Search results for "Drosophila melanogaster"

Immuno-Fluorescence (IF) on interphase polytene chromosomes of Drosophila melanogaster

2008

The Function of Plastic Reproductive Behaviour in Drosophila melanogaster

2022

Phenotypic plasticity is a widespread phenomenon across the tree of life, with far reaching consequences for ecological and evolutionary processes. In species facing strong sexual selection and marked variation in the socio-sexual context in which they reproduce, adaptive plasticity in reproductive behaviour is expected to evolve. In this thesis, we aimed to contribute to this area of evolutionary biology research using the model organism Drosophila melanogaster. The results of this thesis offer a twist to the steadily growing literature of ageing via sensory perception by showing that socio-sexual cues so far documented to accelerate ageing mostly bear fitness benefits in ecologically rele…

Klf15 Is Critical for the Development and Differentiation of Drosophila Nephrocytes

2015

Insect nephrocytes are highly endocytic scavenger cells that represent the only invertebrate model for the study of human kidney podocytes. Despite their importance, nephrocyte development is largely uncharacterised. This work tested whether the insect ortholog of mammalian Kidney Krüppel-Like Factor (Klf15), a transcription factor required for mammalian podocyte differentiation, was required for insect nephrocyte development. It was found that expression of Drosophila Klf15 (dKlf15, previously known as Bteb2) was restricted to the only two nephrocyte populations in Drosophila, the garland cells and pericardial nephrocytes. Loss of dKlf15 function led to attrition of both nephrocyte populat…

How Many Clocks, How Many Times? On the Sensory Basis and Computational Challenges of Circadian Systems

2018

A vital task for every organism is not only to decide what to do but also when to do it. For this reason, “circadian clocks” have evolved in virtually all forms of life. Conceptually, circadian clocks can be divided into two functional domains; an autonomous oscillator creates a ~24 h self-sustained rhythm and sensory machinery interprets external information to alter the phase of the autonomous oscillation. It is through this simple design that variations in external stimuli (for example, daylight) can alter our sense of time. However, the clock’s simplicity ends with its basic concept. In metazoan animals, multiple external and internal stimuli, from light to temperature and even metaboli…

Serotonīna ietekme uz augļu mušu (Drosophila melanogaster) fototaksi

2022

Serotonīns ir iesaistīts daudzos svarīgos procesos dzīvo būtņu organismos, sākot no nervu impulsu pārraidi, garastāvokļa izmaiņām, depresiju un beidzot ar peristaltikas un zarnu trakta darbības regulēšanu. Cilvēka centrālā nervu sistēma psihisko slimību kontekstā ir sarežģīts mehānisms un tā izpēte tiešā veidā nav iespējama. Līdz ar to eksperimentos, depresijas un ar to saistītās uzvedības, izpētei vieglāk izmantot bioloģijā klasisko modeli – augļu mušas Drosophila melanogaster. Šī organisma bāziskas ķīmiskas reakcijas smadzenēs ir līdzīgas reakcijām, kas norisinās cilvēka smadzenēs; turklāt augļu mušas jau tiek izmantotas par cilvēka depresijas modeļorganismu. Eksperimentā tika izmantotas …

Identification of proteins and developmental expression of RNAs encoded by the 65A cuticle protein gene cluster in Drosophila melanogaster

1998

0965-1748 (Print) Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.; Proteins of the third instar larval cuticle of Drosophila melanogaster, LCP5-LCP9, were purified and their N-terminal sequences determined. Three of these proteins (LCP5, 6, and 8) were found to be encoded by two multicopy genes previously mapped to the gene cluster at 65A 5-6 on the left arm of the third chromosome. The analysis of the patterns of developmental expression of the 8 distinct genes at this site showed that all but two were expressed during larval life. The patterns fell into three groups: one where expression was all through larval life, one where expression was primar…

Interspecific transgenic analysis of basal versus heat-shock-induced expression of a Drosophila pseudoobscura hsp82-neo fusion gene in D. melanogaster

1994

Drosophila melanogaster transformants containing a D. pseudoobscura hsp82-neo fusion gene were used to examine the relationship between chromosome structure and its variation to transcriptional activation and gene expression. At normal temperatures (25° C) transgenic hsp82-neo was transcribed in diffuse polytene chromosomal bands encoding antibiotic G418-resistance without intensive puff formation. Substantial basal expression of the transgene was observed in all tissues examined: salivary glands, brain, ventral ganglion, foregut, gastric caeca, midgut, imaginal discs, nurse cells and oocytes. In addition, basal hsp82-neo expression occurred throughout embryogenesis. In third-instar larvae …

Heterogeneity in the Response of Different Subtypes of Drosophila melanogaster Midgut Cells to Viral Infections

2021

This article belongs to the Section Viral Immunology, Vaccines, and Antivirals.

Within-host evolution decreases virulence in an opportunistic bacterial pathogen

2015

Abstract Background Pathogens evolve in a close antagonistic relationship with their hosts. The conventional theory proposes that evolution of virulence is highly dependent on the efficiency of direct host-to-host transmission. Many opportunistic pathogens, however, are not strictly dependent on the hosts due to their ability to reproduce in the free-living environment. Therefore it is likely that conflicting selection pressures for growth and survival outside versus within the host, rather than transmission potential, shape the evolution of virulence in opportunists. We tested the role of within-host selection in evolution of virulence by letting a pathogen Serratia marcescens db11 sequent…

Woc (without children) gene control of ecdysone biosynthesis in Drosophila melanogaster.

2001

Abstract The first step in ecdysteroidogenesis, i.e. the 7,8-dehydrogenation of dietary cholesterol (C) to 7-dehydrocholesterol (7dC), is blocked in Drosophila melanogaster homozygous woc (without children) third instar larval ring glands (source of ecdysone). Unlike ring glands from wild-type D. melanogaster larvae, glands from woc mutants cannot convert radiolabelled C or 25-hydroxycholesterol (25C) to 7dC or 7-dehydro-25-hydroxycholesterol (7d25C) in vitro, nor to ecdysone (E). Yet, when these same glands are incubated with synthetic tracer 7d25C, the rate of metabolism of this polar Δ5,7-sterol into E is identical to that observed with glands from comparably staged wild-type larvae. The…