scholarly journals Developmental Penalties Associated with Inducible Tolerance inHelicoverpa armigerato Insecticidal Toxins fromBacillus thuringiensis

2010 ◽  
Vol 77 (4) ◽  
pp. 1443-1448 ◽  
Author(s):  
Mahbub Rahman ◽  
Richard Glatz ◽  
Rick Roush ◽  
Otto Schmidt

ABSTRACTExposure of insect larvae to sublethal concentrations of crystal toxins from the soil bacteriumBacillus thuringiensis(Bt toxins) causes the induction of immune and metabolic responses that can be transmitted to offspring by epigenetic inheritance mechanisms. Given that the elevated immune status carries significant developmental penalties, we wanted to establish the relationships between immune induction, tolerance to the toxin and developmental penalties. A laboratory culture ofHelicoverpa armigerawas induced by a sublethal bacterial suspension containing crystal toxin Cry1Ac in one generation and maintained in the presence of toxin, acquiring significant levels of tolerance to the toxin within 12 generations of continuous exposure. Comparing tolerant and susceptible insects, we show that the induction of larval immune response and the coincident alteration of development-related metabolic activities by elicitors in the larval gut (larval induction) differs from the elevated immune status transmitted by epigenetic mechanisms (embryonic induction). Because the damaging effects of larval induction processes are higher compared to embryonic induction, it is likely that overall developmental penalties depend on the relative contribution of the two induction processes. When insects are kept with the same amount of toxin in the diet for subsequent generations, the embryonic induction process increases its contribution compared to the larval induction, resulting in reduced overall developmental penalty, while tolerance to the toxin is maintained.

2015 ◽  
Author(s):  
Xiao-Hui Liu ◽  
Jin-Min Lian ◽  
Fei Ling ◽  
Ning Li ◽  
Da-Wei Wang ◽  
...  

Lamarckian inheritance has been largely discredited until the recent discovery of transgenerational epigenetic inheritance. However, transgenerational epigenetic inheritance is still under debate for unable to rule out DNA sequence changes as the underlying cause for heritability. Here, through profiling of the sperm methylomes and genomes of two recently diverged rat subspecies, we analyzed the relationship between epigenetic variation and DNA variation, and their relative contribution to evolution of species. We found that only epigenetic markers located in differentially methylated regions (DMRs) between subspecies, but not within subspecies, can be stably and effectively passed through generations. DMRs in response to both random and stable environmental difference show increased nucleotide diversity, and we demonstrated that it is variance of methylation level but not deamination caused by methylation driving increasing of nucleotide diversity in DMRs, indicating strong relationship between environment-associated changes of chromatin accessibility and increased nucleotide diversity. Further, we detected that accelerated fixation of DNA variants occur only in inter-subspecies DMRs in response to stable environmental difference but not intra-subspecies DMRs in response to random environmental difference or non-DMRs, indicating that this process is possibly driven by environment-associated fixation of divergent methylation status. Our results thus establish a bridge between Lamarckian inheritance and Darwinian selection.


Author(s):  
D.R. Mattie ◽  
C.J. Hixson

Dimethylmethylphosphonate (DMMP) is a simple organophosphate used industrially as a flame retardant and to lower viscosity in polyester and epoxy resins. The military considered the use of DMMP as a nerve gas simulant. Since military use of DMMP involved exposure by inhalation, there was a need for a subchronic inhalation exposure to DMMP to fully investigate its toxic potential.Male Fischer-344 rats were exposed to 25 ppm or 250 ppm DMMP vapor on a continuous basis for 90 days. An equal number of control rats were sham-exposed. Following the 90-day continuous exposure period, 15 male rats were sacrificed from each group. Two rats from each group had the left kidney perfused for electron microscopic examination. The kidneys were perfused from a height of 150 cm water with 1% glutaraldehyde in Sorensen's 0.1M phosphate buffer pH 7.2. An additional kidney was taken from a rat in each group and fixed by immersion in 2.5% glutaraldehyde and 2% paraformaldehyde in 0.1M cacodylate buffer pH 7.4. A portion of the 9 kidneys collected for electron microscopy were processed into Epon 812. Thin sections, stained with uranyl acetate and lead citrate, were examined with a JEOL 100B Transmission Electron Microscope. Microvilli height was measured on photographs of the cells of proximal tubules. This data, along with morphologic features of the cells, allows the proximal convoluted tubules (PCT) to be identified as being S1, S2, or S3 segment PCT.


2014 ◽  
Vol 56 ◽  
pp. 207-219 ◽  
Author(s):  
Chi L.L. Pham ◽  
Ann H. Kwan ◽  
Margaret Sunde

Amyloids are insoluble fibrillar protein deposits with an underlying cross-β structure initially discovered in the context of human diseases. However, it is now clear that the same fibrillar structure is used by many organisms, from bacteria to humans, in order to achieve a diverse range of biological functions. These functions include structure and protection (e.g. curli and chorion proteins, and insect and spider silk proteins), aiding interface transitions and cell–cell recognition (e.g. chaplins, rodlins and hydrophobins), protein control and storage (e.g. Microcin E492, modulins and PMEL), and epigenetic inheritance and memory [e.g. Sup35, Ure2p, HET-s and CPEB (cytoplasmic polyadenylation element-binding protein)]. As more examples of functional amyloid come to light, the list of roles associated with functional amyloids has continued to expand. More recently, amyloids have also been implicated in signal transduction [e.g. RIP1/RIP3 (receptor-interacting protein)] and perhaps in host defence [e.g. aDrs (anionic dermaseptin) peptide]. The present chapter discusses in detail functional amyloids that are used in Nature by micro-organisms, non-mammalian animals and mammals, including the biological roles that they play, their molecular composition and how they assemble, as well as the coping strategies that organisms have evolved to avoid the potential toxicity of functional amyloid.


2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.


2003 ◽  
Vol 8 (4) ◽  
pp. 252-265 ◽  
Author(s):  
Manuel G. Calvo ◽  
P. Avero ◽  
M. Dolores Castillo ◽  
Juan J. Miguel-Tobal

We examined the relative contribution of specific components of multidimensional anxiety to cognitive biases in the processing of threat-related information in three experiments. Attentional bias was assessed by the emotional Stroop word color-naming task, interpretative bias by an on-line inference processing task, and explicit memory bias by sensitivity (d') and response criterion (β) from word-recognition scores. Multiple regression analyses revealed, first, that phobic anxiety and evaluative anxiety predicted selective attention to physical- and ego-threat information, respectively; cognitive anxiety predicted selective attention to both types of threat. Second, phobic anxiety predicted inhibition of inferences related to physically threatening outcomes of ambiguous situations. And, third, evaluative anxiety predicted a response bias, rather than a genuine memory bias, in the reporting of presented and nonpresented ego-threat information. Other anxiety components, such as motor and physiological anxiety, or interpersonal and daily-routines anxiety made no specific contribution to any cognitive bias. Multidimensional anxiety measures are useful for detecting content-specificity effects in cognitive biases.


2004 ◽  
Author(s):  
B. J. Gumilevsky ◽  
V. N. Tzygan ◽  
O. P. Gumilevskaya
Keyword(s):  

2014 ◽  
Vol 9 (S 01) ◽  
Author(s):  
O D'Orlando ◽  
R Puff ◽  
A Henniger ◽  
S Krause ◽  
F Haupt ◽  
...  

2019 ◽  
Vol 322 (2) ◽  
pp. 27-31
Author(s):  
V.V. Fedyuk ◽  
◽  
E.I. Fedyuk ◽  
A.A. Tyutyunnikova ◽  
◽  
...  
Keyword(s):  

2020 ◽  
pp. 4-6

The present study was carried out in the Labs of collage of education for pure science, during period from January 2017 to endDecember of the same year. The immune status investigates for CLpatients by measuring the levels of cytokines (IL6and IL10) in sera using a technique enzyme-linked immune Sorbent adsorptive (ELISA). The study included 120 subjects with (60 CLpatientsL.majar and 60 CLpatients L. tropica with and (30) were healthy control. Increased mean Serum level of IL6 was in the observed in the total patients as compared to control Subjects (224.53pg/ml,70.70pg/ml), the result indicate there was significant difference at (p<0.05) ,such observation was consistent in the patient infected with L.majar and L. tropica (104 .90 pg/ml and 112.78 pg/ml) respectively. The results of the IL10 showed significant difference at (p<0.05)increased of mean Serum level in the total CL patients as compared to control Subjects(226.90 pg/ml 46.77pg/ml,).Ahighly significant difference at (p<0.05) increased observed in patients group infected with L.majar and followed by patients group infected L. tropica (112.78pg/ml and 114.12pg/ml) respectively.These results revealed that the excessive presence of cytokines might play a role in CL patients.


Sign in / Sign up

Export Citation Format

Share Document