1
|
Teething during sleep: Ultrastructural analysis of pharyngeal muscle and cuticular grinder during the molt in Caenorhabditis elegans. PLoS One 2020; 15:e0233059. [PMID: 32433687 PMCID: PMC7239488 DOI: 10.1371/journal.pone.0233059] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 04/27/2020] [Indexed: 11/26/2022] Open
Abstract
Complex extracellular structures exist throughout phylogeny, but the dynamics of their formation and dissolution are often opaque. One example is the pharyngeal grinder of the nematode Caenorhabditis elegans, an extracellular structure that ruptures bacteria during feeding. During each larval transition stage, called lethargus, the grinder is replaced with one of a larger size. Here, we characterize at the ultrastructural level the deconstruction of the larval grinder and the construction of the adult grinder during the fourth larval stage (L4)-to-adult transition. Early in L4 lethargus, pharyngeal muscle cells trans-differentiate from contractile to secretory cells, as evidenced by the appearance of clear and dense core vesicles and disruptions in sarcomere organization. This is followed, within minutes, by the dissolution of the L4 grinder and the formation and maturation of the adult grinder. Components of the nascent adult grinder are deposited basally, and are separated from the dissolving larval grinder by a visible apical layer. The complete grinder is a lamellated extracellular matrix comprised of five layers. Following grinder formation, pharyngeal muscle cells regain ultrastructural contractile properties, and muscle contractions resume. Our findings add to our understanding of how complex extracellular structures assemble and dissemble.
Collapse
|
2
|
Nardi JB, Bee CM, Wallace CL. Remodeling of the abdominal epithelial monolayer during the larva-pupa-adult transformation of Manduca. Dev Biol 2018; 438:10-22. [PMID: 29571610 DOI: 10.1016/j.ydbio.2018.03.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/05/2018] [Accepted: 03/19/2018] [Indexed: 11/25/2022]
Abstract
During metamorphosis of insect epithelial monolayers, cells die, divide, and rearrange. In Drosophila undifferentiated diploid cells destined to form the adult cuticle of each abdominal segment segregate early in development from the surrounding polyploid larval epithelial cells of that segment as eight groups of diploid histoblast cells. The larval polyploid cells are programmed to die and be replaced by divisions and rearrangements of histoblast cells. By contrast, abdominal epithelial cells of Manduca larvae form a monolayer of cells representing different ploidy levels with no definitive segregation of diploid cells destined to form adult structures. These epithelial cells of mixed ploidy levels produce a thick smooth larval cuticle with sparsely distributed sensory bristles. Adult descendants of this larval monolayer produce a thinner cuticle with densely packed scale cells. The transition between these differentiated states of Manduca involves divisions of cells, changes in ploidy levels, and sorting of certain polyploid cells into circular rosette patches to minimize contacts of these polyploid cells with surrounding cells of equal or smaller size. Cells within the rosettes and some surrounding cells are destined to die and be replaced by remaining epithelial cells of uniform size and ploidy at pupa-adult apolysis.
Collapse
Affiliation(s)
- James B Nardi
- Department of Entomology, University of Illinois, 320 Morrill Hall, 505 S Goodwin Avenue, Urbana, IL 61801, United States.
| | - Charles Mark Bee
- Imaging Technology Group, Beckman Institute for Advanced Science and Technology, University of Illinois, 405 N. Mathews Avenue, Urbana, IL 61801, United States.
| | - Catherine Lee Wallace
- Imaging Technology Group, Beckman Institute for Advanced Science and Technology, University of Illinois, 405 N. Mathews Avenue, Urbana, IL 61801, United States.
| |
Collapse
|
3
|
Steroid hormone 20-hydroxyecdysone promotes higher calcium mobilization to induce apoptosis. Cell Calcium 2016; 60:1-12. [DOI: 10.1016/j.ceca.2016.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 04/11/2016] [Accepted: 05/04/2016] [Indexed: 12/31/2022]
|
4
|
Weller J, Sun GC, Zhou B, Lan Q, Hiruma K, Riddiford LM. Isolation and developmental expression of two nuclear receptors, MHR4 and betaFTZ-F1, in the tobacco hornworm, Manduca sexta. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2001; 31:827-837. [PMID: 11378418 DOI: 10.1016/s0965-1748(00)00188-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The cDNAs for two members of the nuclear receptor superfamily were isolated from the tobacco hornworm, Manduca sexta. The deduced amino acid sequence of MHR4 shows 93-95% identity in the DNA-binding domain and the first portion of the hinge (D) region with the germ cell nuclear factor (GCNF)-related factors (GRFs) of the silkworm, Bombyx mori, and the mealworm, Tenebrio molitor, and with a genomic sequence from the fruit fly, Drosophila melanogaster. Northern blot hybridization showed that a 7.5 kb MHR4 mRNA appeared in Manduca abdominal epidermis just as the ecdysteroid titer began to decline during the larval molt, disappeared about 12 h later, then transiently reappeared shortly before larval ecdysis. During the pupal and adult molts, a similar pattern of expression was seen (the very end of the adult molt was not studied). At peak times of expression in the epidermis, MHR4 mRNA was also present in fat body and the central nervous system (CNS). The deduced amino acid sequence of Manduca FTZ-F1 is 100% and 96% identical to that of B. mori and Drosophila betaFTZ-F1, respectively, in the DNA-binding domain and the adjacent hinge region including the FTZ-F1 box. Northern blot analysis showed that the >9.5 kb betaFTZ-F1 mRNA appeared in Manduca epidermis during the decline of the ecdysteroid titer in the larval, pupal and adult molts as the first peak of MHR4 mRNA declined, then it disappeared in the larval and pupal molts before the second peak of MHR4 appeared. betaFTZ-F1 mRNA was also found in fat body and the CNS at the time of peak expression in the epidermis during the larval and pupal molts. Both MHR4 and betaFTZ-F1 mRNAs were found in the testis during the onset of spermatogenesis in the prepupal period.
Collapse
Affiliation(s)
- J Weller
- Department of Zoology, University of Washington, Box 351800, Seattle, WA 98195-1800, USA
| | | | | | | | | | | |
Collapse
|
5
|
Zhou B, Riddiford LM. Hormonal regulation and patterning of the broad-complex in the epidermis and wing discs of the tobacco hornworm, Manduca sexta. Dev Biol 2001; 231:125-37. [PMID: 11180957 DOI: 10.1006/dbio.2000.0143] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Expression of Manduca Broad-Complex (BR-C) mRNA in the larval epidermis is under the dual control of ecdysone and juvenile hormone (JH). Immunocytochemistry with antibodies that recognize the core, Z2, and Z4 domains of Manduca BR-C proteins showed that BR-C appearance not only temporally correlates with pupal commitment of the epidermis on day 3 of the fifth (final) larval instar, but also occurs in a strict spatial pattern within the abdominal segment similar to that seen for the loss of sensitivity to JH. Levels of Z2 and Z4 BR-C proteins shift with Z2 predominating at pupal commitment and Z4 dominant during early pupal cuticle synthesis. Both induction of BR-C mRNA in the epidermis by 20-hydroxyecdysone (20E) and its suppression by JH were shown to be independent of new protein synthesis. For suppression JH must be present during the initial exposure to 20E. When JH was given 6 h after 20E, suppression was only seen in those regions that had not yet expressed BR-C. In the wing discs BR-C was first detected earlier 1.5 days after ecdysis, coincident with the pupal commitment of the wing. Our findings suggest that BR-C expression is one of the first molecular events underlying pupal commitment of both epidermis and wing discs.
Collapse
Affiliation(s)
- B Zhou
- Department of Zoology, University of Washington, Seattle, Washington 98195-1800, USA
| | | |
Collapse
|
6
|
Zhou B, Hiruma K, Shinoda T, Riddiford LM. Juvenile hormone prevents ecdysteroid-induced expression of broad complex RNAs in the epidermis of the tobacco hornworm, Manduca sexta. Dev Biol 1998; 203:233-44. [PMID: 9808776 DOI: 10.1006/dbio.1998.9059] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A cDNA homolog of the Drosophila melanogaster Broad Complex (BRC) gene was isolated from the tobacco hornworm, Manduca sexta, which shows a predicted 88% amino acid identity with Drosophila BRC in the N-terminal BTB domain. Three zinc finger domains encoding homologs of the Drosophila Z2, Z3, and Z4 domains (93, 100, and 85% identity, respectively) were obtained by RT-PCR. In Manduca dorsal abdominal epidermis, BRC RNAs were not observed during the larval molt. Three BRC transcripts-6.0, 7.0, and 9.0 kb-first appeared at the end of the feeding stage of the fifth (final) instar when the epidermis is exposed to ecdysteroids in the absence of juvenile hormone (JH) and becomes committed to pupal differentiation. These RNAs were induced in day 2 fifth larval epidermis in vitro by 20-hydroxyecdysone (20E) in the absence of JH with dose-response and time courses similar to the induction of pupal commitment. This induction by 20E in vitro was prevented by the presence of JH I at levels seen in vivo during the larval molt. In the wing discs, the BRC RNAs appeared shortly after ecdysis to the fifth instar and coincided with the onset of metamorphic competence of these discs. Application of a JH analogue pyriproxifen during the fourth instar molt delayed and reduced the levels of BRC mRNAs seen in the wing discs in the early fifth instar, but did not completely prevent their appearance in this tissue that first differentiates at metamorphosis. The expression of the BRC transcription factors thus appears to be one of the first molecular indications of the genetic reprogramming of the epidermis necessary for insect metamorphosis. How JH prevents BRC expression in this epidermis may provide the key to understanding how this hormone controls metamorphosis.
Collapse
Affiliation(s)
- B Zhou
- Department of Zoology, University of Washington, Seattle, Washington, 98195-1800, USA
| | | | | | | |
Collapse
|
7
|
Palli SR, Brownwright AJ, Davis CN, Tomkins WL, MacDonald A, Retnakaran A. Ultrastructural Effects of a Non-Steroidal Ecdysone Agonist, RH-5992, on the Sixth Instar Larva of the Spruce Budworm, Choristoneura fumiferana. JOURNAL OF INSECT PHYSIOLOGY 1997; 43:55-68. [PMID: 12769930 DOI: 10.1016/s0022-1910(96)00062-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Force feeding of RH-5992 (Tebufenozide), a non-steroidal ecdysone agonist to newly moulted sixth instar larvae of the spruce budworm, Choristoneura fumiferana, (Lepidoptera: Tortricidae) initiates a precocious, incomplete moult. Within 6h post treatment (pt) the larva stops feeding and remains quiescent. Around 12hpt, the head capsule slips partially revealing an untanned new head capsule that appears wrinkled and poorly formed. By 24hrpt, the head capsule slippage is pronounced and there is a mid-dorsal split of the old cuticle in the thoracic region but there is no ecdysis. The larva remains moribund in this state and ultimately dies of starvation and desiccation. The temporal sequence of the external and internal changes of the integument were studied using both scanning and transmission electron microscopy. Within 3hpt, there is hypertrophy of the Golgi complex indicating synthetic activity and soon after, large, putative ecdysial droplets are seen. Within 24h, a new cuticle that lacks the endocuticular lamellae is formed. The formation of the various cuticular components, the degradation of the old cuticle and changes in the organelles of the epidermal cells of the mesothoracic tergite are described. The difference between the natural moult and the one induced by RH-5992 are explained on the basis of molecular events that take place during the moulting cycle. The persistence of this ecdysone agonist in the tissues permits the expression of all the genes that are up-regulated by the presence of the natural hormone but those that are turned on in the absence of the hormone are not expressed.
Collapse
Affiliation(s)
- S R. Palli
- Natural Resources Canada, Canadian Forest Service, 1219 Queen Street East, PO Box 490, Sault Ste Marie, Canada
| | | | | | | | | | | |
Collapse
|
8
|
BALAMANI E, NAIR VS. On the morphogenetic role of juvenile hormone in the prepupal stage of Spodoptera maurittaBoisd. (Lepidoptera: Noctuidae). INVERTEBR REPROD DEV 1991. [DOI: 10.1080/07924259.1991.9672197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
9
|
Porcheron P. Insect tissue culture systems: models for study of hormonal control of development. IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY : JOURNAL OF THE TISSUE CULTURE ASSOCIATION 1991; 27A:479-82. [PMID: 1869489 DOI: 10.1007/bf02631148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The regulation of growth and development of insects is under endocrine control and involves both juvenile hormones and ecdysteroids. Neuropeptides are master regulators which control the secretion of these hormones. Most experiments in insect endocrinology have been conducted in vivo, but tissue culture methodology is playing an increasing role due to the great interest in simpler model systems for the study of complex processes that occur in vivo. The availability of appropriate media has allowed the culture of a variety of insect organs and cell lines of defined origin which have kept certain properties of the parent tissues. Tissue culture approaches have been useful for studying hormonal control of morphogenetic processes. Cell lines are particularly suited to the study of hormonally regulated mechanisms of macromolecular biosynthesis and gene expression. Thus, the value of in vitro analysis in studies of regulation of hormone production is now recognized. Results obtained from tissue culture allow more precise definition of the hormonal requirements of insect cells and tissues for growth and differentiation and might make possible the discovery of new growth regulators.
Collapse
Affiliation(s)
- P Porcheron
- Laboratoire d'Evolution, Université Pierre et Marie Curie, Paris, France
| |
Collapse
|
10
|
|
11
|
Temporal events in the invasion of the codling moth, Cydia pomonella, by a granulosis virus: An electron microscope study. J Invertebr Pathol 1987. [PMCID: PMC7130536 DOI: 10.1016/0022-2011(87)90108-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The replication cycle of the granulosis virus of Cydia pomonella, the codling moth, was studied at the cellular and tissue level. Membranelike complexes were observed forming within the remnants of the nucleolus in the cytoplasm of infected cells. Differences in cell polarity relative to the sites of virus entry assembly and budding as well as differences in the temporal aspects of replication were observed between midgut, fat body, and epidermal cells. The progressive spread of virus throughout larval tissues was studied at 24, 32, 48, 56, and 72 hr postinfection. The basal lamina seemed to be an effective barrier for the release of budded progeny virus into the hemocoel and large numbers of budded virus were produced.
Collapse
|
12
|
Goodman WG, Tatham G, Nesbit DJ, Bultmann H, Sutton RD. The role of juvenile hormone in endocrine control of pigmentation in Manduca sexta. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/0020-1790(87)90121-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
13
|
|
14
|
Trost JT, Goodman WG. Hemolymph titers of the biliprotein, insecticyanin, during development of Manduca sexta. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0020-1790(86)90047-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
15
|
Kiely ML, Riddiford LM. Temporal programming of epidermal cell protein synthesis during the larval-pupal transformation ofManduca sexta. ACTA ACUST UNITED AC 1985. [DOI: 10.1007/bf00877370] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
16
|
Rinterknecht E. Cuticulogenesis correlated with ultrastructural changes in oenocytes and epidermal cells in the late cockroach embryo. Tissue Cell 1985; 17:723-43. [DOI: 10.1016/0040-8166(85)90007-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/1985] [Revised: 06/06/1985] [Indexed: 11/17/2022]
|
17
|
|
18
|
Sedlak BJ, Marchione L, Devorkin B, Davino R. Correlations between endocrine gland ultrastructure and hormone titers in the fifth larval instar of Manduca sexta. Gen Comp Endocrinol 1983; 52:291-310. [PMID: 6654038 DOI: 10.1016/0016-6480(83)90125-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Correlations were made between endocrine gland ultrastructure and circulating hormone titers of Manduca sexta to investigate the mechanisms of hormone biosynthesis and secretion. Both the prothoracic glands (PTG), which secrete ecdysone, and the corpora allata (CA), which secrete juvenile hormone (JH), were studied. In the prothoracic glands, the intracellular spaces increase in area and reach their maximum size following the major ecdysteroid peak in the fourth and fifth larval instars. Within the intercellular spaces are multivesicular sacs (MVS), structures which are clusters of vesicles bounded by another membrane. Since these sacs are largely depleted of their internal vesicles after the second cycle of tropic hormone stimulates the PTG to secrete ecdysone, the MVS probably release a gland cell product at this time. In the CA, concentric whorls of smooth endoplasmic reticulum are present in larval glands, when the JH titer is high, but are absent from pupal CA when the JH titer is low. The peak of JH at Days 6-8 of the fifth larval instar occurs after an increase is seen in the neurosecretory cell axon diameters suggesting that the CA are stimulated by a brain hormone to release JH. The number of Golgi complexes increases in pupal CA and dense bodies are present in pupal but not larval glands. These Golgi complexes may be involved in the manufacture of lysosomal enzymes which degrade JH within the gland itself.
Collapse
|
19
|
Germond JE, Diehl PA, Morici M. Correlations between integument structure and ecdysteroid titers in fifth-stage nymphs of the tick, Ornithodoros moubata (Murray, 1877; sensu Walton, 1962). Gen Comp Endocrinol 1982; 46:255-66. [PMID: 7106547 DOI: 10.1016/0016-6480(82)90207-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
20
|
|
21
|
Gilbert LI, Bollenbacher WE, Goodman W, Smith SL, Agui N, Granger N, Sedlak BJ. Hormones controlling insect metamorphosis. RECENT PROGRESS IN HORMONE RESEARCH 1980; 36:401-449. [PMID: 6251519 DOI: 10.1016/b978-0-12-571136-4.50017-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|