly journals Genomic and transcriptomic investigations of the evolutionary transition from oviparity to viviparity

2019 ◽  
Vol 116 (9) ◽  
pp. 3646-3655 ◽  
Author(s):  
Wei Gao ◽  
Yan-Bo Sun ◽  
Wei-Wei Zhou ◽  
Zi-Jun Xiong ◽  
Luonan Chen ◽  
...  
Keyword(s):  
Reproductive Tract ◽  
Expression Patterns ◽  
Amino Acid Replacement ◽  
Egg Laying ◽  
Female Reproductive Tract ◽  
Evolutionary Transition ◽  
Placental Development ◽  
Squamate Reptiles ◽  
Low Levels ◽  
Parity Mode

Viviparous (live-bearing) vertebrates have evolved repeatedly within otherwise oviparous (egg-laying) clades. Over two-thirds of these changes in vertebrate reproductive parity mode happened in squamate reptiles, where the transition has happened between 98 and 129 times. The transition from oviparity to viviparity requires numerous physiological, morphological, and immunological changes to the female reproductive tract, including eggshell reduction, delayed oviposition, placental development for supply of water and nutrition to the embryo by the mother, enhanced gas exchange, and suppression of maternal immune rejection of the embryo. We performed genomic and transcriptomic analyses of a closely related oviparous–viviparous pair of lizards (Phrynocephalus przewalskii and Phrynocephalus vlangalii) to examine these transitions. Expression patterns of maternal oviduct through reproductive development of the egg and embryo differ markedly between the two species. We found changes in expression patterns of appropriate genes that account for each of the major aspects of the oviparity to viviparity transition. In addition, we compared the gene sequences in transcriptomes of four oviparous–viviparous pairs of lizards in different genera (Phrynocephalus, Eremias, Scincella, and Sphenomorphus) to look for possible gene convergence at the sequence level. We discovered low levels of convergence in both amino acid replacement and evolutionary rate shift. This suggests that most of the changes that produce the oviparity–viviparity transition are changes in gene expression, so occasional reversals to oviparity from viviparity may not be as difficult to achieve as has been previously suggested.

scholarly journals The evolution of strong reproductive isolation between sympatric intertidal snails

2020 ◽  
Vol 375 (1806) ◽  
pp. 20190545 ◽  
Author(s):  
Sean Stankowski ◽  
Anja M. Westram ◽  
Zuzanna B. Zagrodzka ◽  
Isobel Eyres ◽  
Thomas Broquet ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Biological Diversity ◽  
Demographic History ◽  
Egg Laying ◽  
Female Reproduction ◽  
Open Questions ◽  
Geographical Separation ◽  
Short Period ◽  
Littorina Arcana ◽  
Subsequent Effect

The evolution of strong reproductive isolation (RI) is fundamental to the origins and maintenance of biological diversity, especially in situations where geographical distributions of taxa broadly overlap. But what is the history behind strong barriers currently acting in sympatry? Using whole-genome sequencing and single nucleotide polymorphism genotyping, we inferred (i) the evolutionary relationships, (ii) the strength of RI, and (iii) the demographic history of divergence between two broadly sympatric taxa of intertidal snail. Despite being cryptic, based on external morphology, Littorina arcana and Littorina saxatilis differ in their mode of female reproduction (egg-laying versus brooding), which may generate a strong post-zygotic barrier. We show that egg-laying and brooding snails are closely related, but genetically distinct. Genotyping of 3092 snails from three locations failed to recover any recent hybrid or backcrossed individuals, confirming that RI is strong. There was, however, evidence for a very low level of asymmetrical introgression, suggesting that isolation remains incomplete. The presence of strong, asymmetrical RI was further supported by demographic analysis of these populations. Although the taxa are currently broadly sympatric, demographic modelling suggests that they initially diverged during a short period of geographical separation involving very low gene flow. Our study suggests that some geographical separation may kick-start the evolution of strong RI, facilitating subsequent coexistence of taxa in sympatry. The strength of RI needed to achieve sympatry and the subsequent effect of sympatry on RI remain open questions. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.

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