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Short CA, Walters JL, Hahn DA. Bigger isn't always better: Challenging assumptions about the associations between diapause, body weight, and overwintering survival. Ecol Evol 2024; 14:e11511. [PMID: 38835525 PMCID: PMC11148123 DOI: 10.1002/ece3.11511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/06/2024] [Accepted: 05/16/2024] [Indexed: 06/06/2024] Open
Abstract
During the winter, animals face limited food availability. Many animals enter dormancy to reduce their winter energy expenditure. Most insects spend the winter in diapause, a state of programmed dormancy. It is often assumed that diapausing insects need nutrient stores to fuel their many months of basal metabolism and must grow heavier than their non-diapause-programmed counterparts. However, the extent to which food limitation affects body weight during overwintering preparation as well as the likelihood and duration of diapause remains unclear. We limited the duration of the feeding period and thus the total quantity of food available to diapause-destined larvae of the pupal-diapausing flesh fly, Sarcophaga crassipalpis, to test how food limitation affects body weight in the context of diapause programming. We also tested the extent to which food deprivation and body weight affect the likelihood and duration of diapause. We hypothesized that diapause-destined larvae grow more quickly and pupariate at a heavier body weight than non-diapause larvae. We also hypothesized that body weight is more dramatically reduced by food limitations when a larva is programmed for diapause. Finally, we hypothesized that larvae with lighter body weight (i.e., food limited) are less likely to enter pupal diapause and also stay in diapause for a shorter duration than heavier, well-fed, individuals. Contrary to our hypotheses that diapausing insects are heavier than their non-diapausing counterparts, we found diapausing pupae weighed less than non-diapausing pupae, especially when larvae received limited food. We found light pupae did not abort their diapause program. In both diapausing and non-diapausing pupae, body weight was positively correlated with simulated winter survival. However, above a weight threshold, body weight no longer affected simulated winter survival in diapausing pupae. Contrary to our predictions and the general consensus in much of the diapause literature, we also found that lighter pupae stayed in diapause longer than heavier pupae. Overall, our results challenge the precept that body weight and diapause are positively associated. The relationship between body weight and diapause is complex and may be affected by the availability of food before and after winter, the availability of high-quality overwintering sites, and the life history of a particular insect.
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Affiliation(s)
- Clancy A Short
- Department of Entomology and Nematology The University of Florida Gainesville Florida USA
| | - Jared L Walters
- Department of Entomology and Nematology The University of Florida Gainesville Florida USA
| | - Daniel A Hahn
- Department of Entomology and Nematology The University of Florida Gainesville Florida USA
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2
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Yan G, Li D, Wang G, Wu L. Diet Affects the Temperature-Size Relationship in the Blowfly Aldrichina grahami. INSECTS 2024; 15:246. [PMID: 38667376 PMCID: PMC11049999 DOI: 10.3390/insects15040246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 03/28/2024] [Accepted: 04/01/2024] [Indexed: 04/28/2024]
Abstract
In warmer environments, most ectotherms exhibit a plastic reduction in body size (the temperature-size rule, TSR). However, in such environments, growth is usually accelerated and would be expected to result in maturation at a larger body size, leading to increases in fecundity, survival, and mating success, compared to maturation at a smaller size (the 'life-history puzzle'). To explore these mechanisms, we reared Aldrichina grahami at 20 °C, 25 °C, and 30 °C, and added a nutritional challenge by using dilutions of pork liver paste to provide diets that ranged in quality from high (undiluted) to moderate (1/8), low (1/16), and poor (1/24). Larvae were randomly sampled for weighing from hatching. Growth curves were fitted to the relationships between growth rate and weight for the third instar larvae. Our results showed that body size was affected by an interaction between temperature and diet, and that following or not following the TSR can vary depending on underfeeding. Moreover, when the TSR was followed as temperature increased, there was a cross-over point that divided the two growth curves into early and later stages, which could be used to help understand the life-history puzzle in warmer temperatures, with the instantaneous growth rate being faster in the early stages of development and then slower in later stages. This study reminds us that animals have evolved to cope with multiple simultaneous environmental changes, and it has thus offered a better understanding of life-history puzzles.
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Affiliation(s)
- Guanjie Yan
- Henan International Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, Nanyang Normal University, Nanyang 473061, China; (G.Y.)
| | - Dandan Li
- Henan International Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, Nanyang Normal University, Nanyang 473061, China; (G.Y.)
| | - Guangshuai Wang
- Farmland Irrigation Research Institute, Chinese Academy of Agriculture Sciences/Shangqiu Station of National Field Agro-Ecosystem Experimental Network, Shangqiu 476000, China
| | - Lingbing Wu
- School of Tropical Agriculture and Forestry, Hainan University, Renmin Road 58, Haikou 570228, China
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3
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Winant M, Buhler K, Callaerts P. Ectopic expression in commonly used transgenic Drosophila GAL4 driver lines. Genesis 2024; 62:e23600. [PMID: 38665068 DOI: 10.1002/dvg.23600] [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: 04/03/2024] [Accepted: 04/09/2024] [Indexed: 06/28/2024]
Abstract
Transgenic tools such as the GAL4/UAS system in Drosophila have been used extensively to induce spatiotemporally controlled changes in gene expression and tissue-specific expression of a range of transgenes. We previously discovered unexpected expression of the commonly used dilp2-GAL4 line in tracheal tissue which significantly impacted growth phenotypes. We realized that few GAL4 lines have been thoroughly characterized, particularly when considering transient activity that may have significant impact on phenotypic readouts. Here, we characterized a further subset of 12 reportedly tissue-specific GAL4 lines commonly used in genetic studies of development, growth, endocrine regulation, and metabolism. Ten out of 12 GAL4 lines exhibited ectopic activity in other larval tissues, with seven being active in the larval trachea. Since this ectopic activity may result in phenotypes that do not depend on the manipulation in the intended target tissue, it is recommended to carefully analyze the outcome while taking this aspect into consideration.
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Affiliation(s)
- Mattias Winant
- Laboratory of Behavioral and Developmental Genetics, Department of Human Genetics, KU Leuven - University of Leuven, Leuven, Belgium
| | - Kurt Buhler
- Laboratory of Behavioral and Developmental Genetics, Department of Human Genetics, KU Leuven - University of Leuven, Leuven, Belgium
| | - Patrick Callaerts
- Laboratory of Behavioral and Developmental Genetics, Department of Human Genetics, KU Leuven - University of Leuven, Leuven, Belgium
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4
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Ponton F, Tan YX, Forster CC, Austin AJ, English S, Cotter SC, Wilson K. The complex interactions between nutrition, immunity and infection in insects. J Exp Biol 2023; 226:jeb245714. [PMID: 38095228 DOI: 10.1242/jeb.245714] [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] [Indexed: 12/18/2023]
Abstract
Insects are the most diverse animal group on the planet. Their success is reflected by the diversity of habitats in which they live. However, these habitats have undergone great changes in recent decades; understanding how these changes affect insect health and fitness is an important challenge for insect conservation. In this Review, we focus on the research that links the nutritional environment with infection and immune status in insects. We first discuss the research from the field of nutritional immunology, and we then investigate how factors such as intracellular and extracellular symbionts, sociality and transgenerational effects may interact with the connection between nutrition and immunity. We show that the interactions between nutrition and resistance can be highly specific to insect species and/or infection type - this is almost certainly due to the diversity of insect social interactions and life cycles, and the varied environments in which insects live. Hence, these connections cannot be easily generalised across insects. We finally suggest that other environmental aspects - such as the use of agrochemicals and climatic factors - might also influence the interaction between nutrition and resistance, and highlight how research on these is essential.
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Affiliation(s)
- Fleur Ponton
- School of Natural Sciences , Macquarie University, North Ryde, NSW 2109, Australia
| | - Yin Xun Tan
- School of Natural Sciences , Macquarie University, North Ryde, NSW 2109, Australia
| | - Casey C Forster
- School of Natural Sciences , Macquarie University, North Ryde, NSW 2109, Australia
| | | | - Sinead English
- School of Biological Sciences , University of Bristol, Bristol, BS8 1QU, UK
| | | | - Kenneth Wilson
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK
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5
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Oliveira AC, Homem CCF. Opposing effects of ecdysone signaling regulate neuroblast proliferation to ensure coordination of brain and organism development. Dev Biol 2023; 503:53-67. [PMID: 37549863 DOI: 10.1016/j.ydbio.2023.08.001] [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: 01/13/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/09/2023]
Abstract
Growth regulation must be robust to ensure correct final size, but also adaptative to adjust to less favorable environmental conditions. Developmental coordination between whole-organism and the brain is particularly important, as the brain is a critical organ with little adaptability. Brain growth mainly depends on neural stem cell (NSC) proliferation to generate differentiated neural cells, it is however unclear how organism developmental progression is coordinated with NSCs. Here we demonstrate that the steroid hormone ecdysone plays a multi-step, stage specific role in regulating Drosophila NSCs, the neuroblasts. We used animals that are unable to synthesize ecdysone, to show that the developmental milestone called "critical weight peak", the peak that informs the body has reached minimum viable weight to survive metamorphosis, acts a checkpoint necessary to set neuroblast cell cycle pace during larval neurogenesis. The peaks of ecdysone that occur post-critical weight are no longer required to maintain neuroblast division rate. We additionally show that in a second stage, at the onset of pupariation, ecdysone is instead required to trigger neuroblast's proliferation exit and consequently the end of neurogenesis. We demonstrate that, without this signal from ecdysone, neuroblasts lose their ability to exit proliferation. Interestingly, although these neuroblasts proliferate for a longer period, the number of differentiated neurons is smaller compared to wild-type brains, suggesting a role for ecdysone in neuron maintenance. Our study provides insights into how neural stem cells coordinate their division rate with the pace of body growth, identifying a novel coordination mechanism between animal development and NSC proliferation.
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Affiliation(s)
- Andreia C Oliveira
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Catarina C F Homem
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade Nova de Lisboa, Lisboa, Portugal.
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6
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Clark JM, Gibbs AG. Starvation selection reduces and delays larval ecdysone production and signaling. J Exp Biol 2023; 226:jeb246144. [PMID: 37671530 PMCID: PMC10560552 DOI: 10.1242/jeb.246144] [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: 06/08/2023] [Accepted: 08/22/2023] [Indexed: 09/07/2023]
Abstract
Previous studies have shown that selection for starvation resistance in Drosophila melanogaster results in delayed eclosion and increased adult fat stores. It is assumed that these traits are caused by the starvation selection pressure, but its mechanism is unknown. We found that our starvation-selected (SS) population stores more fat during larval development and has extended larval development and pupal development time. Developmental checkpoints in the third instar associated with ecdysteroid hormone pulses are increasingly delayed. The delay in the late larval period seen in the SS population is indicative of reduced and delayed ecdysone signaling. An enzyme immunoassay for ecdysteroids (with greatest affinity to the metabolically active 20-hydroxyecdysone and the α-ecdysone precursor) confirmed that the SS population had reduced and delayed hormone production compared with that of fed control (FC) flies. Feeding third instar larvae on food supplemented with α-ecdysone partially rescued the developmental delay and reduced subsequent adult starvation resistance. This work suggests that starvation selection causes reduced and delayed production of ecdysteroids in the larval stage and affects the developmental delay phenotype that contributes to subsequent adult fat storage and starvation resistance.
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Affiliation(s)
- Jennifer M. Clark
- School of Life Sciences, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV 89154-4004, USA
| | - Allen G. Gibbs
- School of Life Sciences, University of Nevada, Las Vegas, 4505 S. Maryland Pkwy, Las Vegas, NV 89154-4004, USA
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7
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Bresgen N, Kovacs M, Lahnsteiner A, Felder TK, Rinnerthaler M. The Janus-Faced Role of Lipid Droplets in Aging: Insights from the Cellular Perspective. Biomolecules 2023; 13:912. [PMID: 37371492 DOI: 10.3390/biom13060912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/22/2023] [Accepted: 05/29/2023] [Indexed: 06/29/2023] Open
Abstract
It is widely accepted that nine hallmarks-including mitochondrial dysfunction, epigenetic alterations, and loss of proteostasis-exist that describe the cellular aging process. Adding to this, a well-described cell organelle in the metabolic context, namely, lipid droplets, also accumulates with increasing age, which can be regarded as a further aging-associated process. Independently of their essential role as fat stores, lipid droplets are also able to control cell integrity by mitigating lipotoxic and proteotoxic insults. As we will show in this review, numerous longevity interventions (such as mTOR inhibition) also lead to strong accumulation of lipid droplets in Saccharomyces cerevisiae, Caenorhabditis elegans, Drosophila melanogaster, and mammalian cells, just to name a few examples. In mammals, due to the variety of different cell types and tissues, the role of lipid droplets during the aging process is much more complex. Using selected diseases associated with aging, such as Alzheimer's disease, Parkinson's disease, type II diabetes, and cardiovascular disease, we show that lipid droplets are "Janus"-faced. In an early phase of the disease, lipid droplets mitigate the toxicity of lipid peroxidation and protein aggregates, but in a later phase of the disease, a strong accumulation of lipid droplets can cause problems for cells and tissues.
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Affiliation(s)
- Nikolaus Bresgen
- Department of Biosciences and Medical Biology, Paris-Lodron University Salzburg, 5020 Salzburg, Austria
| | - Melanie Kovacs
- Department of Biosciences and Medical Biology, Paris-Lodron University Salzburg, 5020 Salzburg, Austria
| | - Angelika Lahnsteiner
- Department of Biosciences and Medical Biology, Paris-Lodron University Salzburg, 5020 Salzburg, Austria
| | - Thomas Klaus Felder
- Department of Laboratory Medicine, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Mark Rinnerthaler
- Department of Biosciences and Medical Biology, Paris-Lodron University Salzburg, 5020 Salzburg, Austria
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8
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Farfán-Pira KJ, Martínez-Cuevas TI, Evans TA, Nahmad M. A cis-regulatory sequence of the selector gene vestigial drives the evolution of wing scaling in Drosophila species. J Exp Biol 2023; 226:jeb244692. [PMID: 37078652 PMCID: PMC10234621 DOI: 10.1242/jeb.244692] [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: 06/23/2022] [Accepted: 04/13/2023] [Indexed: 04/21/2023]
Abstract
Scaling between specific organs and overall body size has long fascinated biologists, being a primary mechanism by which organ shapes evolve. Yet, the genetic mechanisms that underlie the evolution of scaling relationships remain elusive. Here, we compared wing and fore tibia lengths (the latter as a proxy of body size) in Drosophila melanogaster, Drosophila simulans, Drosophila ananassae and Drosophila virilis, and show that the first three of these species have roughly a similar wing-to-tibia scaling behavior. In contrast, D. virilis exhibits much smaller wings relative to their body size compared with the other species and this is reflected in the intercept of the wing-to-tibia allometry. We then asked whether the evolution of this relationship could be explained by changes in a specific cis-regulatory region or enhancer that drives expression of the wing selector gene, vestigial (vg), whose function is broadly conserved in insects and contributes to wing size. To test this hypothesis directly, we used CRISPR/Cas9 to replace the DNA sequence of the predicted Quadrant Enhancer (vgQE) from D. virilis for the corresponding vgQE sequence in the genome of D. melanogaster. Strikingly, we discovered that D. melanogaster flies carrying the D. virilis vgQE sequence have wings that are significantly smaller with respect to controls, partially shifting the intercept of the wing-to-tibia scaling relationship towards that observed in D. virilis. We conclude that a single cis-regulatory element in D. virilis contributes to constraining wing size in this species, supporting the hypothesis that scaling could evolve through genetic variations in cis-regulatory elements.
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Affiliation(s)
- Keity J. Farfán-Pira
- Department of Physiology, Biophysics and Neurosciences, Centre for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav-IPN), Mexico City 07360, Mexico
| | - Teresa I. Martínez-Cuevas
- Department of Physiology, Biophysics and Neurosciences, Centre for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav-IPN), Mexico City 07360, Mexico
| | - Timothy A. Evans
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | - Marcos Nahmad
- Department of Physiology, Biophysics and Neurosciences, Centre for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav-IPN), Mexico City 07360, Mexico
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9
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Sustar AE, Strand LG, Zimmerman SG, Berg CA. Imaginal disk growth factors are Drosophila chitinase-like proteins with roles in morphogenesis and CO2 response. Genetics 2023; 223:iyac185. [PMID: 36576887 PMCID: PMC9910413 DOI: 10.1093/genetics/iyac185] [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: 07/18/2022] [Revised: 07/18/2022] [Accepted: 11/16/2022] [Indexed: 12/29/2022] Open
Abstract
Chitinase-like proteins (CLPs) are members of the family 18 glycosyl hydrolases, which include chitinases and the enzymatically inactive CLPs. A mutation in the enzyme's catalytic site, conserved in vertebrates and invertebrates, allowed CLPs to evolve independently with functions that do not require chitinase activity. CLPs normally function during inflammatory responses, wound healing, and host defense, but when they persist at excessive levels at sites of chronic inflammation and in tissue-remodeling disorders, they correlate positively with disease progression and poor prognosis. Little is known, however, about their physiological function. Drosophila melanogaster has 6 CLPs, termed Imaginal disk growth factors (Idgfs), encoded by Idgf1, Idgf2, Idgf3, Idgf4, Idgf5, and Idgf6. In this study, we developed tools to facilitate characterization of the physiological roles of the Idgfs by deleting each of the Idgf genes using the CRISPR/Cas9 system and assessing loss-of-function phenotypes. Using null lines, we showed that loss of function for all 6 Idgf proteins significantly lowers viability and fertility. We also showed that Idgfs play roles in epithelial morphogenesis, maintaining proper epithelial architecture and cell shape, regulating E-cadherin and cortical actin, and remarkably, protecting these tissues against CO2 exposure. Defining the normal molecular mechanisms of CLPs is a key to understanding how deviations tip the balance from a physiological to a pathological state.
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Affiliation(s)
- Anne E Sustar
- Department of Genome Sciences, University of Washington, Foege Bldg. S-250, 3720 15th Ave NE, Seattle, WA 98195-5065, USA
| | - Liesl G Strand
- Department of Genome Sciences, University of Washington, Foege Bldg. S-250, 3720 15th Ave NE, Seattle, WA 98195-5065, USA
| | - Sandra G Zimmerman
- Department of Genome Sciences, University of Washington, Foege Bldg. S-250, 3720 15th Ave NE, Seattle, WA 98195-5065, USA
| | - Celeste A Berg
- Department of Genome Sciences, University of Washington, Foege Bldg. S-250, 3720 15th Ave NE, Seattle, WA 98195-5065, USA
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10
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Schang K, Garant R, Long TA. Phenotypic extremes or extreme phenotypes? On the use of large and small-bodied "phenocopied" Drosophila melanogaster males in studies of sexual selection and conflict. CURRENT RESEARCH IN INSECT SCIENCE 2023; 3:100052. [PMID: 36794123 PMCID: PMC9922682 DOI: 10.1016/j.cris.2023.100052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/30/2023] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
In the fruit fly, Drosophila melanogaster, variation in body size is influenced by a number of different factors and may be strongly associated with individual condition, performance and success in reproductive competitions. Consequently, intra-sexual variation in size in this model species has been frequently explored in order to better understand how sexual selection and sexual conflict may operate and shape evolutionary trajectories. However, measuring individual flies can often be logistically complicated and inefficient, which can result in limited sample sizes. Instead, many experiments use large and/or small body sizes that are created by manipulating the developmental conditions experienced during the larval stages, resulting in "phenocopied" flies whose phenotypes resemble what is seen at the extremes of a population's size distribution. While this practice is fairly common, there has been remarkedly few direct tests to empirically compare the behaviour or performance of phenocopied flies to similarly-sized individuals that grew up under typical developmental conditions. Contrary to assumptions that phenocopied flies are reasonable approximations, we found that both large and small-bodied phenocopied males frequently differed from their standard development equivalents in their mating frequencies, their lifetime reproductive successes, and in their effects on the fecundity of the females they interacted with. Our results highlight the complicated contributions of environment and genotype to the expression of body size phenotypes and lead us to strongly urge caution in the interpretation of studies solely replying upon phenocopied individuals.
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Affiliation(s)
- Kyle Schang
- Department of Biology, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON, Canada
- School of Environment, Resources and Sustainability, Faculty of Environment, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada
| | - Renée Garant
- Department of Biology, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON, Canada
- Department of Animal Biosciences, University of Guelph, 50 Stone Road East, Guelph, ON, Canada
| | - Tristan A.F. Long
- Department of Biology, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON, Canada
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11
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Cao J, Zheng HS, Zhang R, Xu YP, Pan H, Li S, Liu C, Cheng TC. Dimmed gene knockout shortens larval growth and reduces silk yield in the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2023; 32:26-35. [PMID: 36082617 DOI: 10.1111/imb.12810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
The bHLH domain transcription factor, Bombyx mori-derived dimmed (Bmdimm), is directly regulated by the JH-BmMet/BmSRC-BmKr-h1 pathway and plays a key role in regulating the expression of FibH, which codes the main component of silk protein. However, the other roles of Bmdimm in silk protein synthesis remain unclear. Here, we established a Bmdimm knockout (KO) line containing a 7-bp deletion via CRISPR/Cas9 system, which led to the absence of the bHLH domain. The expression level of silk protein genes and silk yield decreased significantly in the Bmdimm KO line. Moreover, knocking out Bmdimm led to shortened larval stages and significant weight loss in larvae and adults. Bmdimm was found to be highly expressed in the silk gland, but it was also expressed in the fat body. The expression level of Bmkr-h1 in the fat body was significantly downregulated in the Bmdimm KO line. Exogenous JHA treatment upregulated Bmkr-h1 and rescued the phenotype of larval growth in the Bmdimm KO line. In conclusion, knocking out Bmdimm led to a shortened larval stage via the inhibition of Bmkr-h1 expression, then reduced silk yield. These findings help to elucidate the regulatory mechanism of fibroin synthesis and larval development in silkworms.
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Affiliation(s)
- Jun Cao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Hong-Sheng Zheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ran Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yong-Ping Xu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Huan Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Shan Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Chun Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Ting-Cai Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
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12
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Chakraborty A, Walter GM, Monro K, Alves AN, Mirth CK, Sgrò CM. Within-population variation in body size plasticity in response to combined nutritional and thermal stress is partially independent from variation in development time. J Evol Biol 2023; 36:264-279. [PMID: 36208146 PMCID: PMC10092444 DOI: 10.1111/jeb.14099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 01/11/2023]
Abstract
Ongoing climate change has forced animals to face changing thermal and nutritional environments. Animals can adjust to such combinations of stressors via plasticity. Body size is a key trait influencing organismal fitness, and plasticity in this trait in response to nutritional and thermal conditions varies among genetically diverse, locally adapted populations. The standing genetic variation within a population can also influence the extent of body size plasticity. We generated near-isogenic lines from a newly collected population of Drosophila melanogaster at the mid-point of east coast Australia and assayed body size for all lines in combinations of thermal and nutritional stress. We found that isogenic lines showed distinct underlying patterns of body size plasticity in response to temperature and nutrition that were often different from the overall population response. We then tested whether plasticity in development time could explain, and therefore regulate, variation in body size to these combinations of environmental conditions. We selected five genotypes that showed the greatest variation in response to combined thermal and nutritional stress and assessed the correlation between response of developmental time and body size. While we found significant genetic variation in development time plasticity, it was a poor predictor of body size among genotypes. Our results therefore suggest that multiple developmental pathways could generate genetic variation in body size plasticity. Our study emphasizes the need to better understand genetic variation in plasticity within a population, which will help determine the potential for populations to adapt to ongoing environmental change.
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Affiliation(s)
| | - Greg M Walter
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Keyne Monro
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - André N Alves
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Christen K Mirth
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Carla M Sgrò
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
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13
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Mateus ARA, Beldade P. Developmental Plasticity in Butterfly Eyespot Mutants: Variation in Thermal Reaction Norms Across Genotypes and Pigmentation Traits. INSECTS 2022; 13:1000. [PMID: 36354827 PMCID: PMC9699518 DOI: 10.3390/insects13111000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/25/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
Developmental plasticity refers to the property by which a genotype corresponds to distinct phenotypes depending on the environmental conditions experienced during development. This dependence of phenotype expression on environment is graphically represented by reaction norms, which can differ between traits and between genotypes. Even though genetic variation for reaction norms provides the basis for the evolution of plasticity, we know little about the genes that contribute to that variation. This includes understanding to what extent those are the same genes that contribute to inter-individual variation in a fixed environment. Here, we quantified thermal plasticity in butterfly lines that differ in pigmentation phenotype to test the hypothesis that alleles affecting pigmentation also affect plasticity therein. We characterized thermal reaction norms for eyespot color rings of distinct Bicyclus anynana genetic backgrounds, corresponding to allelic variants affecting eyespot size and color composition. Our results reveal genetic variation for the slope and curvature of reaction norms, with differences between eyespots and between eyespot color rings, as well as between sexes. Our report of prevalent temperature-dependent and compartment-specific allelic effects underscores the complexity of genotype-by-environment interactions and their consequence for the evolution of developmental plasticity.
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Affiliation(s)
| | - Patrícia Beldade
- Instituto Gulbenkian de Ciência (IGC), 2780-156 Oeiras, Portugal
- CNRS—UMR 5174, Evolution et Diversité Biologique (EDB), Université Paul Sabatier (UPS), 31077 Toulouse, France
- Center for Ecology, Evolution and Environmental Changes (cE3c) & Global Change and Sustainability Institute (CHANGE), Faculty of Sciences, University of Lisbon (FCUL), 1749-016 Lisbon, Portugal
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14
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Brooks D, Bawa S, Bontrager A, Stetsiv M, Guo Y, Geisbrecht ER. Independent pathways control muscle tissue size and sarcomere remodeling. Dev Biol 2022; 490:1-12. [PMID: 35760368 PMCID: PMC9648737 DOI: 10.1016/j.ydbio.2022.06.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/03/2022] [Accepted: 06/21/2022] [Indexed: 01/09/2023]
Abstract
Cell growth and proliferation must be balanced during development to attain a final adult size with the appropriate proportions of internal organs to maximize fitness and reproduction. While multiple signaling pathways coordinate Drosophila development, it is unclear how multi-organ communication within and between tissues converge to regulate systemic growth. One such growth pathway, mediated by insulin-like peptides that bind to and activate the insulin receptor in multiple target tissues, is a primary mediator of organismal size. Here we uncover a signaling role for the NUAK serine/threonine kinase in muscle tissue that impinges upon insulin pathway activity to limit overall body size, including a reduction in the growth of individual organs. In skeletal muscle tissue, manipulation of NUAK or insulin pathway components influences sarcomere number concomitant with modulation of thin and thick filament lengths, possibly by modulating the localization of Lasp, a nebulin repeat protein known to set thin filament length. This mode of sarcomere remodeling does not occur in other mutants that also exhibit smaller muscles, suggesting that a sensing mechanism exists in muscle tissue to regulate sarcomere growth that is independent of tissue size control.
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Affiliation(s)
- David Brooks
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
| | - Simranjot Bawa
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
| | - Alexandria Bontrager
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
| | - Marta Stetsiv
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
| | - Yungui Guo
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA
| | - Erika R Geisbrecht
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, 66506, USA.
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15
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Cobham AE, Neumann B, Mirth CK. Maintaining robust size across environmental conditions through plastic brain growth dynamics. Open Biol 2022; 12:220037. [PMID: 36102061 PMCID: PMC9471992 DOI: 10.1098/rsob.220037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Organ growth is tightly regulated across environmental conditions to generate an appropriate final size. While the size of some organs is free to vary, others need to maintain constant size to function properly. This poses a unique problem: how is robust final size achieved when environmental conditions alter key processes that regulate organ size throughout the body, such as growth rate and growth duration? While we know that brain growth is ‘spared’ from the effects of the environment from humans to fruit flies, we do not understand how this process alters growth dynamics across brain compartments. Here, we explore how this robustness in brain size is achieved by examining differences in growth patterns between the larval body, the brain and a brain compartment—the mushroom bodies—in Drosophila melanogaster across both thermal and nutritional conditions. We identify key differences in patterns of growth between the whole brain and mushroom bodies that are likely to underlie robustness of final organ shape. Further, we show that these differences produce distinct brain shapes across environments.
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Affiliation(s)
- Ansa E Cobham
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Brent Neumann
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Christen K Mirth
- School of Biological Sciences, Monash University, Melbourne, Australia
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16
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Moczek AP. When the end modifies its means: the origins of novelty and the evolution of innovation. Biol J Linn Soc Lond 2022. [DOI: 10.1093/biolinnean/blac061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
The origin of novel complex traits constitutes a central yet largely unresolved challenge in evolutionary biology. Intriguingly, many of the most promising breakthroughs in understanding the genesis of evolutionary novelty in recent years have occurred not in evolutionary biology itself, but through the comparative study of development and, more recently, the interface of developmental biology and ecology. Here, I discuss how these insights are changing our understanding of what matters in the origin of novel, complex traits in ontogeny and evolution. Specifically, my essay has two major objectives. First, I discuss how the nature of developmental systems biases the production of phenotypic variation in the face of novel or stressful environments toward functional, integrated and, possibly, adaptive variants. This, in turn, allows the production of novel phenotypes to precede (rather than follow) changes in genotype and allows developmental processes that are the product of past evolution to shape evolutionary change that has yet to occur. Second, I explore how this nature of developmental systems has itself evolved over time, increasing the repertoire of ontogenies to pursue a wider range of objectives across an expanding range of conditions, thereby creating an increasingly extensive affordance landscape in development and developmental evolution. Developmental systems and their evolution can thus be viewed as dynamic processes that modify their own means across ontogeny and phylogeny. The study of these dynamics necessitates more than the strict reductionist approach that currently dominates the fields of developmental and evolutionary developmental biology.
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Affiliation(s)
- Armin P Moczek
- Department of Biology, Indiana University , Bloomington, IN , USA
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17
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Nogueira Alves A, Oliveira MM, Koyama T, Shingleton A, Mirth CK. Ecdysone coordinates plastic growth with robust pattern in the developing wing. eLife 2022; 11:72666. [PMID: 35261337 PMCID: PMC8947767 DOI: 10.7554/elife.72666] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 03/07/2022] [Indexed: 11/25/2022] Open
Abstract
Animals develop in unpredictable, variable environments. In response to environmental change, some aspects of development adjust to generate plastic phenotypes. Other aspects of development, however, are buffered against environmental change to produce robust phenotypes. How organ development is coordinated to accommodate both plastic and robust developmental responses is poorly understood. Here, we demonstrate that the steroid hormone ecdysone coordinates both plasticity of organ size and robustness of organ pattern in the developing wings of the fruit fly Drosophila melanogaster. Using fed and starved larvae that lack prothoracic glands, which synthesize ecdysone, we show that nutrition regulates growth both via ecdysone and via an ecdysone-independent mechanism, while nutrition regulates patterning only via ecdysone. We then demonstrate that growth shows a graded response to ecdysone concentration, while patterning shows a threshold response. Collectively, these data support a model where nutritionally regulated ecdysone fluctuations confer plasticity by regulating disc growth in response to basal ecdysone levels and confer robustness by initiating patterning only once ecdysone peaks exceed a threshold concentration. This could represent a generalizable mechanism through which hormones coordinate plastic growth with robust patterning in the face of environmental change.
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Affiliation(s)
| | | | | | - Alexander Shingleton
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, United States
| | - Christen K Mirth
- School of Biological Sciences, Monash University, Melbourne, Australia
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18
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Kamiyama T, Niwa R. Transcriptional Regulators of Ecdysteroid Biosynthetic Enzymes and Their Roles in Insect Development. Front Physiol 2022; 13:823418. [PMID: 35211033 PMCID: PMC8863297 DOI: 10.3389/fphys.2022.823418] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 01/12/2022] [Indexed: 12/23/2022] Open
Abstract
Steroid hormones are responsible for coordinating many aspects of biological processes in most multicellular organisms, including insects. Ecdysteroid, the principal insect steroid hormone, is biosynthesized from dietary cholesterol or plant sterols. In the last 20 years, a number of ecdysteroidogenic enzymes, including Noppera-bo, Neverland, Shroud, Spook/Spookier, Cyp6t3, Phantom, Disembodied, Shadow, and Shade, have been identified and characterized in molecular genetic studies using the fruit fly Drosophila melanogaster. These enzymes are encoded by genes collectively called the Halloween genes. The transcriptional regulatory network, governed by multiple regulators of transcription, chromatin remodeling, and endoreplication, has been shown to be essential for the spatiotemporal expression control of Halloween genes in D. melanogaster. In this review, we summarize the latest information on transcriptional regulators that are crucial for controlling the expression of ecdysteroid biosynthetic enzymes and their roles in insect development.
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Affiliation(s)
- Takumi Kamiyama
- College of Biological Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Ryusuke Niwa
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Japan
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19
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Abstract
The Drosophila wing imaginal disc is a tissue of undifferentiated cells that are precursors of the wing and most of the notum of the adult fly. The wing disc first forms during embryogenesis from a cluster of ∼30 cells located in the second thoracic segment, which invaginate to form a sac-like structure. They undergo extensive proliferation during larval stages to form a mature larval wing disc of ∼35,000 cells. During this time, distinct cell fates are assigned to different regions, and the wing disc develops a complex morphology. Finally, during pupal stages the wing disc undergoes morphogenetic processes and then differentiates to form the adult wing and notum. While the bulk of the wing disc comprises epithelial cells, it also includes neurons and glia, and is associated with tracheal cells and muscle precursor cells. The relative simplicity and accessibility of the wing disc, combined with the wealth of genetic tools available in Drosophila, have combined to make it a premier system for identifying genes and deciphering systems that play crucial roles in animal development. Studies in wing imaginal discs have made key contributions to many areas of biology, including tissue patterning, signal transduction, growth control, regeneration, planar cell polarity, morphogenesis, and tissue mechanics.
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Affiliation(s)
- Bipin Kumar Tripathi
- Department of Molecular Biology and Biochemistry, Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA
| | - Kenneth D Irvine
- Department of Molecular Biology and Biochemistry, Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA
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20
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Kapila R, Poddar S, Meena N, Prasad NG. Investment in adult reproductive tissues is affected by larval growth conditions but not by evolution under poor larval growth conditions in Drosophila melanogaster. CURRENT RESEARCH IN INSECT SCIENCE 2022; 2:100027. [PMID: 36003263 PMCID: PMC9387493 DOI: 10.1016/j.cris.2021.100027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/30/2022]
Abstract
Growing at different larval densities affect the investment in reproductive tissues Increased larval density negatively affects the testis and accessory gland size Relative investment in testis is not affected by larval densities Increased larval densities affect relative accessory gland size negatively Adaptation to high larval crowding does not affect investment in reproductive tissues
In many insects, the larval environment is confined to the egg-laying site, which often leads to crowded larval conditions, exposing the developing larvae to poor resource availability and toxic metabolic wastes. Larval crowding imposes two opposing selection pressures. On one hand, due to poor nutritional resources during developmental stages, adults from the crowded larval environment have reduced investment in reproductive tissues. On the other hand, a crowded larval environment acts as a cue for future reproductive competition inducing increased investment in reproductive tissues. Both these selection pressures are likely affected by the level of crowding. The evolutionary consequence of adaptation to larval crowding environment on adult reproductive investment is bound to be a result of the interaction of these two opposing forces. In this study, we used experimentally evolved populations of Drosophila melanogaster adapted to larval crowding to investigate the effect of adaptation to larval crowding on investment in reproductive organs (testes and accessory glands) of males. Our results show that there is a strong effect of larval developmental environment on absolute sizes of testes and accessory glands. However, there was no effect of the developmental environment when testis size was scaled by body size. We also found that flies from crowded cultures had smaller accessory gland sizes relative to body size. Moreover, the sizes of the reproductive organs were not affected by the selection histories of the populations. This study highlights that adaptation to two extremely different developmental environments does not affect the patterns of reproductive investment. We discuss the possibility that differential investment in reproductive tissues could be influenced by the mating dynamics and/or investment in larval survival traits, rather than just the developmental environment of the populations.
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21
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Kamei H, Duan C. Alteration of organ size and allometric scaling by organ-specific targeting of IGF signaling. Gen Comp Endocrinol 2021; 314:113922. [PMID: 34606746 DOI: 10.1016/j.ygcen.2021.113922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 08/21/2021] [Accepted: 09/29/2021] [Indexed: 11/16/2022]
Abstract
The size of an organ is proportional to the other body parts or the whole body. This relationship is known as allometry. Understanding how allometry is determined is a fundamental question in biology. Here we tested the hypothesis that local insulin-like growth factor (Igf) signaling is critical in regulating organ size and its allometric scaling by organ-specific expression of Igf binding protein (Igfbp). Overexpression of Igfbp2a or 5b in the developing zebrafish eye, heart, and inner ear resulted in a disproportional reduction in their growth relative to the body. Stable transgenic zebrafish with lens-specific Igfbp5b expression selectively reduced adult eye size. The action is Igf-dependent because an Igf-binding deficient Igfbp5b mutant had no effect. Targeted expression of a dominant-negative Igf1 receptor (dnIgf1r) in the lens caused a similar reduction in relative eye growth. Furthermore, co-expression of IGF-1 with an Igfbp restored the eye size. Finally, co-expression of a constitutively active form of Akt with Igfbp or dnIgf1r restored the relative eye growth. These data suggest that local Igf availability and Igf signaling activity are critical determinants of organ size and allometric scaling in zebrafish.
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Affiliation(s)
- Hiroyasu Kamei
- Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University 11-4-1, Ossaka, Noto, Ishikawa 927-0552, Japan.
| | - Cunming Duan
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109-1048, United States
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22
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Strassburger K, Lutz M, Müller S, Teleman AA. Ecdysone regulates Drosophila wing disc size via a TORC1 dependent mechanism. Nat Commun 2021; 12:6684. [PMID: 34795214 PMCID: PMC8602387 DOI: 10.1038/s41467-021-26780-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 10/15/2021] [Indexed: 11/09/2022] Open
Abstract
Most cells in a developing organ stop proliferating when the organ reaches a correct, final size. The underlying molecular mechanisms are not understood. We find that in Drosophila the hormone ecdysone controls wing disc size. To study how ecdysone affects wing size, we inhibit endogenous ecdysone synthesis and feed larvae exogenous ecdysone in a dose-controlled manner. For any given ecdysone dose, discs stop proliferating at a particular size, with higher doses enabling discs to reach larger sizes. Termination of proliferation coincides with a drop in TORC1, but not Dpp or Yki signaling. Reactivating TORC1 bypasses the termination of proliferation, indicating that TORC1 is a main downstream effector causing proliferation termination at the maximal ecdysone-dependent size. Experimental manipulation of Dpp or Yki signaling can bypass proliferation termination in hinge and notum regions, but not the pouch, suggesting that the mechanisms regulating proliferation termination may be distinct in different disc regions.
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Affiliation(s)
- Katrin Strassburger
- grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Heidelberg University, 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373CellNetworks - Cluster of Excellence, Heidelberg University, Heidelberg, Germany ,grid.4488.00000 0001 2111 7257Present Address: Technische Universität Dresden, 01217 Dresden, Germany
| | - Marilena Lutz
- grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Heidelberg University, 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373CellNetworks - Cluster of Excellence, Heidelberg University, Heidelberg, Germany
| | - Sandra Müller
- grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Heidelberg University, 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373CellNetworks - Cluster of Excellence, Heidelberg University, Heidelberg, Germany
| | - Aurelio A. Teleman
- grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Heidelberg University, 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373CellNetworks - Cluster of Excellence, Heidelberg University, Heidelberg, Germany
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23
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Chakraborty A, Sgrò CM, Mirth CK. The proximate sources of genetic variation in body size plasticity: The relative contributions of feeding behaviour and development in Drosophila melanogaster. JOURNAL OF INSECT PHYSIOLOGY 2021; 135:104321. [PMID: 34653505 DOI: 10.1016/j.jinsphys.2021.104321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/03/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
Body size is a key life-history trait that influences many aspects of an animal's biology and is shaped by a variety of factors, both genetic and environmental. While we know that locally-adapted populations differ in the extent to which body size responds plastically to environmental conditions like diet, we have a limited understanding of what causes these differences. We hypothesized that populations could differ in the way body size responds to nutrition either by modulating growth rate, development time, feeding rate, or a combination of the above. Using three locally-adapted populations of Drosophila melanogaster from along the east coast of Australia, we investigated body size plasticity across five different diets. We then assessed how these populations differed in feeding behaviour and developmental timing on each of the diets. We observed population-specific plastic responses to nutrition for body size and feeding rate, but not development time. However, differences in feeding rate did not fully explain the differences in the way body size responded to diet. Thus, we conclude that body size variation in locally-adapted populations is shaped by a combination of growth rate and feeding behaviour. This paves the way for further studies that explore how differences in the regulation of the genetic pathways that control feeding behaviour and growth rate contribute to population-specific responses of body size to diet.
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Affiliation(s)
| | - Carla M Sgrò
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia.
| | - Christen K Mirth
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia.
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24
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Tiwari P, Rengarajan H, Saunders TE. Scaling of internal organs during Drosophila embryonic development. Biophys J 2021; 120:4264-4276. [PMID: 34087212 PMCID: PMC8516638 DOI: 10.1016/j.bpj.2021.05.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 05/04/2021] [Accepted: 05/27/2021] [Indexed: 11/20/2022] Open
Abstract
Many species show a diverse range of sizes; for example, domestic dogs have large variation in body mass. Yet, the internal structure of the organism remains similar, i.e., the system scales to organism size. Drosophila melanogaster has been a powerful model system for exploring scaling mechanisms. In the early embryo, gene expression boundaries scale very precisely to embryo length. Later in development, the adult wings grow with remarkable symmetry and scale well with animal size. Yet, our knowledge of whether internal organs initially scale to embryo size remains largely unknown. Here, we utilize artificially small Drosophila embryos to explore how three critical internal organs-the heart, hindgut, and ventral nerve cord (VNC)-adapt to changes in embryo morphology. We find that the heart scales precisely with embryo length. Intriguingly, reduction in cardiac cell length, rather than number, appears to be important in controlling heart length. The hindgut, which is the first chiral organ to form, displays scaling with embryo size under large-scale changes in the artificially smaller embryos but shows few hallmarks of scaling within wild-type size variation. Finally, the VNC only displays weak scaling behavior; even large changes in embryo geometry result in only small shifts in VNC length. This suggests that the VNC may have an intrinsic minimal length that is largely independent of embryo length. Overall, our work shows that internal organs can adapt to embryo size changes in Drosophila, but the extent to which they scale varies significantly between organs.
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Affiliation(s)
- Prabhat Tiwari
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | | | - Timothy E Saunders
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore, Singapore; Institute of Molecular and Cell Biology, A(∗)Star, Singapore, Singapore; Warwick Medical School, University of Warwick, Coventry, United Kingdom.
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25
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Zia A, Farkhondeh T, Sahebdel F, Pourbagher-Shahri AM, Samarghandian S. Key miRNAs in Modulating Aging and Longevity: A Focus on Signaling Pathways and Cellular Targets. Curr Mol Pharmacol 2021; 15:736-762. [PMID: 34533452 DOI: 10.2174/1874467214666210917141541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 05/02/2021] [Accepted: 05/24/2021] [Indexed: 11/22/2022]
Abstract
Aging is a multifactorial procedure accompanied by gradual deterioration of most biological procedures of cells. MicroRNAs (miRNAs) are a class of short non-coding RNAs that post-transcriptionally regulate the expression of mRNAs through sequence-specific binding, and contributing to many crucial aspects of cell biology. Several miRNAs are expressed differently in various organisms through aging. The function of miRNAs in modulating aging procedures has been disclosed recently with the detection of miRNAs that modulate longevity in the invertebrate model organisms, through the IIS pathway. In these model organisms, several miRNAs have been detected to both negatively and positively regulate lifespan via commonly aging pathways. miRNAs modulate age-related procedures and disorders in different mammalian tissues by measuring their tissue-specific expression in older and younger counterparts, including heart, skin, bone, brain, and muscle tissues. Moreover, several miRNAs have been contributed to modulating senescence in different human cells, and the roles of these miRNAs in modulating cellular senescence have allowed illustrating some mechanisms of aging. The review discusses the available data on miRNAs through the aging process and we highlight the roles of miRNAs as aging biomarkers and regulators of longevity in cellular senescence, tissue aging, and organism lifespan.
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Affiliation(s)
- Aliabbas Zia
- Department of Biochemistry, Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | - Tahereh Farkhondeh
- Cardiovascular Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Faezeh Sahebdel
- Department of Rehabilitation Medicine, University of Minnesota Medical School, Minneapolis, MN, United States
| | | | - Saeed Samarghandian
- Noncommunicable Diseases Research Center, Neyshabur University of Medical Sciences, Neyshabur, Iran
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26
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The involvement of translationally controlled tumor protein during lamb rumen epithelium development. Acta Histochem 2021; 123:151737. [PMID: 34116359 DOI: 10.1016/j.acthis.2021.151737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 11/22/2022]
Abstract
Early weaning is usually applied to improve the reproductive efficiency of sheep in mutton production, while the development of rumen is of vital importance for sheep weaning age. Translationally controlled tumor protein (TCTP) is a highly conserved protein which participates in multiple tissue and organ development. Thus, we hypothesized that TCTP was involved in sheep rumen development. Histological analyses of sheep rumen epithelium showed that the epithelium formed tough shaped papillae without growing from birth to day 15 of age, after which it rapidly developed to functional epithelia on day 45 of age. We then found TCTP expressed in stratum basale, stratum spinosum and stratum granulosum of rumen epithelium. TCTP protein expression remained at a relative low level from day 0 to day 15 of age, it then significantly increased on day 30 (p < 0.05) and gradually decreased until day 60. Furthermore, to explore the role of TCTP in sheep rumen and its regulation, we found the ratio of Ki67 positive cell in stratum basale cells followed the similar pattern as the expression of TCTP. We also found the ratio of acetate:propionate in rumen fluid decreased from day 30 to day 60 of age (p < 0.05). To conclude, our data indicated that TCTP participated in rumen papillae growth by promoting rumen stratum basale cell proliferation.
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27
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High fat diet induced abnormalities in metabolism, growth, behavior, and circadian clock in Drosophila melanogaster. Life Sci 2021; 281:119758. [PMID: 34175317 DOI: 10.1016/j.lfs.2021.119758] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/11/2021] [Accepted: 06/13/2021] [Indexed: 01/15/2023]
Abstract
AIMS The current lifestyle trend has made people vulnerable to diabetes and related diseases. Years of scientific research have not been able to yield a cure to the disease completely. The current study aims to investigate a link between high-fat diet mediated diabesity and circadian rhythm in the Drosophila model and inferences that might help in establishing a cure to the dreaded disease. MAIN METHODS Several experimental methods including phenotypical, histological, biochemical, molecular, and behavioral assays were used in the study to detect obesity, diabetes, and changes in the circadian clock in the fly model. KEY FINDINGS The larva and adults of Drosophila melanogaster exposed to high-fat diet (HFD) displayed excess deposition of fat as lipid droplets and micronuclei formation in the gut, fat body, and crop. Larva and adults of HFD showed behavioral defects. The higher amount of triglyceride, glucose, trehalose in the whole body of larva and adult fly confirmed obesity-induced hyperglycemia. The overexpression of insulin gene (Dilp2) and tribble (trbl) gene expression confirmed insulin resistance in HFD adults. We also observed elevated ROS level, developmental delay, altered metal level, growth defects, locomotory rhythms, sleep fragmentation, and expression of circadian genes (per, tim, and clock) in HFD larva and adults. Thus, HFD impairs the metabolism to produce obesity, insulin resistance, disruption of clock, and circadian clock related co-mordities in D. melanogaster. SIGNIFICANCE The circadian gene expression provides an innovative perspective to understand and find a new treatment for type-II diabetes and circadian anomalies.
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Mykles DL. Signaling Pathways That Regulate the Crustacean Molting Gland. Front Endocrinol (Lausanne) 2021; 12:674711. [PMID: 34234741 PMCID: PMC8256442 DOI: 10.3389/fendo.2021.674711] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/28/2021] [Indexed: 12/25/2022] Open
Abstract
A pair of Y-organs (YOs) are the molting glands of decapod crustaceans. They synthesize and secrete steroid molting hormones (ecdysteroids) and their activity is controlled by external and internal signals. The YO transitions through four physiological states over the molt cycle, which are mediated by molt-inhibiting hormone (MIH; basal state), mechanistic Target of Rapamycin Complex 1 (mTORC1; activated state), Transforming Growth Factor-β (TGFβ)/Activin (committed state), and ecdysteroid (repressed state) signaling pathways. MIH, produced in the eyestalk X-organ/sinus gland complex, inhibits the synthesis of ecdysteroids. A model for MIH signaling is organized into a cAMP/Ca2+-dependent triggering phase and a nitric oxide/cGMP-dependent summation phase, which maintains the YO in the basal state during intermolt. A reduction in MIH release triggers YO activation, which requires mTORC1-dependent protein synthesis, followed by mTORC1-dependent gene expression. TGFβ/Activin signaling is required for YO commitment in mid-premolt. The YO transcriptome has 878 unique contigs assigned to 23 KEGG signaling pathways, 478 of which are differentially expressed over the molt cycle. Ninety-nine contigs encode G protein-coupled receptors (GPCRs), 65 of which bind a variety of neuropeptides and biogenic amines. Among these are putative receptors for MIH/crustacean hyperglycemic hormone neuropeptides, corazonin, relaxin, serotonin, octopamine, dopamine, allatostatins, Bursicon, ecdysis-triggering hormone (ETH), CCHamide, FMRFamide, and proctolin. Contigs encoding receptor tyrosine kinase insulin-like receptor, epidermal growth factor (EGF) receptor, and fibroblast growth factor (FGF) receptor and ligands EGF and FGF suggest that the YO is positively regulated by insulin-like peptides and growth factors. Future research should focus on the interactions of signaling pathways that integrate physiological status with environmental cues for molt control.
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Affiliation(s)
- Donald L. Mykles
- Department of Biology, Colorado State University, Fort Collins, CO, United States
- University of California-Davis Bodega Marine Laboratory, Bodega Bay, CA, United States
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29
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Taubenheim J, Kortmann C, Fraune S. Function and Evolution of Nuclear Receptors in Environmental-Dependent Postembryonic Development. Front Cell Dev Biol 2021; 9:653792. [PMID: 34178983 PMCID: PMC8222990 DOI: 10.3389/fcell.2021.653792] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 05/06/2021] [Indexed: 12/14/2022] Open
Abstract
Nuclear receptors (NRs) fulfill key roles in the coordination of postembryonal developmental transitions in animal species. They control the metamorphosis and sexual maturation in virtually all animals and by that the two main environmental-dependent developmental decision points. Sexual maturation and metamorphosis are controlled by steroid receptors and thyroid receptors, respectively in vertebrates, while both processes are orchestrated by the ecdysone receptor (EcR) in insects. The regulation of these processes depends on environmental factors like nutrition, temperature, or photoperiods and by that NRs form evolutionary conserved mediators of phenotypic plasticity. While the mechanism of action for metamorphosis and sexual maturation are well studied in model organisms, the evolution of these systems is not entirely understood and requires further investigation. We here review the current knowledge of NR involvement in metamorphosis and sexual maturation across the animal tree of life with special attention to environmental integration and evolution of the signaling mechanism. Furthermore, we compare commonalities and differences of the different signaling systems. Finally, we identify key gaps in our knowledge of NR evolution, which, if sufficiently investigated, would lead to an importantly improved understanding of the evolution of complex signaling systems, the evolution of life history decision points, and, ultimately, speciation events in the metazoan kingdom.
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Affiliation(s)
- Jan Taubenheim
- Zoology and Organismic Interactions, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Constantin Kortmann
- Zoology and Organismic Interactions, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sebastian Fraune
- Zoology and Organismic Interactions, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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30
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Li C, He M, Cui Y, Peng Y, Liu J, Yun Y. Insights into the mechanism of shortened developmental duration and accelerated weight gain associated with Wolbachia infection in Hylyphantes graminicola. Integr Zool 2021; 17:420-429. [PMID: 33881802 DOI: 10.1111/1749-4877.12550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Wolbachia infection is known to affect host reproduction and development. To date, however, the underlying mechanism related to the effects of Wolbachia on host development has not yet been reported. Here, we compared the developmental duration and body weight in different instars of Wolbachia-positive (W+ ) and Wolbachia-negative (W- ) spiders (Hylyphantes graminicola) and detected the relative expression levels of 6 insulin-related genes and 3 ecdysone-related genes using reverse transcription qPCR. Results showed that the developmental duration was significantly shortened in W+ spiders compared with W- spiders. Furthermore, W+ spiders were significantly heavier than W- spiders at the 3rd and 4th instars, although no significant differences in body weight were observed after maturity. We also found that the expression levels of insulin-like growth factor-2 mRNA-binding protein-1, insulin-degrading enzyme, and ecdysone-inducible protein-1 genes were significantly down-regulated in W+ spiders compared with W- spiders, whereas the expression levels of insulin-like growth factor-binding protein-1, insulin-like peptide receptor, insulin receptor substrate 2-B, insulin-like, ecdysone-induced protein-2, and ecdysone receptor genes were significantly up-regulated in W+ spiders. Our results suggest that Wolbachia may influence host development by affecting insulin and ecdysone signaling pathways.
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Affiliation(s)
- Chunfen Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Meng He
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Yinjie Cui
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Yu Peng
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Jie Liu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Yueli Yun
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
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31
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GWAS reveal a role for the central nervous system in regulating weight and weight change in response to exercise. Sci Rep 2021; 11:5144. [PMID: 33664357 PMCID: PMC7933348 DOI: 10.1038/s41598-021-84534-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 02/17/2021] [Indexed: 01/16/2023] Open
Abstract
Body size and weight show considerable variation both within and between species. This variation is controlled in part by genetics, but also strongly influenced by environmental factors including diet and the level of activity experienced by the individual. Due to the increasing obesity epidemic in much of the world, there is considerable interest in the genetic factors that control body weight and how weight changes in response to exercise treatments. Here, we address this question in the Drosophila model system, utilizing 38 strains of the Drosophila Genetics Reference Panel. We use GWAS to identify the molecular pathways that control weight and weight changes in response to exercise. We find that there is a complex set of molecular pathways controlling weight, with many genes linked to the central nervous system (CNS). The CNS also plays a role in the weight change with exercise, in particular, signaling from the CNS. Additional analyses revealed that weight in Drosophila is driven by two factors, animal size, and body composition, as the amount of fat mass versus lean mass impacts the density. Thus, while the CNS appears to be important for weight and exercise-induced weight change, signaling pathways are particularly important for determining how exercise impacts weight.
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32
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Millington JW, Brownrigg GP, Chao C, Sun Z, Basner-Collins PJ, Wat LW, Hudry B, Miguel-Aliaga I, Rideout EJ. Female-biased upregulation of insulin pathway activity mediates the sex difference in Drosophila body size plasticity. eLife 2021; 10:e58341. [PMID: 33448263 PMCID: PMC7864645 DOI: 10.7554/elife.58341] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
Nutrient-dependent body size plasticity differs between the sexes in most species, including mammals. Previous work in Drosophila showed that body size plasticity was higher in females, yet the mechanisms underlying increased female body size plasticity remain unclear. Here, we discover that a protein-rich diet augments body size in females and not males because of a female-biased increase in activity of the conserved insulin/insulin-like growth factor signaling pathway (IIS). This sex-biased upregulation of IIS activity was triggered by a diet-induced increase in stunted mRNA in females, and required Drosophila insulin-like peptide 2, illuminating new sex-specific roles for these genes. Importantly, we show that sex determination gene transformer promotes the diet-induced increase in stunted mRNA via transcriptional coactivator Spargel to regulate the male-female difference in body size plasticity. Together, these findings provide vital insight into conserved mechanisms underlying the sex difference in nutrient-dependent body size plasticity.
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Affiliation(s)
- Jason W Millington
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - George P Brownrigg
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Charlotte Chao
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Ziwei Sun
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Paige J Basner-Collins
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Lianna W Wat
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
| | - Bruno Hudry
- MRC London Institute of Medical Sciences, and Institute of Clinical Sciences, Faculty of Medicine, Imperial College LondonLondonUnited Kingdom
| | - Irene Miguel-Aliaga
- MRC London Institute of Medical Sciences, and Institute of Clinical Sciences, Faculty of Medicine, Imperial College LondonLondonUnited Kingdom
| | - Elizabeth J Rideout
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British ColumbiaVancouverCanada
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Mirth CK, Saunders TE, Amourda C. Growing Up in a Changing World: Environmental Regulation of Development in Insects. ANNUAL REVIEW OF ENTOMOLOGY 2021; 66:81-99. [PMID: 32822557 DOI: 10.1146/annurev-ento-041620-083838] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
All organisms are exposed to changes in their environment throughout their life cycle. When confronted with these changes, they adjust their development and physiology to ensure that they can produce the functional structures necessary for survival and reproduction. While some traits are remarkably invariant, or robust, across environmental conditions, others show high degrees of variation, known as plasticity. Generally, developmental processes that establish cell identity are thought to be robust to environmental perturbation, while those relating to body and organ growth show greater degrees of plasticity. However, examples of plastic patterning and robust organ growth demonstrate that this is not a hard-and-fast rule.In this review, we explore how the developmental context and the gene regulatory mechanisms underlying trait formation determine the impacts of the environment on development in insects. Furthermore, we outline future issues that need to be resolved to understand how the structure of signaling networks defines whether a trait displays plasticity or robustness.
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Affiliation(s)
- Christen K Mirth
- School of Biological Sciences, Monash University, Melbourne 3800, Victoria, Australia;
| | - Timothy E Saunders
- Mechanobiology Institute, National University of Singapore, Singapore 117411, Republic of Singapore
- Department of Biological Sciences, National University of Singapore, Singapore 117588, Republic of Singapore
- Institute of Molecular and Cell Biology, A*Star, Proteos, Singapore 138673, Republic of Singapore
| | - Christopher Amourda
- MRC London Institute of Medical Sciences, Imperial College London, London W12 0NN, United Kingdom
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34
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Abstract
Abstract
Background
Organisms show an incredibly diverse array of body and organ shapes that are both unique to their taxon and important for adapting to their environment. Achieving these specific shapes involves coordinating the many processes that transform single cells into complex organs, and regulating their growth so that they can function within a fully-formed body.
Main text
Conceptually, body and organ shape can be separated in two categories, although in practice these categories need not be mutually exclusive. Body shape results from the extent to which organs, or parts of organs, grow relative to each other. The patterns of relative organ size are characterized using allometry. Organ shape, on the other hand, is defined as the geometric features of an organ’s component parts excluding its size. Characterization of organ shape is frequently described by the relative position of homologous features, known as landmarks, distributed throughout the organ. These descriptions fall into the domain of geometric morphometrics.
Conclusion
In this review, we discuss the methods of characterizing body and organ shape, the developmental programs thought to underlie each, highlight when and how the mechanisms regulating body and organ shape might overlap, and provide our perspective on future avenues of research.
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35
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Rosello-Diez A. Size and scale during development and regeneration. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 9:e393. [PMID: 32786055 DOI: 10.1002/wdev.393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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36
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Feng S, Zacharioudaki E, Millen K, Bray SJ. The SLC36 transporter Pathetic is required for neural stem cell proliferation and for brain growth under nutrition restriction. Neural Dev 2020; 15:10. [PMID: 32741363 PMCID: PMC7398078 DOI: 10.1186/s13064-020-00148-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 07/16/2020] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Drosophila neuroblasts (NBs) are neural stem cells whose maintenance relies on Notch activity. NBs proliferate throughout larval stages to generate a large number of adult neurons. Their proliferation is protected under conditions of nutrition restriction but the mechanisms responsible are not fully understood. As amino acid transporters (Solute Carrier transporters, SLCs), such as SLC36, have important roles in coupling nutrition inputs to growth pathways, they may have a role in this process. For example, an SLC36 family transporter Pathetic (Path) that supports body size and neural dendrite growth in Drosophila, was identified as a putative Notch target in genome-wide studies. However, its role in sustaining stem cell proliferation and maintenance has not been investigated. This study aimed to investigate the function of Path in the larval NBs and to determine whether it is involved in protecting them from nutrient deprivation. METHODS The expression and regulation of Path in the Drosophila larval brain was analysed using a GFP knock-in allele and reporter genes containing putative Notch regulated enhancers. Path function in NB proliferation and overall brain growth was investigated under different nutrition conditions by depleting it from specific cell types in the CNS, using mitotic recombination to generate mutant clones or by directed RNA-interference. RESULTS Path is expressed in both NBs and glial cells in the Drosophila CNS. In NBs, path is directly targeted by Notch signalling via Su(H) binding at an intronic enhancer, PathNRE. This enhancer is responsive to Notch regulation both in cell lines and in vivo. Loss of path in neural stem cells delayed proliferation, consistent with it having a role in NB maintenance. Expression from pathNRE was compromised in conditions of amino acid deprivation although other Notch regulated enhancers are unaffected. However, NB-expressed Path was not required for brain sparing under amino acid deprivation. Instead, it appears that Path is important in glial cells to help protect brain growth under conditions of nutrient restriction. CONCLUSIONS We identify a novel Notch target gene path that is required in NBs for neural stem cell proliferation, while in glia it protects brain growth under nutrition restriction.
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Affiliation(s)
- Shiyun Feng
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Evanthia Zacharioudaki
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Kat Millen
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Sarah J Bray
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK.
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37
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Upadhyay A, Peterson AJ, Kim MJ, O'Connor MB. Muscle-derived Myoglianin regulates Drosophila imaginal disc growth. eLife 2020; 9:e51710. [PMID: 32633716 PMCID: PMC7371420 DOI: 10.7554/elife.51710] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 07/04/2020] [Indexed: 01/05/2023] Open
Abstract
Organ growth and size are finely tuned by intrinsic and extrinsic signaling molecules. In Drosophila, the BMP family member Dpp is produced in a limited set of imaginal disc cells and functions as a classic morphogen to regulate pattern and growth by diffusing throughout imaginal discs. However, the role of TGFβ/Activin-like ligands in disc growth control remains ill-defined. Here, we demonstrate that Myoglianin (Myo), an Activin family member, and a close homolog of mammalian Myostatin (Mstn), is a muscle-derived extrinsic factor that uses canonical dSmad2-mediated signaling to regulate wing size. We propose that Myo is a myokine that helps mediate an allometric relationship between muscles and their associated appendages.
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Affiliation(s)
- Ambuj Upadhyay
- Department of Genetics, Cell Biology and Development University of MinnesotaMinneapolisUnited States
| | - Aidan J Peterson
- Department of Genetics, Cell Biology and Development University of MinnesotaMinneapolisUnited States
| | - Myung-Jun Kim
- Department of Genetics, Cell Biology and Development University of MinnesotaMinneapolisUnited States
| | - Michael B O'Connor
- Department of Genetics, Cell Biology and Development University of MinnesotaMinneapolisUnited States
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38
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Dombrovski M, Kuhar R, Mitchell A, Shelton H, Condron B. Cooperative foraging during larval stage affects fitness in Drosophila. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2020; 206:743-755. [PMID: 32623493 PMCID: PMC7392940 DOI: 10.1007/s00359-020-01434-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 06/18/2020] [Accepted: 06/26/2020] [Indexed: 12/18/2022]
Abstract
Cooperative behavior can confer advantages to animals. This is especially true for cooperative foraging which provides fitness benefits through more efficient acquisition and consumption of food. While examples of group foraging have been widely described, the principles governing formation of such aggregations and rules that determine group membership remain poorly understood. Here, we take advantage of an experimental model system featuring cooperative foraging behavior in Drosophila. Under crowded conditions, fly larvae form coordinated digging groups (clusters), where individuals are linked together by sensory cues and group membership requires prior experience. However, fitness benefits of Drosophila larval clustering remain unknown. We demonstrate that animals raised in crowded conditions on food partially processed by other larvae experience a developmental delay presumably due to the decreased nutritional value of the substrate. Intriguingly, same conditions promote the formation of cooperative foraging clusters which further extends larval stage compared to non-clustering animals. Remarkably, this developmental retardation also results in a relative increase in wing size, serving an indicator of adult fitness. Thus, we find that the clustering-induced developmental delay is accompanied by fitness benefits. Therefore, cooperative foraging, while delaying development, may have evolved to give Drosophila larvae benefits when presented with competition for limited food resources.
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Affiliation(s)
- Mark Dombrovski
- Department of Biology, University of Virginia, Charlottesville, VA, 22901, USA
- Department of Biological Chemistry, HHMI, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Rives Kuhar
- Department of Biology, University of Virginia, Charlottesville, VA, 22901, USA
| | - Alexandra Mitchell
- Department of Biology, University of Virginia, Charlottesville, VA, 22901, USA
| | - Hunter Shelton
- Department of Biology, University of Virginia, Charlottesville, VA, 22901, USA
| | - Barry Condron
- Department of Biology, University of Virginia, Charlottesville, VA, 22901, USA.
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Casasa S, Zattara EE, Moczek AP. Nutrition-responsive gene expression and the developmental evolution of insect polyphenism. Nat Ecol Evol 2020; 4:970-978. [PMID: 32424280 DOI: 10.1038/s41559-020-1202-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 04/09/2020] [Indexed: 01/05/2023]
Abstract
Nutrition-responsive development is a ubiquitous and highly diversified example of phenotypic plasticity, yet its underlying molecular and developmental mechanisms and modes of evolutionary diversification remain poorly understood. We measured genome-wide transcription in three closely related species of horned beetles exhibiting strikingly diverse degrees of nutrition responsiveness in the development of male weaponry. We show that (1) counts of differentially expressed genes between low- and high-nutritional backgrounds mirror species-specific degrees of morphological nutrition responsiveness; (2) evolutionary exaggeration of morphological responsiveness is underlain by both amplification of ancestral nutrition-responsive gene expression and recruitment of formerly low nutritionally responsive genes; and (3) secondary loss of morphological responsiveness to nutrition coincides with a dramatic reduction in gene expression plasticity. Our results further implicate genetic accommodation of ancestrally high variability of gene expression plasticity in both exaggeration and loss of nutritional plasticity, yet reject a major role of taxon-restricted genes in the developmental regulation and evolution of nutritional plasticity.
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Affiliation(s)
- Sofia Casasa
- Department of Biology, Indiana University, Bloomington, IN, USA.
| | - Eduardo E Zattara
- Department of Biology, Indiana University, Bloomington, IN, USA. .,INIBIOMA, Universidad Nacional del Comahue - CONICET, Bariloche, Argentina.
| | - Armin P Moczek
- Department of Biology, Indiana University, Bloomington, IN, USA
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40
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Casares F, McGregor AP. The evolution and development of eye size in flies. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 10:e380. [PMID: 32400100 DOI: 10.1002/wdev.380] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 03/08/2020] [Accepted: 03/12/2020] [Indexed: 01/19/2023]
Abstract
The compound eyes of flies exhibit striking variation in size, which has contributed to the adaptation of these animals to different habitats and their evolution of specialist behaviors. These differences in size are caused by differences in the number and/or size of ommatidia, which are specified during the development of the retinal field in the eye imaginal disc. While the genes and developmental mechanisms that regulate the formation of compound eyes are understood in great detail in the fruit fly Drosophila melanogaster, we know very little about the genetic changes and mechanistic alterations that lead to natural variation in ommatidia number and/or size, and thus overall eye size, within and between fly species. Understanding the genetic and developmental bases for this natural variation in eye size not only has great potential to help us understand adaptations in fly vision but also determine how eye size and organ size more generally are regulated. Here we explore the genetic and developmental mechanisms that could underlie natural differences in compound eye size within and among fly species based on our knowledge of eye development in D. melanogaster and the few cases where the causative genes and mechanisms have already been identified. We suggest that the fly eye provides an evolutionary and developmental framework to better understand the regulation and diversification of this crucial sensory organ globally at a systems level as well as the gene regulatory networks and mechanisms acting at the tissue, cellular and molecular levels. This article is categorized under: Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Invertebrate Organogenesis > Flies Comparative Development and Evolution > Regulation of Organ Diversity.
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Affiliation(s)
| | - Alistair P McGregor
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
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41
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Simões P, Santos MA, Carromeu-Santos A, Quina AS, Santos M, Matos M. Beneficial developmental acclimation in reproductive performance under cold but not heat stress. J Therm Biol 2020; 90:102580. [DOI: 10.1016/j.jtherbio.2020.102580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/09/2020] [Accepted: 03/30/2020] [Indexed: 01/03/2023]
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42
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Kakanj P, Eming SA, Partridge L, Leptin M. Long-term in vivo imaging of Drosophila larvae. Nat Protoc 2020; 15:1158-1187. [DOI: 10.1038/s41596-019-0282-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/09/2019] [Indexed: 02/07/2023]
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Barrett M, Fiocca K, Waddell EA, McNair C, O'Donnell S, Marenda DR. Larval mannitol diets increase mortality, prolong development and decrease adult body sizes in fruit flies ( Drosophila melanogaster). Biol Open 2020; 8:bio.047084. [PMID: 31822472 PMCID: PMC6955208 DOI: 10.1242/bio.047084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ability of polyols to disrupt holometabolous insect development has not been studied and identifying compounds in food that affect insect development can further our understanding of the pathways that connect growth rate, developmental timing and body size in insects. High-sugar diets prolong development and generate smaller adult body sizes in Drosophila melanogaster We tested for concentration-dependent effects on development when D. melanogaster larvae are fed mannitol, a polyalcohol sweetener. We also tested for amelioration of developmental effects if introduction to mannitol media is delayed past the third instar, as expected if there is a developmental sensitive-period for mannitol effects. Both male and female larvae had prolonged development and smaller adult body sizes when fed increasing concentrations of mannitol. Mannitol-induced increases in mortality were concentration dependent in 0 M to 0.8 M treatments with mortality effects beginning as early as 48 h post-hatching. Larval survival, pupariation and eclosion times were unaffected in 0.4 M mannitol treatments when larvae were first introduced to mannitol 72 h post-hatching (the beginning of the third instar); 72 h delay of 0.8 M mannitol introduction reduced the adverse mannitol effects. The developmental effects of a larval mannitol diet closely resemble those of high-sugar larval diets.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Meghan Barrett
- Department of Biology, Drexel University, Philadelphia, PA, USA 19104
| | - Katherine Fiocca
- Department of Biology, Drexel University, Philadelphia, PA, USA 19104
| | - Edward A Waddell
- Department of Biology, Drexel University, Philadelphia, PA, USA 19104
| | - Cheyenne McNair
- Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, PA, USA 19104
| | - Sean O'Donnell
- Department of Biology, Drexel University, Philadelphia, PA, USA 19104.,Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, PA, USA 19104
| | - Daniel R Marenda
- Department of Biology, Drexel University, Philadelphia, PA, USA 19104 .,Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA, 19104
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44
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Flatt T. Life-History Evolution and the Genetics of Fitness Components in Drosophila melanogaster. Genetics 2020; 214:3-48. [PMID: 31907300 PMCID: PMC6944413 DOI: 10.1534/genetics.119.300160] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 10/03/2019] [Indexed: 12/28/2022] Open
Abstract
Life-history traits or "fitness components"-such as age and size at maturity, fecundity and fertility, age-specific rates of survival, and life span-are the major phenotypic determinants of Darwinian fitness. Analyzing the evolution and genetics of these phenotypic targets of selection is central to our understanding of adaptation. Due to its simple and rapid life cycle, cosmopolitan distribution, ease of maintenance in the laboratory, well-understood evolutionary genetics, and its versatile genetic toolbox, the "vinegar fly" Drosophila melanogaster is one of the most powerful, experimentally tractable model systems for studying "life-history evolution." Here, I review what has been learned about the evolution and genetics of life-history variation in D. melanogaster by drawing on numerous sources spanning population and quantitative genetics, genomics, experimental evolution, evolutionary ecology, and physiology. This body of work has contributed greatly to our knowledge of several fundamental problems in evolutionary biology, including the amount and maintenance of genetic variation, the evolution of body size, clines and climate adaptation, the evolution of senescence, phenotypic plasticity, the nature of life-history trade-offs, and so forth. While major progress has been made, important facets of these and other questions remain open, and the D. melanogaster system will undoubtedly continue to deliver key insights into central issues of life-history evolution and the genetics of adaptation.
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Affiliation(s)
- Thomas Flatt
- Department of Biology, University of Fribourg, CH-1700, Switzerland
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Lin X, Smagghe G. Roles of the insulin signaling pathway in insect development and organ growth. Peptides 2019; 122:169923. [PMID: 29458057 DOI: 10.1016/j.peptides.2018.02.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 02/13/2018] [Accepted: 02/13/2018] [Indexed: 12/16/2022]
Abstract
Organismal development is a complex process as it requires coordination of many aspects to grow into fit individuals, such as the control of body size and organ growth. Therefore, the mechanisms of precise control of growth are essential for ensuring the growth of organisms at a correct body size and proper organ proportions during development. The control of the growth rate and the duration of growth (or the cessation of growth) are required in size control. The insulin signaling pathway and the elements involved are essential in the control of growth. On the other hand, the ecdysteroid molting hormone determines the duration of growth. The secretion of these hormones is controlled by environmental factors such as nutrition. Moreover, the target of rapamycin (TOR) pathway is considered as a nutrient sensing pathway. Important cross-talks have been shown to exist among these pathways. In this review, we outline the control of body and organ growth by the insulin/TOR signaling pathway, and also the interaction between nutrition via insulin/TOR signaling and ecdysteroids at the coordination of organismal development and organ growth in insects, mainly focusing on the well-studied fruit fly Drosophila melanogaster.
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Affiliation(s)
- Xianyu Lin
- Department of Crop Protection, Ghent University, 9000 Ghent, Belgium
| | - Guy Smagghe
- Department of Crop Protection, Ghent University, 9000 Ghent, Belgium.
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Liu Z, Xu J, Ling L, Zhang R, Shang P, Huang Y. CRISPR disruption of TCTP gene impaired normal development in the silkworm Bombyx mori. INSECT SCIENCE 2019; 26:973-982. [PMID: 29316276 PMCID: PMC7380024 DOI: 10.1111/1744-7917.12567] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 11/14/2017] [Accepted: 11/27/2017] [Indexed: 06/07/2023]
Abstract
The translationally controlled tumor protein (TCTP) is a highly conserved and multifunctional protein with activities ranging from cytoskeletal regulation to transcription regulation in numerous organisms. In insects, TCTP is essential for cell growth and proliferation. Recently, TCTP has been reported to affect the innate intestinal immune pathway in the Bombyx mori silkworm, a lepidopteran model insect. However, the comprehensive physiological roles of TCTP in the silkworm remain poorly understood. Here, we performed functional analysis of BmTCTP by using a binary transgenic CRISPR/Cas9 (clustered regularly interspaced short palindromic repeat/RNA-guided CRISPER-associated protein 9 nucleases) system. Disruption of BmTCTP led to developmental arrestment and subsequent lethality in third instar larvae. Histological analysis revealed that growth impairment originated from decreased cell size, and the proliferation and differentiation of intestinal epithelial cells were also affected. RNA-seq analysis revealed that genes involved in carbohydrate metabolism, lipid metabolism and digestive system pathways were significantly affected by BmTCTP depletion. Together, the results demonstrated that BmTCTP plays a key role in controlling larval growth and development.
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Affiliation(s)
- Zu‐Lian Liu
- Faculty of Life SciencesNorthwestern Polytechnical UniversityXi'anChina
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Jun Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Lin Ling
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Ru Zhang
- Faculty of Life SciencesNorthwestern Polytechnical UniversityXi'anChina
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
| | - Peng Shang
- Faculty of Life SciencesNorthwestern Polytechnical UniversityXi'anChina
| | - Yong‐Ping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghaiChina
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Moss-Taylor L, Upadhyay A, Pan X, Kim MJ, O'Connor MB. Body Size and Tissue-Scaling Is Regulated by Motoneuron-Derived Activinß in Drosophila melanogaster. Genetics 2019; 213:1447-1464. [PMID: 31585954 PMCID: PMC6893369 DOI: 10.1534/genetics.119.302394] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/29/2019] [Indexed: 01/17/2023] Open
Abstract
Correct scaling of body and organ size is crucial for proper development, and the survival of all organisms. Perturbations in circulating hormones, including insulins and steroids, are largely responsible for changing body size in response to both genetic and environmental factors. Such perturbations typically produce adults whose organs and appendages scale proportionately with final size. The identity of additional factors that might contribute to scaling of organs and appendages with body size is unknown. Here, we report that loss-of-function mutations in DrosophilaActivinβ (Actβ), a member of the TGF-β superfamily, lead to the production of small larvae/pupae and undersized rare adult escapers. Morphometric measurements of escaper adult appendage size (wings and legs), as well as heads, thoraxes, and abdomens, reveal a disproportional reduction in abdominal size compared to other tissues. Similar size measurements of selected Actβ mutant larval tissues demonstrate that somatic muscle size is disproportionately smaller when compared to the fat body, salivary glands, prothoracic glands, imaginal discs, and brain. We also show that Actβ control of body size is dependent on canonical signaling through the transcription-factor dSmad2 and that it modulates the growth rate, but not feeding behavior, during the third-instar period. Tissue- and cell-specific knockdown, and overexpression studies, reveal that motoneuron-derived Actβ is essential for regulating proper body size and tissue scaling. These studies suggest that, unlike in vertebrates, where Myostatin and certain other Activin-like factors act as systemic negative regulators of muscle mass, in Drosophila, Actβ is a positive regulator of muscle mass that is directly delivered to muscles by motoneurons. We discuss the importance of these findings in coordinating proportional scaling of insect muscle mass to appendage size.
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Affiliation(s)
- Lindsay Moss-Taylor
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Ambuj Upadhyay
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Xueyang Pan
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Myung-Jun Kim
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| | - Michael B O'Connor
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
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Nanda KP, Kumari C, Dubey M, Firdaus H. Chronic lead (Pb) exposure results in diminished hemocyte count and increased susceptibility to bacterial infection in Drosophila melanogaster. CHEMOSPHERE 2019; 236:124349. [PMID: 31326753 DOI: 10.1016/j.chemosphere.2019.124349] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 06/10/2023]
Abstract
Heavy metal Pb is a common toxic pollutant present in our environment adversely affecting health of the living organisms. Recent studies suggest positive correlation between heavy metal exposure and immune dysfunction and present work utilizes Drosophila to address this issue in relation to Pb exposure. In-vivo Pb toxicity was established by dietary intake where essential parameters like development and life span were found to be hampered and augmented upon metallothionein B (mtnB) downregulation hinting towards potential role of mtnB in Pb detoxification. Further response of Drosophila to B. subtilis bacterial infection was monitored by carrying out oral infections. Pb fed flies showed increased susceptibility to infection as compared to their controls. Since Drosophila hemocytes play dual role as immune cells, we checked for the total hemocyte count and found significant decrease in hemocyte numbers in Pb fed larvae. Both crystal cells and plasmatocytes, the two major hemocytes in third instar larval hemolymph were reduced. However we did not find any visible morphological changes in Giemsa stained hemocytes. Crystal cells are crucial for synthesis and release of phenoloxidase (PO), an enzyme required for melanin clot synthesis and deposition. PO activity assessed from total hemolymph protein isolates was found to be substantially decreased in Pb raised animals. Results were also confirmed by spot test and native gel activity assay of PO. Overall our results suggest immunotoxic effect of Pb through decrease in hemocyte count including crystal cell which in turn leads to decreased PO activity and increased susceptibility to B. subtilis.
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Affiliation(s)
- Kumari Pragati Nanda
- Department of Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi, 835205, Jharkhand, India
| | - Chandani Kumari
- Department of Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi, 835205, Jharkhand, India
| | - Madhavi Dubey
- Department of Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi, 835205, Jharkhand, India
| | - Hena Firdaus
- Department of Life Sciences, Central University of Jharkhand, Ratu-Lohardaga Road, Brambe, Ranchi, 835205, Jharkhand, India.
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Luecke DM, Kopp A. Sex-specific evolution of relative leg size in Drosophila prolongata results from changes in the intersegmental coordination of tissue growth. Evolution 2019; 73:2281-2294. [PMID: 31595502 PMCID: PMC6834887 DOI: 10.1111/evo.13847] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/27/2019] [Accepted: 09/07/2019] [Indexed: 01/22/2023]
Abstract
Evolution of relative organ size is the most prolific source of morphological diversity, yet the underlying molecular mechanisms that modify growth control are largely unknown. Models where organ proportions have undergone recent evolutionary changes hold the greatest promise for understanding this process. Uniquely among Drosophila species, Drosophila prolongata displays a dramatic, male-specific increase in the size of its forelegs relative to other legs. By comparing leg development between males and females of D. prolongata and its closest relative Drosophila carrolli, we show that the exaggerated male forelegs are produced by a sex- and segment-specific increase in mitosis during the final larval instar. Intersegmental compensatory control, where smaller leg primordia grow at a faster rate, is observed in both species and sexes. However, the equilibrium growth rates that determine the final relative proportion between the first and second legs have shifted in male D. prolongata compared both to conspecific females and to D. carrolli. We suggest that the observed developmental changes that produce new adult proportions reflect an interplay between conserved growth coordination mechanisms and evolving organ-specific growth targets.
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Affiliation(s)
- David Michael Luecke
- Department of Evolution and Ecology, University of California-Davis, Davis, California, 95616
- Current address: Department of Integrative Biology, Michigan State University, East Lansing, MI, 48824
| | - Artyom Kopp
- Department of Evolution and Ecology, University of California-Davis, Davis, California, 95616
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Okada H, Yagi R, Gardeux V, Deplancke B, Hafen E. Sex-dependent and sex-independent regulatory systems of size variation in natural populations. Mol Syst Biol 2019; 15:e9012. [PMID: 31777173 PMCID: PMC6878047 DOI: 10.15252/msb.20199012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 11/21/2022] Open
Abstract
Size of organs/organisms is a polygenic trait. Many of the growth-regulatory genes constitute conserved growth signaling pathways. However, how these multiple genes are orchestrated at the systems level to attain the natural variation in size including sexual size dimorphism is mostly unknown. Here we take a multi-layered systems omics approach to study size variation in the Drosophila wing. We show that expression levels of many critical growth regulators such as Wnt and TGFβ pathway components significantly differ between sexes but not between lines exhibiting size differences within each sex, suggesting a primary role of these regulators in sexual size dimorphism. Only a few growth genes including a receptor of steroid hormone ecdysone exhibit association with between-line size differences. In contrast, we find that between-line size variation is largely regulated by genes with a diverse range of cellular functions, most of which have never been implicated in growth. In addition, we show that expression quantitative trait loci (eQTLs) linked to these novel growth regulators accurately predict population-wide, between-line wing size variation. In summary, our study unveils differential gene regulatory systems that control wing size variation between and within sexes.
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Affiliation(s)
- Hirokazu Okada
- Institute of Molecular Systems BiologyETH ZurichZürichSwitzerland
| | - Ryohei Yagi
- Institute of Molecular Systems BiologyETH ZurichZürichSwitzerland
| | - Vincent Gardeux
- Laboratory of Systems Biology and GeneticsInstitute of BioengineeringSchool of Life SciencesEcole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of BioinformaticsLausanneSwitzerland
| | - Bart Deplancke
- Laboratory of Systems Biology and GeneticsInstitute of BioengineeringSchool of Life SciencesEcole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of BioinformaticsLausanneSwitzerland
| | - Ernst Hafen
- Institute of Molecular Systems BiologyETH ZurichZürichSwitzerland
- Faculty of ScienceUniversity of ZurichZurichSwitzerland
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