scholarly journals Inferring temporal organization of postembryonic development from high-content behavioral tracking

2020 ◽  
Author(s):  
Denis F. Faerberg ◽  
Victor Gurarie ◽  
Ilya Ruvinsky
Keyword(s):  
Larval Stage ◽  
Developmental Time ◽  
Postembryonic Development ◽  
Individual Variability ◽  
Temporal Organization ◽  
Temporal Regulation ◽  
Larval Stages ◽  
Behavioral Tracking ◽  
Scaling Relationship ◽  
Important Challenge

AbstractUnderstanding temporal regulation of development remains an important challenge. Whereas average, species-typical timing of many developmental processes has been established, less is known about inter-individual variability and correlations in timing of specific events. We addressed these questions in the context of postembryonic development in Caenorhabditis elegans. Based on patterns of locomotor activity of freely moving animals, we inferred durations of four larval stages (L1-L4) in over 100 individuals. Analysis of these data supports several notable conclusions. Individuals have consistently faster or slower rates of development because durations of L1 through L3 stages are positively correlated. The last larval stage, the L4, is less variable than earlier stages and its duration is largely independent of the rate of early larval development, implying existence of two distinct larval epochs. We argue that characteristic patterns of variation and correlation arise because duration of each stage tends to scale relative to total developmental time. This scaling relationship suggests that each larval stage is not limited by an absolute duration, but is instead terminated when a subset of events that must occur prior to adulthood have been completed. The approach described here offers a scalable platform that will facilitate the study of temporal regulation of postembryonic development.

scholarly journals Analysis of a lin-42/period Null Allele Implicates All Three Isoforms in Regulation of Caenorhabditis elegans Molting and Developmental Timing

2016 ◽  
Vol 6 (12) ◽  
pp. 4077-4086 ◽  
Author(s):  
Theresa L B Edelman ◽  
Katherine A McCulloch ◽  
Angela Barr ◽  
Christian Frøkjær-Jensen ◽  
Erik M Jorgensen ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Null Allele ◽  
Postembryonic Development ◽  
Developmental Timing ◽  
Critical Element ◽  
Coding Region ◽  
Protein Coding ◽  
Temporal Regulation ◽  
Larval Stages ◽  
Hypomorphic Alleles

Abstract The Caenorhabditis elegans heterochronic gene pathway regulates the relative timing of events during postembryonic development. lin-42, the worm homolog of the circadian clock gene, period, is a critical element of this pathway. lin-42 function has been defined by a set of hypomorphic alleles that cause precocious phenotypes, in which later developmental events, such as the terminal differentiation of hypodermal cells, occur too early. A subset of alleles also reveals a significant role for lin-42 in molting; larval stages are lengthened and ecdysis often fails in these mutant animals. lin-42 is a complex locus, encoding overlapping and nonoverlapping isoforms. Although existing alleles that affect subsets of isoforms have illuminated important and distinct roles for this gene in developmental timing, molting, and the decision to enter the alternative dauer state, it is essential to have a null allele to understand all of the roles of lin-42 and its individual isoforms. To remedy this problem and discover the null phenotype, we engineered an allele that deletes the entire lin-42 protein-coding region. lin-42 null mutants are homozygously viable, but have more severe phenotypes than observed in previously characterized hypomorphic alleles. We also provide additional evidence for this conclusion by using the null allele as a base for reintroducing different isoforms, showing that each isoform can provide heterochronic and molting pathway activities. Transcript levels of the nonoverlapping isoforms appear to be under coordinate temporal regulation, despite being driven by independent promoters. The lin-42 null allele will continue to be an important tool for dissecting the functions of lin-42 in molting and developmental timing.

scholarly journals Density and body size of the larval stages of the invasive golden mussel (Limnoperna fortunei) in two neotropical rivers

2012 ◽  
Vol 23 (3) ◽  
pp. 282-292 ◽  
Author(s):  
Vivianne Eilers ◽  
Márcia Divina de Oliveira ◽  
Kennedy Francis Roche
Keyword(s):  
Body Size ◽  
Larval Stage ◽  
Larval Density ◽  
Limnoperna Fortunei ◽  
Larval Size ◽  
Larval Stages ◽  
Positive Effects ◽  
Paraguay River ◽  
Body Sizes ◽  
Golden Mussel

AIM: The present study involved an analysis of the monthly variations in the population densities and body sizes of the different stages of planktonic larvae of the invasive golden mussel (Limnoperna fortunei), in the rivers Paraguay and Miranda; METHODS: The study was carried out between February 2004 and January 2005. Monthly collection of the plankton samples was accompanied by physical, chemical and biological analyses of the water; RESULTS: The Miranda River presented higher values of calcium, pH, alkalinity, conductivity and total phosphorous. Larval density varied from 0-24 individuals.L-1 in the Paraguay River, with a peak in March of 2004, while in the Miranda River, densities varied between 0-9 individuals.L-1 with a peak in February of 2004. No larvae were encountered during the coldest months, May and June. No significant correlations were found between environmental variables and larval density in either river. Only the valved larval stages were recorded. The "D" and veliger forms were most abundant; umbonate larvae were rare in the Miranda River samples. Mean body sizes of "D", veliger and umbonate larval stages were, respectively, 111, 135 and 152 µm, in the Paraguay River, and 112, 134 and 154 µm in the Miranda River. Principal Components Analysis indicated positive relationships between "D" larval stage size and the ratio between inorganic and organic suspended solids, while negative relationships were found between larval size and calcium and chlorophyll-<img border=0 width=7 height=8 src="/img/revistas/alb/2012nahead/ALB_AOP_230307car01.jpg">; CONCLUSIONS: The larvae were recorded in the plankton during most of the year, with the exception of the two colder months. Neither densities nor larval stage body sizes were significantly different between the two rivers. Possible positive effects of food and calcium concentrations on body size were not recorded. This species may be adapted to grow in environments with elevated sediment concentrations.

Notes on the Myiasis-producing Diptera of Man and Animals

1921 ◽  
Vol 12 (3) ◽  
pp. 239-261 ◽  
Author(s):  
W. S. Patton
Keyword(s):  
Human Body ◽  
Larval Stage ◽  
Common Condition ◽  
Larval Stages

Myiasis has been defined by Austen as follows:—“There remains yet a third category of flies, chiefly belonging to the great Family Muscidae, the larval stage of which is sometimes actually passed in the living human body, the presence of the larvae in the various organs and tissues, and the disorders or destruction of tissue caused thereby, being comprehensively known as Myiasis.” It will be noted that this definition only refers to the larval stages of flies, but as the eggs, and in one case at least, pupae and adults, may be found in the human body, and as myiasis is a common condition in many animals, the definition may now be amplified as follows:— The condition or conditions, resulting from the invasion of the tissues and organs of man and other animals by all the stages of the Diptera.

scholarly journals Efficacy of Bacillus thuringiensis (Berliner) isolates on fig moth, Ephestia cautella (Walker) Larvae

2014 ◽  
Vol 11 (2) ◽  
pp. 943-951
Author(s):  
Baghdad Science Journal
Keyword(s):  
Bacillus Thuringiensis ◽  
Larval Stage ◽  
Filter Paper ◽  
Larval Instar ◽  
Ephestia Cautella ◽  
Larval Stages ◽  
The Third ◽  
Total Percentage ◽  
First Instar ◽  
Paper Method

The following dilution 5×10-1, 10-1, 10?2 , 10-3 gm/L for the indigenous isolate of Bacillus thuringiensis bacteria and the commercially isalate were used for experiments against the different stages of fig moth of E.cautella which exposed by filter paper method. The results showed that mortality of larval stages was increased with the increasing concentration of the biocide, in addition to increase in the mortality of the larval stages reached to the highest percentage in the third days of treatment of the larval stage in comparison with the first and second days of exposure. The results also showed that the sensitivity of larval stages was increased in first and second instars while reduced in the last instars .The high percentage of first instar mortality for the indigenous isolate in the concentration of 5×10-1 was 72.8% , while the low percentage of mortality showed in the concentration of 5×10-1 for the fifth instar larvae which was 13.3% in third days of treatment while a high percentage of mortality was showed for the first instar larvae for the commercially isulate in the concentration of 5×10-1 was 59.4% Furthermore, low percentage of mortality was shown in the concentration of 5×10-1 in fifth instar larval which was 8.3% in the third days of treatment. The results also showed that the indigenous isolated was more effective than the commercially produced bacteria for killing larval instars of fig moth E.cautella .The total percentage of larval instar mortality reached to 44.5 % after the third days of treatment in concentration 5×10-1 in the indigenous isolate , and it was 33.8 % in the commercially produced bacteria .

Morphological and biological characteristics of Taenia rileyi Loewen, 1929 (Cestoda: Taeniidae)

1981 ◽  
Vol 59 (4) ◽  
pp. 653-666 ◽  
Author(s):  
R. L. Rausch
Keyword(s):  
Geographic Distribution ◽  
Larval Stage ◽  
Tissue Response ◽  
Biological Characteristics ◽  
Natural Cycle ◽  
Larval Stages

The development and structure of the larval Taenia rileyi Loewen, 1929, a cestode of nearctic felids, were studied in rodents infected experimentally with eggs from strobilae from lynx, Felis lynx L. The larval stage, intermediate in form between a cysticercus and a strobilocysticercus, was found to be unlike that of any other known species of Taenia and is designated a hemistrobilocysticercus. The tissue response in experimentally infected rodents is described. Morphologic features of the strobilar and larval stages by which T. rileyi is distinguished from Taenia omissa Lühe, 1910 are defined, and observations are included concerning geographic distribution and natural cycle.

Growth and reproduction of Halicarcinus australis (Haswell) (Crustacea, Brachyura) in the Swan estuary, Western Australia. II. Larval stages

1970 ◽  
Vol 21 (2) ◽  
pp. 163 ◽  
Author(s):  
JS Lucas ◽  
EP Hodgkin
Keyword(s):  
Larval Development ◽  
Larval Stage ◽  
Spatial Distributions ◽  
Laboratory Rearing ◽  
Larval Stages ◽  
Third Stage ◽  
Temperature Ranges ◽  
Causes Of Mortality ◽  
Temporal And Spatial ◽  
Growth And Reproduction

Larvae of Halicarcinus australis (Haswell) were collected in vertical plankton samples from eight stations in the Swan estuary during two summers. The majority of samples included live and dead larvae; the high proportion of dead larvae shows that there are other important causes of mortality besides predation. Third stage zoeae (the final larval stage) occur over more restricted salinity and temperature ranges than earlier zoeal stages, and their temporal and spatial distributions in the estuary are also more restricted. Laboratory rearing of H. australis larvae at 16 chlorinity-temperature combinations shows that larvae are less tolerant of extremes of these parameters than crabs. Hydrological conditions unfavourable for larval development occur throughout the estuary in winter and in upstream regions in summer. However, during much of these periods ovigerous females are present in crab populations and larvae are released, thus accounting for some of the mortality apparent from the plankton samples. Third stage zoeae are found progressively further up stream in summer associated with the advance of favourable salinities and with a zone of plankton abundance. Recruitment into crab populations reflects the time of completion of larval development at each locality.

Description of the first zoeal stage of Synalpheus apioceros Coutière, 1909 (Caridea: Alpheidae), including a comparative analysis with larval morphology from the genus Synalpheus Spence Bate, 1888

Zootaxa ◽  
2020 ◽  
Vol 4838 (1) ◽  
pp. 71-82
Author(s):  
RAFAEL C. SANTOS ◽  
RÉGIS A. PESCINELLI ◽  
ROGERIO C. COSTA
Keyword(s):  
Comparative Analysis ◽  
Larval Development ◽  
Larval Stage ◽  
Morphological Characteristics ◽  
Plumose Seta ◽  
Zoeal Stage ◽  
Larval Morphology ◽  
Morphological Similarity ◽  
Similar Morphology ◽  
Larval Stages

Herein, the Zoea I of Synalpheus apioceros is described, followed by a comparative analysis of the first larval stage from Synalpheus. Larvae were obtained from two ovigerous females sampled in Ubatuba, São Paulo. The morphology of the Zoea I of S. apioceros was compared to five other Synalpheus species whose structures were previously described: S. biunguiculatus, S. minus, S. neomeris, S. pectiniger, and S. tumidomanus. A set of unique morphological characteristics was found for S. apioceros: exopod of antennule with 4 aesthetascs and 1 plumose seta; coxal endite of maxillule with 2 simple setae plus 2 plumose setae; basial endite of maxillule with 2 simple setae plus 2 short spines; endopod of maxillule with 1 plumose seta plus 2 simple setae; basial endite of maxilla bilobed with 2 (1 plumose and 1 simple) + 2 (1 plumose and 1 simple) setae; coxal endite of maxilla bilobed with 2 + 1 plumose setae; endopod of maxilla with 3 (1 plumose and 2 simple) terminal setae + 2 simple setae; endopod of first maxilliped unsegmented with 3 terminal simple setae; basis of first maxilliped with 5 spines; endopod of second maxilliped 5-segmented with 0, 0, 0, 1 plumodenticulate, 4 (1 serrate + 3 simple) setae; endopod of third maxilliped 5-segmented with 0, 0, 0, 1 simple, 3 simple setae; pereiopods 1st to 3rd birramous and 4th and 5th uniramous. S. apioceros shows higher morphological similarity with S. minus, followed by S. tumidomanus, S. neomeris and S. pectiniger, probably since these species present extended larval development. Besides the similar morphology among species, the unique attributes presented here are important for the genus’ taxonomy, being fundamental for identifying the first larval stages of Synalpheus, as well as for subsidizing information for species identification keys. 

Host Age Effects on Ovipositional and Developmental Biology of Baryscapus chrysopae (Hymenoptera: Eulophidae), a Parasitoid of Chrysopid Larvae

1995 ◽  
Vol 30 (2) ◽  
pp. 287-293
Author(s):  
John R. Ruberson ◽  
Timothy J. Kring
Keyword(s):  
Developmental Biology ◽  
Sex Ratio ◽  
Developmental Time ◽  
Age Effects ◽  
Host Age ◽  
Larval Stages ◽  
Chrysoperla Rufilabris ◽  
Host Stage ◽  
Gregarious Parasitoid

The parasitoid, Baryscapus (=Tetrastichus) chrysopae (Crawford), is a widely-distributed gregarious parasitoid of chrysopid larvae. The ovipositional and developmental biology of this parasitoid in relation to the stage of its host, Chrysoperla rufilabris (Burmeister), was examined. Female B. chrysopae attacked all larval stages of the host tested (instars 1 to 3), and paralyzed all hosts soon after mounting and stinging. During the host's paralysis, females oviposited in and fed on hosts. The time females spent on hosts was directly related to host stage. All hosts recovered from paralysis. Parasitoid developmental time was inversely related to host stage and ranged from 27.5 d in 1-d-old hosts to 20.5 d in 10-d-old hosts. Most development of parasitoid larvae appears to occur after the host has spun its pupal cocoon. The number of parasitoids produced per host was unrelated to host stage, ranging from 10.5 (in 1-d-old hosts) to 14.2 (in 7-d-old hosts) parasitoids per host. The sex ratio was skewed toward females (81.6% pooled across host stages) and was unrelated to host stage. The developmental biology of B. chrysopae appears to be well synchronized with that of its host.

scholarly journals Influense of curcumin on lifespan if it is applied at the larval stage of drosophila melanogaster

2020 ◽  
pp. 89-96
Author(s):  
Anatoly Pisaruk ◽  
Natalya Koshel ◽  
Ludmila Mekhova ◽  
Oksana Zabuga ◽  
Stephen Ivanov
Keyword(s):  
Drosophila Melanogaster ◽  
Life Span ◽  
Developmental Stage ◽  
Larval Stage ◽  
Developmental Duration ◽  
Larval Stages ◽  
Epigenetic Programming ◽  
Males And Females ◽  
Adult Drosophila ◽  
Different Doses

In this study we have applied the different doses of curcumin at the larval stages of a fruitfly Drosophila melanogaster and subsequently ivestigated its effect on the developmental duration and life expectancy of imago. It has been shown a 2-day delay in the hatching of the flies, which were developing in the medium containing 500 mM of curcumin. Exposure to curcumin significantly influenced on the average and maximum lifespan (ALS and MLS respectively) of all Drosofila in the study: ALS – F=13.01, p<0.001 for males and F=14.3, p<0.001 for females; MLS – F=35.9, p<0.001 for males and F=16.7, p <0.001 for females. Thus, the ALS in the males, which at the larval stage were kept in the medium containing 125 mM, 250 mM and 500 mM of curcumin, was significantly higher (p<0.001) comparing to the control. In females, such kind of significant increase in ALS has been shown at a dose of 500 mM of curcumin (p<0.001) in the medium during the developmental stage comparing to the control. In other words, the ALS of the imago has increased in correlation to the increase in the dose of curcumin applied at the developmental stage in males by 9%, 16%, 13%, and 23% and in females by 0%, 1%, 3%, 16% respectively. There has been also shown the sharp raise in MLS in both males and females, which at the larval stage were kept in the medium containing more than 125 mM of curcumin. To sum up we can assume that in this study consumption of curcumin at the larval stage of fruit flies significantly increased the developmental duration and life span of adult Drosophila, and this may demonstrate the effect of curcumin on the epigenetic programming of pace of life. Keywords: Development; Life span; Curcumin; Drosophila

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