Genetic Dissection of the Drosophila Nervous System by means of Mosaics

Given a mutant having abnormal behavior, the anatomical domain responsible for the deficit may be identified by the use of genetic mosaicism. Individuals may be produced in which a portion of the body is mutant male while the rest is normal female. In such sex mosaics, or gynandromorphs, the division line between normal and mutant parts can occur in various orientations. Mutants of five different genes (cistrons) on the X-chromosome of Drosophila melanogaster, having various abnormalities in visual function, have been tested by this method. All of these have been found to be autonomous, i.e., a mutant eye always functions abnormally, regardless of the amount of normal tissue present elsewhere, indicating that the primary causes of the behavioral deficits in these mutants are within the eye

Courtship in Drosophila Mosaics: Sex-Specific Foci for Sequential Action Patterns

Mosaic fate mapping is used to locate the foci determining sex-specific steps in the mating behavior of Drosophila. Male performance of following females and displaying wing vibration toward them requires that a focus inside the head be constituted of male tissue, regardless of the sex of the head sense organs, the legs, the wings, or the thoracic ganglion. For attempted copulation to occur, a second focus in the thoracic region must also be male. Courtship by males is induced by a posteriorly located focus in the female, but an anterior female focus determines receptivity to attempted copulation. The interplay of male and female foci in the complex behavioral sequence is delineated

How Accurate Is Coarse-grained Clone Detection?: Comparision with Fine-grained Detectors

Research on clone detection has been quite successful over the past two decades, which produced a number of state-of-the-art clone detectors.However, it has been still challenging to detect clones, even with such successful detectors, across multiple projects or on thousands of revisions of code in limited time.A simple and coarse-grained detector will be an alternative of detectors using fine-grained analysis.It will drastically reduce time required for detection although it may miss some of clones that fine-grained detectors can detect.Hence, it should be adequate for a tentative analysis of clones if it has an acceptable accuracy.However, it is not clear how accurate such a coarse-grained approach is.This paper evaluates the accuracy of a coarse-grained clone detector compared with some fine-grained clone detectors.Our experiment provides an empirical evidence about acceptable accuracy of such a coarse-grained approach.Thus, we conclude that coarse-grained detection is adequate to make a summary of clone analysis and to be a starter of detailed analysis including manual inspections and bug detection

Mindin/F-spondin Family: Novel ECM Proteins Expressed in the Zebrafish Embryonic Axis

AbstractF-spondin is a secreted protein expressed at high levels by the floor plate cells. The C-terminal half of the protein contains six thrombospondin type 1 repeats, while the N-terminal half exhibited virtually no similarity to any other protein until recently, when aDrosophilagene termedM-spondinwas cloned; its product was found to share two conserved domains with the N-terminal half of F-spondin. We report the molecular cloning of four zebrafish genes encoding secreted proteins with these conserved domains. Two are zebrafish homologs ofF-spondin,while the other two, termedmindin1andmindin2,encode mutually related novel proteins, which are more related to theDrosophilaM-spondin than to F-spondin. During embryonic development, all four genes are expressed in the floor plate cells. In addition to the floor plate,mindin1is expressed in the hypochord cells, whilemindin2is expressed in the sclerotome cells. When ectopically expressed, Mindin proteins selectively accumulate in the basal lamina, suggesting that Mindins are extracellular matrix (ECM) proteins with high affinity to the basal lamina. We also report the spatial distribution of one of the F-spondin proteins, F-spondin2. F-spondin2 is localized to the thread-like structure in the central canal of the spinal cord, which is likely to correspond to Reissner's fiber known to be present in the vertebrate phylum. In summary, our study has defined a novel gene family of ECM molecules in the vertebrate, all of which may potentially be involved in development of the midline structure

CD59 protects rat kidney from complement mediated injury in collaboration with Crry

CD59 protects rat kidney from complement mediated injury in collaboration with Crry.BackgroundAs previously reported, the membrane-bound complement regulator at the C3 level (Crry/p65) is important in maintaining normal integrity of the kidney in rats. However, the role of a complement regulator at the C8/9 level (CD59) is not clear, especially when activation of complement occurs at the C3 level. The aim of this work was to elucidate the in vivo role of CD59 under C3 activating conditions.MethodsTwo monoclonal antibodies, 5I2 and 6D1, were used to suppress the function of Crry and CD59, respectively. In order to activate alternative the pathway of complement, the left kidney was perfused with 5I2 and/or 6D1 and was recirculated.ResultsIn the kidneys perfused with 5I2 alone, deposition of C3 and membrane attack complex (MAC) was observed in the peritubular capillaries, vasa recta, and tubular basement membranes. Cast formation, tubular dilation and degeneration, and cellular infiltration were observed at days 1 and 4, and they recovered by day 7. Further suppression of CD59 by 6D1 significantly enhanced the deposition of MAC and worsened the already exacerbated tubulointerstitial injury. These effects of 6D1 were dose dependent. Perfusion with 6D1 alone did not induce histologic damage or MAC deposition in the tubulointerstitium.ConclusionsIn rats, CD59 maintains normal integrity of the kidney in collaboration with Crry in rats against complement-mediated damage in vivo

Abnormal Electroretinograms in Visual Mutants of Drosophila

Two mutants of Drosophila, tan and ebony, have normal eye pigments but show abnormalities in visual behaviour. Both show in their electroretinograms that the primary photoreception process occurs normally, but genetic defects block the usual consequent neural events. Ambient light has opposite effects on the two mutants

Mapping of Behaviour in Drosophila Mosaics

By making genetic mosaics and constructing embryonic “fate maps” it is possible to locate the anatomical site of abnormalities affecting behaviour