Probing Drosophila gene function by antisense RNA

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 422-425 ◽  
Author(s):  
Reinhard Schuh ◽  
Herbert Jäckle
Keyword(s):  
Antisense Rna ◽  
Germ Line ◽  
Conventional Technique ◽  
Transcription Unit ◽  
The Body ◽  
Mutant Phenotype ◽  
Drosophila Embryo ◽  
Alternative Approach ◽  
Pattern Forming ◽  
Germ Line Transformation

The conventional technique for assigning a particular genetic function to a cloned transcription unit has relied on the rescue of the mutant phenotype by germ line transformation. An alternative approach is to mimic a mutant phenotype by the use of antisense RNA injections to produce phenocopies. This approach has been successfully used to identify genes involved in early pattern forming processes in the Drosophila embryo. At the time when antisense RNA is injected, the embryo develops as a syncytium composed of about 5000 nuclei which share a common cytoplasm. The gene interactions required to establish the body plan occur before cellularization at the blastoderm stage. Thus the nuclei and their exported transcripts are accessible to the injected antisense RNA. The antisense RNA interferes with the endogenous RNA by an as yet unidentified mechanism. The extent of interference is only partial and produces phenocopies with characteristics of weak mutant alleles. In our lab and others, this approach has been successfully used to identify several genes required for normal Drosophila pattern formation.Key words: Drosophila segmentation, phenocopy, antisense RNA, Krüppel gene.

Germ-line transformation and RNAi of the ladybird beetle, Harmonia axyridis

2006 ◽  
Vol 15 (4) ◽  
pp. 507-512 ◽  
Author(s):  
H. Kuwayama ◽  
T. Yaginuma ◽  
O. Yamashita ◽  
T. Niimi
Keyword(s):  
Harmonia Axyridis ◽  
Germ Line ◽  
Ladybird Beetle ◽  
Germ Line Transformation

scholarly journals Minimum convex hull mass estimations of complete mounted skeletons

2012 ◽  
Vol 8 (5) ◽  
pp. 842-845 ◽  
Author(s):  
W. I. Sellers ◽  
J. Hepworth-Bell ◽  
P. L. Falkingham ◽  
K. T. Bates ◽  
C. A. Brassey ◽  
...  
Keyword(s):  
Convex Hull ◽  
Body Mass ◽  
Laser Scanning ◽  
Regression Line ◽  
The Body ◽  
Alternative Approach ◽  
Subjective Input ◽  
Skeletal Reconstruction ◽  
Volumetric Methods ◽  
User Intervention

Body mass is a critical parameter used to constrain biomechanical and physiological traits of organisms. Volumetric methods are becoming more common as techniques for estimating the body masses of fossil vertebrates. However, they are often accused of excessive subjective input when estimating the thickness of missing soft tissue. Here, we demonstrate an alternative approach where a minimum convex hull is derived mathematically from the point cloud generated by laser-scanning mounted skeletons. This has the advantage of requiring minimal user intervention and is thus more objective and far quicker. We test this method on 14 relatively large-bodied mammalian skeletons and demonstrate that it consistently underestimates body mass by 21 per cent with minimal scatter around the regression line. We therefore suggest that it is a robust method of estimating body mass where a mounted skeletal reconstruction is available and demonstrate its usage to predict the body mass of one of the largest, relatively complete sauropod dinosaurs: Giraffatitan brancai (previously Brachiosaurus ) as 23200 kg.

scholarly journals The orbitopterygoid corridor as a deep keyhole for endoscopic access to the paranasal sinuses and clivus

2020 ◽  
pp. 1-10
Author(s):  
Kenichi Oyama ◽  
Kentaro Watanabe ◽  
Shunya Hanakita ◽  
Pierre-Olivier Champagne ◽  
Thibault Passeri ◽  
...  
Keyword(s):  
Nasal Cavity ◽  
Skull Base ◽  
Paranasal Sinuses ◽  
Middle Cranial Fossa ◽  
The Body ◽  
Middle Fossa Approach ◽  
Alternative Approach ◽  
Endoscopic Assistance ◽  
Skull Base Lesions ◽  
Cranial Fossa

OBJECTIVEThe anteromedial triangle (AMT) is the triangle formed by the ophthalmic (V1) and maxillary (V2) nerves. Opening of this bony space offers a limited access to the sphenoid sinus (SphS). This study aims to demonstrate the utility of the orbitopterygopalatine corridor (OPC), obtained by enlarging the AMT and transposing the contents of the pterygopalatine fossa (PPF) and V2, as an entrance to the SphS, maxillary sinus (MaxS), and nasal cavity.METHODSFive formalin-injected cadaveric specimens were used for this study (10 approaches). A classic pterional approach was performed. An OPC was created through the inferior orbital fissure, between the orbit and the PPF, by transposing the PPF inferiorly. The extent of the OPC was measured using neuronavigation and manual measurements. Two illustrative cases using the OPC to access skull base tumors are presented in the body of the article.RESULTSVia the OPC, the SphS, MaxS, ethmoid sinus (EthS), and nasal cavity could be accessed. The use of endoscopic assistance through the OPC achieved better visualization of the EthS, SphS, MaxS, clivus, and nasal cavity. A significant gain in the area of exposure could be achieved using the OPC compared to the AMT (22.4 mm2 vs 504.1 mm2).CONCLUSIONSOpening of the AMT and transposition of V2 and the contents of the PPF creates the OPC, a potentially useful deep keyhole to access the paranasal sinuses and clival region through a middle fossa approach. It is a valuable alternative approach to reach deep-seated skull base lesions infiltrating the cavernous sinus and middle cranial fossa and extending into the paranasal sinus.

scholarly journals Plant male germ line transformation

1997 ◽  
Vol 12 (4) ◽  
pp. 949-956 ◽  
Author(s):  
A. Touraev ◽  
E. Stoger ◽  
V. Voronin ◽  
E. Heberle-Bors
Keyword(s):  
Germ Line ◽  
Male Germ Line ◽  
Germ Line Transformation

Transformation mapping of the regulatory elements of the ecdysone-inducible P1 gene of Drosophila melanogaster

1991 ◽  
Vol 11 (5) ◽  
pp. 2913-2917
Author(s):  
F Maschat ◽  
M L Dubertret ◽  
J A Lepesant
Keyword(s):  
Drosophila Melanogaster ◽  
Hormonal Regulation ◽  
Germ Line ◽  
Regulatory Elements ◽  
Fat Bodies ◽  
Germ Line Transformation ◽  
Third Instar Larvae

The transcription of the P1 gene is induced by 20-hydroxyecdysone in fat bodies of third-instar larvae. Germ line transformation showed that sequences between -138 to +276 contain elements required for a qualitatively correct developmental and hormonal regulation of P1 transcription. Sequences from -138 to -68 are essential for this expression.

The molecular basis for metameric pattern in the Drosophila embryo

Development ◽  
1987 ◽  
Vol 101 (1) ◽  
pp. 1-22 ◽  
Author(s):  
M. Akam
Keyword(s):  
Molecular Basis ◽  
Subsequent Development ◽  
The Body ◽  
Drosophila Embryo ◽  
Homeotic Genes ◽  
Simple Pattern ◽  
Segment Polarity ◽  
Maternal Determinants ◽  
Segment Pattern ◽  
Pair Rule

The metameric organization of the Drosophila embryo is generated in the first 5 h after fertilization. An initially rather simple pattern provides the foundation for subsequent development and diversification of the segmented part of the body. Many of the genes that control the formation of this pattern have been identified and at least twenty have been cloned. By combining the techniques of genetics, molecular biology and experimental embryology, it is becoming possible to unravel the role played by each of these genes. The repeating segment pattern is defined by the persistent expression of engrailed and of other genes of the ‘segment polarity’ class. The establishment of this pattern is directed by a transient molecular prepattern that is generated in the blastoderm by the activity of the ‘pair-rule’ genes. Maternal determinants at the poles of the egg coordinate this prepattern and define the anteroposterior sequence of pattern elements. The primary effect of these determinants is not known, but genes required for their production have been identified and the product of one of these, bicoid is known to be localized at the anterior of the egg. One early consequence of their activity is to define domains along the A-P axis within which a series of ‘cardinal’ genes are transcribed. The activity of the cardinal genes is required both to coordinate the process of segmentation and to define the early domains of homeotic gene expression. Further interactions between the homeotic genes and other classes of segmentation genes refine the initial establishment of segment identities.

scholarly journals Transscleral ultrasonographic measurements of the optic nerve sheath diameter and a regression analysis with morphometric measures of the globe in dogs

2019 ◽  
Vol 64 (No. 11) ◽  
pp. 490-496
Author(s):  
M Vinas ◽  
U Zeyen ◽  
N D'Anna ◽  
M Vignoli
Keyword(s):  
Regression Analysis ◽  
Optic Nerve ◽  
Optic Nerve Sheath Diameter ◽  
The Body ◽  
Optic Nerve Sheath ◽  
Morphometric Measurements ◽  
Lens Thickness ◽  
Nerve Sheath ◽  
Alternative Approach ◽  
Linear Probe

To describe transscleral ultrasonography as a novel alternative approach for visualising the optic nerve sheath and measuring its diameter and to analyse the linear regressions of the optic nerve sheath diameter value with the weights and morphometric measurements of the globe in dogs. Forty healthy dogs admitted for routine sterilisation were examined. Under general anaesthesia, a B-mode ultrasonography with a linear probe (9–18 MHz) was applied transscleral in the dorso-temporal quadrant. The optic nerve sheath diameter was measured 3 mm behind the caudal aspect of the globe. The morphometric measurements, including the axial globe, lens thickness and vitreous chamber, were estimated by two observers using the direct corneal approach. Univariate and multivariate multiple linear regression analyses were performed to explore the associations of the independent predictors with dependent variables. The optic nerve sheath diameter intraclass correlation coefficient (ICC) analyses revealed interobserver 0.91 (ICC = 0.83–0.95) and intraobserver 0.93 (ICC = 0.87–0.96) reliability. The multiple regression analysis revealed that the optic nerve sheath diameter was associated with the weight (R<sup>2</sup> = 0.60, P &lt; 0.0001) but not with the axial globe (P = 0.48), the lens thickness (P = 0.73) or the vitreous chamber (P = 0.99). The findings of this study suggest that transscleral ultrasonography may be a valid alternative approach for the optic nerve visualisation and optic nerve sheath diameter measurements with excellent intra- and interobserver repeatability. The optic nerve sheath diameter was associated with the body weight, but not with the morphometric measurements of the globe.

scholarly journals Structure and expression of a gene encoding a putative GTP-binding protein identified by provirus integration in a transgenic mouse strain.

1991 ◽  
Vol 11 (2) ◽  
pp. 886-893 ◽  
Author(s):  
K Mooslehner ◽  
U Müller ◽  
U Karls ◽  
L Hamann ◽  
K Harbers
Keyword(s):  
Mouse Strain ◽  
Embryonal Carcinoma ◽  
Germ Line ◽  
Leukemia Virus ◽  
Embryonic Stem ◽  
Mutagenic Effect ◽  
Cell Types ◽  
Transcription Unit ◽  
Preimplantation Embryos ◽  
Gtp Binding

The Mov-10 mouse strain was derived by infection of preimplantation embryos with the Moloney murine leukemia virus and carries one copy of the provirus in its germ line. Here we show that the provirus has integrated into an evolutionarily conserved gene that can code for a protein of 110 kDa containing the three consensus elements characteristic for GTP-binding proteins. The Mov-10 locus was expressed in a variety of cell types, including embryonal carcinoma and embryonic stem cells. Transcription of the gene was down-regulated about 10-fold when F9 embryonal carcinoma cells are differentiated into parietal endodermlike cells and about 2-fold when they are differentiated into visceral endodermlike cells. High levels of Mov-10 transcripts were also found at different stages of embryonal development and in the testes and thymus of adult animals. Expression was cell cycle controlled, with steady-state RNA levels significantly higher in growth-arrested than in growth-stimulated cells. The results suggest that the Mov-10 locus has an important function in development and/or control of cell proliferation. The provirus was shown to have integrated into intron 1 of the gene without disrupting expression, indicating that integration into intronic sequences of a transcription unit does not necessarily affect transcription. This result together with previous results from the Mov-13 mouse strain suggested that proviruses exert their mutagenic effect only by integration in specific sites, such as cis-regulatory DNA elements.

Germ-line transformation of the Australian sheep blowflyLucilia cuprina

2002 ◽  
Vol 11 (1) ◽  
pp. 1-10 ◽  
Author(s):  
J. C. Heinrich ◽  
X. Li ◽  
R. A. Henry ◽  
N. Haack ◽  
L. Stringfellow ◽  
...  
Keyword(s):  
Germ Line ◽  
Australian Sheep ◽  
Germ Line Transformation
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