scholarly journals Mode of action evaluation for reduced reproduction in Daphnia pulex exposed to the insensitive munition, 1-methyl-3-nitro-1-nitroguanidine (MeNQ)

Ecotoxicology ◽  
2021 ◽  
Author(s):  
Kurt A. Gust ◽  
Guilherme R. Lotufo ◽  
Natalie D. Barker ◽  
Qing Ji ◽  
Lauren K. May
Keyword(s):  
Egg Production ◽  
Daphnia Pulex ◽  
Indirect Costs ◽  
Energy Budgets ◽  
Exposure Level ◽  
Transcriptional Expression ◽  
Canonical Pathways ◽  
Significant Enrichment ◽  
Inducible Protein ◽  
Reproductive Processes

AbstractThe US Department of Defense (DOD) is developing insensitive munitions (IMs) that are resistant to unintended detonation to protect warfighters. To enable material life-cycle analysis for the IM, 1-methyl-3-nitro-1-nitroguanidine (MeNQ), ecotoxicological impacts assessment was required. A previous investigation of MeNQ exposures in Daphnia pulex revealed concentration-responsive decreases in reproduction relative to controls (0 mg/L) across a 174, 346, 709, 1385, and 2286 mg/L exposure range. The present study used those exposures to conduct global transcriptomic expression analyses to establish hypothetical mode(s) of action underlying inhibited reproduction. The number of significantly affected transcripts and the magnitude of fold-change differences relative to controls tended to increase with increasing MeNQ concentration where hierarchical clustering analysis identified separation among the “low” (174 and 346 mg/L) and “high” (709, 1385, and 2286 mg/L) exposures. Vitellogenin is critical to Daphnia reproductive processes and MeNQ exposures significantly decreased transcriptional expression for vitellogenin-1 precursor at the lowest exposure level (174 mg/L) with benchmark dose (BMD) levels closely tracking concentrations that caused inhibited reproduction. Additionally, juvenile hormone-inducible protein, chorion peroxidase, and high choriolytic enzyme transcriptional expression were impacted by MeNQ exposure having potential implications for egg production / maturation and overall fecundity. In concert with these effects on specific genes involved in Daphnia reproductive physiology, MeNQ exposures caused significant enrichment of several canonical-pathways responsible for metabolism of cellular energy substrates where BMD levels for transcriptional expression were observed at ≤100 mg/L. These observations imply possible effects on whole-organism energy budgets that may also incur indirect costs on reproduction.

scholarly journals Serine hydroxymethyltransferase controls blood-meal digestion in the midgut of Aedes aegypti mosquitoes

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuemei Li ◽  
Jinyu Yang ◽  
Qian Pu ◽  
Xinyue Peng ◽  
Lili Xu ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Blood Meal ◽  
Digestive Enzymes ◽  
Egg Production ◽  
Sequence Similarity ◽  
Mrna Level ◽  
Serine Hydroxymethyltransferase ◽  
Blood Protein ◽  
Transcriptional Expression ◽  
Blood Meal Digestion

Abstract Background Female Aedes aegypti mosquitoes are vectors of arboviruses that cause diverse diseases of public health significance. Blood protein digestion by midgut proteases provides anautogenous mosquitoes with the nutrients essential for oocyte maturation and egg production. Midgut-specific miR-1174 affects the functions of the midgut through its target gene serine hydroxymethyltransferase (SHMT). However, less is known about SHMT-regulated processes in blood digestion by mosquitoes. Methods RNAi of SHMT was realized by injection of the double-stranded RNA at 16 h post-eclosion. The expression of SHMT at mRNA level and protein level was assayed by real-time PCR and Western blotting, respectively. Statistical analyses were performed with GraphPad7 using Student’s t-test. Results Here, we confirmed that digestion of blood was inhibited in SHMT RNAi-silenced female A. aegypti mosquitoes. Evidence is also presented that all SHMT-depleted female mosquitoes lost their flight ability and died within 48 h of a blood meal. Furthermore, most examined digestive enzymes responded differently in their transcriptional expression to RNAi depletion of SHMT, with some downregulated, some upregulated and some remaining stable. Phylogenetic analysis showed that transcriptional expression responses to SHMT silence were largely unrelated to the sequence similarity between these enzymes. Conclusions Overall, this research shows that SHMT was expressed at a low level in the midgut of Aedes aegypti mosquitoes, but blood-meal digestion was inhibited when SHMT was silenced. Transcriptional expressions of different digestive enzymes were affected in response to SHMT depletion, suggesting that SHMT is required for the blood-meal digestion in the midgut and targeting SHMT could provide an effective strategy for vector mosquito population control.

scholarly journals Biodetection of a specific odor signature in mallard feces associated with infection by low pathogenic avian influenza A virus

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251841
Author(s):  
Glen J. Golden ◽  
Meredith J. Grady ◽  
Hailey E. McLean ◽  
Susan A. Shriner ◽  
Airn Hartwig ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Egg Production ◽  
Food Service ◽  
Indirect Costs ◽  
Service Industries ◽  
In Situ Monitoring ◽  
Sample Collection ◽  
Infectious Laryngotracheitis Virus ◽  
Avian Influenza A Virus

Outbreaks of avian influenza virus (AIV) infection included the spread of highly pathogenic AIV in commercial poultry and backyard flocks in the spring of 2015. This resulted in estimated losses of more than $8.5 million from federal government expenditures, $1.6 billion from direct losses to produces arising from destroyed turkey and chicken egg production, and economy-wide indirect costs of $3.3 billion from impacts on retailers and the food service industries. Additionally, these outbreaks resulted in the death or depopulation of nearly 50 million domestic birds. Domesticated male ferrets (Mustela putorius furo) were trained to display a specific conditioned behavior (i.e. active scratch alert) in response to feces from AIV-infected mallards in comparison to feces from healthy ducks. In order to establish that ferrets were identifying samples based on odors associated with infection, additional experiments controlled for potentially confounding effects, such as: individual duck identity, housing and feed, inoculation concentration, and day of sample collection (post-infection). A final experiment revealed that trained ferrets could detect AIV infection status even in the presence of samples from mallards inoculated with Newcastle disease virus or infectious laryngotracheitis virus. These results indicate that mammalian biodetectors are capable of discriminating the specific odors emitted from the feces of non-infected versus AIV infected mallards, suggesting that the health status of waterfowl can be evaluated non-invasively for AIV infection via monitoring of volatile fecal metabolites. Furthermore, in situ monitoring using trained biodetectors may be an effective tool for assessing population health.

scholarly journals Implication of transcriptome profiling of spermatozoa for stallion fertility

2018 ◽  
Vol 30 (8) ◽  
pp. 1087 ◽  
Author(s):  
Yara Suliman ◽  
Frank Becker ◽  
Klaus Wimmers
Keyword(s):  
Rna Binding ◽  
Transcriptome Profiling ◽  
Transcript Abundance ◽  
Fold Change ◽  
Receptor Interaction ◽  
Biological Functions ◽  
Pathways Analysis ◽  
Canonical Pathways ◽  
Significant Enrichment ◽  
First Time

Poor fertility of breeding stallions is a recognised problem in the equine industry. The aim of the present study was to detect molecular pathways using two groups of stallions that differed in pregnancy rates as well as in the proportion of normal and motile spermatozoa. RNA was isolated from spermatozoa of each stallion and microarray data were analysed to obtain a list of genes for which transcript abundance differed between the groups (P ≤0.05, fold change ≥1.2). In all, there were 437 differentially expressed (DE) genes between the two groups (P ≤ 0.05, fold change ≥1.2). Next, the DE genes were analysed using Database for Annotation, Visualisation, and Integrated Discovery (DAVID). Finally, ingenuity pathways analysis (IPA) was used to identify top biological functions and significant canonical pathways associated with the DE genes. Analysis using the DAVID database showed significant enrichment in the gene ontology (GO) term ‘RNA binding’ (P = 0.05) and in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway cytokine–cytokine receptor interaction (P = 0.02). Furthermore, IPA analysis showed interconnected biological functions and canonical pathways involved in the regulation of spermatogenesis and male fertility. In addition, significantly enriched metabolic pathways were identified. In conclusion, the present study has identified, for the first time, molecular processes in stallion spermatozoa that could be associated with stallion fertility.

scholarly journals Significant enrichment of Herpesvirus interactors in GWAS data suggests causal inferences for the association between Epstein Barr virus and multiple sclerosis

2019 ◽  
Author(s):  
Rosella Mechelli ◽  
Renato Umeton ◽  
Sundararajan Srinivasan ◽  
Arianna Fornasiero ◽  
Michela Ferraldeschi ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Epstein Barr Virus ◽  
Human Herpesvirus ◽  
Mechanistic Explanation ◽  
Complex Disorders ◽  
Multifactorial Diseases ◽  
Barr Virus ◽  
Canonical Pathways ◽  
Significant Enrichment ◽  
Epstein Barr

SUMMARYWe exploited genetic information to assess the role of non-genetic factors in multifactorial diseases. To this aim we isolated candidate “interactomes” (i.e. groups of genes whose products are known to physically interact with environmental exposures and biological processes, plausibly relevant for disease pathogenesis) and analyzed nominal statistical evidence of association with genetic predisposition to multiple sclerosis (MS) and other inflammatory and non-inflammatory complex disorders. The interaction between genotype and Herpesviruses emerged as specific for MS, with Epstein Barr virus (EBV) showing higher levels of significance compared to Human Herpesvirus 8 (HHV8) and, more evidently, to cytomegalovirus (CMV). In accord with this result, when we classified the MS-associated genes contained in the interactomes into canonical pathways, the analysis converged towards biological functions of B cells, in particular the CD40 pathway. When we analyzed peripheral blood transcriptomes in persons with MS, we found a significant dysregulation of MS-associated genes belonging to the EBV interactome in primary progressive MS. This study indicates that the interaction between herpesviruses and predisposing genetic background is of causal significance in MS, and provides a mechanistic explanation for the long-recognized association between EBV and this condition.

Bioenergetics of the granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae)

1976 ◽  
Vol 54 (5) ◽  
pp. 786-798 ◽  
Author(s):  
A. Campbell ◽  
N. B. Singh ◽  
R. N. Sinha
Keyword(s):  
Egg Production ◽  
Production Efficiency ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Energy Budgets ◽  
Sitophilus Granarius ◽  
Cumulative Energy ◽  
Granary Weevil ◽  
Larval Stages ◽  
Larval Production

Cumulative energy budgets were determined for the immature and adult stages of Sitophilus granarius (L.) reared on single wheat kernels, Triticum aestivum L. Caloric values (cal/mg dry weight) for S. granarius stages reared at 30 °C and 70% relative humidity (RH) were 5.792 for eggs, 5.989 for third-instar larvae, 6.474 for prepupae, 5.985 for pupae, and 5.975 for adults. Larval production increased exponentially from 0.13 cal in early first-instar larvae to 12.0 cal for 20-day-old fourth-instar larvae and prepupae, and declined to 6.9 cal during the pupal stage.To complete development larvae consumed a mean 62.6% of a 126-cal kernel, whereas an average adult consumed over 3.5 times more than the total larval consumption. Assimilation efficiencies for larval development were similar (73.9 to 76.2%) at three temperatures, 20, 25, and 30 °C. Of energy consumed during larval and pupal development, 65.7% was explained by respiration. Net production efficiency was 20% for all larval stages and 48% for total egg production by an adult.

Studies on Daphnia pulex Leydig in sewage oxidation ponds

1978 ◽  
Vol 56 (6) ◽  
pp. 1392-1401 ◽  
Author(s):  
Graham R. Daborn ◽  
John A. Hayward ◽  
Terry E. Quinney
Keyword(s):  
Seasonal Changes ◽  
Egg Production ◽  
Sewage Treatment ◽  
Daphnia Pulex ◽  
High Fecundity ◽  
Numerical Abundance ◽  
Oxidation Ponds ◽  
Maximum Body ◽  
Maximum Body Size

Populations of Daphnia pulex Leydig inhabiting two aerated sewage treatment ponds at Canning, Nova Scotia, were studied from May to September 1975 and October 1976 to January 1977. Very large females (< 4.4-mm total length) present in May exhibited high fecundity, producing up to 70 parthenogenetic eggs per brood (average, 29.5). These nonephippial eggs hatched immediately, giving rise to population densities as high as 932 ℓ−1 in mid-June. Maximum body size and fecundity decreased during summer 1975 to 2.5 mm and two eggs per brood respectively. Two periods of parthenogenetic ephippial egg production were recorded, one in May to June and a second in September to October. Males were not found at any time. Seasonal changes in abundance, an inverse relationship between numerical abundance and oxygen saturation levels, and changes in fecundity are considered to indicate that the summer populations were at times food limited. During the winter, mean densities declined from 473 and 178 ℓ−1 in October 1976 to zero by 21 January 1977. A complete shift from nonephippial to ephippial egg production occurred in October, but less than 25% of ephippia collected in January contained eggs. The role of Daphnia in sewage oxidation ponds is discussed.

scholarly journals Regulation of reproductive processes with dynamic energy budgets

2019 ◽  
Vol 33 (5) ◽  
pp. 819-832 ◽  
Author(s):  
Erik B. Muller ◽  
Konstadia Lika ◽  
Roger M. Nisbet ◽  
Irvin R. Schultz ◽  
Jérôme Casas ◽  
...  
Keyword(s):  
Energy Budgets ◽  
Reproductive Processes ◽  
Dynamic Energy Budgets

scholarly journals Behavioral and physiological flexibility are used by birds to manage energy and support investment in the early stages of reproduction

2010 ◽  
Vol 56 (6) ◽  
pp. 767-792 ◽  
Author(s):  
François Vézina ◽  
Katrina G. Salvante
Keyword(s):  
Egg Production ◽  
Egg Size ◽  
Behavioral Flexibility ◽  
Reproductive Investment ◽  
Tissue Remodeling ◽  
Reproductive Organs ◽  
Energy Budgets ◽  
Phenotypic Flexibility ◽  
Zebra Finches ◽  
Daily Energy

Abstract Interest in phenotypic flexibility has increased dramatically over the last decade, but flexibility during reproduction has received relatively little attention from avian scientists, despite its possible impact on fitness. Because most avian species maintain atrophied reproductive organs when not active, reproduction in birds requires major tissue remodeling in preparation for breeding. Females undergo rapid (days) recrudescence and regression of their reproductive organs at each breeding attempt, while males grow their organs ahead of time at a much slower rate (weeks) and may maintain them at maximal size throughout the breeding season. Reproduction is associated with significant metabolic costs. Egg production leads to a 22%-27% increase in resting metabolic rate (RMR) over non-reproductive values. This is partly due to the activity of the oviduct, an organ that may allow females to adjust reproductive investment by modulating egg size and quality. In males, gonadal recrudescence may lead to a 30% increase in RMR, but the data are inconsistent and general conclusions regarding energetic costs of reproduction in males will require more research. Recent studies on captive female zebra finches describe the impacts of these costs on daily energy budgets and highlight the strategies used by birds to maintain their investment in reproduction when energy is limited. Whenever possible, birds use behavioral flexibility as a first means of saving energy. Decreasing locomotor activity saves energy during challenges such as egg production or exposure to cold temperatures and is an efficient way to buffer variation in individual daily energy budgets. However, when behavioral flexibility is not possible, birds must rely on flexibility at the physiological level to meet energy demands. In zebra finches breeding in the cold, this results in a reduced pace of laying, likely due to down-regulation of both reproductive and non-reproductive function, allowing females to defend minimal egg size and maintain reproductive success. More research involving a range of species in captive and free-living conditions is needed to determine how phenotypic flexibility during tissue remodeling and early reproductive investment translates to natural conditions and affects fitness.

Maternal investment in egg production: environmental and population-specific effects on offspring performance in the snapping shrimp Alpheus nuttingi (Schmitt, 1924) (Decapoda, Alpheidae)

2010 ◽  
Vol 60 (3) ◽  
pp. 237-247 ◽  
Author(s):  
Emerson Mossolin ◽  
Fernando Mantelatto ◽  
Caio Pavanelli
Keyword(s):  
Environmental Factors ◽  
Egg Production ◽  
Marine Invertebrates ◽  
Maternal Investment ◽  
Reproductive Pattern ◽  
Offspring Performance ◽  
Snapping Shrimp ◽  
Specific Effects ◽  
Large Size ◽  
Reproductive Processes

AbstractAmong marine invertebrates, the overall biomass invested in egg production varies widely within populations, which can result from the interaction of endogenous and exogenous factors. Species that have constant reproduction throughout the year can be good models to study the influence of environmental factors on reproductive processes. We conducted a seasonal comparison of egg production in the intertidal snapping shrimp Alpheus nuttingi, which shows a continuous reproductive pattern, to examine the hypothesis that differences in egg production are driven by environmental conditions and population features. This population showed an uncommon strategy, characterized by females that produce eggs of varying sizes within their clutches, with reduced egg volume when the number of eggs is higher (Spring-Summer). In these seasons, higher temperatures and greater food availability may allow the production of more eggs compared to the Autumn-Winter seasons. Compared to other alpheid shrimps, this population produces small eggs, but in larger numbers. Despite the higher fecundity, the reproductive output is relatively low, this production being supported by the large size of females from the southern Atlantic region. Our findings showed that the egg production of A. nuttingi was greatly influenced by environmental factors. Therefore, this shrimp, and probably other decapods that possess continuous reproduction, adopt different reproductive strategies during the year.

scholarly journals Reproductive functions and genetic architecture of the seminal fluid and sperm proteomes of the mosquito Aedes aegypti

2018 ◽  
Author(s):  
Ethan C. Degner ◽  
Yasir H. Ahmed-Braimah ◽  
Kiril Borziak ◽  
Mariana F. Wolfner ◽  
Laura C. Harrington ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Seminal Fluid ◽  
Protein Translation ◽  
Chromosome 1 ◽  
Composition Analysis ◽  
Seminal Fluid Proteins ◽  
Accessory Glands ◽  
Significant Enrichment ◽  
Intimate Knowledge ◽  
Reproductive Processes

AbstractThe yellow fever mosquito, Aedes aegypti, transmits several viruses, including dengue, Zika, and chikungunya. Some proposed efforts to control this vector involve manipulating reproduction to suppress wild populations or replacing them with disease-resistant mosquitoes. The design of such strategies requires an intimate knowledge of reproductive processes, yet our basic understanding of reproductive genetics in this vector remains largely incomplete. To accelerate future investigations, we have comprehensively catalogued sperm and seminal fluid proteins (SFPs) transferred to females in the ejaculate using tandem mass spectrometry. By excluding female-derived proteins using an isotopic labelling approach, we identified 870 sperm proteins and 280 seminal fluid proteins. Functional composition analysis revealed parallels with known aspects of sperm biology and SFP function in other insects. To corroborate our proteome characterization, we also generated transcriptomes for testes and the male accessory glands—the primary contributors to Ae. aegypti sperm and seminal fluid, respectively. Differential gene expression of accessory glands from virgin and mated males suggests that protein translation is upregulated post-mating. Several SFP transcripts were also modulated after mating, but >90% remained unchanged. Finally, a significant enrichment of SFPs was observed on chromosome 1, which harbors the male sex determining locus in this species. Our study provides a comprehensive proteomic and transcriptomic characterization of ejaculate production and composition and thus provides a foundation for future investigations of Ae. aegypti reproductive biology, from functional analysis of individual proteins to broader examination of reproductive processes.

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