1
|
Maeno KO, Piou C, Leménager N. Egg size-dependent embryonic development in the desert locust, Schistocerca gregaria. JOURNAL OF INSECT PHYSIOLOGY 2023; 145:104467. [PMID: 36528090 DOI: 10.1016/j.jinsphys.2022.104467] [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: 08/11/2022] [Revised: 09/26/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
Phenotypic plasticity in body size is a product of modification of the developmental pathway. Although hatchlings of the desert locust, Schistocerca gregaria, show egg size-dependent plasticity in body size, it remains unclear how embryogenesis during egg development regulates final embryonic body size. To determine the developmental pathway causing body size variation at hatching, we examined egg and embryonic development at the early, middle, and late egg developmental stages in S. gregaria by comparing small and large eggs. Crowd-reared females produced larger eggs than isolated-reared females. The daily egg developmental rate was similar between small and large eggs: eggs dramatically absorbed external water after days 3 to 7 and nearly doubled the initial egg weight at the late stage of day 12. Morphological measurements of eggs and embryos at different days after oviposition revealed that large eggs were longer than small eggs throughout developmental stages. However, embryo length was similar between small and large eggs at the early stage (anatrepsis). Embryos begin to absorb yolk into their bodies after blastokinesis. The size of large-egg embryos increased significantly from the middle stage (katatrepsis) due to absorption of more yolk than small eggs. Egg length and embryo length were conspicuously larger in large eggs than in small eggs on day 12 of late katatrepsis. These results suggest that egg size did not influence the egg developmental rate and initial embryo size. Large eggs had more yolk and space, resulting in larger final embryos than small eggs. The amount of yolk and size of eggshells during katatrepsis could play a key role in determining hatchling body size in S. gregaria.
Collapse
Affiliation(s)
- Koutaro Ould Maeno
- Japan International Research Center for Agricultural Sciences (JIRCAS), Livestock and Environment Division, Ohwashi 1-1, Tsukuba, Ibaraki 305-8686, Japan.
| | - Cyril Piou
- CIRAD, UMR CBGP, INRAE, Institut Agro, IRD, Université Montpellier, F-34398 Montpellier, France
| | - Nicolas Leménager
- CIRAD, UMR CBGP, INRAE, Institut Agro, IRD, Université Montpellier, F-34398 Montpellier, France
| |
Collapse
|
2
|
Hiroyoshi S, Mitsunaga T, Ganaha-Kikumura T, Reddy GVP. Effects of Age, Phase Variation and Pheromones on Male Sperm Storage in the Desert Locust, Schistocerca gregaria. INSECTS 2021; 12:insects12070642. [PMID: 34357302 PMCID: PMC8307635 DOI: 10.3390/insects12070642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 11/22/2022]
Abstract
Simple Summary We investigated male sperm storage in the desert locust Schistocerca gregaria. Phase (solitary or gregarious) did not affect sperm distribution in the vas deferens and seminal vesicle, whereas sperm accumulation of the seminal vesicle in gregarious locusts was promoted more than in solitary ones. Pheromones received from neither mature adults nor nymphs affected sperm distribution in the vas deferens and seminal vesicle. However, sperm accumulation in the seminal vesicle was more promoted in the gregarious locusts which received pheromones from mature adults than those obtained from nymphs at early adult stage, especially seven days after adult emergence. Abstract In general, sperm produced in the testis are moved into the seminal vesicle via the vas deferens in insects, where they are stored. How this sperm movement is controlled is less well understood in locusts or grasshoppers. In this study, the effects of age, phase variation and pheromones on male sperm storage were investigated in the desert locust, Schistocerca gregaria (Forskål). In this locust, a pair of ducts, the vasa deferentia, connect the testes to a pair of the long, slender seminal vesicles that are folded approximately thirty times, and where the sperm are stored. We found that phase variation affected the level of sperm storage in the seminal vesicle. Moreover, adult males that detected pheromones emitted by mature adult males showed enhanced sperm storage compared with males that received the pheromones emitted from nymphs: The former, adult male pheromones are known to promote sexual maturation of immature adults of both sexes, whereas the latter, nymphal pheromones delay sexual maturation. Most mature adult males had much sperm in the vasa deferentia at all times examined, suggesting daily sperm movement from the testes to the seminal vesicles via the vasa deferentia. As adult males aged, sperm were accumulated from the proximal part to the distal end of the seminal vesicle. Many sperm remained in the seminal vesicle after mating. These results suggest that young or new sperm located near the proximal part of the seminal vesicle could be used for mating, whereas old sperm not used for mating are stored in the distal part of the seminal vesicle.
Collapse
Affiliation(s)
- Satoshi Hiroyoshi
- Department of Chemical Ecology, International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya
- Independent Researcher, Kawagoe 350-1115, Saitama, Japan
- Correspondence:
| | - Takayuki Mitsunaga
- Institute of Plant Protection National Agriculture and Food Research Organization, 2-1-18 Kannondai, Tsukuba 305-8602, Ibaraki, Japan;
| | | | - Gadi V. P. Reddy
- USDA-ARS-Southern Insect Management Research Unit, 141 Experiment Station Road, P.O. Box 346, Stoneville, MS 38776, USA;
| |
Collapse
|
3
|
Cheng Y, Sappington TW, Luo L, Zhang L, Jiang X. Starvation on First or Second Day of Adulthood Reverses Larval-Stage Decision to Migrate in Beet Webworm (Lepidoptera: Pyralidae). ENVIRONMENTAL ENTOMOLOGY 2021; 50:523-531. [PMID: 33693559 DOI: 10.1093/ee/nvab015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Indexed: 06/12/2023]
Abstract
A facultative commitment to adult migration in the larval stage can be modified again after adult emergence in some Lepidoptera when influenced by an appropriate environmental cue during a sensitive stage. This phenomenon is termed secondary regulation of migration. The sensitive stage in adult beet webworm, Loxostege sticticalis L. (Lepidoptera: Pyralidae), was determined experimentally by starvation of presumed migrant females reared from gregarious-phase larvae (induced by crowding at 10 larvae per 650-ml jar). When presumed migrant adults were starved for 24 h on either of the first 2 d after emergence, the preoviposition period was shortened. In contrast, preoviposition periods were not significantly shortened for migrants starved on day 3 or when starvation lasted for more than 1 d after emergence. Because the preoviposition period corresponds to the migratory period in beet webworm, the results suggest that the first 2 d of adult life in the beet webworm is the sensitive stage during which presumed migrants can be switched to residents by an appropriate environmental cue. During the sensitive stage or not, starvation did not influence lifetime fecundity, oviposition period, longevity, or hatching rate of eggs laid by the starvation-stressed moths. Starvation on the first day also increased tethered flight performance and accelerated both flight muscle and ovarian development. The results suggest that a pulse of starvation in the sensitive period may inhibit the expected migration by accelerating and compressing the cycle of migratory flight muscle development and degeneration, while accelerating ovarian development, which is normally suppressed until after migration.
Collapse
Affiliation(s)
- Yunxia Cheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Thomas W Sappington
- USDA-Agricultural Research Service, Corn Insects and Crop Genetics Research Unit, 503 Science Hall II, 2310 Pammel Drive, Ames, IA 50011, USA
| | - Lizhi Luo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Lei Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Xingfu Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| |
Collapse
|
4
|
Maeno KO, Piou C, Ghaout S. The desert locust, Schistocerca gregaria, plastically manipulates egg size by regulating both egg numbers and production rate according to population density. JOURNAL OF INSECT PHYSIOLOGY 2020; 122:104020. [PMID: 32035952 DOI: 10.1016/j.jinsphys.2020.104020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/21/2019] [Accepted: 02/06/2020] [Indexed: 06/10/2023]
Abstract
Egg-size adjustment is one of the important plastic life-history traits for animals living in heterogeneous environments. The adaptive investment hypothesis predicts that mothers should increase progeny size according to certain cues predicting adverse future conditions of their offspring. However, reproductive resources are limited, and females have to simultaneously reduce egg number to allocate more resources to increase size. It remains unclear how single individuals alter egg size and number according to temporally heterogeneous environments. In the present study, we examined how desert locusts, Schistocerca gregaria, plastically alter egg size and number according to population density. We also investigated the trans-generational maternal effects on progeny characteristics as well as their own maternal physiological response (oviposition interval). Females kept in crowded conditions laid significantly larger and heavier eggs by reducing clutch size (number of eggs per egg pod) compared to isolated females, suggesting the existence of a reproductive trade-off between the two traits. The crowding-forced isolated females induced concerted changes not only in egg size but also in egg number tending towards those characteristics of gregarious control, implying that single individuals showed trade-off when egg size was increased. Double-blind testing confirmed the rapid crowding effects on egg size. Females also responded to crowding by extending the oviposition interval. As the oviposition interval extended, egg size increased, but clutch size decreased. Eggs from crowding-forced isolated females began to produce gregarious-phase type hatchlings (large and black) instead of solitarious-phase type ones (small and green). These results suggested that S. gregaria plastically manipulate egg size by regulating egg numbers and egg production rate, and indicated the presence of trans-generational maternal effects on progeny phase.
Collapse
Affiliation(s)
- Koutaro Ould Maeno
- Japan International Research Center for Agricultural Sciences (JIRCAS), Livestock and Environment Division, Ohwashi 1-1, Tsukuba, Ibaraki 305-8686, Japan; Laboratory of Insect Ecology, Graduate School of Agriculture Kyoto University Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
| | - Cyril Piou
- CIRAD, UMR CBGP, F-34398 Montpellier, France; Centre National de Lutte Anti-acridienne (CNLAA), Aït-Melloul, BP 125, Inezgane, Agadir, Morocco; Ibn Zohr University, Agadir, Morocco
| | - Saïd Ghaout
- Centre National de Lutte Anti-acridienne (CNLAA), Aït-Melloul, BP 125, Inezgane, Agadir, Morocco
| |
Collapse
|
5
|
Maeno KO, Piou C, Ould Babah MA, Nakamura S. Eggs and hatchlings variations in desert locusts: phase related characteristics and starvation tolerance. Front Physiol 2013; 4:345. [PMID: 24363645 PMCID: PMC3850081 DOI: 10.3389/fphys.2013.00345] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 11/08/2013] [Indexed: 11/21/2022] Open
Abstract
LOCUSTS ARE GRASSHOPPER SPECIES THAT EXPRESS PHASE POLYPHENISM modifying their behavior, morphology, coloration, life history and physiology in response to crowding. Desert locusts, Schistocerca gregaria, epigenetically modify progeny quality and quantity in response to crowding. Gregarious (crowded) females produce larger but fewer progeny than do solitarious (isolated) ones. The variability of progeny quality within single egg pod and the reasons why gregarious progeny have a better survival rate than solitarious ones remains unclear. This study investigated 1) the effects of rearing density on the variation in egg size within single egg pods 2) the starvation tolerance of hatchlings from mothers with different phases and 3) the physiological differences in hatchling energy reserve. Isolated females produced smaller but more eggs than did crowded ones. The variation in egg size within egg pods was greater in the latter than in the former. A negative relationship between egg size and number of eggs per egg pod was observed for both groups. Under starvation conditions, gregarious hatchlings survived significantly longer than solitarious ones. Among the solitarious hatchlings, the survival time was longer with increased hatchling body size. However, small individuals survived as long as large ones among the gregarious hatchlings. The percentage of water content per fresh body weight was almost equal between the two phases, before and after starvation. In contrast, the percentage of lipid content per dry body weight was significantly higher in gregarious hatchlings than in solitarious ones before starvation, but became almost equal after starvation. These results demonstrate that female locusts not only trade-off to modify their progeny size and number, but also vary progenies' energy reserves. We hypothesize that gregarious females enhance their fitness by producing progeny differently adapted to high environmental variability and particularly to starvation conditions.
Collapse
Affiliation(s)
- Koutaro O. Maeno
- CIRAD, UMR CBGPF-34398 Montpellier, France
- The Mauritanian Desert Locust Centre, Centre National de Lutte AntiacridienneNouakchott, Mauritania
| | - Cyril Piou
- CIRAD, UMR CBGPF-34398 Montpellier, France
| | - Mohamed A. Ould Babah
- The Mauritanian Desert Locust Centre, Centre National de Lutte AntiacridienneNouakchott, Mauritania
| | - Satoshi Nakamura
- Japan International Research Center for Agricultural SciencesTsukuba, Japan
| |
Collapse
|
6
|
Van Wielendaele P, Badisco L, Vanden Broeck J. Neuropeptidergic regulation of reproduction in insects. Gen Comp Endocrinol 2013; 188:23-34. [PMID: 23454669 DOI: 10.1016/j.ygcen.2013.02.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/01/2013] [Accepted: 02/10/2013] [Indexed: 12/17/2022]
Abstract
Successful animal reproduction depends on multiple physiological and behavioral processes that take place in a timely and orderly manner in both mating partners. It is not only necessary that all relevant processes are well coordinated, they also need to be adjusted to external factors of abiotic and biotic nature (e.g. population density, mating partner availability). Therefore, it is not surprising that several hormonal factors play a crucial role in the regulation of animal reproductive physiology. In insects (the largest class of animals on planet Earth), lipophilic hormones, such as ecdysteroids and juvenile hormones, as well as several neuropeptides take part in this complex regulation. While some peptides can affect reproduction via an indirect action (e.g. by influencing secretion of juvenile hormone), others exert their regulatory activity by directly targeting the reproductive system. In addition to insect peptides with proven activities, several others were suggested to also play a role in the regulation of reproductive physiology. Because of the long evolutionary history of many insect orders, it is not always clear to what extent functional data obtained in a given species can be extrapolated to other insect taxa. In this paper, we will review the current knowledge concerning the neuropeptidergic regulation of insect reproduction and situate it in a more general physiological context.
Collapse
Affiliation(s)
- Pieter Van Wielendaele
- Molecular Developmental Physiology and Signal Transduction, Department of Animal Physiology and Neurobiology, University of Leuven, Naamsestraat 59, P.O. Box 02465, B-3000 Leuven, Belgium
| | | | | |
Collapse
|
7
|
Van Wielendaele P, Wynant N, Dillen S, Badisco L, Marchal E, Vanden Broeck J. In vivo effect of Neuropeptide F on ecdysteroidogenesis in adult female desert locusts (Schistocerca gregaria). JOURNAL OF INSECT PHYSIOLOGY 2013; 59:624-630. [PMID: 23524065 DOI: 10.1016/j.jinsphys.2013.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 03/11/2013] [Accepted: 03/12/2013] [Indexed: 06/02/2023]
Abstract
Neuropeptides are important regulatory factors that mediate key life processes, both in vertebrates and invertebrates. Many insect neuropeptides display pleiotropic activities, which means that they can influence multiple aspects of insect physiology. In the fruit fly, Drosophila melanogaster, Neuropeptide F (NPF) mediates diverse physiological processes, such as learning, stress responses, feeding and male courtship behavior. In locusts, only a truncated form of the predicted "full-length" NPF, the nonapeptide "trNPF", has been isolated. This nonapeptide previously proved to be biologically active, since it was shown to influence food intake and weight increase, as well as oocyte growth in adult female desert locusts (Schistocerca gregaria [Forskål]). In the present study, we have further analyzed the effect of trNPF on female reproductive physiology in S. gregaria. We confirmed that daily trNPF injections in adult females elicit an increase of oocyte size. In addition, an RNAi-mediated knockdown of the Schgr-NPF precursor transcript in adult female locusts resulted in the opposite effect, i.e. significantly smaller oocytes. Moreover, we discovered that daily injections of trNPF in adult female S. gregaria, caused higher ecdysteroid titers in the ovaries and accelerated the appearance of ecdysteroid peaks in the hemolymph of these animals. The RNAi-based knockdown of the Schgr-NPF precursor transcript clearly resulted in reduction of both hemolymph and ovarian ecdysteroid concentrations, confirming the stimulatory effects of trNPF injections on adult female ecdysteroid levels. The observed results are discussed in relation to previous reports on NPF activities in locusts and other insects.
Collapse
Affiliation(s)
- Pieter Van Wielendaele
- Molecular Developmental Physiology and Signal Transduction, Department of Animal Physiology and Neurobiology, Zoological Institute, K.U. Leuven, Naamsestraat 59, B-3000 Leuven, Belgium.
| | | | | | | | | | | |
Collapse
|
8
|
CRF-like diuretic hormone negatively affects both feeding and reproduction in the desert locust, Schistocerca gregaria. PLoS One 2012; 7:e31425. [PMID: 22363645 PMCID: PMC3282710 DOI: 10.1371/journal.pone.0031425] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 01/07/2012] [Indexed: 11/19/2022] Open
Abstract
Diuretic hormones (DH) related to the vertebrate Corticotropin Releasing Factor (CRF) have been identified in diverse insect species. In the migratory locust, Locusta migratoria, the CRF-like DH (CRF/DH) is localized in the same neurosecretory cells as the Ovary Maturating Parsin (OMP), a neurohormone that stimulates oocyte growth, vitellogenesis and hemolymph ecdysteroid levels in adult female locusts. In this study, we investigated whether CRF-like DH can influence feeding and reproduction in the desert locust, Schistocerca gregaria. We identified two highly similar S. gregaria CRF-like DH precursor cDNAs, each of which also encodes an OMP isoform. Alignment with other insect CRF-like DH precursors shows relatively high conservation of the CRF/DH sequence while the precursor region corresponding to OMP is not well conserved. Quantitative real-time RT-PCR revealed that the precursor transcripts mainly occur in the central nervous system and their highest expression level was observed in the brain. Injection of locust CRF/DH caused a significantly reduced food intake, while RNAi knockdown stimulated food intake. Therefore, our data indicate that CRF-like DH induces satiety. Furthermore, injection of CRF/DH in adult females retarded oocyte growth and caused lower ecdysteroid titers in hemolymph and ovaries, while RNAi knockdown resulted in opposite effects. The observed effects of CRF/DH may be part of a wider repertoire of neurohormonal activities, constituting an integrating control system that affects food intake and excretion, as well as anabolic processes like oocyte growth and ecdysteroidogenesis, following a meal. Our discussion about the functional relationship between CRF/DH and OMP led to the hypothesis that OMP may possibly act as a monitoring peptide that can elicit negative feedback effects.
Collapse
|