Evolution of ageing in laboratory populations of Acanthoscelides obtectus: role of mitochondria and oxidative stress

Biološki fakultetKljučna pretpostavka evolucione teorije starenja jeste da opadanje uzrasno-specifičnog preživljavanja organizama predstavlja rezultat smanjenja intenziteta prirodne selekcije nakon početka reprodukcije. U osnovi evolucije starenja nalaze se dva populaciono-genetička mehanizma: akumulacija mutacija (AM) i antagonistička plejotropija (AP). U skladu sa pretpostavkama evolucione teorije starenja, kod eksperimentalnih populacija pasuljevog žiška (Acanthoscelides obtectus) selektovanih više od 170 generacija za ranu (E režim) ili kasnu (L režim) reprodukciju, uočena je divergencija u dužini života i drugim preadultnim i adultnim osobinama životne istorije. Evolucija veće dužine života u L režimu u saglasnosti je sa pretpostavkama AP modela, dok u evoluciji kraćeg života E žižaka važnu ulogu ima akumulacija mutacija. Tretiranjem E i L žižaka pesticidima (parakvat i tebufenpirad) koji generišu slobodne radikale, potvrđena je pozitivna korelacija između dužine života i otpornosti na oksidativni stres. Budući da mitohondrija predstavlja glavno mesto sinteze energije i slobodnih radikala, u ovoj tezi je istraženo da li je uzrasno-specifična selekcija oblikovala varijabilnost mtDNK, nDNK i njihovih epistatičkih interakcija. Genotipizacijom mitohondrijskog COI gena i mikrosatelitskih lokusa pokazana je efikasnost uzrasno-specifične selekcije u međupopulacionoj divergenciji mitohondrijskog i jedarnog genskog pula kod pasuljevog žiška. Odvijanje procesa mito-jedarne koevolucije analizirano je korišćenjem mito-jedarnih linija u kojima su E i L mitohondrijski genomi kombinovani sa E i L jedarnim genomima. Pokazano je da su linije sa narušenim mito-jedarnim interakcijama imale niže aktivnosti mitohondrijskih kompleksa elektron transportnog lanca i lošiju preadultnu performansu.According to the evolutionary theory of ageing, age-specific decline in survival is the result of decreasing intensity of natural selection after the onset of reproduction. The evolution of ageing may be explained by two different, but not mutually exclusive, genetic mechanisms: antagonistic pleiotropy (AP) and mutation accumulation (MA). In accordance with evolutionary theory of ageing, two sets of the seed beetle (Acanthoscelides obtectus) experimental lines selected for more than 170 generations for early (E regime) or late (L regime) reproduction, show divergence in longevity and ageing patterns, as well as in other preadult and adult life history traits. Evolution of long life in L regime is predominantly based on antagonistic pleiotropy gene effects, while mutation accumulation plays important role in evolution of short life in E regime. By exposure of E and L beetles to two pesticides (paraquat and tebufenpyrad) that generate free radicals, it was confirmed that extended longevity in L beetles (especially in females) was associated with higher oxidative stress resistance. Additionally, since mitochondria are main site of free radical and energy production, effects of age-specific laboratory selection on mtDNA, nDNA and their epistatic interaction were assessed. Genotyping of mitochondrial COI gene and nuclear microsatellite loci showed that selection in E and L regimes led to divergent evolution of mtDNA and nDNA gene pools. Mitonuclear coevolution was investigated using mitonuclear introgression lines in which E and L mitochondrial genomes were expressed in both E and L nuclear background. It was found that lines with disrupted mitonuclear interactions had lower activity of the mitochondrial electron transport chain complexes and lower preadult performance

Evolution of ageing in laboratory populations of Acanthoscelides obtectus: role of mitochondria and oxidative stress

Biološki fakultetKljučna pretpostavka evolucione teorije starenja jeste da opadanje uzrasno-specifičnog preživljavanja organizama predstavlja rezultat smanjenja intenziteta prirodne selekcije nakon početka reprodukcije. U osnovi evolucije starenja nalaze se dva populaciono-genetička mehanizma: akumulacija mutacija (AM) i antagonistička plejotropija (AP). U skladu sa pretpostavkama evolucione teorije starenja, kod eksperimentalnih populacija pasuljevog žiška (Acanthoscelides obtectus) selektovanih više od 170 generacija za ranu (E režim) ili kasnu (L režim) reprodukciju, uočena je divergencija u dužini života i drugim preadultnim i adultnim osobinama životne istorije. Evolucija veće dužine života u L režimu u saglasnosti je sa pretpostavkama AP modela, dok u evoluciji kraćeg života E žižaka važnu ulogu ima akumulacija mutacija. Tretiranjem E i L žižaka pesticidima (parakvat i tebufenpirad) koji generišu slobodne radikale, potvrđena je pozitivna korelacija između dužine života i otpornosti na oksidativni stres. Budući da mitohondrija predstavlja glavno mesto sinteze energije i slobodnih radikala, u ovoj tezi je istraženo da li je uzrasno-specifična selekcija oblikovala varijabilnost mtDNK, nDNK i njihovih epistatičkih interakcija. Genotipizacijom mitohondrijskog COI gena i mikrosatelitskih lokusa pokazana je efikasnost uzrasno-specifične selekcije u međupopulacionoj divergenciji mitohondrijskog i jedarnog genskog pula kod pasuljevog žiška. Odvijanje procesa mito-jedarne koevolucije analizirano je korišćenjem mito-jedarnih linija u kojima su E i L mitohondrijski genomi kombinovani sa E i L jedarnim genomima. Pokazano je da su linije sa narušenim mito-jedarnim interakcijama imale niže aktivnosti mitohondrijskih kompleksa elektron transportnog lanca i lošiju preadultnu performansu.According to the evolutionary theory of ageing, age-specific decline in survival is the result of decreasing intensity of natural selection after the onset of reproduction. The evolution of ageing may be explained by two different, but not mutually exclusive, genetic mechanisms: antagonistic pleiotropy (AP) and mutation accumulation (MA). In accordance with evolutionary theory of ageing, two sets of the seed beetle (Acanthoscelides obtectus) experimental lines selected for more than 170 generations for early (E regime) or late (L regime) reproduction, show divergence in longevity and ageing patterns, as well as in other preadult and adult life history traits. Evolution of long life in L regime is predominantly based on antagonistic pleiotropy gene effects, while mutation accumulation plays important role in evolution of short life in E regime. By exposure of E and L beetles to two pesticides (paraquat and tebufenpyrad) that generate free radicals, it was confirmed that extended longevity in L beetles (especially in females) was associated with higher oxidative stress resistance. Additionally, since mitochondria are main site of free radical and energy production, effects of age-specific laboratory selection on mtDNA, nDNA and their epistatic interaction were assessed. Genotyping of mitochondrial COI gene and nuclear microsatellite loci showed that selection in E and L regimes led to divergent evolution of mtDNA and nDNA gene pools. Mitonuclear coevolution was investigated using mitonuclear introgression lines in which E and L mitochondrial genomes were expressed in both E and L nuclear background. It was found that lines with disrupted mitonuclear interactions had lower activity of the mitochondrial electron transport chain complexes and lower preadult performance

Evolution in laboratory populations of Acanthoscelides obtectus: role of mitochondria and oxidative stress

Ključna pretpostavka evolucione teorije starenja jeste da opadanje uzrasno-specifičnog preživljavanja organizama predstavlja rezultat smanjenja intenziteta prirodne selekcije nakon početka reprodukcije. U osnovi evolucije starenja nalaze se dva populaciono-genetička mehanizma: akumulacija mutacija (AM) i antagonistička plejotropija (AP). U skladu sa pretpostavkama evolucione teorije starenja, kod eksperimentalnih populacija pasuljevog žiška (Acanthoscelides obtectus) selektovanih više od 170 generacija za ranu (E režim) ili kasnu (L režim) reprodukciju, uočena je divergencija u dužini života i drugim preadultnim i adultnim osobinama životne istorije. Evolucija veće dužine života u L režimu u saglasnosti je sa pretpostavkama AP modela, dok u evoluciji kraćeg života E žižaka važnu ulogu ima akumulacija mutacija. Tretiranjem E i L žižaka pesticidima (parakvat i tebufenpirad) koji generišu slobodne radikale, potvrđena je pozitivna korelacija između dužine života i otpornosti na oksidativni stres. Budući da mitohondrija predstavlja glavno mesto sinteze energije i slobodnih radikala, u ovoj tezi je istraženo da li je uzrasno-specifična selekcija oblikovala varijabilnost mtDNK, nDNK i njihovih epistatičkih interakcija. Genotipizacijom mitohondrijskog COI gena i mikrosatelitskih lokusa pokazana je efikasnost uzrasno-specifične selekcije u međupopulacionoj divergenciji mitohondrijskog i jedarnog genskog pula kod pasuljevog žiška. Odvijanje procesa mito-jedarne koevolucije analizirano je korišćenjem mito-jedarnih linija u kojima su E i L mitohondrijski genomi kombinovani sa E i L jedarnim genomima. Pokazano je da su linije sa narušenim mito-jedarnim interakcijama imale niže aktivnosti mitohondrijskih kompleksa elektron transportnog lanca i lošiju preadultnu performansu.According to the evolutionary theory of ageing, age-specific decline in survival is the result of decreasing intensity of natural selection after the onset of reproduction. The evolution of ageing may be explained by two different, but not mutually exclusive, genetic mechanisms: antagonistic pleiotropy (AP) and mutation accumulation (MA). In accordance with evolutionary theory of ageing, two sets of the seed beetle (Acanthoscelides obtectus) experimental lines selected for more than 170 generations for early (E regime) or late (L regime) reproduction, show divergence in longevity and ageing patterns, as well as in other preadult and adult life history traits. Evolution of long life in L regime is predominantly based on antagonistic pleiotropy gene effects, while mutation accumulation plays important role in evolution of short life in E regime. By exposure of E and L beetles to two pesticides (paraquat and tebufenpyrad) that generate free radicals, it was confirmed that extended longevity in L beetles (especially in females) was associated with higher oxidative stress resistance. Additionally, since mitochondria are main site of free radical and energy production, effects of age-specific laboratory selection on mtDNA, nDNA and their epistatic interaction were assessed. Genotyping of mitochondrial COI gene and nuclear microsatellite loci showed that selection in E and L regimes led to divergent evolution of mtDNA and nDNA gene pools. Mitonuclear coevolution was investigated using mitonuclear introgression lines in which E and L mitochondrial genomes were expressed in both E and L nuclear background. It was found that lines with disrupted mitonuclear interactions had lower activity of the mitochondrial electron transport chain complexes and lower preadult performance

Analiza naponsko-deformacionog stanja vratila pogonskog bubnja

The paper presents an analysis ofthe stress deformation state o f shafts o f characteristic drive pulleys on belt conveyors in Drmno open pit mine. The shape and dimensions o f the shafts were defined based on the original technical documentation, and the stress state was verified by applying the finite difference method in the Catia software package. Loads were simulated for real working conditions in exploitation. The analysis results showed that shafts with cone between locking device and bearing have the best load distribution and that T-shaped end disks most favourably transfer loads to the shaft. The analyses also showed that the values o f stresses formed in shafts at the failure site are not high enough to lead to shaft failure due to overload and that failure cause should be sought in fatigue, then in plastic deformation, residual stresses after shaft repair and pulley weight unbalance.Publishe

Host-associated divergence in the activity of digestive enzymes in two populations of the gypsy moth Lymantria dispar (Lepidoptera: Erebidae)

The gypsy moth is a generalist insect pest with an extremely wide host range. Adaptive responses of digestive enzymes are important for the successful utilization of plant hosts that differ in the contents and ratios of constituent nutrients and allelochemicals. In the present study, we examined the responses of α-amylase, trypsin, and leucine aminopeptidase to two tree hosts (suitable oak, Quercus cerris, and unsuitable locust tree, Robinia pseudoacacia) in the fourth, fifth, and sixth instars of gypsy moth larvae originating from oak and locust tree forest populations (hereafter assigned as Quercus and Robinia populations, respectively). Gypsy moths from the Robinia forest had been adapting to this unsuitable host for more than 40 generations. To test for population-level host plant specialization, we applied a two-population × two-host experimental design. We compared the levels, developmental patterns, and plasticities of the activities of enzymes. The locust tree diet increased enzyme activity in the fourth instar and reduced activity in advanced instars of the Quercus larvae in comparison to the oak diet. These larvae also exhibited opposite developmental trajectories on the two hosts, i.e. activity increased on the oak diet and decreased on the locust tree diet with the progress of instar. Larvae of the Robinia population were characterized by reduced plasticity of enzyme activity and its developmental trajectories. In addition, elevated trypsin activity in response to an unsuitable host was observed in all instar larvae of the Robinia population, which demonstrated that Robinia larvae had an improved digestive performance than did Quercus larvae

TRUCK SUPPORTIVE CHASSIS STRUCTURAL STATIC ANALYSIS

The vehicle chassis is a very important part of a vehicle system. During the vehicle projecting a lot of attention is devoted to the vehicle chassis, because it is exposed to strong statics and dynamics loads. In early projecting phases it is possible to get reliable information about the chassis material, dimensions and projecting solutions by static analysis. This paper presents a truck's supportive chassis structural static analysis of Mercedes Benz Ascot 2 truck. The paper also shows the comparison of static structural analysis and results of analytical calculation. The paper concludes with a discussion and guidelines for further work.Publishe

Influence of type and quantity of filler on change of density of sulfur concrete

Concrete is a material that has been used for centuries and is often modified using polymers. In the last fifty years, synthetic polymers have been used for the modification of concrete, but also for the production of concrete. In recent decades, sulfur concrete has been an interesting product that can be used mainly in low-rise construction due to its characteristics. In this work, we used the starting mixture for the preparation of sulfur concrete (sand, elemental sulfur with the addition of modified sulfur and fillers) heated to a temperature of 120 ºC to 170 ºC and homogenized. The results of previous research on the production of sulfur concrete showed that the density of the obtained product changes depending on the type as well as the amount of filler added to the basic mixture based on raw materials. Talc, microsilicon, plate alumina and fly ash were used as fillers. The amounts of fillers were 0%, 1%, 3%, 5%, 7% and 10%

Transformations of mechanochemical activated Na2CO3

During mechanical activation, energy of treated material is increase to a higher level. This can lead to chemical transformation of the activated material. This is the point where we can talk about mechanochemical transformations that have occurred as a result of mechanical activation. The subject of this paper is to monitor mass changes of material after different degrees of activation. One of the substances which is often used in the processes of mechanochemical synthesis is sodium carbonate. The mass changes occurring during the treatment were detected and measured by various methods, depending on the processing environment. The mass increase was attributed to chemisorption of moisture and carbon-dioxide present in air, as a consequence of the sodium carbonate activation. The methods we used were calcimetric chemical analysis. According to obtained results, it was found that activated sodium carbonate is mass-transformed into sodium bicarbonate, whereby these changes are functionally dependent on activation time and the processing atmosphere