Disease relevance of Blastoderm

• Absence of detectable acetylated alpha-tubulin prior to cellular blastoderm seems to be due to rapid turnover of microtubule arrays rather than to lack of the enzyme required for modification, since acetylated alpha-tubulin appeared in early embryos when micro-tubules were stabilized by taxol treatment or anoxia [1].
• Replication-defective recombinant retroviruses produced from vesicular stomatitis virus G glycoprotein pseudotyped retrovirus vector system were injected beneath the blastoderm of non-incubated chicken embryos (stage X) [2].
• METHODS: The DT40 cells incorporated with exogenous gene ( lacZ constructs encoding Escherichia coli beta-galactosidase: beta-gal) were introduced into chick embryos by the injection of cells into stage X blastoderm [3].

High impact information on Blastoderm

• Facilitated transport of a Dpp/Scw heterodimer by Sog/Tsg leads to robust patterning of the Drosophila blastoderm embryo [4].
• Here, we use a new RNA anchoring assay in living Drosophila blastoderm embryos to show that apical anchoring of mRNA after completion of dynein transport does not depend on actin or on continuous active transport by the motor [5].
• Dynein anchors its mRNA cargo after apical transport in the Drosophila blastoderm embryo [5].
• By contrast, the co-repressor proteins Groucho and dCtBP, and the histone deacetylase Rpd3, do not affect establishment but instead maintain repression after the blastoderm stage [6].
• We have elucidated the mechanism of apical localization of wingless and pair-rule transcripts in the Drosophila blastoderm embryo by directly visualizing intermediates along the entire path of transcript movement [7].

Biological context of Blastoderm

• The ftz gene encodes a single 1.9 kb poly(A)+ RNA expressed exclusively from the early blastoderm to gastrula stages of embryonic development [8].
• One of these mutants, statHJ, mapped to the same chromosomal region (92E) as does D-Stat, had an incompletely penetrant pair rule phenotype, and exhibited aberrant expression of the pair rule gene even skipped (eve) at the cellular blastoderm stage [9].
• Non-nucleolar RNP fibril gradients covering up to 8 mum of genome are also first observed at the cellular blastoderm stage [10].
• Here we examine the ftz pattern on blastoderm embryos derived from maternal-haploid 1182 (mh 1182) and daughterless-abo-like (dal) females which possess cell densities and sizes both above and below the wild-type levels [11].
• This structure-activity relationship conforms with that previously observed in studies of steroid induction of ALA-synthase in avian embryo liver cells and hemoglobin synthesis in the cultured avian blastoderm [12].

Anatomical context of Blastoderm

• Thus, hkb is necessary for endoderm development and its activity defines spatial limits within the blastoderm embryo in which the germ layers are established [13].
• We find that Notch is expressed in a tissue-specific manner as early as the cellular blastoderm stage, when cells of the presumptive mesoderm clearly express less Notch than adjacent ectodermal precursors [14].
• Furthermore, when affinity-purified anti-KLP67A antisera are used to stain blastoderm embryos, mitochondria in the region of the spindle asters are labeled [15].
• Regulated expression of nullo is required for the formation of distinct apical and basal adherens junctions in the Drosophila blastoderm [16].
• Germ line transformation demonstrated that these three regions are sufficient to direct the alpha 1t core promoter to begin transcribing at the stage of cellular blastoderm formation and to continue thereafter at high levels in all tissues and developmental stages [17].

Associations of Blastoderm with chemical compounds

• Tyrosine phosphorylation accompanying the cellularization of the syncytial blastoderm of Drosophila [18].
• Simultaneously with this pair-rule expression, the complete machinery of serotonin synthesis is present and leads to a peak of ligand concomitant with a peak of 5-HT2-specific receptor sites in blastoderm embryos [19].
• Our conclusions are based on combined analysis of reporter expression from P[GAL4] driver lines, horseradish peroxidase injections into blastoderm stage embryos, cell labeling via heat-shock-induced flip-out in the embryo, bromodeoxyuridine birth dating and staining for programmed cell death [20].
• A low frequency (3.1%) of apoptotic blastodermal cells was observed in Hoechst 33342-vitally stained cytological preparations of complete blastoderms from unincubated eggs [21].
• In the presence of dilysine, HeLa cells adhere to the apical side of epithelia and to the dorsal side of the upper layer of the blastoderm [22].

Gene context of Blastoderm

• At the blastoderm stage, tld RNA is expressed dorsally, similar to that described for dpp [23].
• Here, we describe a novel Drosophila protein, Discs Lost (DLT), that plays a crucial role in the polarization of embryonic epithelia during cellular blastoderm formation [24].
• Regulation of segment polarity genes in the Drosophila blastoderm by fushi tarazu and even skipped [25].
• During the late cellular blastoderm stage of Drosophila embryo-genesis the segmentation genes engrailed, en, and wingless, wg, become expressed in two series of 14 stripes which will subsequently coincide with the anterior and posterior limits of each parasegment [25].
• At early blastoderm stage, tsl protein forms a symmetrical concentration gradient at the poles on the surface of the devitellinized embryo [26].

Analytical, diagnostic and therapeutic context of Blastoderm

• Immunofluorescence probes against the protein product of one such gene, fushi tarazu (ftz), reveal that it is distributed in seven evenly spaced stripes across the cellularized cycle-14 blastoderm embryo [11].
• Indirect immunofluorescence microscopy reveals that Dsrc28C protein is localized to the cell periphery during cellular blastoderm and gastrulation [27].
• In situ hybridization shows that the quantity of snail1 RNA increases at the margin of the blastoderm in cells that involute during gastrulation [28].
• We studied cyclic reorganizations of filamentous actin, myosin II and microtubules in syncytial Drosophila blastoderms using drug treatments, time-lapse movies and laser scanning confocal microscopy of fixed stained embryos (including multiprobe three-dimensional reconstructions) [29].
• Several factors known to be expressed in hypoblast, and retinoic acid, synergistically induce Gnot-1 and Gnot-2 expression in blastoderm cell culture [30].

References