scholarly journals Dynamic Hsp83 RNA localization during Drosophila oogenesis and embryogenesis.

1993 ◽  
Vol 13 (6) ◽  
pp. 3773-3781 ◽  
Author(s):  
D Ding ◽  
S M Parkhurst ◽  
S R Halsell ◽  
H D Lipshitz
Keyword(s):  
Polar Granule ◽  
Rna Degradation ◽  
Posterior Pole ◽  
Drosophila Embryo ◽  
Polar Granules ◽  
Local Protection ◽  
Early Drosophila Embryo ◽  
Drosophila Homolog ◽  
Developmental Significance ◽  
Blastoderm Stage

Hsp83 is the Drosophila homolog of the mammalian Hsp90 family of regulatory molecular chaperones. We show that maternally synthesized Hsp83 transcripts are localized to the posterior pole of the early Drosophila embryo by a novel mechanism involving a combination of generalized RNA degradation and local protection at the posterior. This protection of Hsp83 RNA occurs in wild-type embryos and embryos produced by females carrying the maternal effect mutations nanos and pumilio, which eliminate components of the posterior polar plasm without disrupting polar granule integrity. In contrast, Hsp83 RNA is not protected at the posterior pole of embryos produced by females carrying maternal mutations that disrupt the posterior polar plasm and the polar granules--cappuccino, oskar, spire, staufen, tudor, valois, and vasa. Mislocalization of oskar RNA to the anterior pole, which has been shown to result in induction of germ cells at the anterior, leads to anterior protection of maternal Hsp83 RNA. These results suggest that Hsp83 RNA is a component of the posterior polar plasm that might be associated with polar granules. In addition, we show that zygotic expression of Hsp83 commences in the anterior third of the embryo at the syncytial blastoderm stage and is regulated by the anterior morphogen, bicoid. We consider the possible developmental significance of this complex control of Hsp83 transcript distribution.

scholarly journals Dynamic Hsp83 RNA localization during Drosophila oogenesis and embryogenesis

1993 ◽  
Vol 13 (6) ◽  
pp. 3773-3781
Author(s):  
D Ding ◽  
S M Parkhurst ◽  
S R Halsell ◽  
H D Lipshitz
Keyword(s):  
Polar Granule ◽  
Rna Degradation ◽  
Posterior Pole ◽  
Drosophila Embryo ◽  
Polar Granules ◽  
Local Protection ◽  
Early Drosophila Embryo ◽  
Drosophila Homolog ◽  
Developmental Significance ◽  
Blastoderm Stage

Hsp83 is the Drosophila homolog of the mammalian Hsp90 family of regulatory molecular chaperones. We show that maternally synthesized Hsp83 transcripts are localized to the posterior pole of the early Drosophila embryo by a novel mechanism involving a combination of generalized RNA degradation and local protection at the posterior. This protection of Hsp83 RNA occurs in wild-type embryos and embryos produced by females carrying the maternal effect mutations nanos and pumilio, which eliminate components of the posterior polar plasm without disrupting polar granule integrity. In contrast, Hsp83 RNA is not protected at the posterior pole of embryos produced by females carrying maternal mutations that disrupt the posterior polar plasm and the polar granules--cappuccino, oskar, spire, staufen, tudor, valois, and vasa. Mislocalization of oskar RNA to the anterior pole, which has been shown to result in induction of germ cells at the anterior, leads to anterior protection of maternal Hsp83 RNA. These results suggest that Hsp83 RNA is a component of the posterior polar plasm that might be associated with polar granules. In addition, we show that zygotic expression of Hsp83 commences in the anterior third of the embryo at the syncytial blastoderm stage and is regulated by the anterior morphogen, bicoid. We consider the possible developmental significance of this complex control of Hsp83 transcript distribution.

scholarly journals Localization of vasa, a component of Drosophila polar granules, in maternal-effect mutants that alter embryonic anteroposterior polarity

Development ◽  
1990 ◽  
Vol 109 (2) ◽  
pp. 425-433 ◽  
Author(s):  
B. Hay ◽  
L.Y. Jan ◽  
Y.N. Jan
Keyword(s):  
Germ Cell ◽  
Maternal Effect ◽  
Polar Granule ◽  
Cell Lineage ◽  
Posterior Pole ◽  
Drosophila Embryo ◽  
Polar Granules ◽  
Early Drosophila Embryo ◽  
Anteroposterior Polarity ◽  
Source Of Information

Cytoplasm at the posterior pole of the early Drosophila embryo, known as polar plasm, serves as a source of information necessary for germ cell determination and for specification of the abdominal region. Likely candidates for cytoplasmic elements important in one or both of these processes are polar granules, organelles concentrated in the cortical cytoplasm of the posterior pole. Females homozygous for any one of the maternal-effect mutations, tudor, oskar, staufen, vasa, or valois give rise to embryos that lack localized polar granules, fail to form the germ cell lineage and have abdominal segment deletions. Using antibodies against a polar granule component, the vasa protein, we find that vasa synthesis or localization is affected by these mutations. In vasa mutants, synthesis of vasa protein is absent or severely restricted. In oskar and staufen mutant females, vasa synthesis appears normal, but the vasa protein is not localized. In tudor and valois mutant females, vasa is localized to the posterior pole of oocytes, but this localization is lost following egg activation. In addition to the posterior localized vasa, there is a low level of vasa distributed throughout the embryo. A function for this distributed vasa is postulated based on the observation that embryos from Bicaudal-D mothers, in which abdominal determinants are incorrectly localized to the anterior pole, do not show any ectopic vasa localization, though abdomen development at the anterior end depends on the amount of vasa protein in the embryo.

Distribution of tudor protein in the Drosophila embryo suggests separation of functions based on site of localization

Development ◽  
1993 ◽  
Vol 119 (1) ◽  
pp. 207-219 ◽  
Author(s):  
A. Bardsley ◽  
K. McDonald ◽  
R.E. Boswell
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Germ Plasm ◽  
Primordial Germ Cells ◽  
Posterior Pole ◽  
Drosophila Embryo ◽  
Normal Functioning ◽  
Polar Granules ◽  
Pole Cells

Mutations in the tudor locus of Drosophila affect two distinct determinative processes in embryogenesis; segmentation of the abdomen and determination of the primordial germ cells. The distribution of tudor protein during embryogenesis, and the effect of various mutations on its distribution, suggest that tudor protein may carry out these functions separately, based on its location in the embryo. The protein is concentrated in the posterior pole cytoplasm (germ plasm), where it is found in polar granules and mitochondria. Throughout the rest of the embryo, tudor protein is associated with the cleavage nuclei. Mutations in all maternal genes known to be required for the normal functioning of the germ plasm eliminate the posterior localization of tudor protein, whereas mutations in genes required for the functioning of the abdominal determinant disrupt the localization around nuclei. Analysis of embryos of different maternal genotypes indicates that the average number of pole cells formed is correlated with the amount of tudor protein that accumulates in the germ plasm. Our results suggest that tudor protein localized in the germ plasm is instrumental in germ cell determination, whereas nuclear-associated tudor protein is involved in determination of segmental pattern in the abdomen.

Microtubule distribution reveals superficial metameric patterns in the early Drosophila embryo

Development ◽  
1989 ◽  
Vol 107 (1) ◽  
pp. 35-41
Author(s):  
G. Callaini
Keyword(s):  
Fluorescence Microscopy ◽  
Drosophila Embryo ◽  
Alpha Tubulin ◽  
Ventral Furrow ◽  
Early Drosophila Embryo ◽  
Blastoderm Stage ◽  
Whole Mounts ◽  
Drosophila Embryos

Microtubule distribution was examined in whole mounts of Drosophila embryos from the cellularization of the syncytial blastoderm (stage 6) to the completion of the gastrulation (stage 7) by fluorescence microscopy. During ventral furrow formation, the fluorescence of tubulin network was not uniform, but disposed in zebra stripes. Antibodies against alpha-tubulin showed 14 alternating pairs of darker and brighter transverse areas. The possible significance of this pattern is discussed.

The Cytoskeleton of the Early Drosophila Embryo

1986 ◽  
Vol 1986 (Supplement 5) ◽  
pp. 311-328 ◽  
Author(s):  
R. M. WARN
Keyword(s):  
Drosophila Embryo ◽  
Early Drosophila Embryo

scholarly journals A Sponge-like Structure Involved in the Association and Transport of Maternal Products during Drosophila Oogenesis

1997 ◽  
Vol 139 (3) ◽  
pp. 817-829 ◽  
Author(s):  
Michaela Wilsch-Bräuninger ◽  
Heinz Schwarz ◽  
Christiane Nüsslein-Volhard
Keyword(s):  
Xenopus Oocytes ◽  
Polar Granule ◽  
Rna Localization ◽  
Drosophila Embryo ◽  
Fibrillar Structure ◽  
Subcellular Structure ◽  
Cytoplasmic Bridges ◽  
Dense Mass ◽  
Mitochondrial Cloud ◽  
Surrounding Membrane

Localization of maternally provided RNAs during oogenesis is required for formation of the antero–posterior axis of the Drosophila embryo. Here we describe a subcellular structure in nurse cells and oocytes which may function as an intracellular compartment for assembly and transport of maternal products involved in RNA localization. This structure, which we have termed “sponge body,” consists of ER-like cisternae, embedded in an amorphous electron-dense mass. It lacks a surrounding membrane and is frequently associated with mitochondria. The sponge bodies are not identical to the Golgi complexes. We suggest that the sponge bodies are homologous to the mitochondrial cloud in Xenopus oocytes, a granulo-fibrillar structure that contains RNAs involved in patterning of the embryo. Exuperantia protein, the earliest factor known to be required for the localization of bicoid mRNA to the anterior pole of the Drosophila oocyte, is highly enriched in the sponge bodies but not an essential structural component of these. RNA staining indicates that sponge bodies contain RNA. However, neither the intensity of this staining nor the accumulation of Exuperantia in the sponge bodies is dependent on the amount of bicoid mRNA present in the ovaries. Sponge bodies surround nuage, a possible polar granule precursor. Microtubules and microfilaments are not present in sponge bodies, although transport of the sponge bodies through the cells is implied by their presence in cytoplasmic bridges. We propose that the sponge bodies are structures that, by assembly and transport of included molecules or associated structures, are involved in localization of mRNAs in Drosophila oocytes.

scholarly journals Assembly of yolk spindles in the early Drosophila embryo

2003 ◽  
Vol 120 (4) ◽  
pp. 441-454 ◽  
Author(s):  
Maria Giovanna Riparbelli ◽  
Giuliano Callaini
Keyword(s):  
Drosophila Embryo ◽  
Early Drosophila Embryo
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