scholarly journals Maternal proteins that are phospho-regulated upon egg activation include crucial factors for oogenesis, egg activation and embryogenesis in Drosophila melanogaster

2017 ◽  
Author(s):  
Zijing Zhang ◽  
Amber R. Krauchunas ◽  
Stephanie Huang ◽  
Mariana F. Wolfner
Keyword(s):  
Drosophila Melanogaster ◽  
Egg Production ◽  
Large Scale ◽  
Developmental State ◽  
Mature Oocyte ◽  
Early Embryo ◽  
Early Embryogenesis ◽  
Egg Activation ◽  
Initiation Of Translation ◽  
Significant Impairment

ABSTRACTEgg activation is essential for the successful transition from a mature oocyte to a developmentally competent egg. It consists of a series of events including the resumption and completion of meiosis, initiation of translation of some maternal mRNAs and destruction of others, and changes to the vitelline envelope. This drastic change of cell state is accompanied by large scale alteration of the phospho-proteome of the cell. Despite the importance of this transition in cell and developmental state, it has been difficult to find many of its regulators. We hypothesize that phosphorylation state changes between oocyte and early embryo regulate the activities of proteins that are necessary during or after this transition, and thus that the set of phospho-regulated proteins would be an enriched source for finding critical players in the egg-to-embryo transition. To test this, we used germline-specific RNAi to examine the function of 189 maternal proteins that are phospho-regulated during egg activation in Drosophila melanogaster. We identified 53 genes whose knockdown reduced or abolished egg production, as well as 50 genes for which maternal knockdown led to significant impairment or abolishment of the eggs’ ability to hatch (hatchability). We observed different stages of developmental arrest in the embryos with impaired hatchability and several distinct categories of abnormalities in the maternal knockdown embryos that arrest early in development, suggesting potential roles of the candidates in egg activation and early embryogenesis. Our results, validated by our detection of multiple genes with previously-documented maternal-effect phenotypes among the proteins we tested, revealed 15 genes with new roles in egg activation and early embryogenesis. Given that protein phospho-regulation also occurs during this transition in other organisms, we suggest that the phospho-regulated proteins may provide an enriched dataset for identifying important players in the egg-to-embryo transition.

scholarly journals The GNU subunit of PNG kinase, the developmental regulator of mRNA translation, binds BIC-C to localize to RNP granules

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Emir E Avilés-Pagán ◽  
Masatoshi Hara ◽  
Terry L Orr-Weaver
Keyword(s):  
Translational Regulation ◽  
Mrna Translation ◽  
Mature Oocyte ◽  
Early Embryogenesis ◽  
Egg Activation ◽  
Maternal Mrna ◽  
Rnp Granules

Control of mRNA translation is a key mechanism by which the differentiated oocyte transitions to a totipotent embryo. In Drosophila, the PNG kinase complex regulates maternal mRNA translation at the oocyte-to-embryo transition. We previously showed the GNU activating subunit is crucial in regulating PNG and timing its activity to the window between egg activation and early embryogenesis (Hara et al., 2017). In this study, we find associations between GNU and proteins of RNP granules and demonstrate that GNU localizes to cytoplasmic RNP granules in the mature oocyte, identifying GNU as a new component of a subset of RNP granules. Furthermore, we define roles for the domains of GNU. Interactions between GNU and the granule component BIC-C reveal potential conserved functions for translational regulation in metazoan development. We propose that by binding to BIC-C, upon egg activation GNU brings PNG to its initial targets, translational repressors in RNP granules.

The casein kinase 1 alpha gene of Drosophila melanogaster is developmentally regulated and the kinase activity of the protein induced by DNA damage

1996 ◽  
Vol 109 (7) ◽  
pp. 1847-1856 ◽  
Author(s):  
J.A. Santos ◽  
E. Logarinho ◽  
C. Tapia ◽  
C.C. Allende ◽  
J.E. Allende ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Kinase Activity ◽  
Early Embryo ◽  
Casein Kinase ◽  
Early Embryogenesis ◽  
Kinase Gene ◽  
Casein Kinase 1 ◽  
Adult Females ◽  
Early Embryos

We report the molecular cloning and characterisation of the first CK1(casein kinase) gene of Drosophila melanogaster (dmCK1). The protein sequence (DMCK1) shares significant homology with other mammalian CK1 protein kinases of the alpha sub-class. The dmCK1 gene is expressed only in adult females and during early embryonic development as a single transcript. Western blot analysis of total protein extracts of different stages of development show that the gene product is likewise present during early embryogenesis and in adult females. Kinase activity studies show that DMCK1 is active when in vitro translated but inactive when immunoprecipitated from total early embryo extracts. However, after dephosphorylation treatment the immunoprecipitates show high kinase activity. More significantly, DMCK1 kinase activity present in the immunoprecipitates can be specifically activated by gamma-irradiation of early embryos. Also, when DMCK1 is immunoprecipitated after irradiation it appears to undergo phosphorylation. Immunolocalization of DMCK1 in early embryos shows that the protein is predominantly cytoplasmic but after irradiation there is a significant relocalization to the interphase nucleus. The results suggest a possible requirement of the Drosophila CK1 alpha for mechanisms associated with DNA repair during early embryogenesis.

Drosophila virilis oskar transgenes direct body patterning but not pole cell formation or maintenance of mRNA localization in D. melanogaster

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 2027-2037 ◽  
Author(s):  
P.J. Webster ◽  
J. Suen ◽  
P.M. Macdonald
Keyword(s):  
Drosophila Melanogaster ◽  
Germ Cell ◽  
Cell Formation ◽  
Mrna Localization ◽  
Early Embryo ◽  
Posterior Pole ◽  
Early Embryogenesis ◽  
Drosophila Virilis ◽  
Pole Cell ◽  
Body Patterning

The Drosophila melanogaster gene oskar is required for both posterior body patterning and germline formation in the early embryo; precisely how oskar functions is unknown. The oskar transcript is localized to the posterior pole of the developing oocyte, and oskar mRNA and protein are maintained at the pole through early embryogenesis. The posterior maintenance of oskar mRNA is dependent upon the presence of oskar protein. We have cloned and characterized the Drosophila virilis oskar homologue, virosk, and examined its activity as a transgene in Drosophila melanogaster flies. We find that the cis-acting mRNA localization signals are conserved, although the virosk transcript also transiently accumulates at novel intermediate sites. The virosk protein, however, shows substantial differences from oskar: while virosk is able to rescue body patterning in a D. melanogaster oskar- background, it is impaired in both mRNA maintenance and pole cell formation. Furthermore, virosk induces a dominant maternal-effect lethality when introduced into a wild-type background, and interferes with the posterior maintenance of the endogenous oskar transcript in early embryogenesis. Our data suggest that virosk protein is unable to anchor at the posterior pole of the early embryo; this defect could account for all of the characteristics of virosk mentioned above. Our observations support a model in which oskar protein functions both by nucleating the factors necessary for the activation of the posterior body patterning determinant and the germ cell determinant, and by anchoring these factors to the posterior pole of the embryo. While the posterior body patterning determinant need not be correctly localized to provide body patterning activity, the germ cell determinant may need to be highly concentrated adjacent to the cortex in order to direct pole cell formation.

scholarly journals INTRACISTRONIC MAPPING OF ELECTROPHORETIC SITES IN DROSOPHILA MELANOGASTER: FIDELITY OF INFORMATION TRANSFER BY GENE CONVERSION

Genetics ◽  
1974 ◽  
Vol 76 (2) ◽  
pp. 289-299
Author(s):  
Margaret McCarron ◽  
William Gelbart ◽  
Arthur Chovnick
Keyword(s):  
Drosophila Melanogaster ◽  
Information Transfer ◽  
Large Scale ◽  
Genetic Basis ◽  
Xanthine Dehydrogenase ◽  
Specific Protein ◽  
Wild Type ◽  
Electrophoretic Variation ◽  
The Stability ◽  
Recombination Experiments

ABSTRACT A convenient method is described for the intracistronic mapping of genetic sites responsible for electrophoretic variation of a specific protein in Drosophila melanogaster. A number of wild-type isoalleles of the rosy locus have been isolated which are associated with the production of electrophoretically distinguishable xanthine dehydrogenases. Large-scale recombination experiments were carried out involving null enzyme mutants induced on electrophoretically distinct wild-type isoalleles, the genetic basis for which is followed as a nonselective marker in the cross. Additionally, a large-scale recombination experiment was carried out involving null enzyme rosy mutants induced on the same wild-type isoallele. Examination of the electrophoretic character of crossover and convertant products recovered from the latter experiment revealed that all exhibited the same parental electrophoretic character. In addition to documenting the stability of the xanthine dehydrogenase electrophoretic character, this observation argues against a special mutagenesis hypothesis to explain conversions resulting from allele recombination studies.

A NOTE ON KIDWELL'S CHROMOSOMAL ANALYSIS OF EGG PRODUCTION AND CHAETA NUMBER IN DROSOPHILA MELANOGASTER

1970 ◽  
Vol 12 (2) ◽  
pp. 356-358 ◽  
Author(s):  
P. Glaser ◽  
J. F. Kldwell
Keyword(s):  
Drosophila Melanogaster ◽  
Egg Production ◽  
Genetic Variance ◽  
Chromosomal Analysis ◽  
Epistatic Variance

An earlier paper (Kidwell, J.F., 1969, Can. J. Genet. Cytol 11: 547-557) has described partitioning of the genetic variance of egg production and chaeta number in Drosophila melanogaster, assuming equal frequencies of all chromosomes. Kidwell's data were analyzed again, and the new analyses were based on several panmictic populations with varying frequencies for each genotype. The importances of the several portions of the genetic variance were estimated for each population; several cases are presented. In most cases the ranges were substantial, especially those of the dominance and four-factor epistatic variances. The results of the present study generally support Kidwell's previous conclusions and suggest that epistatic variance should not routinely be assumed negligible.

scholarly journals Cross-Species RNAi Rescue Platform in Drosophila melanogaster

Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 1165-1173 ◽  
Author(s):  
Shu Kondo ◽  
Matthew Booker ◽  
Norbert Perrimon
Keyword(s):  
Cell Culture ◽  
Drosophila Melanogaster ◽  
Large Scale ◽  
Transgenic Animals ◽  
Selection Marker ◽  
Bacterial Artificial Chromosomes ◽  
Loss Of Function ◽  
Artificial Chromosomes ◽  
Target Effects

RNAi-mediated gene knockdown in Drosophila melanogaster is a powerful method to analyze loss-of-function phenotypes both in cell culture and in vivo. However, it has also become clear that false positives caused by off-target effects are prevalent, requiring careful validation of RNAi-induced phenotypes. The most rigorous proof that an RNAi-induced phenotype is due to loss of its intended target is to rescue the phenotype by a transgene impervious to RNAi. For large-scale validations in the mouse and Caenorhabditis elegans, this has been accomplished by using bacterial artificial chromosomes (BACs) of related species. However, in Drosophila, this approach is not feasible because transformation of large BACs is inefficient. We have therefore developed a general RNAi rescue approach for Drosophila that employs Cre/loxP-mediated recombination to rapidly retrofit existing fosmid clones into rescue constructs. Retrofitted fosmid clones carry a selection marker and a phiC31 attB site, which facilitates the production of transgenic animals. Here, we describe our approach and demonstrate proof-of-principle experiments showing that D. pseudoobscura fosmids can successfully rescue RNAi-induced phenotypes in D. melanogaster, both in cell culture and in vivo. Altogether, the tools and method that we have developed provide a gold standard for validation of Drosophila RNAi experiments.

scholarly journals Academic resilience: underlying norms and validity of definitions

2021 ◽  
Vol 33 (1) ◽  
pp. 169-202
Author(s):  
Wangqiong Ye ◽  
Rolf Strietholt ◽  
Sigrid Blömeke
Keyword(s):  
Hong Kong ◽  
Large Scale ◽  
Developmental State ◽  
Academic Resilience ◽  
Economic Capital ◽  
Student Background ◽  
Large Scale Assessment ◽  
And Performance ◽  
Diverse Cultures ◽  
Country Specific

AbstractAcademic resilience refers to students’ capacity to perform highly despite a disadvantaged background. Although most studies using international large-scale assessment (ILSA) data defined academic resilience with two criteria, student background and achievement, their conceptualizations and operationalizations varied substantially. In a systematic review, we identified 20 ILSA studies applying different criteria, different approaches to setting thresholds (the same fixed ones across countries or relative country-specific ones), and different threshold levels. Our study on the validity of these differences and how they affected the composition of academically resilient students revealed that the classification depended heavily on the threshold applied. When a fixed background threshold was applied, the classification was likely to be affected by the developmental state of a country. This could result in an overestimation of the proportions of academically resilient students in some countries while an underestimation in others. Furthermore, compared to the application of a social or economic capital indication, applying a cultural capital indicator may lead to lower shares of disadvantaged students classified as academically resilient. The composition of academically resilient students varied significantly by gender and language depending on which indicator of human capital or which thresholds were applied reflecting underlying societal characteristics. Conclusions drawn from such different results depending on the specific conceptualizations and operationalizations would vary greatly. Finally, our study utilizing PISA 2015 data from three countries representing diverse cultures and performance levels revealed that a stronger sense of belonging to a school significantly increased the chances to be classified as academically resilient in Peru, but not in Norway or Hong Kong. In contrast, absence from school was significantly associated with academic resilience in Norway and Hong Kong, but not in Peru.

COMPARATIVE ALLOCATIVE EFFICIENCY AND PROFITABILITY OF DIFFERENT SCALES OF POULTRY-EGG PRODUCTION IN JOS METROPOLIS, PLATEAU STATE, NIGERIA

2021 ◽  
Vol 4 (4) ◽  
pp. 259-273
Author(s):  
Solomon T. Folorunso ◽  
T. Omosebi ◽  
D. A. Agbonika
Keyword(s):  
Egg Production ◽  
Large Scale ◽  
Allocative Efficiency ◽  
Sampling Technique ◽  
Primary Data ◽  
Small Scale ◽  
Stochastic Production Frontier ◽  
Stochastic Production ◽  
Plateau State ◽  
The Government

The study compared the allocative efficiency and profitability of poultry-egg farmers in Jos metropolis of Plateau State, Nigeria, across different scales. To select 143 respondents, a two-stage sampling technique was used.   Using well-structured questionnaire and interview schedules, primary data on socioeconomic variables were collected. Collected data were analyzed using budgetary technique and stochastic production frontier model. Result of allocative efficiency showed the following: The mean allocative efficiency of the small, medium and large scales was 0.68, 0.12 and 0.11 respectively; the minimum allocative efficiency for small, medium and large scales was 0.30, 0.10 and 0.10 respectively. The maximum allocative efficiency was 0.59, 0.18 and 0.11 respectively for small, medium and large scale farmers. The profitability result indicated that egg production for small, medium and large-scale farms was profitable in the study area with N675, 671.79, N4, 897,236.09 and N16, 327,633.66 per farmer. The rate of return on investment per bird was found to be 19.51%, 31.21% and 83.13% respectively for small, medium and large farm sizes. For small, medium and large-scale farmers respectively, the capital turnover per bird was N 1.20, N1.31 and N1.83. Also, the profitability indices for the small, medium and large scales are N0.16, N0.24 and N0.45. The study recommends that; Farmers should be advised to increase production from small scale to large scale through policies that will promote such, special intervention is needed from the government at all levels through farmers’ cooperatives in the area of inputs subsidy, price efficiency of the farmers could

Genetic analysis of pattern formation in the Arabidopsis embryo

Development ◽  
1991 ◽  
Vol 113 (Supplement_1) ◽  
pp. 27-38 ◽  
Author(s):  
Gerd Jürgens ◽  
Ulrike Mayer ◽  
Torres Ruiz Ramon A. ◽  
Thomas Berleth ◽  
Simon Miséra
Keyword(s):  
Pattern Formation ◽  
Large Scale ◽  
Early Embryo ◽  
Flowering Plant ◽  
Abnormal Development ◽  
Mutant Seedling ◽  
Basic Body ◽  
Plant Embryo ◽  
Embryonic Pattern Formation ◽  
Plant Arabidopsis Thaliana

Virtually nothing is known about the mechanisms that generate the basic body pattern in plant embryogenesis. As a first step towards the analysis of pattern formation, we have isolated and begun to characterise putative pattern mutants in the flowering plant, Arabidopsis thaliana. A large-scale screen for morphologically abnormal seedling mutants yielded about 250 lines for further study, and genetic evidence suggests saturation of the genome for this kind of mutation. The phenotypes of putative pattern mutants fall into distinct categories, classes and groups, which may reflect specific aspects of embryonic pattern formation. Mutant seedling phenotypes result from abnormal development in the early embryo. The implications of our findings are discussed with regard to the prospects for a mechanistic understanding of pattern formation in the plant embryo.

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