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Gomez A, Gonzalez S, Oke A, Luo J, Duong JB, Esquerra RM, Zimmerman T, Capponi S, Fung JC, Nystul TG. A High-Throughput Method for Quantifying Drosophila Fecundity. TOXICS 2024; 12:658. [PMID: 39330586 DOI: 10.3390/toxics12090658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2024] [Revised: 08/30/2024] [Accepted: 09/03/2024] [Indexed: 09/28/2024]
Abstract
The fruit fly, Drosophila melanogaster, is an experimentally tractable model system that has recently emerged as a powerful "new approach methodology" (NAM) for chemical safety testing. As oogenesis is well conserved at the molecular and cellular level, measurements of Drosophila fecundity can be useful for identifying chemicals that affect reproductive health across species. However, standard Drosophila fecundity assays have been difficult to perform in a high-throughput manner because experimental factors such as the physiological state of the flies and environmental cues must be carefully controlled to achieve consistent results. In addition, exposing flies to a large number of different experimental conditions (such as chemical additives in the diet) and manually counting the number of eggs laid to determine the impact on fecundity is time-consuming. We have overcome these challenges by combining a new multiwell fly culture strategy with a novel 3D-printed fly transfer device to rapidly and accurately transfer flies from one plate to another, the RoboCam, a low-cost, custom-built robotic camera to capture images of the wells automatically, and an image segmentation pipeline to automatically identify and quantify eggs. We show that this method is compatible with robust and consistent egg laying throughout the assay period and demonstrate that the automated pipeline for quantifying fecundity is very accurate (r2 = 0.98 for the correlation between the automated egg counts and the ground truth). In addition, we show that this method can be used to efficiently detect the effects on fecundity induced by dietary exposure to chemicals. Taken together, this strategy substantially increases the efficiency and reproducibility of high-throughput egg-laying assays that require exposing flies to multiple different media conditions.
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Affiliation(s)
- Andreana Gomez
- Department of Anatomy, University of California, San Francisco, CA 94143, USA
| | - Sergio Gonzalez
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
- Center for Cellular Construction, San Francisco, CA 94158, USA
| | - Ashwini Oke
- OB/GYN Department, University of California, San Francisco, CA 94143, USA
- Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
| | - Jiayu Luo
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
- Center for Cellular Construction, San Francisco, CA 94158, USA
| | - Johnny B Duong
- Center for Cellular Construction, San Francisco, CA 94158, USA
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132, USA
| | - Raymond M Esquerra
- Center for Cellular Construction, San Francisco, CA 94158, USA
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132, USA
| | - Thomas Zimmerman
- Center for Cellular Construction, San Francisco, CA 94158, USA
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, CA 94132, USA
- IBM Almaden Research Center, San Jose, CA 95120, USA
| | - Sara Capponi
- Center for Cellular Construction, San Francisco, CA 94158, USA
- IBM Almaden Research Center, San Jose, CA 95120, USA
| | - Jennifer C Fung
- OB/GYN Department, University of California, San Francisco, CA 94143, USA
- Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
- San Francisco EaRTH Center, University of California, San Francisco, CA 94143, USA
| | - Todd G Nystul
- Department of Anatomy, University of California, San Francisco, CA 94143, USA
- OB/GYN Department, University of California, San Francisco, CA 94143, USA
- Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
- San Francisco EaRTH Center, University of California, San Francisco, CA 94143, USA
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2
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Tsintzas E, Niccoli T. Using Drosophila amyloid toxicity models to study Alzheimer's disease. Ann Hum Genet 2024; 88:349-363. [PMID: 38517001 DOI: 10.1111/ahg.12554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 01/28/2024] [Accepted: 01/29/2024] [Indexed: 03/23/2024]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia and is characterised by a progressive loss of neurons, which manifests as gradual memory decline, followed by cognitive loss. Despite the significant progress in identifying novel biomarkers and understanding the prodromal pathology and symptomatology, AD remains a significant unmet clinical need. Lecanemab and aducanumab, the only Food and Drug Administration approved drugs to exhibit some disease-modifying clinical efficacy, target Aβ amyloid, underscoring the importance of this protein in disease aetiology. Nevertheless, in the absence of a definitive cure, the utilisation of preclinical models remains imperative for the identification of novel therapeutic targets and the evaluation of potential therapeutic agents. Drosophila melanogaster is a model system that can be used as a research tool to investigate neurodegeneration and therapeutic interventions. The short lifespan, low price and ease of husbandry/rearing make Drosophila an advantageous model organism from a practical perspective. However, it is the highly conserved genome and similarity of Drosophila and human neurobiology which make flies a powerful tool to investigate neurodegenerative mechanisms. In addition, the ease of transgenic modifications allows for early proof of principle studies for future therapeutic approaches in neurodegenerative research. This mini review will specifically focus on utilising Drosophila as an in vivo model of amyloid toxicity in AD.
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Affiliation(s)
- Elli Tsintzas
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
| | - Teresa Niccoli
- Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, UK
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3
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Gomez A, Gonzalez S, Oke A, Luo J, Duong JB, Esquerra RM, Zimmerman T, Capponi S, Fung JC, Nystul TG. A high-throughput method for quantifying Drosophila fecundity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.27.587093. [PMID: 38585877 PMCID: PMC10996622 DOI: 10.1101/2024.03.27.587093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Measurements of Drosophila fecundity are used in a wide variety of studies, such as investigations of stem cell biology, nutrition, behavior, and toxicology. In addition, because fecundity assays are performed on live flies, they are suitable for longitudinal studies such as investigations of aging or prolonged chemical exposure. However, standard Drosophila fecundity assays have been difficult to perform in a high-throughput manner because experimental factors such as the physiological state of the flies and environmental cues must be carefully controlled to achieve consistent results. In addition, exposing flies to a large number of different experimental conditions (such as chemical additives in the diet) and manually counting the number of eggs laid to determine the impact on fecundity is time-consuming. We have overcome these challenges by combining a new multiwell fly culture strategy with a novel 3D-printed fly transfer device to rapidly and accurately transfer flies from one plate to another; the RoboCam, a low-cost, custom built robotic camera to capture images of the wells automatically; and an image segmentation pipeline to automatically identify and quantify eggs. We show that this method is compatible with robust and consistent egg laying throughout the assay period; and demonstrate that the automated pipeline for quantifying fecundity is very accurate (r2 = 0.98 for the correlation between the automated egg counts and the ground truth) In addition, we show that this method can be used to efficiently detect the effects on fecundity induced by dietary exposure to chemicals. Taken together, this strategy substantially increases the efficiency and reproducibility of high throughput egg laying assays that require exposing flies to multiple different media conditions.
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Affiliation(s)
- Andreana Gomez
- University of California, San Francisco, Department of Anatomy
| | - Sergio Gonzalez
- San Francisco State University, Department of Biology
- Center for Cellular Construction, San Francisco, CA
| | - Ashwini Oke
- San Francisco State University, Department of Chemistry and Biochemistry; University of California, San Francisco, OB/GYN Department
- IBM Almaden Research Center, San Jose, CA; University of California, San Francisco, Center for Reproductive Sciences
| | - Jiayu Luo
- San Francisco State University, Department of Biology
- Center for Cellular Construction, San Francisco, CA
| | - Johnny B Duong
- Center for Cellular Construction, San Francisco, CA
- San Francisco State University, Department of Chemistry and Biochemistry; University of California, San Francisco, OB/GYN Department
| | - Raymond M Esquerra
- Center for Cellular Construction, San Francisco, CA
- San Francisco State University, Department of Chemistry and Biochemistry; University of California, San Francisco, OB/GYN Department
| | - Thomas Zimmerman
- Center for Cellular Construction, San Francisco, CA
- IBM Almaden Research Center, San Jose, CA; University of California, San Francisco, Center for Reproductive Sciences
| | - Sara Capponi
- Center for Cellular Construction, San Francisco, CA
- IBM Almaden Research Center, San Jose, CA; University of California, San Francisco, Center for Reproductive Sciences
| | - Jennifer C Fung
- San Francisco State University, Department of Chemistry and Biochemistry; University of California, San Francisco, OB/GYN Department
- IBM Almaden Research Center, San Jose, CA; University of California, San Francisco, Center for Reproductive Sciences
- University of California, San Francisco EaRTH Center
| | - Todd G Nystul
- University of California, San Francisco, Department of Anatomy
- San Francisco State University, Department of Chemistry and Biochemistry; University of California, San Francisco, OB/GYN Department
- IBM Almaden Research Center, San Jose, CA; University of California, San Francisco, Center for Reproductive Sciences
- University of California, San Francisco EaRTH Center
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4
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Meng X, Hu J, Plant RE, Carpenter TE, Carey JR. Distinctive egg-laying patterns in terminal versus non-terminal periods in three fruit fly species. Exp Gerontol 2021; 145:111201. [PMID: 33316371 PMCID: PMC7855919 DOI: 10.1016/j.exger.2020.111201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/18/2020] [Accepted: 12/08/2020] [Indexed: 11/22/2022]
Abstract
The specific objective of this study was to use a logistic regression model for determining the degree to which egg laying patterns of individual females at the end of life (i.e., terminal segments) in each of three different fruit fly species could be distinguished from the egg-laying patterns over a similar period in midlife (i.e., non-terminal segments). Extracting data from large-scale databases for 11-day terminal and 11-day non-terminal segments in the vinegar fly (Drosophila melanogaster), the Mexican fruit fly (Anastrepha ludens) and the Mediterranean fruit fly (Ceratitis capitata) and organizing the model's results in a 2 × 2 contingency table, we found that: (1) daily egg-laying patterns in fruit flies can be used to distinguish terminal from non-terminal periods; (2) the overall performance metrics such as precision, accuracy, false positives and true negatives depended heavily on species; (3) differentiating between terminal and non-terminal segments is more difficult when flies die at younger ages; and (4) among the three species the best performing metrics including accuracy and precision were those produced using data on D. melanogaster. We conclude that, although the reliability of the prediction of whether a segment occurred at the end of life is relatively high for most species, it does not follow precisely predicting remaining life will also be highly reliable since classifying an end of life period is a fundamentally different challenge than is predicting an exact day of death.
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Affiliation(s)
- Xiang Meng
- Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Science, Guangzhou 510260, China; College of Life Science, Guangzhou University, Guangzhou 510006, China
| | - Junjie Hu
- College of Life Science, Guangzhou University, Guangzhou 510006, China
| | - Richard E Plant
- Department of Plant Sciences, University of California, Davis, 95616, USA; Department of Biological and Agricultural Engineering, University of California, Davis, 95616, USA
| | - Tim E Carpenter
- Department of Medicine and Epidemiology, University of California, Davis, 95616, USA
| | - James R Carey
- Department of Entomology, University of California, Davis, 95616, USA; Center for the Economic and Demography of Aging, University of California, Berkeley, 94720, USA.
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5
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Behrman EL, Watson SS, O'Brien KR, Heschel MS, Schmidt PS. Seasonal variation in life history traits in two Drosophila species. J Evol Biol 2015; 28:1691-704. [PMID: 26174167 DOI: 10.1111/jeb.12690] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 06/30/2015] [Accepted: 07/01/2015] [Indexed: 01/16/2023]
Abstract
Seasonal environmental heterogeneity is cyclic, persistent and geographically widespread. In species that reproduce multiple times annually, environmental changes across seasonal time may create different selection regimes that may shape the population ecology and life history adaptation in these species. Here, we investigate how two closely related species of Drosophila in a temperate orchard respond to environmental changes across seasonal time. Natural populations of Drosophila melanogaster and Drosophila simulans were sampled at four timepoints from June through November to assess seasonal change in fundamental aspects of population dynamics as well as life history traits. D. melanogaster exhibit pronounced change across seasonal time: early in the season, the population is inferred to be uniformly young and potentially represents the early generation following overwintering survivorship. D. melanogaster isofemale lines derived from the early population and reared in a common garden are characterized by high tolerance to a variety of stressors as well as a fast rate of development in the laboratory environment that declines across seasonal time. In contrast, wild D. simulans populations were inferred to be consistently heterogeneous in age distribution across seasonal collections; only starvation tolerance changed predictably over seasonal time in a parallel manner as in D. melanogaster. These results suggest fundamental differences in population and evolutionary dynamics between these two taxa associated with seasonal heterogeneity in environmental parameters and associated selection pressures.
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Affiliation(s)
- E L Behrman
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - S S Watson
- Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - K R O'Brien
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.,School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
| | - M S Heschel
- Department of Organismal Biology & Ecology, Colorado College, Colorado Springs, CO, USA
| | - P S Schmidt
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
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6
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Harwood JF, Chen K, Liedo P, Müller HG, Wang JL, Morice AE, Carey JR. Female access and diet affect insemination success, senescence, and the cost of reproduction in male Mexican fruit flies Anastrepha ludens. PHYSIOLOGICAL ENTOMOLOGY 2015; 40:65-71. [PMID: 25709143 PMCID: PMC4335655 DOI: 10.1111/phen.12089] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Hypotheses exploring the influence of dietary conditions on the life history trade-off between survival and reproductive success are extensively tested in female insects, but are rarely explored in males. Here, the impact of dietary quality and female access on age-specific reproduction and survival of male Mexican fruit flies, Anastrepha ludens Loew (Diptera: Tephritidae), are examined. There is a clear cost of female access for males with access to dietary protein, measurable as a decrease in life expectancy, which is further influenced by the age when females are introduced. A protein deficient diet reduces the lifespan benefit of virginity and masks the detrimental effect of female access on male life expectancy. Dietary protein is not necessary for reproductive success, but access to protein at eclosion improves the lifetime reproductive success of males compared to when it is delayed. Overall, reproductive success diminishes as the male flies age, regardless of the dietary conditions, providing evidence for reproductive senescence in males. Delaying the males' access to a protein source fails to influence the negative effect of age on reproductive ability. Because age specific reproductive rates decline with age, regardless of diet, male fitness does not benefit from lifespan extension. Therefore, males can be expected to allocate available resources towards reproductive effort in favour of extended lifespan, regardless of mate and protein availability.
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Affiliation(s)
- James F Harwood
- Department of Entomology, University of California, Davis, California, U.S.A
| | - Kehui Chen
- Department of Statistics, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A. ; Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, U.S.A
| | - Pablo Liedo
- Departamento de Agricultura, Sociedad y Ambiente, El Colegio de la Frontera Sur (ECOSUR), Tapachula, Chiapas, Mexico
| | - Hans-Georg Müller
- Department of Statistics, University of California, Davis, California, U.S.A
| | - Jane-Ling Wang
- Department of Statistics, University of California, Davis, California, U.S.A
| | - Amy E Morice
- Department of Entomology, University of California, Davis, California, U.S.A
| | - James R Carey
- Department of Entomology, University of California, Davis, California, U.S.A
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7
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Dinh Hoai T, Hutson KS. Reproductive strategies of the insidious fish ectoparasite, Neobenedenia sp. (Capsalidae: Monogenea). PLoS One 2014; 9:e108801. [PMID: 25264931 PMCID: PMC4181869 DOI: 10.1371/journal.pone.0108801] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 08/31/2014] [Indexed: 11/18/2022] Open
Abstract
Fish monogeneans are lethal parasites in aquaculture. We provide the first experimental evidence that a notorious fish monogenean, Neobenedenia sp., can produce viable eggs in isolation for three consecutive generations. We infected individual, isolated, farmed barramundi, Lates calcarifer (Bloch) with a single oncomiracidium (larva) of the hermaphroditic monogenean Neobenedenia sp.. Isolated parasites reached sexual maturity at day 10 post-hatch (24°C, 35‰) and laid ∼3,300 embryonated eggs over 17 days [corrected]. Egg production rapidly increased following sexually maturity on day 10 (58±15 eggs) and peaked on day 15 (496±68 eggs) before gradually decreasing. Neobenedenia sp. exhibited egg laying and egg hatching rhythms. Parasites laid eggs continuously, but egg production increased in periods of darkness (64.3%), while the majority of oncomiracidia (81%) emerged from eggs in the first three hours of light. Eggs laid by isolated 'parent' parasites hatched and individual emerging oncomiracidia were used to infect more individual, isolated fish, with three consecutive, isolated, parasite generations (F1, F2 and F3) raised in the laboratory. Infection success and egg hatching success did not differ between generations. Our data show that one parasite, in the absence of a mate, presents a severe threat to captive fish populations.
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Affiliation(s)
- Truong Dinh Hoai
- Marine Parasitology Laboratory, Centre for Sustainable Tropical Fisheries and Aquaculture and the School of Marine and Tropical Biology, James Cook University, Queensland, Australia
- Aquatic Environment and Fish Pathology Department, Faculty of Animal Science and Aquaculture, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Kate S. Hutson
- Marine Parasitology Laboratory, Centre for Sustainable Tropical Fisheries and Aquaculture and the School of Marine and Tropical Biology, James Cook University, Queensland, Australia
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8
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Michalkova V, Benoit JB, Attardo GM, Medlock J, Aksoy S. Amelioration of reproduction-associated oxidative stress in a viviparous insect is critical to prevent reproductive senescence. PLoS One 2014; 9:e87554. [PMID: 24763119 PMCID: PMC3998933 DOI: 10.1371/journal.pone.0087554] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 12/20/2013] [Indexed: 11/19/2022] Open
Abstract
Impact of reproductive processes upon female health has yielded conflicting results; particularly in relation to the role of reproduction-associated stress. We used the viviparous tsetse fly to determine if lactation, birth and involution lead to damage from oxidative stress (OS) that impairs subsequent reproductive cycles. Tsetse females carry an intrauterine larva to full term at each pregnancy cycle, and lactate to nourish them with milk secretions produced by the accessory gland ( = milk gland) organ. Unlike most K-strategists, tsetse females lack an apparent period of reproductive senescence allowing the production of 8-10 progeny over their entire life span. In a lactating female, over 47% of the maternal transcriptome is associated with the generation of milk proteins. The resulting single larval offspring weighs as much as the mother at birth. In studying this process we noted an increase in specific antioxidant enzyme (AOE) transcripts and enzymatic activity at critical times during lactation, birth and involution in the milk gland/fat body organ and the uterus. Suppression of superoxide dismutase (sod) decreased fecundity in subsequent reproductive cycles in young mothers and nearly abolished fecundity in geriatric females. Loss of fecundity was in part due to the inability of the mother to produce adequate milk to support larval growth. Longevity was also impaired after sod knockdown. Generation of OS in virgin females through exogenous treatment with hydrogen peroxide at times corresponding to pregnancy intervals reduced survival, which was exacerbated by sod knockdown. AOE expression may prevent oxidative damage associated with the generation of nutrients by the milk gland, parturition and milk gland breakdown. Our results indicate that prevention of OS is essential for females to meet the growing nutritional demands of juveniles during pregnancy and to repair the damage that occurs at birth. This process is particularly important for females to remain fecund during the latter portion of their lifetime.
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Affiliation(s)
- Veronika Michalkova
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United State of America
- Section of Molecular and Applied Zoology, Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Joshua B. Benoit
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United State of America
- * E-mail:
| | - Geoffrey M. Attardo
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United State of America
| | - Jan Medlock
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, United States of America
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United State of America
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9
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Novoseltsev VN, Novoseltseva JA. Why is individual reproduction in Drosophila flies stochastic? Front Genet 2013; 3:324. [PMID: 23386859 PMCID: PMC3558672 DOI: 10.3389/fgene.2012.00324] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 12/28/2012] [Indexed: 11/30/2022] Open
Affiliation(s)
- V N Novoseltsev
- Institute of Control Sciences, Russian Academy of Sciences Moscow, Russia
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10
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Otti O, McTighe AP, Reinhardt K. In vitroantimicrobial sperm protection by an ejaculate-like substance. Funct Ecol 2012. [DOI: 10.1111/1365-2435.12025] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Ejaculate components delay reproductive senescence while elevating female reproductive rate in an insect. Proc Natl Acad Sci U S A 2009; 106:21743-7. [PMID: 19996174 DOI: 10.1073/pnas.0905347106] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Increased female reproductive rates usually result in accelerated senescence. This correlation provides a link between the evolutionary conflict of the sexes and aging when ejaculate components elevate female reproductive rates at the cost of future reproduction. It is not clear whether this female cost is manifest as shorter lifespan or an earlier onset or a steeper rate of reproductive senescence. It also is unclear whether beneficial ejaculates release females from reproductive trade-offs and, if so, which senescence parameters are affected. We examined these issues in the bedbug, Cimex lectularius, a long-lived insect that shows reduced female lifespan as well as female reproductive senescence at the male-determined mating frequency. We demonstrate experimentally that, independently of the mating frequency, females receiving more ejaculate show increased reproductive rates and enter reproductive senescence later than females receiving less ejaculate. The rate of reproductive senescence did not differ between treatments, and reproductive rates did not predict mortality. The ejaculate effects were consistent in inter- and intra-population crosses, suggesting they have not evolved recently and are not caused by inbreeding. Our results suggest that ejaculate components compensate for the costs of elevated female reproductive rates in bedbugs by delaying the onset of reproductive senescence. Ejaculate components that are beneficial to polyandrous females could have arisen because male traits that protect the ejaculate have positive pleiotropic effects and/or because female counteradaptations to antagonistic male traits exceed the neutralization of those traits. That males influence female reproductive senescence has important consequences for trade-offs between reproduction and longevity and for studies of somatic senescence.
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12
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Kapelnikov A, Rivlin PK, Hoy RR, Heifetz Y. Tissue remodeling: a mating-induced differentiation program for the Drosophila oviduct. BMC DEVELOPMENTAL BIOLOGY 2008; 8:114. [PMID: 19063748 PMCID: PMC2636784 DOI: 10.1186/1471-213x-8-114] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 12/08/2008] [Indexed: 12/11/2022]
Abstract
BACKGROUND In both vertebrates and invertebrates, the oviduct is an epithelial tube surrounded by visceral muscles that serves as a conduit for gamete transport between the ovary and uterus. While Drosophila is a model system for tubular organ development, few studies have addressed the development of the fly's oviduct. Recent studies in Drosophila have identified mating-responsive genes and proteins whose levels in the oviduct are altered by mating. Since many of these molecules (e.g. Muscle LIM protein 84B, Coracle, Neuroglian) have known roles in the differentiation of muscle and epithelia of other organs, mating may trigger similar differentiation events in the oviduct. This led us to hypothesize that mating mediates the last stages of oviduct differentiation in which organ-specific specializations arise. RESULTS Using electron- and confocal-microscopy we identified tissue-wide post-mating changes in the oviduct including differentiation of cellular junctions, remodeling of extracellular matrix, increased myofibril formation, and increased innervation. Analysis of once- and twice-mated females reveals that some mating-responsive proteins respond only to the first mating, while others respond to both matings. CONCLUSION We uncovered ultrastructural changes in the mated oviduct that are consistent with the roles that mating-responsive proteins play in muscle and epithelial differentiation elsewhere. This suggests that mating triggers the late differentiation of the oviduct. Furthermore, we suggest that mating-responsive proteins that respond only to the first mating are involved in the final maturation of the oviduct while proteins that remain responsive to later matings are also involved in maintenance and ongoing function of the oviduct. Taken together, our results establish the oviduct as an attractive system to address mechanisms that regulate the late stages of differentiation and maintenance of a tubular organ.
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Affiliation(s)
- Anat Kapelnikov
- Department of Entomology, The Hebrew University, Rehovot, Israel.
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13
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Martin I, Grotewiel MS. Distinct genetic influences on locomotor senescence in Drosophila revealed by a series of metrical analyses. Exp Gerontol 2006; 41:877-81. [PMID: 16891076 DOI: 10.1016/j.exger.2006.06.052] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Revised: 06/20/2006] [Accepted: 06/27/2006] [Indexed: 11/19/2022]
Abstract
Decline of locomotor function is a prominent feature of aging in most species. We previously described a series of metrical analyses for quantifying functional declines associated with aging. Here, we have applied these metrics to elucidate differences in the nature of locomotor senescence between Drosophila cohorts from four different genetic backgrounds (Canton-S, Oregon-R, Samarkand and Lausanne-S) and two long-lived mutant strains, Indy(206) and chico(1). These analyses demonstrate that senescence of locomotor function in Oregon-R and Canton-S proceeds more rapidly than in Samarkand and Lausanne-S flies. Our analyses also show that while chico(1) and Indy mutants both exhibit attenuated locomotor declines, the impact of chico loss of function on locomotor senescence is substantially greater. Our studies illustrate how important differences in functional senescence characteristics can be unveiled by in-depth analysis on functional senescence data sets.
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Affiliation(s)
- Ian Martin
- Department of Human Genetics and Neuroscience Program, Virginia Commonwealth University School of Medicine, Richmond, VA 23298, USA
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Wilson M, Widdicombe JH, Gohil K, Burtis KC, Reznick AZ, Cross CE, Eiserich JP. Are Drosophila a useful model for understanding the toxicity of inhaled oxidative pollutants: a review. Inhal Toxicol 2006; 17:765-74. [PMID: 16195212 DOI: 10.1080/08958370500225141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Oxidative atmospheric pollutants represent a significant stress and cause injury to both vertebrate and invertebrate species. In both, the biosurfaces of their respiratory apparatus are directly exposed to oxidizing pollutant-induced stresses. Respiratory-tract surfaces contain integrated antioxidant systems that appear to provide a primary defense against environmental insults caused by inhaled atmospheric reactive oxygen species (ROS) and reactive nitrogen species (RNS), whether gaseous or particulate. When the biosurface antioxidant defenses are overwhelmed, oxidative and nitrosative stress to the acellular and cellular components of the exposed biosurfaces can ensue via direct chemical reactions that lead to the induction of inflammatory, adaptive, injurious, and reparative processes. The study of model invertebrates (e.g., Drosophila) has a long history of yielding valuable insights into both fundamental biology and pathobiology. Mutants and/or transgenic insects, with specific alterations in key components of innate and/or adaptive antioxidant defense systems and immune genes, offer opportunities to dissect the complex systems that maintain respiratory tract surface defenses against environmental oxidants and the ensuing host responses. In this article, we use a comparative absfont approach to consider interactions of atmospheric oxidant pollutants with selected biosystems. We focused primarily on ozone (O(3)) as the pollutant, vertebrate and invertebrate respiratory tracts as the exposed biosystems, and nonenzymatic micronutrient antioxidants as significant contributors to overall antioxidant defense strategies. We present parallels among these diverse organisms with regard to their protective strategies against environmental atmospheric oxidants, with particular focus given to using the invertebrate Drosophila as a potentially useful model for vertebrate respiratory-tract responses to inhaled oxidants specifically and pollutants in general. We conclude that the insect respiratory system has considerable promise toward understanding novel aspects of vertebrate respiratory tract responses to inhaled oxidative environmental challenges.
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Affiliation(s)
- Malinda Wilson
- Division of Pulmonary Medicine, University of California, Davis, California 95817, USA
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Rauser CL, Tierney JJ, Gunion SM, Covarrubias GM, Mueller LD, Rose MR. Evolution of late-life fecundity in Drosophila melanogaster. J Evol Biol 2006; 19:289-301. [PMID: 16405599 DOI: 10.1111/j.1420-9101.2005.00966.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Late-life fecundity has been shown to plateau at late ages in Drosophila analogously to late-life mortality rates. In this study, we test an evolutionary theory of late life based on the declining force of natural selection that can explain the occurrence of these late-life plateaus in Drosophila. We also examine the viability of eggs laid by late-age females and test a population genetic mechanism that may be involved in the evolution of late-life fecundity: antagonistic pleiotropy. Together these experiments demonstrate that (i) fecundity plateaus at late ages, (ii) plateaus evolve according to the age at which the force of natural selection acting on fecundity reaches zero, (iii) eggs laid by females in late life are viable and (iv) antagonistic pleiotropy is involved in the evolution of late-life fecundity. This study further supports the evolutionary theory of late life based on the age-specific force of natural selection.
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Affiliation(s)
- C L Rauser
- Department of Ecology and Evolutionary Biology, University of California, Irvine, 92697-2525, USA.
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Novoseltsev VN, Arking R, Carey JR, Novoseltseva JA, Yashin AI. Individual fecundity and senescence in Drosophila and medfly. J Gerontol A Biol Sci Med Sci 2005; 60:953-62. [PMID: 16127096 PMCID: PMC2441907 DOI: 10.1093/gerona/60.8.953] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Evolutionary theory postulates that there should be a robust relationship between fecundity and longevity. Prior work has generally supported this concept, but has not shed much light on the mechanisms at play. In preceding work, we have developed and verified a mathematical model of Drosophila melanogaster female fecundity based on the analysis of empirical studies independently done by several different laboratories. Then we applied this technique to Mediterranean fruit fly (medfly) populations. In this article we analyze associations between individual longevity and the parameters of individual fecundity pattern in Drosophila and medfly. We cluster both Drosophila and medfly individuals by life span and discuss the differences. It allows us to demonstrate that only one fecundity-related parameter is associated with longevity in Drosophila, whereas two such parameters can be found in medflies. This difference demonstrates different ways of aging in various Diptera species. Finally, we discuss the possible implications of this finding.
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Novoseltsev VN, Carey RJ, Novoseltseva JA, Papadopoulos NT, Blay S, Yashin AI. Systemic mechanisms of individual reproductive life history in female Medflies. Mech Ageing Dev 2004; 125:77-87. [PMID: 14706240 DOI: 10.1016/j.mad.2003.10.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This paper is the second one in a series of two papers hypothesizing and testing systemic grounds of reproductive life history in the female fruit fly. In the first paper, we analyzed mechanisms of individual fecundity scheduling and have drawn the following conclusions. Individual fecundity in female flies is endowed as a flat pattern with a steady-state period of a constant rate of egg-laying. An individual female reveals three stages in her adult life history: maturation, maturity, and senescence. The first stage is a transient period of achieving a steady state at maturity, which can be maintained until the senescence stage. Thus, an individual fecundity pattern has no maximum. The maximums observed experimentally are averaging-caused artifacts. Two natural causes of deaths exist in flies, senescence-caused ones and premature deaths, probably due to a reproductive overload. In this paper, to confirm these findings, we use individual daily scores of egg-laying in four populations of Mediterranean fruit flies. Based on fecundity scores, we divide each Medfly population into four classes, namely zero-egg, short-, medium- and long-lived egg-layers. We demonstrate that, indeed, the three above findings definitely exist in Medflies. Our procedure allows the efficient storage of individual fecundity in parametric form, with only five numbers for each fly. Finally, this protocol will allow a more precise analysis of fecundity-energy trade-offs in flies carrying appropriate longevity mutations.
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