Search results for "Drosophila."

An ion channel-gated adenylyl cyclase

1992

Serpent and a hibris reporter are co-expressed in migrating cells during Drosophila hematopoiesis and Malpighian tubule formation

2006

Motile mesodermal cells contribute several cell types to developing embryos. In Drosophila, blood cell precursors or prohemocytes, are first detected in the procephalic mesoderm by the expression of the GATA transcription factor Serpent. Once specified, a subset of prohemocytes migrate posteriorly to populate most of the embryo and further differentiate as plasmatocytes. Similarly, Drosophila nephrogenesis involves integration of posterior mesodermal cells into the Malpighian tubule primordia where these cells differentiate as stellate cells. Here we investigated the possibility that the immunoglobulin-domain protein Hibris and the GATA factor Serpent were co-expressed in motile mesodermal …

CONSERVED CELLULAR AND MOLECULAR MECHANISMS IN DEVELOPMENT

2002

This review discusses examples of conserved cellular and molecular mechansims in development, including the pathway of signal transduction between the photoreceptors R8 and R7 in Drosophila, which is compared to vulval induction in Caenorhabditis elegans. The Wg pathway in Drosophila is compared, first, to the Wnt pathway in dorsal mesoderm specification in Xenopus: second, to the same pathway in sea urchins; third, to the equivalent in the mom cascade of C. elegans; and finally, to parts of the equivalent pathway in Dictyostelium discoideum. The conserved expression of some hox genes in vertebrate limb buds and in the heads or tails of several invertebrate and vertebrate embryos is also il…

Oligonucleotide probes detect splicing variants insituinDrosophilaembryos

1992

We describe a method for the in situ detection of specific splicing variants. The method is based on the use of antisense oligonucleotides designed to span splice junctions labelled with digoxigenin by terminal transferase tailing. We find that the spatial patterns of Ubx splicing variants Ia and IIa are similar in early embryos, but differ in late embryos. Variant IVa is only detected in the CNS (ps6) at stages 16 and 17. We also present evidence indicating that the first splicing event is cotranscriptional.

Expression of en and wg in the embryonic head and brain of Drosophila indicates a refolded band of seven segment remnants

1992

ABSTRACT Based on the expression pattern of the segment polarity genes engrailed and wingless during the embryonic development of the larval head, we found evidence that the head of Drosophila consists of remnants of seven segments (4 pregnathal and 3 gnathal) all of which contribute cells to neuromeres in the central nervous system. Until completion of germ band retraction, the four pregnathal segment remnants and their corresponding neuromeres become arranged in an S-shape. We discuss published evidence for seven head segments and morphogenetic movements during head formation in various insects (and crustaceans).

Development of novel immunoglobulin G (IgG), IgA, and IgM enzyme immunoassays based on recombinant Puumala and Dobrava hantavirus nucleocapsid protei…

2006

ABSTRACT Human infections with Asian and European hantaviruses can result in hemorrhagic fever with renal syndromes of differing severities characterized by renal dysfunction and sometimes by pulmonary symptoms. For the serological detection of human infections by hantaviruses relevant for Europe, we developed monoclonal antibody capture immunoglobulin G (IgG) and IgA enzyme-linked immunosorbent assays (ELISAs) based on yeast-expressed nucleocapsid proteins of Puumala and Dobrava hantaviruses. Moreover, for diagnosis of acute infections, μ-capture IgM ELISAs were established with nucleocapsid proteins expressed in Drosophila melanogaster Schneider S2 cells. The cutoff values of the ELISAs w…

Mutations in KATNB1 Cause Complex Cerebral Malformations by Disrupting Asymmetrically Dividing Neural Progenitors

2014

SummaryExome sequencing analysis of over 2,000 children with complex malformations of cortical development identified five independent (four homozygous and one compound heterozygous) deleterious mutations in KATNB1, encoding the regulatory subunit of the microtubule-severing enzyme Katanin. Mitotic spindle formation is defective in patient-derived fibroblasts, a consequence of disrupted interactions of mutant KATNB1 with KATNA1, the catalytic subunit of Katanin, and other microtubule-associated proteins. Loss of KATNB1 orthologs in zebrafish (katnb1) and flies (kat80) results in microcephaly, recapitulating the human phenotype. In the developing Drosophila optic lobe, kat80 loss specificall…

Signals of demographic expansion in Drosophila virilis

2008

Background. The pattern of genetic variation within and among populations of a species is strongly affected by its phylogeographic history. Analyses based on putatively neutral markers provide data from which past events, such as population expansions and colonizations, can be inferred. Drosophila virilis is a cosmopolitan species belonging to the virilis group, where divergence times between different phylads go back to the early Miocene. We analysed mitochondrial DNA sequence variation among 35 Drosophila virilis strains covering the species' range in order to detect demographic events that could be used to understand the present characteristics of the species, as well as its differences …

Characterization of the length polymorphism in the A + T-rich region of the Drosophila obscura group species

1993

In the twelve Drosophila obscura group species studied, belonging to the affinis, obscura, and pseudoobscura subgroups, the mitochondrial DNA length ranges from 15.8 to 17.2 kb. This length polymorphism is mainly due to insertions/deletions in the variable region of the A + T-rich region. In addition, one species (D. tristis) possess a tandem duplication of a 470-bp fragment that contains the replication origin. The same duplication has occurred at least twice in the Drosophila evolutionary history due to the fact that the repetition is analogous to repetitions found in the four species of the D. melanogaster complex. By comparing the nucleotide sequence of the conserved region in D. ambigu…

Diagnosis of sibling species of Drosophila involved in the colonization of North America by D. subobscura

1997

To determine the effects of the recent colonization of the west coast of North America by the Palaearctic species Drosophila subobscura on the dynamics of the Drosophila populations, the sibling species D. athabasca and D. azteca must be classified unambiguously. We have characterized these two species using three molecular techniques: allozymes, mtDNA and RAPDs. All three techniques allow the classification of any individual as belonging to either species. The study of five localities in northern California and southern Oregon show that the area of overlap is larger than previously described.