Waveform Plasticity under Entrainment to 12-h T-cycles in Drosophila melanogaster: Behavior, Neuronal Network, and Evolution

2020 ◽  
Vol 35 (2) ◽  
pp. 145-157
Author(s):  
Lakshman Abhilash ◽  
Aishwarya Ramakrishnan ◽  
Srishti Priya ◽  
Vasu Sheeba
Keyword(s):  
Drosophila Melanogaster ◽  
Neuronal Network ◽  
Divergent Evolution ◽  
The Past ◽  
Rodent Behavior ◽  
Long Day ◽  
Darwinian Fitness ◽  
Clock Component ◽  
Activity Bout ◽  
Acute Changes

A crucial property of circadian clocks is the ability to regulate the shape of an oscillation over its cycle length (waveform) appropriately, thus enhancing Darwinian fitness. Many studies over the past decade have revealed interesting ways in which the waveform of rodent behavior could be manipulated, one of which is that the activity bout bifurcates under environments that have 2 light/dark cycles within one 24-h day (LDLD). It has been observed that such unique, although unnatural, environments reveal acute changes in the circadian clock network. However, although adaptation of waveforms to different photoperiods is well studied, modulation of waveforms under LDLD has received relatively less attention in research on insect rhythms. Therefore, we undertook this study to ask the following questions: what is the extent of waveform plasticity that Drosophila melanogaster exhibits, and what are the neuronal underpinnings of such plasticity under LDLD? We found that the activity/rest rhythms of wild-type flies do not bifurcate under LDLD. Instead, they show similar but significantly different behavior from that under a long-day LD cycle. This behavior is accompanied by differences in the organization of the circadian neuronal network, which include changes in waveforms of a core clock component and an output molecule. In addition, to understand the functional significance of such variations in the waveform, we examined laboratory selected populations that exhibit divergent eclosion chronotypes (and therefore, waveforms). We found that populations selected for predominant eclosion in an evening window ( late chronotypes) showed reduced amplitude plasticity and increased phase plasticity of activity/rest rhythms. This, we argue, is reflective of divergent evolution of circadian neuronal network organization in our laboratory selected flies.

scholarly journals Expanding the Junction: New Insights into Non-Occluding Roles for Septate Junction Proteins during Development

2021 ◽  
Vol 9 (1) ◽  
pp. 11
Author(s):  
Clinton Rice ◽  
Oindrila De ◽  
Haifa Alhadyian ◽  
Sonia Hall ◽  
Robert E. Ward
Keyword(s):  
Drosophila Melanogaster ◽  
Barrier Function ◽  
Septate Junction ◽  
Accessory Proteins ◽  
Organ Function ◽  
The Past ◽  
Core Components ◽  
Developmental Contexts ◽  
Mechanistic Understanding ◽  
Junction Proteins

The septate junction (SJ) provides an occluding function for epithelial tissues in invertebrate organisms. This ability to seal the paracellular route between cells allows internal tissues to create unique compartments for organ function and endows the epidermis with a barrier function to restrict the passage of pathogens. Over the past twenty-five years, numerous investigators have identified more than 30 proteins that are required for the formation or maintenance of the SJs in Drosophila melanogaster, and have determined many of the steps involved in the biogenesis of the junction. Along the way, it has become clear that SJ proteins are also required for a number of developmental events that occur throughout the life of the organism. Many of these developmental events occur prior to the formation of the occluding junction, suggesting that SJ proteins possess non-occluding functions. In this review, we will describe the composition of SJs, taking note of which proteins are core components of the junction versus resident or accessory proteins, and the steps involved in the biogenesis of the junction. We will then elaborate on the functions that core SJ proteins likely play outside of their role in forming the occluding junction and describe studies that provide some cell biological perspectives that are beginning to provide mechanistic understanding of how these proteins function in developmental contexts.

scholarly journals The genomic organization of the region containing the Drosophila melanogaster rpL7a (Surf-3) gene differs from those of the mammalian and avian Surfeit loci.

1995 ◽  
Vol 15 (5) ◽  
pp. 2367-2373 ◽  
Author(s):  
N Armes ◽  
M Fried
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Cluster ◽  
Ribosomal Protein Gene ◽  
Single Copy ◽  
Gene Organization ◽  
Genomic Region ◽  
Divergent Evolution ◽  
Close Proximity ◽  
Rapid Amplification ◽  
Rna Blots

The Surf-3 gene of the unusually tight mouse Surfeit locus gene cluster has been identified as the highly conserved ribosomal protein gene L7a (rpL7a). The topography and juxtaposition of the Surfeit locus genes are conserved for the 600 million years of divergent evolution between mammals and birds. This suggests cis interaction and/or coregulation of the genes and suggests that, within this locus, gene organization plays an important role in gene expression. The further evolutionary conservation of the organization of the Surfeit locus was investigated. A cDNA encoding the Drosophila melanogaster homolog of the Surf-3/rpL7a gene was cloned, was shown to be present as a single copy, and was expressed constitutively at high levels throughout development. Genomic cosmid clones encompassing the gene and its surrounding DNA were isolated. The gene was determined to have five introns, of which two were located in the 5' untranslated region of the gene. The remaining three introns had splice sites at positions equivalent to those found in the Surf-3/rpL7a mammalian homologs. S1 analysis and 5' rapid amplification of cDNA ends both confirmed the start of transcription to occur in a polypyrimidine tract in the absence of a TATA box in the promoter. The genomic region around the Surf-3/rpL7a gene was analyzed by low-stringency hybridization with murine Surfeit gene probes, by partial sequence analysis, and by hybridization of fragments to Northern (RNA) blots. No homologs of other members of the Surfeit gene cluster were detected in close proximity to the D. melanogaster Surf-3/rpL7a gene. However, a gene which was detected directly 3' to the Surf-3/rpL7a gene was shown to encode a homolog of a mammalian serine-pyruvate aminotransferase.

scholarly journals A scenario for the hobo transposable element invasion, deduced from the structure of natural populations of Drosophila melanogaster using tandem TPE repeats

2000 ◽  
Vol 75 (1) ◽  
pp. 13-23 ◽  
Author(s):  
ERIC BONNIVARD ◽  
CLAUDE BAZIN ◽  
BEATRICE DENIS ◽  
DOMINIQUE HIGUET
Keyword(s):  
Drosophila Melanogaster ◽  
Molecular Markers ◽  
World Wide ◽  
Tandem Repeats ◽  
Natural Populations ◽  
The Past ◽  
The World ◽  
Historical Pattern ◽  
The 1960S ◽  
Two Stages

Temporal surveys of hobo transposable elements in natural populations reveal a historical pattern suggesting a recent world-wide invasion of D. melanogaster by these transposons, perhaps following a recent horizontal transfer. To clarify the dynamics of hobo elements in natural populations, and thus to provide further data for our understanding of the hobo invasion, TPE tandem repeats, observed in the polymorphic S region of the element, were used as molecular markers. The number of TPE repeats was studied in 101 current populations from around the world, and in 63 strains collected in the past. This revealed a geographical distribution which seems to have been stable since the beginning of the 1960s. This distribution is compatible with a number of hypotheses for the dynamics of hobo elements. We propose a scenario based on an invasion in two stages: first, a complete invasion by elements with three TPE repeats, followed by the beginning of a new invasion involving hobo elements with five or seven repeats.

Physiological significance of volume-regulatory transporters

1999 ◽  
Vol 276 (5) ◽  
pp. C995-C1011 ◽  
Author(s):  
W. Charles O’Neill
Keyword(s):  
Cell Volume ◽  
Volume Regulation ◽  
Mammalian Cells ◽  
Ion Transporters ◽  
Subsequent Growth ◽  
The Past ◽  
Shrinkage And Swelling ◽  
Acute Changes

Research over the past 25 years has identified specific ion transporters and channels that are activated by acute changes in cell volume and that serve to restore steady-state volume. The mechanism by which cells sense changes in cell volume and activate the appropriate transporters remains a mystery, but recent studies are providing important clues. A curious aspect of volume regulation in mammalian cells is that it is often absent or incomplete in anisosmotic media, whereas complete volume regulation is observed with isosmotic shrinkage and swelling. The basis for this may lie in an important role of intracellular Cl− in controlling volume-regulatory transporters. This is physiologically relevant, since the principal threat to cell volume in vivo is not changes in extracellular osmolarity but rather changes in the cellular content of osmotically active molecules. Volume-regulatory transporters are also closely linked to cell growth and metabolism, producing requisite changes in cell volume that may also signal subsequent growth and metabolic events. Thus, despite the relatively constant osmolarity in mammals, volume-regulatory transporters have important roles in mammalian physiology.

Genetic maps of the proximal half of chromosome arm 2L of Drosophila melanogaster

Genome ◽  
2007 ◽  
Vol 50 (2) ◽  
pp. 137-141 ◽  
Author(s):  
Sylvia Glen Levine ◽  
Suchot Sunday ◽  
Ruth E. Dörig ◽  
Beat Suter ◽  
Paul Lasko
Keyword(s):  
Drosophila Melanogaster ◽  
Large Scale ◽  
Research Community ◽  
Genetic Maps ◽  
Past Century ◽  
The Past ◽  
Proximal Half ◽  
Chromosome Arm ◽  
Physiologic Function ◽  
Complementation Groups

Drosophila mutants have played an important role in elucidating the physiologic function of genes. Large-scale projects have succeeded in producing mutations in a large proportion of Drosophila genes. Many mutant fly lines have also been produced through the efforts of individual laboratories over the past century. In an effort to make some of these mutants more useful to the research community, we systematically mapped a large number of mutations affecting genes in the proximal half of chromosome arm 2L to more precisely defined regions, defined by deficiency intervals, and, when possible, by individual complementation groups. To further analyze regions 36 and 39–40, we produced 11 new deficiencies with gamma irradiation, and we constructed 6 new deficiencies in region 30–33, using the DrosDel system. trans-heterozygous combinations of deficiencies revealed 5 additional functions, essential for viability or fertility.

scholarly journals Competitive mating in Drosophila melanogaster

1982 ◽  
Vol 40 (2) ◽  
pp. 201-205 ◽  
Author(s):  
Paul M. Sharp
Keyword(s):  
Drosophila Melanogaster ◽  
Test Procedure ◽  
Limited Resource ◽  
Receptive Female ◽  
Male Mating ◽  
Large Reduction ◽  
Mating Ability ◽  
Male Ratio ◽  
The Past

SUMMARYSelective differences among male Drosophila melanogaster due to differences in ability to compete for mates may often have been under-estimated in the past because, under the test procedure used, females did not represent a limited resource. In the experiment reported here, no difference was detected between inbred and outbred males ‘competing’ to mate with an equal number of females. When the receptive female: male ratio was halved a large reduction in male mating ability due to inbreeding became apparent.

scholarly journals Tirant stealthily invaded natural Drosophila melanogaster populations during the last century

2020 ◽  
Author(s):  
Florian Schwarz ◽  
Filip Wierzbicki ◽  
Kirsten-André Senti ◽  
Robert Kofler
Keyword(s):  
Drosophila Melanogaster ◽  
Insertion Site ◽  
Natural Populations ◽  
P Element ◽  
Past Century ◽  
Time Points ◽  
The Past ◽  
Living Fossils ◽  
Late Discovery ◽  
Comprehensive Study

AbstractIt was long thought that solely three different transposable elements - the I-element, the P-element and hobo - invaded natural D. melanogaster populations within the last century. By sequencing the ‘living fossils’ of Drosophila research, i.e. D. melanogaster strains sampled from natural populations at different time points, we show that a fourth TE, Tirant, invaded D. melanogaster populations during the past century. Tirant likely spread in D. melanogaster populations around 1938, followed by the I-element, hobo, and, lastly, the P-element. In addition to the recent insertions of the canonical Tirant, D. melanogaster strains harbour degraded Tirant sequences in the heterochromatin which are likely due to an ancient invasion, possibly predating the split of D. melanogaster and D. simulans. In contrast to the I-element, P-element and hobo, we did not find that Tirant induces any hybrid dysgenesis symptoms. This absence of apparent phenotypic effects may explain the late discovery of the Tirant invasion. Recent Tirant insertions were found in all investigated natural populations. Populations from Tasmania carry distinct Tirant sequences, likely due to a founder effect. By investigating the TE composition of natural populations and strains sampled at different time points, insertion site polymorphisms, piRNAs and phenotypic effects, we provide a comprehensive study of a natural TE invasion.

scholarly journals Histology of larval eye—antennal disks and cephalic ganglia of Drosophila cultured in vitro

Development ◽  
1966 ◽  
Vol 15 (3) ◽  
pp. 271-279
Author(s):  
Imogene Schneider
Keyword(s):  
Drosophila Melanogaster ◽  
Larval Instar ◽  
Prepupal Stage ◽  
Culture In Vitro ◽  
Histological Studies ◽  
The Past

In the past decade, a relatively large number of reports have been published on the culture in vitro of organs of Drosophila melanogaster. The majority of these reports have been concerned with the development of the eye-antennal complex explanted, with or without the attached cephalic ganglia, from the prepupal stage (Demal, 1956) or from late second and third larval instar stages (Kuroda & Yamaguchi, 1956; Gottschewski, 1958, 1960, 1962; Gottschewski & Querner, 1961; Fugio, 1962; Schneider, 1964). With the exception of the work of Demal (1956), the above reports have been confined to descriptions of the developing explants solely in morphological terms and, as such, are not wholly adequate for comparisons to be made between development in vivo and in vitro. If, however, such descriptions are supplemented with histological studies, a more valid appreciation can be gained of the potentialities as well as the limitations of such explants under conditions in vitro.

Regulation of fetal breathing

1996 ◽  
Vol 8 (1) ◽  
pp. 23 ◽  
Author(s):  
H Rigatto
Keyword(s):  
Molecular Mass ◽  
Umbilical Cord ◽  
Neuronal Network ◽  
Respiratory Activity ◽  
In Utero ◽  
Cold Stimulation ◽  
The Past ◽  
Fetal Breathing ◽  
Central Respiratory Activity ◽  
Made In

Traditionally, the idea of transient asphyxia plus some degree of cold stimulation has been used to explain the establishment of continuous breathing at birth. This idea was nurtured by observations made in the acute fetal preparation at a time when fetal breathing was considered absent. Experimental observations made in the past two decades have challenged this traditional view. First, complete peripheral chemodenervation, essential to the hypoxic stimulus theory, did not affect fetal breathing or the establishment of continuous breathing at birth. Second, occlusion of the umbilical cord in utero, as long as some oxygenation is provided to the fetus in order to avoid fetal hypoxaemia, establishes continuous breathing in utero, in the absence of all sensorial input thought to be important for the establishment of continuous breathing. These observations led us to hypothesize the presence of a placental factor responsible for the inhibition of breathing in utero. This placental factor appears to be a peptide with a molecular mass between 3.5 and 10 kDa. This review will also explore some new observations regarding the generation of central respiratory activity in the fetus, and suggests that the rhythm generator is a neuronal network in which the unit is a pacemaker-like cell uniquely responsive to CO2.

scholarly journals Hamiltonian inclusive fitness: a fitter fitness concept

2013 ◽  
Vol 9 (6) ◽  
pp. 20130335 ◽  
Author(s):  
James T. Costa
Keyword(s):  
Nineteenth Century ◽  
Twentieth Century ◽  
Social Insects ◽  
Inclusive Fitness ◽  
The Past ◽  
Early Twentieth Century ◽  
Darwinian Fitness ◽  
Caste Polymorphism

In 1963–1964 W. D. Hamilton introduced the concept of inclusive fitness, the only significant elaboration of Darwinian fitness since the nineteenth century. I discuss the origin of the modern fitness concept, providing context for Hamilton's discovery of inclusive fitness in relation to the puzzle of altruism. While fitness conceptually originates with Darwin, the term itself stems from Spencer and crystallized quantitatively in the early twentieth century. Hamiltonian inclusive fitness, with Price's reformulation, provided the solution to Darwin's ‘special difficulty’—the evolution of caste polymorphism and sterility in social insects. Hamilton further explored the roles of inclusive fitness and reciprocation to tackle Darwin's other difficulty, the evolution of human altruism. The heuristically powerful inclusive fitness concept ramified over the past 50 years: the number and diversity of ‘offspring ideas’ that it has engendered render it a fitter fitness concept, one that Darwin would have appreciated.

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