Functional analysis of Scr during embryonic and post-embryonic development in the cockroach, Periplaneta americana

AbstractThe cockroach, Periplaneta americana represents a basal insect lineage that undergoes the ancestral hemimetabolous mode of development. Here, we examine the embryonic and post-embryonic functions of the hox gene Scr in Periplaneta as a way of better understanding the roles of this gene in the evolution of insect body plans. During embryogenesis, Scr function is strictly limited to the head with no role in the prothorax. This indicates that the ancestral embryonic function of Scr was likely restricted to the head, and that the posterior expansion of expression in the T1 legs may have preceded any apparent gain of function during evolution. In addition, Scr plays a pivotal role in the formation of the dorsal ridge, a structure that separates the head and thorax in all insects. This is evidenced by the presence of a supernumerary segment that occurs between the labial and T1 segments of RNAiScr first nymphs and is attributed to an alteration in engrailed (en) expression. The fact that similar Scr phenotypes are observed in Tribolium but not in Drosophila or Oncopeltus reveals the presence of lineage-specific variation in the genetic architecture that controls the formation of the dorsal ridge. In direct contrast to the embryonic roles, Scr has no function in the head region during post-embryogenesis in Periplaneta, and instead, strictly acts to provide identity to the T1 segment. Furthermore, the strongest Periplaneta RNAiScr phenotypes develop ectopic wing-like tissue that originates from the posterior region of the prothoracic segment. This finding provides a novel insight into the current debate on the morphological origin of insect wings

Short germ insects utilize both the ancestral and derived mode of Polycomb group-mediated epigenetic silencing of Hox genes

In insect species that undergo long germ segmentation, such as Drosophila, all segments are specified simultaneously at the early blastoderm stage. As embryogenesis progresses, the expression boundaries of Hox genes are established by repression of gap genes, which is subsequently replaced by Polycomb group (PcG) silencing. At present, however, it is not known whether patterning occurs this way in a more ancestral (short germ) mode of embryogenesis, where segments are added gradually during posterior elongation. In this study, two members of the PcG family, Enhancer of zeste (E(z)) and Suppressor of zeste 12 (Su(z)12), were analyzed in the short germ cricket, Gryllus bimaculatus. Results suggest that although stepwise negative regulation by gap and PcG genes is present in anterior members of the Hox cluster, it does not account for regulation of two posterior Hox genes, abdominal-A (abd-A) and Abdominal-B (Abd-B). Instead, abd-A and Abd-B are predominantly regulated by PcG genes, which is the mode present in vertebrates. These findings suggest that an intriguing transition of the PcG-mediated silencing of Hox genes may have occurred during animal evolution. The ancestral bilaterian state may have resembled the current vertebrate mode of regulation, where PcG-mediated silencing of Hox genes occurs before their expression is initiated and is responsible for the establishment of individual expression domains. Then, during insect evolution, the repression by transcription factors may have been acquired in anterior Hox genes of short germ insects, while PcG silencing was maintained in posterior Hox genes

Uticaj potapanja semena na parametre klijanja soje

The objective of this study was to examine the effect of primers on seed quality parameters using different starting values of germination. For this purpose, ten soybean lines selected at the Institute of Field and Vegetable Crops, Novi Sad were evaluated. The starting values of germination ranged between 48% and 89%. Seeds were surface sterilized with 3% sodium hypochlorite and immersed in different primers: 1% potassium nitrate, 1% potassium chloride and 1% hydrogen peroxide. Untreated seeds were used as the control. The obtained results revealed that the effects of priming depended on soybean line and treatment, whereas the efficiency of this pre-sowing treatment was not affected by the starting value of seed germination. Some lines responded favorably to immersion, while in others priming had an inhibitory effect, causing a significant decrease in germination. There was an increase in germination up to 12% or a decrease up to 11%, depending on line and treatment. Lines that were positively affected by this method also exhibited increased values for other germination parameters: mean germination time (MGT) and time to 50% germination (T50). Lower values of MGT and T50 were observed in lines which showed a negative response to priming and a decrease in germination, but also a more rapid radicle protrusion, as compared to the control. In conclusion, there is no universal applicability of one single primer as it might cause a negative response in some lines and thus reduce seed quality.Cilj ovog istraživanja bio je da se ispita efekat prajmera na parametre kvaliteta semena pri različitim početnim vrednostima klijavosti. Za istraživanje je korišćeno seme deset linija soje koje su selekcionisane na Institutu za ratarstvo i povrtarstvo u Novom Sadu. Početna vrednost klijavosti semena linija kretala se od 48% do 89%. Seme je površinski sterilisano 3% rastvorom natrijumhipohlorita, a onda je potapano u različite prajmere: kalijum-nitrat 1%, kalijumhlorid 1%, vodonik-peroksid 1% i kontrola - netretirano seme. Rezultati su pokazali da efekat prajmiranja zavisi od linije i tretmana, a da početna vrednost klijavosti semena ne utiče na efikasnost ove predsetvene mere. Neke linije su veoma dobro reagovale na potapanje, dok je kod drugih došlo do inhibitornog delovanja, pa se vrednost klijavosti značajno smanjila. Povećanje klijavosti se kretalo, u zavisnosti od linija i tretmana, do 12%, a smanjenje do 11%. Kod linija gde je primenom ove mere ostvaren pozitivan efekat, povećane su vrednosti i ostalih parametara klijanja: srednje vreme klijanja (MGT) i vreme do 50% klijavosti (T50). Linije koje su negativno reagovale na prajmiranje i kod kojih je klijavost smanjena imale su niže vrednosti MGT i T50, ali i bržu pojavu klicinog korenčića u odnosu na kontrolnu varijantu. Dobijeni rezultati ukazuju na to da se ne može govoriti o univerzalnoj primeni jednog prajmera, jer se može dogoditi da on ne odgovara određenoj liniji, pa može doći do pogoršanja kvaliteta semena.

Uticaj potapanja semena soje na energiju klijanja

Six varieties were chosen from three different maturity groups: Galina and NS Princeza (0), Sava and NS Apolo (I), and Rubin and NS Zita (II) in order to examine the effect of priming on germination energy depending on soybean seed age. The seeds were produced in the period from 2012 to 2014, i.e., one- to three-year-old seeds were used. The following treatments were used for priming: distilled water - hydropriming (H2O), ascorbic acid 250 mg/l (ASA), folic acid 15 mg/l (Fol.), hydrogen peroxide 1% (H2O2), and control - non-treated seeds (C). Results showed that the effects of priming depended on the variety, seed age, as well as on the applied treatment. Some varieties reacted to priming very well, while others had an inhibited reaction, so germination energy was significantly reduced. Rubin variety had the most favourable reaction, whereby all treatments of this variety led to an increase of quality, with an average increase of 2-8%. The application of primers on one-year-old soybean seeds had a weaker effect than on two- and three -year-old seeds. However, one-year-old seeds had minor oscillations in quality due to priming. The application of priming on one-year-old seeds can lead to an increase or decrease of germination energy by 3%, while two- and three-year-old seeds reached 7%. The results showed that seed priming in ascorbic acid had a positive effect, while the application of other primers did not affect the value of germination energy, nor did it lead to a decrease of its value. Ascorbic acid activity led to the largest increase in the quality of three-year-old soybean seeds by 2.83%, while the increase in the quality of two- and three-year-old seeds was 1.87%. Therefore, we can conclude that there is no universal use of one single primer, as it might not be suitable for each particular variety and can ultimately result in the seed quality decrease.Da bi se ispitao efekat potapanja na energiju klijanja starog semena soje, za analizu je odabrano šest sorti iz tri različite grupe zrenja: Galina i NS Princeza (0 grupa), Sava i NS Apolo (I grupa), Rubin i NS Zita (II grupa zrenja). Seme je proizvedeno u periodu od 2012. do 2014. godine, odnosno seme starosti tri, dve i jednu godinu. Za potapanje su korišćeni sledeći tretmani: destilovana voda (H2O), askorbinska kiselina 250 mg/l (ASA), folna kiselina 15 mg/l (Fol.), vodonik-peroksid 1% (H2O2) i kontrola - netretirano seme (C). Rezultati su pokazali da efekat potapanja zavisi od sorte, starosti semena, ali i tretmana koji se koristi. Neke sorte veoma dobro reaguju na potapanje, dok kod drugih dolazi do inhibitornog delovanja, pa se energija klijanja semena značajno smanjuje. Sorta Rubin je najbolje reagovala i jedino su kod ove sorte svi tretmani doveli do povećanja kvaliteta, u proseku od 2% do 8%. Primena prajmera kod jednogodišnjeg semena soje ostvarila je slabiji efekat nego kod dvogodišnjeg i trogodišnjeg semena. Međutim, kod jednogodišnjeg semena manje su oscilacije u kvalitetu usled potapanja. Kod jednogodišnjeg semena dejstvom prajmera energija klijanja može da se poveća odnosno smanji za 3%, dok se kod dvogodišnjeg i trogodišnjeg ta vrednost kreće do 7%. Rezultati pokazuju da je potapanje semena u askorbinsku kiselinu ostvarilo pozitivan efekat, dok primena ostalih prajmera nije uticala na vrednost energije klijanja ili je dovela do pada njene vrednosti. U proseku, dejstvom askorbinske kiseline najviše je došlo do povećanja kvaliteta trogodišnjeg semena soje - 2,83%, dok je povećanje dvogodišnjeg i trogodišnjeg bilo isto i iznosilo je 1.87%. Zbog toga se ne može govoriti o univerzalnoj primeni samo jednog prajmera, jer se može dogoditi da on ne odgovara određenoj sorti, ali i starosti semena, pa može doći do pada kvaliteta semena

The effect of foliar fertilization on yield and 1000 seed weight of soybean

U cilju sagledavanja uticaja folijarne prihrane na prinos i masu 1000 zrna soje, postavljen je dvogodišnji ogled na parcelama Instituta za ratarstvo i povrtarstvo na Rimskim Šančevima. Prihrana soje NPK đubrivima uz dodatak mikroelemenata statistički veoma značajno povećava prinos zrna i masu 1000 zrna soje. Najniži prinosi i najmanja vrednost za masu 1000 zrna soje bili su na kontrolnoj varijanti, što je statistički veoma značajno manje u odnosu na ostale varijante folijarne prihrane soje.In order to examine the effect of foliar fertilization on yield and 1000 seed weight of soybean, a two year trial was set at Institute of field and vegetable crops on Rimski Šančevi. A foliar fertilization of soybean with NPK fertilizer with added micronutrients significantly increases yield and 1000 seed weight of soybean. The lowest yields and the lowest 1000 seed weight of soybean were on the control variant, which is significantly lower in comparison to other variants of foliar fertilization of soybean

Effect of priming on soybean seed germination parameters

The objective of this study was to examine the effect of primers on seed quality parameters using different starting values of germination. For this purpose, ten soybean lines selected at the Institute of Field and Vegetable Crops, Novi Sad were evaluated. The starting values of germination ranged between 48% and 89%. Seeds were surface sterilized with 3% sodium hypochlorite and immersed in different primers: 1% potassium nitrate, 1% potassium chloride and 1% hydrogen peroxide. Untreated seeds were used as the control. The obtained results revealed that the effects of priming depended on soybean line and treatment, whereas the efficiency of this pre-sowing treatment was not affected by the starting value of seed germination. Some lines responded favorably to immersion, while in others priming had an inhibitory effect, causing a significant decrease in germination. There was an increase in germination up to 12% or a decrease up to 11%, depending on line and treatment. Lines that were positively affected by this method also exhibited increased values for other germination parameters: mean germination time (MGT) and time to 50% germination (T50). Lower values of MGT and T50 were observed in lines which showed a negative response to priming and a decrease in germination, but also a more rapid radicle protrusion, as compared to the control. In conclusion, there is no universal applicability of one single primer as it might cause a negative response in some lines and thus reduce seed quality

Altered cytokine expression in Helicobacter pylori infected patients with bleeding duodenal ulcer

Objective Peptic ulcer disease is a condition in which an important role has infection with H. pylori. The most common complication of peptic ulcer is bleeding. The presence of H. pylori triggers local and systemic cytokine signaling which may affect processes such as healing, gastric or duodenal rupture, and carcinogenesis. In this study, we examined the concentrations of IL-1β, IL-6, IL-10, TNF, TGF-β and IL-17A in serum by enzyme immunoassay and their mRNA expressions in periulcer biopsies obtained from patients with bleeding peptic ulcer by means of real-time-PCR. Results We have shown that pro-inflammatory IL-6 and TNF concentrations in serum were significantly higher in patients who were infected with H. pylori, while the concentrations of TGF-β and IL-17A were significantly lower compared to non-infected subjects. IL-17A expression in periulcer mucosa was significantly higher in patients who were infected with H. pylori, while the expression of other cytokines, there was no significant difference compared to non-infected controls. Considering higher serum concentrations in non-infected subjects and higher IL-17A expression in mucosal tissue of infected patients, our data support the studies that found IL-17A has protective role in eradication of H. pylori infection in infected patients

Ubx Regulates Differential Enlargement and Diversification of Insect Hind Legs

Differential enlargement of hind (T3) legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s) responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug) and Acheta domesticus (house cricket). In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx) is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs

Pogostick: A New Versatile piggyBac Vector for Inducible Gene Over-Expression and Down-Regulation in Emerging Model Systems

Non-traditional model systems need new tools that will enable them to enter the field of functional genetics. These tools should enable the exploration of gene function, via knock-downs of endogenous genes, as well as over-expression and ectopic expression of transgenes.We constructed a new vector called Pogostick that can be used to over-express or down-regulate genes in organisms amenable to germ line transformation by the piggyBac transposable element. Pogostick can be found at www.addgene.org, a non-profit plasmid repository. The vector currently uses the heat-shock promoter Hsp70 from Drosophila to drive transgene expression and, as such, will have immediate applicability to organisms that can correctly interpret this promotor sequence. We detail how to clone candidate genes into this vector and test its functionality in Drosophila by targeting a gene coding for the fluorescent protein DsRed. By cloning a single DsRed copy into the vector, and generating transgenic lines, we show that DsRed mRNA and protein levels are elevated following heat-shock. When cloning a second copy of DsRed in reverse orientation into a flanking site, and transforming flies constitutively expressing DsRed in the eyes, we show that endogenous mRNA and protein levels drop following heat-shock. We then test the over-expression vector, containing the complete cDNA of Ultrabithorax (Ubx) gene, in an emerging model system, Bicyclus anynana. We produce a transgenic line and show that levels of Ubx mRNA expression rise significantly following a heat-shock. Finally, we show how to obtain genomic sequence adjacent to the Pogostick insertion site and to estimate transgene copy number in genomes of transformed individuals.This new vector will allow emerging model systems to enter the field of functional genetics with few hurdles