Search

Larvae and adults of an Hawaiian bivalve, Isognomon californicum, were exposed to sublethal, environmentally realistic concentrations of cadmium (2 and 20 ppb) for 28 d, and the accumulation of cadmium was evaluated. The concentrations of cadmium were expressed in terms of total cadmium (tissue and shell concentrations combined) and tissue cadmium. The accumulation rates of larvae were one to two orders of magnitude greater than adult rates. This study suggests that the faster uptake rates of larvae may explain why larvae are more sensitive than adults. Furthermore, the magnitude of differences between larval and adult accumulation rates may be related to metabolic rate. When larvae and adults were exposed to cadmium for only 14 d, followed by a 14 d depuration period, a substantial loss of cadmium was observed during the depuration period. Possible accumulation mechanisms and their similarity between larvae and adults are discussed. [ABSTRACT FROM AUTHOR]

The article offers information on molecular cascades which ensure proper temporal progression of the neural stem cells in the fruitfly Drosophila melanogaster. It mentions Drosophila's central nervous system (CNS) is developed in two phases which include an embryonic phase in which it establishes the basic wiring and function and the larval phase in which it expands on the framework of the embryonic CNS.

The agave red worm, Comadia redtenbacheri Hamm., is an edible insect in Mexico. Its larval development is affected by the parasitoid Acantholespesia texana (Aldrich & Webber), which is reported for the first time in Mexico, with the agave red worm as a new host. [ABSTRACT FROM AUTHOR]

Larval exposure to pesticides can occur at different times during development and can negatively impact amphibian fitness. We examined the effects of larval green frog ( Rana clamitans) exposure to carbaryl at 2, 4, 8, or 16 weeks of development on juvenile predatory ability. We did not find evidence that predatory ability was affected by exposure to carbaryl, which suggests that carbaryl does not have latent effects on the predatory performance of green frogs in subsequent life stages. Environ. Toxicol. Chem. 2011; 30:1618-1620. © 2011 SETAC [ABSTRACT FROM AUTHOR]

The article presents a study on the phylogenetic analysis of lethal (2) giant larvae (LGL) tumor suppressor protein family. It notes that the LGL protein is represented by two and more homologues encoded by two different genes. Results indicate that the appearance of the system for the control of cellular aggregate proliferation is considered as one of the events leading to the emergence of metazoans.

The article presents a study demonstrating the genetic and phenotypic characteristics of nuclear polyhedrosis virus (NPV) isolates from gypsy moth larvae in natural populations of western Siberia. It notes that these isolates shows phenotypic virus variability in terms of reproductive activity and virulence. It discusses the differences in virulence and reproductive activity between the natural isolates of NPV.

The white-spotted flower chafer, Protaetia brevitarsis seulensis (Kolbe), is used as an important source of medicinal properties, such as anti-cancer activity and prevention of liver-related diseases, in Korea. To use this insect species without endangering wild populations, a mass rearing technique is needed. The present study was carried out to determine whether different diets can affect the larval growth of P. brevitarsis seulensis. Six different diets were investigated in the experiment, and the results showed that 20% rice straw with 80% oakwood sawdust was the best diet for larval growth of this beetle. [ABSTRACT FROM AUTHOR]

The honey bee Apis mellifera is the most abundant managed pollinator in diverse crops worldwide. Consequently, it is exposed to a plethora of environmental stressors, among which are the agrochemicals. In agroecosystems, the herbicide glyphosate (GLY) is one of the most applied. In laboratory assessments, GLY affects the honey bee larval development by delaying its moulting, among other negative effects. However, it is still unknown how GLY affects larval physiology when there are no observable signs of toxicity. We carried out a longitudinal experimental design using the in vitro rearing procedure. Larvae were fed with food containing or not a sub-lethal dose of GLY in chronic exposure (120 h). Individuals without observable signs of toxicity were sampled and their gene expression profile was analyzed with a transcriptomic approach to compare between treatments. Even though 29% of larvae were asymptomatic in the exposed group, they showed transcriptional changes in several genes after the GLY chronic intake. A total of 19 transcripts were found to be differentially expressed in the RNA-Seq experiment, mainly linked with defensive response and intermediary metabolism processes. Furthermore, the enriched functional categories in the transcriptome of the exposed asymptomatic larvae were linked with enzymes with catalytic and redox activity. Our results suggest an enhanced catabolism and oxidative metabolism in honey bee larvae as a consequence of the sub-lethal exposure to GLY, even in the absence of observable symptoms. Image 1 • Honey bee larvae were chronically fed in vitro with food containing glyphosate. • At the end of the cohort study, larvae without signs of toxicity were sampled. • Exposed asymptomatic larvae showed differentially expressed genes in RNA-Seq. • Enriched functional categories suggested high catalytic and oxidative metabolism. [ABSTRACT FROM AUTHOR]

A table of content of the journal "Evolution and Development" including research papers on the larval nervous system in phoronids, developmental evolution of the axial skeleton of odontocetes (Cetacea), and books reviews on evolutionary theory along with the information on subscription is presented.

The late pupal stage (pharate adult) of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) close to adult emergence was irradiated with doses up to 350 Gy to determine a dose that could serve as a phytosanitary treatment against Lepidoptera that may pupate in shipped commodities. Adult emergence was not significantly reduced below that of the non-irradiated control until the dose reached 200 Gy. Not until the dose had been increased to 150 Gy was the number of eggs laid significantly less than the control, and oviposition was completely prevented at ≥ 300 Gy. Egg hatch was not significantly reduced compared with the non-irradiated control until the dose reached 150 Gy, and no eggs hatched at ≥ 250 Gy. This study supports a generic radiation dose for pupae of Lepidoptera of at least 250 Gy. [ABSTRACT FROM AUTHOR]

The article examines the cannibalistic phenotype of the larvae of Oita salamander Hynobius dunni using a captive colony of salamanders. Topics mentioned include the inducement of reproduction in captive H. dunni which originates in Beppu Shi of Oita Prefecture, Japan, larval duration, total length and mortality rates of high- and low-density larvae, as well as the development of cannibalistic morphs.

Background: For capital breeding Lepidoptera, larval food quality is a key determinant of their fitness. A series of studies have suggested that the larval host species or varieties dramatically impact their development and reproductive output. However, few studies have reported the role of foliar age and adult mating success has often been ignored in these studies. In this paper, the influence of host species and needle age on larval performances, adult mating behavior and fitness consequences has been studied using a capital breeding caterpillar, Dendrolimus punctatus Walker (Lepidoptera:Lasiocampidae). Results: In larval performance trial, a strong effect of larval host species and needle age was found on survivorship, developmental duration, body weight, percentage of adult emergence, and growth index, but not on percentage of female progeny. In adult mating trial, larval host species and needle age also significantly affected mating latency and mating duration, but not mating success. In adult fitness trial, female fecundity, longevity and fitness index, but not oviposition duration and fertility, influenced by larval host species and needle age. Conclusions: These results reveal the importance of larval host species and needle age on larval performance and adult reproductive fitness in this capital breeding insect and provide strong evidence that old needles of masson pine P. massoniana is the best host for D. punctatus. [ABSTRACT FROM AUTHOR]

Background: Despite recent work to characterize gene expression changes associated with larval development in oysters, the mechanism by which the larval shell is first formed is still largely unknown. In Crassostrea gigas, this shell forms within the first 24 h post fertilization, and it has been demonstrated that changes in water chemistry can cause delays in shell formation, shell deformations and higher mortality rates. In this study, we use the delay in shell formation associated with exposure to CO2-acidified seawater to identify genes correlated with initial shell deposition. Results: By fitting linear models to gene expression data in ambient and low aragonite saturation treatments, we are able to isolate 37 annotated genes correlated with initial larval shell formation, which can be categorized into 1) ion transporters, 2) shell matrix proteins and 3) protease inhibitors. Clustering of the gene expression data into co-expression networks further supports the result of the linear models, and also implies an important role of dynein motor proteins as transporters of cellular components during the initial shell formation process. Conclusions: Using an RNA-Seq approach with high temporal resolution allows us to identify a conceptual model for how oyster larval calcification is initiated. This work provides a foundation for further studies on how genetic variation in these identified genes could affect fitness of oyster populations subjected to future environmental changes, such as ocean acidification. [ABSTRACT FROM AUTHOR]

The article discusses a study of the optokinetic or swivel reflex of Xenopus larvae by Céline Gravot of the Ludwig-Maximilians-Universität München in Germany. It demonstrates that the swivel reflex of Xenopus larvae depends on the contrast as the tadpoles strongly responded to the bright dots on dark background than the dark spots, understanding the drastic lifestyle change of tadpoles during the metamorphose stage to amphibious hunters affecting their visual processing.

Summary Larval stages can be astonishingly different from their adult forms. A new study in acorn worms shows that the whole larval body is patterned only with a subset of anterior genes, revealing the intricate developmental bases that underlie the evolution of larval forms. [ABSTRACT FROM AUTHOR]

The article presents a study which explores the role of symbionts in manipulating plant defenses through the observation of the larvae of the Colorado potato beetle (CPB) Leptinotarsa decemlineata. It notes that the larvae of CPB secretes bacterial symbionts that can suppress an anti-herbivore defence pathway in tomato plants thus promote larval growth. Researchers have observed that the oral secretions deposited on plant leaves by untreated CPB larvae contained large amounts of bacteria.

In this article the author discusses the study by Pungaliya and colleagues on three small molecule signals that regulate the larval growth and pairing in the nematode Caenorhabditis elegans. The author mentions that the researchers used differential analysis by 2-dimensional nuclear magnetic resonance spectroscopy (DANS) in their study. The author notes that the study by Pungaliya and colleagues describes the importance of the application of DANS in a model system amenable to genetic analysis.

Uracil phosphoribosyltransferase (UPRT) is a pyrimidine salvage pathway enzyme that catalyzes the conversion of uracil to uridine monophosphate (UMP). The enzyme is highly conserved from prokaryotes to humans and yet phylogenetic evidence suggests that UPRT homologues from higher-eukaryotes, including Drosophila, are incapable of binding uracil. Purified human UPRT also do not show any enzymatic activity in vitro, making microbial UPRT an attractive candidate for anti-microbial drug development, suicide-gene therapy, and cell-specific mRNA labeling techniques. Nevertheless, the enzymatic site of UPRT remains conserved across the animal kingdom indicating an in vivo role for the enzyme. We find that the Drosophila UPRT homologue, krishah (kri), codes for an enzyme that is required for larval growth, pre-pupal/pupal viability and long-term adult lifespan. Our findings suggest that UPRT from all higher eukaryotes is likely enzymatically active in vivo and challenges the previous notion that the enzyme is non-essential in higher eukaryotes and cautions against targeting the enzyme for therapeutic purposes. Our findings also suggest that expression of the endogenous UPRT gene will likely cause background incorporation when using microbial UPRT as a cell-specific mRNA labeling reagent in higher eukaryotes. [ABSTRACT FROM AUTHOR]

Population replacement/elimination strategies based on mass-release of sterile or otherwise genetically modified (male) mosquitoes are being considered in order to expand the malaria vector control arsenal on the way to eradication. A challenge in this context, is to produce male mosquitoes that will be able to compete and mate with wild females more efficiently than their wild counterparts, i.e. high fitness males. This study explored the effect of three larval food diets developed by the International Atomic Energy Agency on the overall fitness and mating performance of male Anopheles gambiae s.s. mosquitoes (Kisumu strain). Larval development (pupation and emergence rate, development time) was monitored, and adult wing length and energy reserves at emergence (i.e. lipids, sugars, glycogen and proteins) were measured. Male sexual performance was assessed through an insemination test whereby one male and 10 virgin females were maintained together in the same cage in order to record the number of inseminated females per 24 h. Our results show that males reared on Diets 2 and 3 performed best during larval development. Males provided with treatment 2.2 had a shorter development time and performed best in insemination tests. However, these males had the lowest overall lifespan, suggesting a trade-off between longevity and sexual performances which needs to be taken into consideration when planning release. The results from this work were discussed in the context of sterile insect techniques or genetic control methods which is today one of the strategy in the overall mosquito control and elimination efforts. [ABSTRACT FROM AUTHOR]

A correction to the article "Effect of Temperature on Development Rate of Larvae From Cold-Water American Webster (Homarus Americanus)" by Brady K. Quinn et al. that was published in a 2013 issue is presented

Abstract: The success of reproduction depends greatly upon gamete quality, especially oocytes which carry most of the molecular material necessary for early embryogenesis. However, it remains difficult to find relevant morphologic and/or biochemical parameters to assess oocyte quality and thus have a reliable prediction of the reproduction performance. To understand which criteria are the most reliable to assess the reproductive success of the Eurasian perch (Perca fluviatilis), we measured 14 parameters characterizing female, spawn, oocyte, and embryonic or larval development on 20 independent spawn. A data analysis allowed the definition of two clusters of spawn with different larval characteristics: the first cluster was composed of spawn which led mainly to strong large larvae presenting a low deformity rate, while the second cluster rather corresponds to spawn leading to smaller and weaker larvae with a higher deformity rate. Moreover, a third cluster (unfertilized spawn) was studied. Our analysis revealed that most of the prefertilization biological traits that we studied appeared poorly relevant to predict larval features, proper embryonic development and deformity occurrences. We thus performed a large scale proteomic analysis to highlight proteins differently expressed in each spawn cluster. A 2D-DIGE study followed by an MS/MS spectrometry allowed the identification of 32 proteins involved in several biological functions and differently expressed between spawn clusters. Among them, proteins involved in cell response to the oxidative stress, as well as energetic metabolism, heat shock proteins and Vitellogenins are of particular interest. Several functions appear specific to a spawn cluster and could thus explain their corresponding reproduction performance. In the future, proteins involved in those cellular mechanisms may constitute molecular markers predictive of the reproduction performance in Perca fluviatilis. [Copyright &y& Elsevier]

Summary 1. The temperature-size rule (TSR) is a widespread phenomenon, which describes the phenotypic plastic response of species' size to temperature: individuals reared at colder temperatures mature as larger adults than at warmer temperatures. 2. The TSR is driven by an unequal thermal response of growth and development rates. However, we currently lack an understanding of how these rates change through ontogeny and their decoupling. Further, we do not know how this decoupling varies across generations. 3. Using the brine shrimp Artemia franciscana as a model, we examine growth and development rates through ontogeny at different temperatures across two generations. 4. The slopes of natural-logged weight-specific growth rates against temperature are steeper in earlier than later larval stages, indicating their greater temperature dependence, whereas development rates maintain the same temperature dependence across life stages. An inverse TSR is generated in early larval stages; the typical TSR (smaller size at warmer temperatures) is only established later in ontogeny. 5. Phase-specific temperature dependence of growth and development rates is not significantly different across the 1st and 2nd generation, suggesting the TSR is primarily a within-generation outcome. 6. Ontogenetic size responses in Artemia are compared to other crustacean species to identify patterns within this subphylum. Data for a range of crustaceans follow the same ontogenetic pattern: early larval stages show an inverse or no TSR, with TSR being only established in later stages. Adults often, but not always, show the greatest response. [ABSTRACT FROM AUTHOR]

Vera Candioti, M.F., Nuñez, J.J. and Úbeda, C. 2011. Development of the nidicolous tadpoles of Eupsophus emiliopugini (Anura: Cycloramphidae) until metamorphosis, with comments on systematic relationships of the species and its endotrophic developmental mode. - Acta Zoologica (Stockholm) : 27-45. Species of Eupsophus are unique within Alsodinae in having nidicolous tadpoles. They are characterized by traits typical of generalized exotrophic (e.g., oral disc and spiracular tube) and endotrophic larvae (e.g., scant pigmentation and large hind limbs). The larval morphology and development of E. emiliopugini, including external, buccal, and musculoskeletal features, is described herein. Like the larvae of other alsodines, these larvae have four lingual and four infralabial papillae, quadratoethmoid process, and an m. rectus cervicis with a double insertion. Among the traits exclusive to the genus are: the absence of the pseudopterygoid process and quadrato-orbital commissure; presence of the m. subarcualis rectus I with two slips; and presence of the m. subarcualis rectus II-IV inserting on Ceratobranchial II. The development and metamorphosis of Eupsophus include some characters that develop later (e.g., degeneration of mouthparts and chondrocranium with minimum calcification), characters that develop earlier (e.g., hind-limb appearance and jaw and suspensorium ossification), and characters that develop at the same time (e.g., most external features and cranial muscles) than in most exotrophic species. Some distinctive characters (third lower labial ridge absent, general configuration of the hyobranchial skeleton, skeletal development with retention of larval traits) resemble those of other endotrophic species, and the precocious ossification of jaws and suspensorium is shared with several direct-developing species among recent amphibians. [ABSTRACT FROM AUTHOR]

The article focuses on two studies concerning the implications of transient receptor potential cation channel N1 (TRPN1) in mechanosensation by nematodes and fruitflies. It references the study by L. E. Cheng and colleagues, and L. Kang and colleagues on the role of TRPN1 in larval and adult locomotion, and as a subunit of mechanotransduction channel respectively. It says that through green fluorescent protein construct, the role of TRPN1 for proprioception in Drosophila melanogaster was shown.

Summary: The protein Lethal giant larvae (LGL) regulates cell polarity in diverse animal models. Now, an LGL orthologue has been identified in the worm Caenorhabditis elegans and is shown to function redundantly with a worm-specific polarity protein, PAR-2. [ABSTRACT FROM AUTHOR]

The ligamental apparatus of Thracia comprises external and internal resilient components, as well as a calcified ossicle termed the lithodesma. All these elements have hitherto been considered portions of a single unit and their allometry and functional morphology interpreted as such. However, analyses of the fine structure of the hinge of a growth series of Thracia phaseolina using conventional light, confocal and scanning electron microscopy revealed that, instead, external and internal components comprise distinct, independent layers of fibrous ligament, each formed at different ontogenetic stages. The internal ligament, with a lithodesma along its mid-sagittal sector, comprises the sole early juvenile ligament of the species and its main function is to force the shell valves open, not align them as had been previously suggested. The external (parivincular) ligament only appears at a shell length of c. 2.5 mm, but grows faster than the internal ligament to become the main component of the hinge of adults. Two- and three-parameter power functions (simple and full allometric equations) were fitted to measurements of the different ligament parts, and the performance and appropriateness of these models in describing the allometry of each of the studied traits are evaluated. Use of the full allometric model is recommended whenever the body size (or other standard) at which a trait of interest arises lies within or close to the limits of the sampled range. [ABSTRACT FROM AUTHOR]

The article discusses a report published within the November 2008 issue. The focus of the report is research by Gáspár Jékely and colleagues investigating how two eyespots on the marine worm Platynereis dumerilii perceive light. Also investigated was how the larva of P. dumerilii responded to differential beating of cilia and various swimming actions.

The article discusses the extraordinary tolerance of Polypedilum vanderplanki larvae to dessication. A study was conducted identifying a trehalose transporter called the TRET1 in P. vanderplanki. The study showed evidences of specificity for trehalose versus maltose, sucrose, and lactose as well as the low-affinity function, high capacity facilitated transporter which are also expressed in benignly in mammalian cells. The development and survival of trehalose in dehydrated larvae progressing to become adult midges after rehydration is discussed.