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Analysis of RNA Interference Lines Identifies New Functions of Maternally-Expressed Genes Involved in Embryonic Patterning in Drosophila melanogaster.

Liu N, Lasko P - G3 (Bethesda) (2015)

Bottom Line: As mRNAs from several genes with known functions in anterior-posterior patterning and/or germ cell specification accumulate in RNA islands, we hypothesized that some other mRNAs that localize in this manner might also function in these developmental processes.We observed dorsal appendage defects in a proportion of eggs produced by females expressing double-stranded RNA targeting Mkrn1 or jvl, implicating these two genes in dorsal-ventral patterning.Because the mammalian ortholog of Mkrn1 acts as an E3 ubiquitin ligase, these results suggest an additional link between protein ubiquitination and pole plasm activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, McGill University, 3649 Promenade Sir William Osler, Montréal, Québec, Canada H3G 0B1.

No MeSH data available.


Related in: MedlinePlus

Embryos derived from RNAi knockdown mothers were stained for Vas protein (green) to visualize pole cells. Two embryos are shown for each knockdown line. For those that develop sufficiently, the embryo in the left panel is at the blastoderm stage, whereas the embryo in the right panel is at stage 10, which is the stage at which pole cells are in mid-migration or later. In many cases development does not progress normally beyond the blastoderm stage, and in these instances the embryo in the right panel represents what appears to be the latest stage of development achieved. In some cases, development ceases before cellularization, and then two representative embryos are shown. Wild-type embryos (wt), for comparison, are shown in the first row. The phenotypes observed for each line are discussed in Results.
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fig2: Embryos derived from RNAi knockdown mothers were stained for Vas protein (green) to visualize pole cells. Two embryos are shown for each knockdown line. For those that develop sufficiently, the embryo in the left panel is at the blastoderm stage, whereas the embryo in the right panel is at stage 10, which is the stage at which pole cells are in mid-migration or later. In many cases development does not progress normally beyond the blastoderm stage, and in these instances the embryo in the right panel represents what appears to be the latest stage of development achieved. In some cases, development ceases before cellularization, and then two representative embryos are shown. Wild-type embryos (wt), for comparison, are shown in the first row. The phenotypes observed for each line are discussed in Results.

Mentions: Consistent with the known phenotype for the corresponding mutant (Schüpbach and Wieschaus 1989), cta knockdown embryos failed to properly complete gastrulation. The embryos form a twisted structure with anterior holes (Figure 1, cta). Tao knockdown embryos progress through germ band extension but then do not retract, so they form U-shaped cuticles (Figure 1, Tao). These embryos also have obvious head defects. In milt knockdown embryos, various segments are partially missing or are fused and telsons are also often missing or reduced to rudiments (Figure 1, milt). del, gwl, CG4040, nrv1, and exu knockdown embryos do not progress sufficiently in development to form cuticles (Figure 1, del, gwl, CG4040, nrv1, exu); however, for exu and gwl (Figure 2), this phenotype is somewhat suppressed by a wild-type paternal copy of the gene in that cuticles form but severe anterior–posterior patterning defects are apparent, including a loss of anterior structures (Figure 1, exu with wt male). Loss of anterior structures has been reported as a maternal-effect phenotype of exu mutations (Schüpbach and Wieschaus 1989), and failure of oocytes to arrest in metaphase I of meiosis, resulting in a failure to support embryogenesis, is a phenotype of a hypomorphic gwl allele (Archambault et al. 2007). Finally, in many CG9821 knockdown embryos, mouth parts are malformed and there is loss or fusion of abdominal segments (Figure 1, CG9821). Other CG9821 knockdown embryos are, however, patterned normally.


Analysis of RNA Interference Lines Identifies New Functions of Maternally-Expressed Genes Involved in Embryonic Patterning in Drosophila melanogaster.

Liu N, Lasko P - G3 (Bethesda) (2015)

Embryos derived from RNAi knockdown mothers were stained for Vas protein (green) to visualize pole cells. Two embryos are shown for each knockdown line. For those that develop sufficiently, the embryo in the left panel is at the blastoderm stage, whereas the embryo in the right panel is at stage 10, which is the stage at which pole cells are in mid-migration or later. In many cases development does not progress normally beyond the blastoderm stage, and in these instances the embryo in the right panel represents what appears to be the latest stage of development achieved. In some cases, development ceases before cellularization, and then two representative embryos are shown. Wild-type embryos (wt), for comparison, are shown in the first row. The phenotypes observed for each line are discussed in Results.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4478533&req=5

fig2: Embryos derived from RNAi knockdown mothers were stained for Vas protein (green) to visualize pole cells. Two embryos are shown for each knockdown line. For those that develop sufficiently, the embryo in the left panel is at the blastoderm stage, whereas the embryo in the right panel is at stage 10, which is the stage at which pole cells are in mid-migration or later. In many cases development does not progress normally beyond the blastoderm stage, and in these instances the embryo in the right panel represents what appears to be the latest stage of development achieved. In some cases, development ceases before cellularization, and then two representative embryos are shown. Wild-type embryos (wt), for comparison, are shown in the first row. The phenotypes observed for each line are discussed in Results.
Mentions: Consistent with the known phenotype for the corresponding mutant (Schüpbach and Wieschaus 1989), cta knockdown embryos failed to properly complete gastrulation. The embryos form a twisted structure with anterior holes (Figure 1, cta). Tao knockdown embryos progress through germ band extension but then do not retract, so they form U-shaped cuticles (Figure 1, Tao). These embryos also have obvious head defects. In milt knockdown embryos, various segments are partially missing or are fused and telsons are also often missing or reduced to rudiments (Figure 1, milt). del, gwl, CG4040, nrv1, and exu knockdown embryos do not progress sufficiently in development to form cuticles (Figure 1, del, gwl, CG4040, nrv1, exu); however, for exu and gwl (Figure 2), this phenotype is somewhat suppressed by a wild-type paternal copy of the gene in that cuticles form but severe anterior–posterior patterning defects are apparent, including a loss of anterior structures (Figure 1, exu with wt male). Loss of anterior structures has been reported as a maternal-effect phenotype of exu mutations (Schüpbach and Wieschaus 1989), and failure of oocytes to arrest in metaphase I of meiosis, resulting in a failure to support embryogenesis, is a phenotype of a hypomorphic gwl allele (Archambault et al. 2007). Finally, in many CG9821 knockdown embryos, mouth parts are malformed and there is loss or fusion of abdominal segments (Figure 1, CG9821). Other CG9821 knockdown embryos are, however, patterned normally.

Bottom Line: As mRNAs from several genes with known functions in anterior-posterior patterning and/or germ cell specification accumulate in RNA islands, we hypothesized that some other mRNAs that localize in this manner might also function in these developmental processes.We observed dorsal appendage defects in a proportion of eggs produced by females expressing double-stranded RNA targeting Mkrn1 or jvl, implicating these two genes in dorsal-ventral patterning.Because the mammalian ortholog of Mkrn1 acts as an E3 ubiquitin ligase, these results suggest an additional link between protein ubiquitination and pole plasm activity.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, McGill University, 3649 Promenade Sir William Osler, Montréal, Québec, Canada H3G 0B1.

No MeSH data available.


Related in: MedlinePlus