Organ growth without cell division: somatic polyploidy in a moth, Ephestia kuehniella

Genome ◽  
2012 ◽  
Vol 55 (11) ◽  
pp. 755-763 ◽  
Author(s):  
Lydia Buntrock ◽  
František Marec ◽  
Sarah Krueger ◽  
Walther Traut
Keyword(s):  
Cell Division ◽  
Cell Growth ◽  
Larval Instar ◽  
Malpighian Tubule ◽  
Silk Gland ◽  
Ephestia Kuehniella ◽  
Malpighian Tubules ◽  
Organ Growth ◽  
Gland Cells ◽  
First Instar

Organ growth depends on cell division and (or) cell growth. Here, we present a study on two organs whose growth depends entirely on cell growth, once they are formed in the embryo: Malpighian tubules and silk glands of the flour moth, Ephestia kuehniella . Between first and last larval instar, the volume of Malpighian tubule cells increases by a factor of ∼1800 and that of silk gland cells by a factor of ∼3100. We determined the number of endocyles required to reach these stages by Feulgen cytometry. Cells of Malpighian tubules were in the 2C stage in first instar larvae and reached 1024C after 9 endocycles in last instar larvae (1C = 0.45 pg DNA). Silk gland cells already reached a DNA content of 8C–16C in first instar larvae and attained up to 8192C in last instar larvae after a total of 12 endocycles. The nuclei were small and more or less spherical in first instar larvae, but they were huge, flat, and bizarrely branched in last instar larvae. We consider branching as a compensatory adaptation to improve molecular traffic between nucleus and cytoplasm in these excessively large and highly polyploid cells (i) by reducing the mean distance between nucleus and cytoplasm and (ii) by enlarging the surface-to-volume ratio of these nuclei.

scholarly journals Enhanced Myc Expression in Silkworm Silk Gland Promotes DNA Replication and Silk Production

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 361
Author(s):  
Wenliang Qian ◽  
Yan Yang ◽  
Zheng Li ◽  
Yuting Wu ◽  
Xuechuan He ◽  
...  
Keyword(s):  
Dna Replication ◽  
Cell Growth ◽  
Silk Gland ◽  
Biological Functions ◽  
Gland Cells ◽  
Silk Production ◽  
Myc Gene ◽  
Cell Growth And Proliferation ◽  
Silkworm Silk ◽  
Posterior Silk Gland

Silkworm is an economically important insect that synthetizes silk proteins for silk production in silk gland, and silk gland cells undergo endoreplication during larval period. Transcription factor Myc is essential for cell growth and proliferation. Although silkworm Myc gene has been identified previously, its biological functions in silkworm silk gland are still largely unknown. In this study, we examined whether enhanced Myc expression in silk gland could facilitate cell growth and silk production. Based on a transgenic approach, Myc was driven by the promoter of the fibroin heavy chain (FibH) gene to be successfully overexpressed in posterior silk gland. Enhanced Myc expression in the PSG elevated FibH expression by about 20% compared to the control, and also increased the weight and shell rate of the cocoon shell. Further investigation confirmed that Myc overexpression increased nucleus size and DNA content of the PSG cells by promoting the transcription of the genes involved in DNA replication. Therefore, we conclude that enhanced Myc expression promotes DNA replication and silk protein expression in endoreplicating silk gland cells, which subsequently raises silk yield.

The Comparative Internal Larval Anatomy of Sawflies (Hymenoptera: Symphyta)

1955 ◽  
Vol 87 (S1) ◽  
pp. 5-132 ◽  
Author(s):  
Doreen E. Maxwell
Keyword(s):  
Salivary Glands ◽  
Phylogenetic Relationship ◽  
Parallel Evolution ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Internal Anatomy ◽  
Progressive Change ◽  
Cell Numbers ◽  
Gland Cells

AbstractExamination of 132 recognized species of sawflies (Hymenoptera: Symphyta) from America, Europe, Africa, and Australia, has demonstrated the value of internal anatomical larval detail as a taxonomic tool and an indicator of phylogenetic relationship. Two characters, the salivary glands and Malpighian tubules, proved of major importance. The salivary glands fall into three main categories, narrow squared ducts and incorporated gland cells (the Orthandria with the exception of the Xyelidae), narrow ducts and sheathlike gland cells (the Xyelidae), and either increased cell numbers and narrow branching ducts or expanded ducts (the Tenthredinoidea). Three divisions of the Tenthredinidae are suggested, viz. the Selandriinae-Dolerinae-Athaliinae-Lycaotinae, the Nematinae, and the Blennocampinae-Allantinae-Heterarthrinae-Tenthredininae, corresponding to Malpighian tubule groupings of primitive, intermediate-advanced, and advanced. Character trends are discussed in the light of existing adult arrangements (Ross and Benson), and external larval (Yuasa). The survey emphasizes the need of a revision of family and subfamily limits. Where identification is difficult, internal anatomy is of use in determination to genus and species as well as to family and subfamily. The frequency of parallel evolution does not affect the use of certain characters indicative of progressive change within a group.

The wingless product is required for cell proliferation in the Malpighian tubule anlage of Drosophila melanogaster

Development ◽  
1992 ◽  
Vol 116 (3) ◽  
pp. 745-754 ◽  
Author(s):  
H. Skaer ◽  
A. Martinez Arias
Keyword(s):  
Cell Proliferation ◽  
Drosophila Melanogaster ◽  
Cell Division ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Temperature Sensitive ◽  
Over Expression ◽  
Normal Expression ◽  
Segment Polarity ◽  
Sensitive Allele

Cell division in the Malpighian tubules of Drosophila melanogaster depends on the presence of a specialised cell at the tip of each tubule (Skaer, H. le B (1989) Nature 342, 566–569). Here we show that cell division also depends on the normal expression of the segment polarity gene, wingless. The pattern of wingless RNA and protein in developing tubules is consistent with a requirement for wingless for cell division. Analysis of the temporal requirement for wingless using a temperature- sensitive allele confirms that the normal expression of wingless is necessary during cell proliferation in the Malpighian tubules. Over-expression of the gene, induced in a stock containing the wg gene under the control of a heat-shock promoter, results in supernumerary cells in the tubules. We discuss the role of wingless in the cell interactions that govern cell division in the Malpighian tubules.

scholarly journals Sequential fates in a single cell are established by the neurogenic cascade in the Malpighian tubules of Drosophila

Development ◽  
1994 ◽  
Vol 120 (12) ◽  
pp. 3439-3450 ◽  
Author(s):  
M. Hoch ◽  
K. Broadie ◽  
H. Jackle ◽  
H. Skaer
Keyword(s):  
Cell Division ◽  
Single Cell ◽  
Mutational Analysis ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Genetic Interactions ◽  
Tip Cell ◽  
Neurogenic Genes ◽  
Selection Of

In each Malpighian tubule of Drosophila, one cell is singled out, the tip cell, whose function during embryogenesis is to promote cell division in its neighbours. We follow the segregation of this cell, explore the genetic interactions that underlie its specification and demonstrate that tip cell allocation closely resembles neurogenesis. The tip cell arises by division of a tip mother cell, which is selected from a cluster of equivalent cells in each tubule primordium. Each cluster is marked out by the expression of proneural genes and the selection of a single cell from each group involves lateral inhibition, mediated by the neurogenic genes. We confirm the mitogenic role of the tip cell during embryogenesis by mutational analysis and show that it subsequently adopts a second fate, differentiating neural characteristics. We demonstrate that both stages in the differentiation of this cell are established by the same sequence of genetic interactions, which have not previously been shown to occur outside the neurogenic ectoderm.

Fine Structure of the Malpighian Tubules of the Mosquito, Culex pipiens

1971 ◽  
Vol 29 ◽  
pp. 402-403
Author(s):  
Brendan Clifford
Keyword(s):  
Fine Structure ◽  
Culex Pipiens ◽  
Stellate Cell ◽  
Malpighian Tubule ◽  
Cell Types ◽  
Instar Larva ◽  
Malpighian Tubules ◽  
Calliphora Erythrocephala ◽  
Distinct Cell ◽  
Basal Plasma

An ultrastructural investigation of the Malpighian tubules of the fourth instar larva of Culex pipiens was undertaken as part of a continuing study of the fine structure of transport epithelia.Each of the five Malpighian tubules was found to be morphologically identical and regionally undifferentiated. Two distinct cell types, the primary and stellate, were found intermingled along the length of each tubule. The ultrastructure of the stellate cell was previously described in the Malpighian tubule of the blowfly, Calliphora erythrocephala by Berridge and Oschman.The basal plasma membrane of the primary cell is extremely irregular, giving rise to a complex interconnecting network of basal channels. The compartments of cytoplasm entrapped within this system of basal infoldings contain mitochondria, free ribosomes, and small amounts of rough endoplasmic reticulum. The mitochondria are distinctive in that the cristae run parallel to the long axis of the organelle.

Relations between cell growth and cell division

1961 ◽  
Vol 23 (2) ◽  
pp. 354-360 ◽  
Author(s):  
I.L. Cameron ◽  
D.M. Prescott
Keyword(s):  
Cell Division ◽  
Cell Growth

scholarly journals CRISPR-Mediated Endogenous Activation of Fibroin Heavy Chain Gene Triggers Cellular Stress Responses in Bombyx mori Embryonic Cells

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 552
Author(s):  
Wenbo Hu ◽  
Xiaogang Wang ◽  
Sanyuan Ma ◽  
Zhangchuan Peng ◽  
Yang Cao ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Heavy Chain ◽  
Stress Responses ◽  
Cellular Stress ◽  
Silk Gland ◽  
Cellular Stress Response ◽  
Molar Ratio ◽  
Chain Gene ◽  
Gland Cells ◽  
Cellular Stress Responses

The silkworm Bombyx mori is an economically important insect, as it is the main producer of silk. Fibroin heavy chain (FibH) gene, encoding the core component of silk protein, is specifically and highly expressed in silk gland cells but not in the other cells. Although the silkworm FibH gene has been well studied in transcriptional regulation, its biological functions in the development of silk gland cells remain elusive. In this study, we constructed a CRISPRa system to activate the endogenous transcription of FibH in Bombyx mori embryonic (BmE) cells, and the mRNA expression of FibH was successfully activated. In addition, we found that FibH expression was increased to a maximum at 60 h after transient transfection of sgRNA/dCas9-VPR at a molar ratio of 9:1. The qRT-PCR analysis showed that the expression levels of cellular stress response-related genes were significantly up-regulated along with activated FibH gene. Moreover, the lyso-tracker red and monodansylcadaverine (MDC) staining assays revealed an apparent appearance of autophagy in FibH-activated BmE cells. Therefore, we conclude that the activation of FibH gene leads to up-regulation of cellular stress responses-related genes in BmE cells, which is essential for understanding silk gland development and the fibroin secretion process in B. mori.

Anti-diuresis in the blood-feeding insect Rhodnius prolixus Stål: the peptide CAP2b and cyclic GMP inhibit Malpighian tubule fluid secretion.

1997 ◽  
Vol 200 (17) ◽  
pp. 2363-2367 ◽  
Author(s):  
M C Quinlan ◽  
N J Tublitz ◽  
M J O'Donnell
Keyword(s):  
Cyclic Gmp ◽  
Physiological Role ◽  
Malpighian Tubule ◽  
Fluid Secretion ◽  
Blood Feeding ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Tubule Fluid ◽  
Secretion Rates

Rhodnius prolixus eliminates NaCl-rich urine at high rates following its infrequent but massive blood meals. This diuresis involves stimulation of Malpighian tubule fluid secretion by diuretic hormones released in response to distention of the abdomen during feeding. The precipitous decline in urine flow that occurs several hours after feeding has been thought until now to result from a decline in diuretic hormone release. We suggest here that insect cardioacceleratory peptide 2b (CAP2b) and cyclic GMP are part of a novel mechanism of anti-diuresis. Secretion rates of 5-hydroxytryptamine-stimulated Malpighian tubules are reduced by low doses of CAP2b or cyclic GMP. Maximal secretion rates are restored by exposing tubules to 1 mmol l-1 cyclic AMP. Levels of cyclic GMP in isolated tubules increase in response to CAP2b, consistent with a role for cyclic GMP as an intracellular second messenger. Levels of cyclic GMP in tubules also increase as urine output rates decline in vivo, suggesting a physiological role for this nucleotide in the termination of diuresis.

The Influence of Ephestia Kuehniella on the Development of its Parasite Nemeritis Canescens

1968 ◽  
Vol 48 (2) ◽  
pp. 291-304
Author(s):  
SARAH A. CORBET
Keyword(s):  
Protein Concentration ◽  
Freezing Point ◽  
Larval Instar ◽  
Behavioural Response ◽  
Freezing Point Depression ◽  
Rate Of Development ◽  
First Instar ◽  
Rapid Changes ◽  
Fast Development ◽  
Insect Parasites

1. The first larval instar of Nemeritis lasts longer in young caterpillars of Ephestia than it does in older caterpillars. First-instar Nemeritis larvae in young hosts feed and grow very slowly, but they remain capable of fast growth if transferred to older host caterpillars. 2. Measurements of the protein concentration, the amino acid concentration and the freezing-point depression show rapid changes in the composition of the haemolymph of Ephestia caterpillars at that stage of larval development at which they first become capable of supporting the fast development of first-instar larvae of Nemeritis. 3. It is suggested that the rate of development of Nemeritis larvae depends on their rate of feeding, and that their rate of feeding is determined by a behavioural response to the composition of their food, the host's haemolymph; they feed slowly in young host caterpillars because the concentration of solutes (notably amino acids) in their food is so high. 4. A similar situation may hold when the development of insect parasites is delayed in diapausing hosts.

Sign in / Sign up

Export Citation Format

Share Document