Relationship between expression of serendipity alpha and cellularisation of the Drosophila embryo as revealed by interspecific transformation

Development ◽  
1993 ◽  
Vol 119 (2) ◽  
pp. 471-483 ◽  
Author(s):  
S. Ibnsouda ◽  
F. Schweisguth ◽  
G. de Billy ◽  
A. Vincent
Keyword(s):  
Drosophila Embryo ◽  
Structural Framework ◽  
Myosin Filaments ◽  
Specific Localization ◽  
Zygotic Gene ◽  
Interspecific Transformation ◽  
Alpha Gene ◽  
Complex Regulation ◽  
Species Specific ◽  
Apical Membranes

A dramatic reorganization of the cytoskeleton underlies the cellularisation of the syncytial Drosophila embryo. Formation of a regular network of acto-myosin filaments, providing a structural framework, and possibly a contractile force as well, appears essential for the synchronous invagination of the plasma membrane between adjacent nuclei. The serendipity alpha (sry alpha) gene is required for this complete reorganization of the microfilaments at the onset of membrane invagination. We compare here the structure and expression of sry alpha between D. pseudoobscura, D. subobscura and D. melanogaster. Interspersion of evolutionarily highly conserved and divergent regions is observed in the protein. One such highly conserved region shows sequence similarities to a motif found in proteins of the ezrin-radixin-moesin (ERM) family. Four 7–13 bp motifs are conserved in the 5′ promoter region; two of these are also found, and at the same position relative to the TATA box, in nullo, another zygotic gene recently shown to be involved in cellularisation. The compared patterns of expression of D. melanogaster sry alpha and nullo, and D. pseudoobscura sry alpha reveal a complex regulation of the spatiotemporal accumulation of their transcripts. The D. pseudoobscura sry alpha gene is able to rescue the cellularisation defects associated with a complete loss of sry alpha function in D. melanogaster embryos, even though species-specific aspects of its expression are maintained. Despite their functional homologies, the D. melanogaster and D. pseudoobscura sry alpha RNAs have different subcellular localisations, suggesting that this specific localization has no conserved role in targeting the sry alpha protein to the apical membranes.

scholarly journals MATERNAL-ZYGOTIC GENE INTERACTIONS DURING FORMATION OF THE DORSOVENTRAL PATTERN IN DROSOPHILA EMBRYOS

Genetics ◽  
1983 ◽  
Vol 105 (3) ◽  
pp. 615-632 ◽  
Author(s):  
Pat Simpson
Keyword(s):  
Early Embryo ◽  
Drosophila Embryo ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Mutant Genotype ◽  
Dominant Phenotype ◽  
Zygotic Gene ◽  
Definition Of ◽  
Mutant Phenotypes ◽  
Dominant Lethality

ABSTRACT Maternal-zygotic interactions involving the three genes dorsal (dl), twist (twi) and snail (sna) are described. The results suggest that all three are involved in the process by which the dorsoventral pattern of the Drosophila embryo is established. First, the lethal embryonic mutant phenotypes are rather similar. In homozygous twi or sna embryos invagination of the ventral presumptive mesodermal cells fails to occur, and the resulting embryos are devoid of internal organs. This is very similar to the dominant phenotype described for dl; in the case of dl, however, the effect is a maternal one dependent on the mutant genotype of the female. Second, a synergistic interaction has been found whereby dominant lethality of twi  - or sna-bearing zygotes is observed in embryos derived from heterozygous dl females at high temperature. The temperature sensitivity of this interaction permitted definition of a temperature-sensitive period which is probably that of dl. This was found to extend from approximately 12 hr prior to oviposition to 2— 3 hr of embryogenesis. A zygotic action for the dl gene in addition to the maternal effect was revealed by the finding that extra doses of dl  + in the zygotes can partially rescue the dominant lethality of heterozygous twi embryos derived from heterozygous dl females. Two possible interpretations of the synergism are considered: (1) twi and sna are activated in the embryos as a result of positional signals placed in the egg as a consequence of the functioning of the dl gene during oogenesis and, thus, play a role in embryonic determination. (2) The gene products of dl  + and twi  + (or sna  +) combine to produce a functional molecule that is involved in the specification of dorsoventral pattern in the early embryo.

Determination of spatial domains of zygotic gene expression in the Drosophila embryo by the affinity of binding sites for the bicoid morphogen

Nature ◽  
1989 ◽  
Vol 340 (6232) ◽  
pp. 363-367 ◽  
Author(s):  
Wolfgang Driever ◽  
Gudrun Thoma ◽  
Christiane Nüsslein-Volhard
Keyword(s):  
Gene Expression ◽  
Binding Sites ◽  
Drosophila Embryo ◽  
Zygotic Gene ◽  
Spatial Domains

scholarly journals GAF is essential for zygotic genome activation and chromatin accessibility in the early Drosophila embryo

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Marissa M Gaskill ◽  
Tyler J Gibson ◽  
Elizabeth D Larson ◽  
Melissa M Harrison
Keyword(s):  
Chromatin Accessibility ◽  
Drosophila Embryo ◽  
Gaga Factor ◽  
Zygotic Transcription ◽  
Early Drosophila Embryo ◽  
Zygotic Gene ◽  
Pioneer Factor ◽  
Pioneer Factors ◽  
Genome Activation ◽  
Development Proceeds

Following fertilization, the genomes of the germ cells are reprogrammed to form the totipotent embryo. Pioneer transcription factors are essential for remodeling the chromatin and driving the initial wave of zygotic gene expression. In Drosophila melanogaster, the pioneer factor Zelda is essential for development through this dramatic period of reprogramming, known as the maternal-to-zygotic transition (MZT). However, it was unknown whether additional pioneer factors were required for this transition. We identified an additional maternally encoded factor required for development through the MZT, GAGA Factor (GAF). GAF is necessary to activate widespread zygotic transcription and to remodel the chromatin accessibility landscape. We demonstrated that Zelda preferentially controls expression of the earliest transcribed genes, while genes expressed during widespread activation are predominantly dependent on GAF. Thus, progression through the MZT requires coordination of multiple pioneer-like factors, and we propose that as development proceeds control is gradually transferred from Zelda to GAF.

scholarly journals Zygotic gene activation in the chicken occurs in two waves, the first involving only maternally derived genes

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Young Sun Hwang ◽  
Minseok Seo ◽  
Sang Kyung Kim ◽  
Sohyun Bang ◽  
Heebal Kim ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Gene Activation ◽  
Specific Pattern ◽  
Nucleotide Polymorphisms ◽  
Paternal Genome ◽  
Maternal Genome ◽  
Zygotic Gene ◽  
Zygotic Gene Activation ◽  
Species Specific ◽  
Genome Activation

The first wave of transcriptional activation occurs after fertilisation in a species-specific pattern. Despite its importance to initial embryonic development, the characteristics of transcription following fertilisation are poorly understood in Aves. Here, we report detailed insights into the onset of genome activation in chickens. We established that two waves of transcriptional activation occurred, one shortly after fertilisation and another at Eyal-Giladi and Kochav Stage V. We found 1544 single nucleotide polymorphisms across 424 transcripts derived from parents that were expressed in offspring during the early embryonic stages. Surprisingly, only the maternal genome was activated in the zygote, and the paternal genome remained silent until the second-wave, regardless of the presence of a paternal pronucleus or supernumerary sperm in the egg. The identified maternal genes involved in cleavage that were replaced by bi-allelic expression. The results demonstrate that only maternal alleles are activated in the chicken zygote upon fertilisation, which could be essential for early embryogenesis and evolutionary outcomes in birds.

scholarly journals The nonA Gene in Drosophila Conveys Species-Specific Behavioral Characteristics

Genetics ◽  
2001 ◽  
Vol 158 (4) ◽  
pp. 1535-1543 ◽  
Author(s):  
Susanna Campesan ◽  
Yuri Dubrova ◽  
Jeffrey C Hall ◽  
Charalambos P Kyriacou
Keyword(s):  
Courtship Behavior ◽  
Critical Factor ◽  
Courtship Song ◽  
Drosophila Virilis ◽  
Candidate Gene Approach ◽  
Specific Information ◽  
Closely Related Species ◽  
Period Gene ◽  
Interspecific Transformation ◽  
Species Specific

Abstract The molecular basis of species-specific differences in courtship behavior, a critical factor in preserving species boundaries, is poorly understood. Genetic analysis of all but the most closely related species is usually impossible, given the inviability of hybrids. We have therefore applied interspecific transformation of a single candidate behavioral locus, no-on-transient A (nonA), between Drosophila virilis and D. melanogaster, to investigate whether nonA, like the period gene, might encode species-specific behavioral information. Mutations in nonA can disrupt both visual behavior and the courtship song in D. melanogaster. The lovesong of nonAdiss mutant males superficially resembles that of D. virilis, a species that diverged from D. melanogaster 40–60 mya. Transformation of the cloned D. virilis nonA gene into D. melanogaster hosts carrying a synthetic deletion of the nonA locus restored normal visual function (the phenotype most sensitive to nonA mutation). However, the courtship song of transformant males showed several features characteristic of the corresponding D. virilis signal, indicating that nonA can act as a reservoir for species-specific information. This candidate gene approach, together with interspecific transformation, can therefore provide a direct avenue to explore potential speciation genes in genetically and molecularly tractable organisms such as Drosophila.

scholarly journals SPECIES SPECIFICITY OF HETEROCHROMATIN BLOCK DISTRIBUTION AND rDNA LOCALIZATION IN MITOTIC CHROMOSOMES OF MOSQUITOES SPECIES AEDES EXCRUCIANS, AE. BEHNINGI AND AE. PUNCTOR

2020 ◽  
Author(s):  
S.S. Alekseeva ◽  
◽  
Yu.V. Andreeva ◽  
I.E. Wasserlauf ◽  
A.K. Sibataev ◽  
...  
Keyword(s):  
Mosquito Species ◽  
Chromosome Analysis ◽  
Chromosome Length ◽  
Chromosome 1 ◽  
Mitotic Chromosomes ◽  
Karyotypic Analysis ◽  
Rdna Genes ◽  
Specific Localization ◽  
Species Specific ◽  
Block Distribution

A karyotypic analysis of three mosquito species Aedes excrucians, Ae. behningi and Ae. punctor (Diptera: Culicidae). Differences in the lengths of chromosomes, the distribution of C- and DAPI blocks of heterochromatin, and the localization of rDNA genes on chromosomes were revealed. Aedes excrucians has the largest chromosome length among the three species represented. Ae. punctor differs in the localization of rDNA on the second chromosome, while in Aedes excrucians and Ae. behningi, rDNA genes are located on chromosome 1. All three species have different C-banding and species-specific localization of heterochromatin DAPI blocks. Consequently, chromosome analysis can serve as an additional mechanism for species identification of mosquitoes of the genus Aedes.

scholarly journals Cell cycle control during early embryogenesis

Development ◽  
2021 ◽  
Vol 148 (13) ◽  
Author(s):  
Susanna E. Brantley ◽  
Stefano Di Talia
Keyword(s):  
Cell Cycle ◽  
Quantitative Imaging ◽  
Cell Cycle Control ◽  
Embryonic Cell ◽  
Early Embryogenesis ◽  
Model Systems ◽  
Drosophila Embryo ◽  
Cell Cycles ◽  
Physical Mechanisms ◽  
Species Specific

ABSTRACT Understanding the mechanisms of embryonic cell cycles is a central goal of developmental biology, as the regulation of the cell cycle must be closely coordinated with other events during early embryogenesis. Quantitative imaging approaches have recently begun to reveal how the cell cycle oscillator is controlled in space and time, and how it is integrated with mechanical signals to drive morphogenesis. Here, we discuss how the Drosophila embryo has served as an excellent model for addressing the molecular and physical mechanisms of embryonic cell cycles, with comparisons to other model systems to highlight conserved and species-specific mechanisms. We describe how the rapid cleavage divisions characteristic of most metazoan embryos require chemical waves and cytoplasmic flows to coordinate morphogenesis across the large expanse of the embryo. We also outline how, in the late cleavage divisions, the cell cycle is inter-regulated with the activation of gene expression to ensure a reliable maternal-to-zygotic transition. Finally, we discuss how precise transcriptional regulation of the timing of mitosis ensures that tissue morphogenesis and cell proliferation are tightly controlled during gastrulation.

scholarly journals The pioneer factor GAF is essential for zygotic genome activation and chromatin accessibility in the early Drosophila embryo

2020 ◽  
Author(s):  
Marissa M. Gaskill ◽  
Tyler J. Gibson ◽  
Elizabeth D. Larson ◽  
Melissa M. Harrison
Keyword(s):  
Transcriptional Control ◽  
Chromatin Accessibility ◽  
Drosophila Embryo ◽  
Gaga Factor ◽  
Zygotic Transcription ◽  
Early Drosophila Embryo ◽  
Zygotic Gene ◽  
Pioneer Factor ◽  
Pioneer Factors ◽  
Genome Activation

AbstractFollowing fertilization, the genomes of the germ cells are reprogrammed to form the totipotent embryo. Pioneer transcription factors are required for remodeling the chromatin and driving the initial wave of zygotic gene expression. In Drosophila melanogaster, the pioneer factor Zelda is essential for development through this dramatic period of reprogramming, known as the maternal- to-zygotic transition (MZT). However, it was unknown whether additional pioneer factors were necessary for this transition. We identified an additional maternally encoded factor required for development through the MZT, GAGA Factor (GAF). GAF is needed to activate widespread zygotic transcription and to remodel the chromatin accessibility landscape. We demonstrated that Zelda preferentially controls expression of the earliest transcribed genes, while genes expressed during widespread activation are predominantly dependent on GAF. Thus, progression through the MZT requires coordination of multiple pioneer factors, and we propose that as development proceeds transcriptional control is gradually transferred from Zelda to GAF.

Dorsoventral development of the Drosophila embryo is controlled by a cascade of transcriptional regulators

Development ◽  
1992 ◽  
Vol 116 (Supplement) ◽  
pp. 173-181 ◽  
Author(s):  
Christine Thisse ◽  
Bernard Thisse
Keyword(s):  
Cultured Cells ◽  
Polytene Chromosomes ◽  
Dna Binding Protein ◽  
Drosophila Embryo ◽  
Transcriptional Level ◽  
Gene Promoters ◽  
Mesoderm Formation ◽  
Zygotic Gene

Maternal genes involved in dorsoventral (D/V) patterning of the Drosophila embryo interact to establish a stable nuclear concentration gradient of the Dorsal protein which acts as the morphogen along this axis. This protein belongs to the rel proto-oncogene and NF-KB transcriptional factor family and acts by controlling zygotic gene expression. In the ventral part of the embryo, dorsal specifically activates transcription of the gene twist and ventrally and laterally dorsal represses the expression of zerknüllt, a gene involved in the formation of dorsal derivatives. The extent of dorsal action is closely related to the affinity and the number of dorsal response elements present in these zygotic gene promoters. twist is one of the first zygotic genes necessary for mesoderm formation. It codes for a ‘b-HLH’ DNA-binding protein which can dimerize and bind to DNA in vitro and to polytene chromosomes in vivo. In addition, in cultured cells twist has been shown to be a transcriptional activator. Thus, the first events of embryonic development along the D/V axis are controlled at the transcriptional level.

Sign in / Sign up

Export Citation Format

Share Document