Fat body cells and calcium phosphate spherules induce ice nucleation in the freeze-tolerant larvae of the gall fly Eurosta solidaginis (Diptera, Tephritidae)

1996 ◽  
Vol 199 (2) ◽  
pp. 465-471 ◽  
Author(s):  
J Mugnano ◽  
R Lee ◽  
R Taylor
Keyword(s):  
Calcium Phosphate ◽  
Fat Body ◽  
Freeze Tolerance ◽  
Ice Nucleation ◽  
Malpighian Tubules ◽  
Whole Body ◽  
Eurosta Solidaginis ◽  
New Class ◽  
Ice Nucleators ◽  
Freeze Tolerant

During the autumn, the third-instar larvae of the gall fly Eurosta solidaginis acquire freeze tolerance and their crystallization temperatures increase into the -8 to -10 °C range. Despite conflicting reports, efficient endogenous ice nucleators have not been identified in this freeze-tolerant insect. We found large crystalloid spheres within the Malpighian tubules of overwintering larvae. Energy-dispersive X-ray microanalysis and infrared spectroscopy indicated that the spherules were a hydrate of tribasic calcium phosphate. To test for ice-nucleating activity, we placed the calcium phosphate spherules in 10 µl of Schneider's insect medium and cooled them in a refrigerated bath. The addition of spherules increased the crystallization temperature of Schneider's medium by approximately 8 C, from -18.4±0.8 °C to -10.1±0.9 °C (mean ± s.e.m., N=20). Ice-nucleating activity (-10.9±0.9 °C) was also demonstrated in fat body cells suspended in 10 µl of Schneider's medium. Both calcium phosphate spherules and fat body cells have ice-nucleating activity sufficiently high to explain whole-body crystallization temperatures. Furthermore, other crystalloid deposits, commonly found in diapausing or overwintering insects, also exhibited significant ice-nucleating activity. These endogenous crystalloid deposits represent a new class of heterogeneous ice nucleators that potentially regulate supercooling and promote freeze tolerance in E. solidaginis and possibly in other overwintering insects.

Modeling seasonal changes in intracellular freeze-tolerance of fat body cells of the gall fly Eurosta solidaginis (Diptera, Tephritidae)

1997 ◽  
Vol 200 (1) ◽  
pp. 185-192 ◽  
Author(s):  
V Bennett ◽  
R Lee
Keyword(s):  
Cell Survival ◽  
Seasonal Changes ◽  
Cold Hardiness ◽  
Fat Body ◽  
Freeze Tolerance ◽  
Cellular Level ◽  
Eurosta Solidaginis ◽  
Freeze Tolerant

Although seasonal changes in the freeze-tolerance of third-instar larvae of Eurosta solidaginis have been well documented for the whole organism, the nature of this cold-hardiness at the cellular level has not been examined. Seasonal changes in the survival of fat body cells from E. solidaginis larvae were assessed using fluorescent vital dyes after freezing at -10, -25 or -80 °C for 24 h both in vivo and in vitro. Cells frozen in vitro were frozen with glycerol, with sorbitol (both of which enhanced cell survival) or without cryoprotectants. Both cellular and organismal survival were low in August when larvae were not freeze-tolerant, then increased dramatically during September and October before leveling off from November to January. This observation for cells frozen without cryoprotectants indicates that the cells themselves have adapted. The single most important factor influencing cell survival, as determined by logistic regression modeling, was the time of larval collection, which reflects the level of cold-hardiness achieved by field acclimation. Cells frozen in vivo exhibited greater survival than did those frozen in vitro, even with the addition of cryoprotectants. Since no differences were observed between cells frozen with glycerol or sorbitol, the role of the multi-component cryoprotectant system present in E. solidaginis should be investigated.

Survival of intracellular freezing, lipid coalescence and osmotic fragility in fat body cells of the freeze-tolerant gall fly Eurosta solidaginis

1993 ◽  
Vol 39 (5) ◽  
pp. 445-450 ◽  
Author(s):  
Richard E. Lee ◽  
John J. McGrath ◽  
R. Todd Morason ◽  
Ronald M. Taddeo
Keyword(s):  
Fat Body ◽  
Osmotic Fragility ◽  
Eurosta Solidaginis ◽  
Freeze Tolerant

scholarly journals Evidence for non-colligative function of small cryoprotectants in a freeze-tolerant insect

2019 ◽  
Vol 286 (1899) ◽  
pp. 20190050 ◽  
Author(s):  
Jantina Toxopeus ◽  
Vladimír Koštál ◽  
Brent J. Sinclair
Keyword(s):  
Fat Body ◽  
Ex Vivo ◽  
Freeze Tolerance ◽  
Field Cricket ◽  
Ice Formation ◽  
Low Molecular Weight ◽  
Manipulative Experiments ◽  
Gryllus Veletis ◽  
Freeze Tolerant

Freeze tolerance, the ability to survive internal ice formation, facilitates survival of some insects in cold habitats. Low-molecular-weight cryoprotectants such as sugars, polyols and amino acids are hypothesized to facilitate freeze tolerance, but their in vivo function is poorly understood. Here, we use a combination of metabolomics and manipulative experiments in vivo and ex vivo to examine the function of multiple cryoprotectants in the spring field cricket Gryllus veletis . Cold-acclimated G. veletis are freeze-tolerant and accumulate myo -inositol, proline and trehalose in their haemolymph and fat body. Injecting freeze-tolerant crickets with proline and trehalose increases survival of freezing to lower temperatures or for longer times. Similarly, exogenous myo -inositol and trehalose increase ex vivo freezing survival of fat body cells from freeze-tolerant crickets. No cryoprotectant (alone or in combination) is sufficient to confer freeze tolerance on non-acclimated, freeze-intolerant G. veletis . Given that each cryoprotectant differentially impacts survival in the frozen state, we conclude that small cryoprotectants are not interchangeable and likely function non-colligatively in insect freeze tolerance. Our study is the first to experimentally demonstrate the importance of non-colligative cryoprotectant function for insect freeze tolerance both in vivo and ex vivo , with implications for choosing new molecules for cryopreservation.

scholarly journals Freeze tolerance of Cyphoderris monstrosa (Orthoptera: Prophalangopsidae)

2016 ◽  
Vol 148 (6) ◽  
pp. 668-672 ◽  
Author(s):  
Jantina Toxopeus ◽  
Jacqueline E. Lebenzon ◽  
Alexander H McKinnon ◽  
Brent J. Sinclair
Keyword(s):  
Cold Tolerance ◽  
Freeze Tolerance ◽  
Malpighian Tubules ◽  
Ice Formation ◽  
Freezing And Thawing ◽  
Tolerance Strategy ◽  
Late Instar ◽  
Freeze Tolerant ◽  
Overwintering Survival

AbstractThe great grig, Cyphoderris monstrosa Uhler (Orthoptera: Prophalangopsidae), is a large (20–30 mm, >1 g), nocturnal ensiferan that inhabits montane coniferous forests in northwestern North America. Cyphoderris monstrosa overwinters as a late instar nymphs, but its cold tolerance strategy has not previously been reported. We collected nymphs from near Kamloops, British Columbia, Canada in late spring to determine their cold tolerance strategy. Cyphoderris monstrosa nymphs were active at low temperatures until they froze at −4.6±0.3 °C. The nymphs survived internal ice formation (i.e., are freeze tolerant), had a lethal temperature between −9 °C and −12 °C, and could survive for between five and 10 days at −6 °C. Isolated C. monstrosa gut, Malpighian tubules, and metafemur muscle tissues froze at temperatures similar to whole nymphs, and likely inoculate freezing in vivo. Hemolymph osmolality was 358±51 mOsm, with trehalose and proline comprising ~10% of that total. Glycerol was not detectable in hemolymph from field-fresh nymphs, but accumulated after freezing and thawing. The control of ice formation and presence of hemolymph cryoprotectants may contribute to C. monstrosa freeze tolerance and overwintering survival.

scholarly journals Cold tolerance mechanisms of the free-living stages of Trichostrongylus colubriformis (Nematoda)

1989 ◽  
Vol 145 (1) ◽  
pp. 353-369
Author(s):  
D. A. Wharton ◽  
G. S. Allan
Keyword(s):  
Liquid Paraffin ◽  
Relative Survival ◽  
Freeze Tolerance ◽  
Ice Nucleation ◽  
Free Living ◽  
Trichostrongylus Colubriformis ◽  
Freeze Avoidance ◽  
Major Function ◽  
Stage Juvenile ◽  
Freeze Tolerant

1. All free-living stages of the nematode parasite of sheep, Trichostrongylus colubriformis Giles, survived exposure to freezing temperatures in contact with water, with the exception of the first-stage juvenile (J1). The third-stage juvenile (J3) was the most resistant stage. The order of relative survival of the different stages was different from that of the lowest F50 (the temperature at which 50% froze), suggesting that an ability to supercool was not the only determinant of survival. 2. The F50 was shown to be a good measure of the degree of supercooling and to extend greatly the lower size limit of organisms that could be measured. 3. The J3 uses a freeze-avoiding strategy by supercooling when in air or covered by liquid paraffin. In water it uses a mixture of freeze-avoiding and freeze-tolerant strategies, with a proportion of the population surviving freezing caused by exogenous ice nucleation. 4. Removal of the J3 sheath results in a shift from freeze avoidance to freeze tolerance, with an overall reduction in survival. A major function of the sheath may be to reduce the probability of exogenous ice nucleation.

scholarly journals TmDorX2 positively regulates antimicrobial peptides in Tenebrio molitor gut, fat body, and hemocytes in response to bacterial and fungal infection

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maryam Keshavarz ◽  
Yong Hun Jo ◽  
Ki Beom Park ◽  
Hye Jin Ko ◽  
Tariku Tesfaye Edosa ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Antimicrobial Peptides ◽  
Post Infection ◽  
Fat Body ◽  
Tenebrio Molitor ◽  
Malpighian Tubules ◽  
Whole Body ◽  
Mrna Levels ◽  
E Coli ◽  
Pathogen Invasion

AbstractDorsal, a member of the nuclear factor-kappa B (NF-κB) family of transcription factors, is a critical downstream component of the Toll pathway that regulates the expression of antimicrobial peptides (AMPs) against pathogen invasion. In this study, the full-length ORF of Dorsal was identified from the RNA-seq database of the mealworm beetle Tenebrio molitor (TmDorX2). The ORF of TmDorX2 was 1,482 bp in length, encoding a polypeptide of 493 amino acid residues. TmDorX2 contains a conserved Rel homology domain (RHD) and an immunoglobulin-like, plexins, and transcription factors (IPT) domain. TmDorX2 mRNA was detected in all developmental stages, with the highest levels observed in 3-day-old adults. TmDorX2 transcripts were highly expressed in the adult Malpighian tubules (MT) and the larval fat body and MT tissues. After challenging the larvae with Staphylococcus aureus and Escherichia coli, the TmDorX2 mRNA levels were upregulated 6 and 9 h post infection in the whole body, fat body, and hemocytes. Upon Candida albicans challenge, the TmDorX2 mRNA expression were found highest at 9 h post-infection in the fat body. In addition, TmDorX2-knockdown larvae exposed to E. coli, S. aureus, or C. albicans challenge showed a significantly increased mortality rate. Furthermore, the expression of 11 AMP genes was downregulated in the gut and fat body of dsTmDorX2-injected larvae upon E. coli challenge. After C. albicans and S. aureus challenge of dsTmDorX2-injected larvae, the expression of 11 and 10 AMPs was downregulated in the gut and fat body, respectively. Intriguingly, the expression of antifungal transcripts TmTenecin-3 and TmThaumatin-like protein-1 and -2 was greatly decreased in TmDorX2-silenced larvae in response to C. albicans challenge, suggesting that TmDorX2 regulates antifungal AMPs in the gut in response to C. albicans infection. The AMP expression profiles in the fat body, hemocytes, gut, and MTs suggest that TmDorX2 might have an important role in promoting the survival of T. molitor larvae against all mentioned pathogens.

Freeze-thaw injury in erythrocytes of the freeze-tolerant wood frog, Rana sylvatica

1991 ◽  
Vol 261 (6) ◽  
pp. R1346-R1350 ◽  
Author(s):  
J. P. Costanzo ◽  
R. E. Lee
Keyword(s):  
Cell Injury ◽  
Osmotic Fragility ◽  
Rana Sylvatica ◽  
Freeze Tolerance ◽  
Wood Frog ◽  
In Vitro Tests ◽  
Freezing And Thawing ◽  
Freeze Tolerant ◽  
High Concentrations

Erythrocytes from the freeze-tolerant wood frog (Rana sylvatica) were subjected to in vitro tests of freeze tolerance, cryoprotection, and osmotic fragility. The responses of cells from frogs acclimated to 4 or 15 degrees C were similar. Erythrocytes that were frozen in saline hemolyzed at -4 degrees C or lower. The addition of high concentrations (150 and 1,500 mM) of glucose or glycerol, cryoprotectants produced naturally by freeze-tolerant frogs, significantly reduced cell injury at -8 degrees C, but concentrations of 1.5 or 15 mM were ineffective. Hemolysis was reduced by 94% with 1,500 mM glycerol and by 84% with 1,500 mM glucose; thus glycerol was the more effective cryoprotectant. Mean fragility values for frog erythrocytes incubated in hypertonic and hypotonic saline were 1,938 and 49 mosM, respectively. Survival in freeze tolerance and cryoprotection experiments was comparable for erythrocytes from frogs and humans, suggesting that these cells may respond similarly to freezing-related stresses. However, the breadth of osmotic tolerance, standardized for differences in isotonicity, was greater for frog erythrocytes than for human erythrocytes. Our data suggest that erythrocytes from R. sylvatica are adequately protected by glucose under natural conditions of freezing and thawing.

Ice nucleation activity of bacteria isolated from snow compared with organic and inorganic substrates

2008 ◽  
Vol 5 (6) ◽  
pp. 373 ◽  
Author(s):  
Roya Mortazavi ◽  
Christopher T. Hayes ◽  
Parisa A. Ariya
Keyword(s):  
Bacterial Species ◽  
Ice Nucleation ◽  
Detailed Knowledge ◽  
Bacterial Populations ◽  
Inorganic Aerosols ◽  
Ice Nucleators ◽  
Species Population ◽  
Nucleation Activity ◽  
Ice Nucleation Activity ◽  
Snow Samples

Environmental context. Biological ice nucleators have been found to freeze water at very warm temperatures. The potential of bio-aerosols to greatly influence cloud chemistry and microphysics is becoming increasingly apparent, yet detailed knowledge of their actual role in atmospheric processes is lacking. The formation of ice in the atmosphere has significant local, regional and global influence, ranging from precipitation to cloud nucleation and thus climate. Ice nucleation tests on bacteria isolated from snow and laboratory-grown bacteria, in comparison with those of known organic and inorganic aerosols, shed light on this issue. Abstract. Ice nucleation experiments on bacteria isolated from snow as well as grown in the laboratory, in comparison with those of known organic and inorganic aerosols, examined the importance of bio-aerosols on cloud processes. Snow samples were collected from urban and suburban sites in the greater Montreal region in Canada (45°28′N, 73°45′W). Among many snow bacterial isolates, eight types of bacterial species, none belonging to known effective ice nucleators such as Pseudomonas or Erwinia genera, were identified to show an intermediate range of ice nucleation activity (–12.9 ± 1.3°C to –17.5 ± 2.8°C). Comparable results were also obtained for molten snow samples and inorganic suspensions (kaolin and montmorillonite) of buffered water solutions. The presence of organic molecules (oxalic, malonic and succinic acids) had minimal effect (<2°C) on ice nucleation. Considering experimental limitations, and drawing from observation in snow samples of a variety of bacterial populations with variable ice-nucleation ability, a shift in airborne-species population may significantly alter glaciation processes in clouds.

Sign in / Sign up

Export Citation Format

Share Document