Mid Gut Research Articles

Compartmentalized microbial composition, oxygen gradients and nitrogen fixation in the gut ofOdontotaenius disjunctus

Coarse woody debris is an important biomass pool in forest ecosystems that numerous groups of insects have evolved to take advantage of. These insects are ecologically important and represent useful natural analogs for biomass to biofuel conversion. Using a range of molecular approaches combined with microelectrode measurements of oxygen, we have characterized the gut microbiome and physiology of Odontotaenius disjunctus, a wood-feeding beetle native to the eastern United States. We hypothesized that morphological and physiological differences among gut regions would correspond to distinct microbial populations and activities. In fact, significantly different communities were found in the foregut (FG), midgut (MG)/posterior hindgut (PHG) and anterior hindgut (AHG), with Actinobacteria and Rhizobiales being more abundant toward the FG and PHG. Conversely, fermentative bacteria such as Bacteroidetes and Clostridia were more abundant in the AHG, and also the sole region where methanogenic Archaea were detected. Although each gut region possessed an anaerobic core, micron-scale profiling identified radial gradients in oxygen concentration in all regions. Nitrogen fixation was confirmed by (15)N2 incorporation, and nitrogenase gene (nifH) expression was greatest in the AHG. Phylogenetic analysis of nifH identified the most abundant transcript as related to Ni-Fe nitrogenase of a Bacteroidetes species, Paludibacter propionicigenes. Overall, we demonstrate not only a compartmentalized microbiome in this beetle digestive tract but also sharp oxygen gradients that may permit aerobic and anaerobic metabolism to occur within the same regions in close proximity. We provide evidence for the microbial fixation of N2 that is important for this beetle to subsist on woody biomass.

Honey Bee tissues as a biomarker for Environmental pollution with heavy metals.

The purpose of this study is to verify the importance of the body surface and tissues of foraginghoney bee Apis mellifera as bioaccumulator of heavy metals that can therefore, be included inbiomonitoring programmes of heavy metals in terrestrial ecosystems. The presence of fiverepresentative heavy metals (copper, zinc, cadmium, lead and iron) was investigated in honeybee tissues (mid gut, hind gut and fat body), body surface and wings using proton induced X-rayemission method. X-ray spectrums of mid gut and fat body of forager bees demonstrated smallpeaks for Cd, Pb, Fe and Ni compared to the control. Moreover, slightly larger peaks for Cu andZn were noticed in the X-ray spectrums of whole honey bee mid gut, hind gut and fat body thanthose of the control. Forager honey bee body surface showed small peaks for Cu and Pbcompared to the control. Similarly, small peaks for Cd, Pb and Ni were noticed in the X-rayspectrums of wings and hind gut of the forager honey bee compared to control.

Antiviral Immunity in the Red Swamp Crayfish , Procambarus Clarkii : Hemocyte Production , Proliferation and Apoptosis

In the present study, the pathogenic mechanism of white spot syndrome (WSSV) in crayfish, Procambarus clarkii by investigating activities of immune cells related to innate immune function during infection was explored. White spot disease caused by WSSV leads to devastating losses in crayfish farming. Examination by transmission electron microscopy revealed abundant WSSV particles and significant changes in the different lymphoid organs of infected crayfish. WSSV infection caused parts of the gill epithelium and microvilli to be reduced in number and size or damaged, meanwhile, the mitochondria, morphology changed, with parts of the cristae diminished leaving large vacuoles. Moreover, electron dense deposits appeared and hetero-chromatinized nuclei could be seen in blood cells with ruptured nuclear membranes and outflow of nucleoplasm. Also, evident were very densely basophilic inclusions were found in interstitial hepato-pancreatic tissue, connective tissue underlying the mid gut, cardiac tissue, gill tissue and hematopoietic tissue. Transmission electron microscopy revealed the presence of previously undescribed rod-shaped, enveloped versions in the cytoplasm adjacent to the nuclei of cells from various tissues.

Effect of aqueous macerates of seed powder of Syzigium cumini (l) on the protein contents and mid gut enzyme activities in the fifth instar larvae of silk worm, bombyx mori (l) (race: pm x csr2)

Different concentrations (5.0 ppm; 10.0 ppm; 20.0 ppm & 50.0 ppm) of the aqueous solution of seed powder of Syzigium cumini (L) concentrations was used to treat the leaves of mulberry & fed to the fifth instar larvae of polyvoltine, crossbreed silkworm, Bombyx mori (L) (Race : PM x CSR2 ) for first three days; second day & third day; third day (only). The larvae fed with untreated & water treated leaves were also maintained. Bioassays of proteins (S.P. & T.P.) & enzymes (protease & amylase) were carried out on fifth day through the use of mid gut homogenate. Treating the mulberry leaves with herbal preparations ( Syzigium cumini ) & feeding them to fifth instar larvae was found reflected into significant improvement in the levels of proteins (S.P. & T.P.) & velocities of biochemical reactions catalyzed by protease & amylase. The pattern of increase in soluble proteins & total proteins in the mid gut tissue were 32.147 to 90.074 percent & 5.657 to 39.052 percent respectively. The activities of mid gut protease & amylase were increased by 21.444 to 83.706 percent and 14.54 to 52.257 percent respectively. The nutrient contents of seed powder of Syzigium cumini (L) serve to improve the digestibility & exert the influence of efficient metabolism in the fifth instar larvae of silkworm, Bombyx mori (L). The Syzigium seed powder treatment may gear overall biochemical constituency of silkworm larvae, through the significant improvement in the velocity of mid gut enzyme catalyzed biochemical reactions.

Anatomical structure of the digestive tract of <I>Holotrichia oblita</I> Fald. (Coleoptera: Melolonthidae)

The paper aimed to explore the anatomical structure of digestive tract of female and male adults of Holotrichia oblita Fald.through optical microscopy and scanning electron microscope(SEM).The results showed that the foregut of digestive tract consists of mouth,pharynx,oesophagus,crop and proventriculus.The crop was well developed and cylinder shaped with its inner surface showing ruffling structure.The proventriculus had hair-like structure on the inner membrane.The mid gut was long with rich microvilli and spherical micro-protrusions on the inner surface,besides,small amount of goblet cells also distributed on the inner surface.The hindgut includes ileum,colon and rectum.The rectum had well developed rectal pads.No difference was found in characteristics of digestive tract between the male and the female adults.The results provide evidence that the structure features of digestive tract of Holotrichia oblita Fald.are adapted to its digestion,feeding behavior and inhabiting habit.

Maize toxin degrades peritrophic matrix proteins and stimulates compensatory transcriptome responses in fall armyworm midgut

Understanding the molecular mechanisms underlying insect compensatory responses to plant defenses could lead to improved plant resistance to herbivores. The Mp708 inbred line of maize produces the maize insect resistant 1-cysteine protease (Mir1-CP) toxin. Reduced feeding and growth of fall armyworm larvae fed on Mp708 was previously linked to impairment of nutrient utilization and degradation of the midgut (MG) peritrophic matrix (PM) by Mir1-CP. Here we examine the biochemical and transcriptional responses of fall armyworm larvae to Mir1-CP. Insect Intestinal Mucin (IIM) was severely depleted from pure PMs treated in vitro with recombinant Mir1-CP. Larvae fed on Mp708 midwhorls excrete frass largely depleted of IIM. Cracks, fissures and increased porosity previously observed in the PM of larvae fed on Mp708 midwhorls could ensue when Mir1-CP degrades the IIM that cross-links chitin fibrils in the PM. Both targeted and global transcriptome analyses were performed to determine how complete dissolution of the structure and function of the PM is prevented, enabling larvae to continue growing in the presence of Mir1-CP. The MGs from fall armyworm fed on Mp708 upregulate expression of genes encoding proteins involved in PM production as an apparent compensation to replace the disrupted PM structure and restore appropriate counter-current MG gradients. Also, several families of digestive enzymes (endopeptidases, aminopeptidases, lipases, amylase) were more highly expressed in MGs from larvae fed on Mp708 than MGs from larvae fed on diets lacking Mir1-CP (artificial diet, midwhorls from Tx601 or B73 maize). Impaired growth of larvae fed on Mp708 probably results from metabolic costs associated with higher production of PM constituents and digestive enzymes in a compensatory attempt to maintain MG function.

Electrophoretic Patterns of Esterases in Eri silkworm Samia Cynthia ricini

The present study was carried out to investigate the patterns of esterase isozymes extracted from the silk gland, haemolymph and mid gut of Eri silkworm (Samia Cynthia ricini). The qualitative analysis of esterases was carried out by 7.5% of native Polyacrylamide Gel Electrophoresis (PAGE). The inhibitor sensitivity of the enzymes towards paraxon, eserine and pCMB was used to classify the individual zones of esterases. Three zones of esterases were observed in different tissues of Eri silkworm. Silk gland esterases were classified as CHsp (Cholinesterase like enzymes) esterases. The haemolymph and mid gut esterases were classified into Esdp (Enzyme inhibited by paraxon and pCMB).

Effect of insect growth regulators combined with nucleopolyhedrovirus on certain biological and histological aspects of Spodopera littoralis

Five insect growth regulators (IGR's) were tested for increasing the susceptibility of the cotton leaf worm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) to its homologous nucleopolyhedrovirus (SpliMNPV). S. littoralis MNPV was tested alone or in combination with IGR's at LC10 level against the 2nd instar larvae of the pest. An increased viral infection rate was detected in the mixture treatment in the case of using Chlorfluazuron, Flufenoxuron, Triflumuron, Hexaflumuron or Teflubenzuron at 10%. The LC50 value of the virus alone treatment 1x107 PIB's was reduced to 4.3x106, 9.9x104, 4.9x104, 3.1x105 and 1.69x106 PIB's, with the tested five IGR's, respectively. It was observed that Flufenoxuron and Triflumuron mixtures slightly prolongated larval duration compared either untreated control or IGR's alone treatments. The highest rate of decrease in the pupation percentage (47%) was recorded in case of Triflumuron mixed with SpliMNPV followed by Flufenoxuron and Chlrofluazuron mixes. On the other hand there is no significance difference in pupal weight for all treatments. Changes Adult longevity was increased for all treatments compared to untreated control. Addition Flufenxuron (LC10) to SpliMNPV (LC50) showed histopathological effects to mid gut e.g. loss of the compact appearance of the muscularis layer, vaculation and exfoliation of the columnar cells.

Chylous ascites: Why exercise is bad for you

INTRODUCTIONThe development of chylous ascites is usually associated with trauma, iatrogenic or otherwise. Blunt abdominal trauma producing hyperextension or hyperflexion may cause disruption to lymphatic vessels causing chylous ascites. PRESENTATION OF CASEThis report describes the case of a 38-year-old gentleman who presented to the emergency department with severe abdominal pain after completing a triathlon. As the patient was in severe pain, an abdominal CT was performed which demonstrated a possible mid gut volvulus. Subsequent laparotomy noted a significant volume of intra-abdominal chyle with no other abnormalities. DISCUSSIONThis is the first report of chylous ascites occurring without associated abdominal pathology after a period of strenuous exercise. CONCLUSIONChylous ascites can occur as a result of hyperreflexion and hyperextension injuries sustained during strenuous exercise.

When a turbot catches a fly: Evaluation of a pre-pupae meal of the Black Soldier Fly (Hermetia illucens) as fish meal substitute — Growth performance and chitin degradation in juvenile turbot (Psetta maxima)

Larvae of black soldier flies (Hermetia illucens) are commercially produced on agricultural waste streams and convert these into animal body protein and fat. A feeding trial was carried out for 56days in a recirculating aquaculture system (RAS) by replacing fish meal protein subsequently by Hermetia meal (HM) protein. Six diets were formulated for the replacement and contained 0%, 17%, 33%, 49%, 64%, and 76% of HM (54.1±1.1% crude protein, 13.4±0.7% crude lipid, dry matter basis). The diets were fed to triplicate groups of turbot 54.9±0.9g once a day by hand until apparent satiation. Feed intake was affected by dietary HM inclusion and decreased with increasing HM incorporation due to low palatability. Growth performance was high, but affected by dietary HM inclusion. SGR was lower in all treatments containing HM whereas FCR was significantly higher at HM inclusion levels>33%. Protein retention was highest at HM inclusion≤33% and decreased significantly with increasing HM supplementation. Whole-body protein content was not affected by treatment, while body lipid decreased with increasing HM inclusion levels. The apparent digestibility coefficients (ADC) of HM were low for organic matter, crude protein, crude lipid, and gross energy. Chitinase activity or chitinolytic active bacteria were not detected in the mid gut of turbot. The presence of chitin might have influenced the feed intake, availability, and digestibility of the nutrients and therefore growth performance. In general, our study shows that the incorporation of HM protein in fish diets is possible, but limited by its low nutritive value. Considering that HM is produced on local greenhouse waste streams, HM might be a feasible alternative protein source for the partial replacement of fish meal. Further research on HM meal processing to increase nutrient utilization is needed.

Nutritional evaluation of rapeseed protein isolate as fish meal substitute for juvenile turbot (Psetta maxima L.) — Impact on growth performance, body composition, nutrient digestibility and blood physiology

The potential of a highly concentrated rapeseed protein isolate (RPI) as partial or total fish meal (FM) alternative in diets for turbot (Psetta maxima L.) was evaluated. In a feeding trial 12 experimental tanks of a saltwater recirculation system were stocked with 15 fish each. Fish were organized in triplicate groups and received isonitrogenous and isoenergetic experimental diets with 0, 33, 66, or 100% (designated as control, RPI 33, RPI 66, RPI 100) of FM protein replaced with RPI. Fish were fed over a period of 56days until apparent satiation.Feed intake, feed conversion ratio and growth performance did not significantly vary between fish fed the RPI 33 (129g RPIkg−1 diet) and the control diet. The RPI 66 (258g RPIkg−1 diet) and the RPI 100 (391g RPIkg−1 diet) diets caused reduced feed ingestion and feed efficiencies, resulting in lower growth performance. Apparent digestibility coefficient (ADC) of dry matter and protein calculated on the basis of stripped feces revealed significantly reduced values for fish fed with RPI 66 diet compared to control diet, whereas ADC in the RPI 100 group recovered to control value. Protein retention decreased with increasing FM substitution levels. Body composition of fish showed a significant reduction in dry matter and crude protein values of the RPI 66 and RPI 100 group compared to control group. Gross energy content varied between the RPI 33 and RPI 100 group, while crude lipid and ash content were unaffected among the treatment groups, suggesting no limitations in dietary mineral or phosphorus availability. Blood parameters including hematocrit, glucose, triglycerides and cortisol were similar between the treatment groups. Histopathology of liver tissue revealed a slight hypertrophy of hepatocytes in the control group and a severe hypertrophy in fish fed with RPI 33 diet. In line with a reduced condition factor and hepatosomatic index a slight hypotrophy of hepatocytes was observed in fish fed with the RPI 100 diet. Neither inflammatory nor degenerative changes of the mid gut were observed among dietary treatments.In conclusion, 66% (314gkg−1) of dietary FM could be replaced by RPI (258gkg−1) without affecting physiological parameters of turbot in terms of animal welfare, but growth performance decreased using FM protein replacement levels above 33% (corresponding to 157gkg−1).

The Influence of Sex and Fly Species on the Development of Trypanosomes in Tsetse Flies

Unlike other dipteran disease vectors, tsetse flies of both sexes feed on blood and transmit pathogenic African trypanosomes. During transmission, Trypanosoma brucei undergoes a complex cycle of proliferation and development inside the tsetse vector, culminating in production of infective forms in the saliva. The insect manifests robust immune defences throughout the alimentary tract, which eliminate many trypanosome infections. Previous work has shown that fly sex influences susceptibility to trypanosome infection as males show higher rates of salivary gland (SG) infection with T. brucei than females. To investigate sex-linked differences in the progression of infection, we compared midgut (MG), proventriculus, foregut and SG infections in male and female Glossina morsitans morsitans. Initially, infections developed in the same way in both sexes: no difference was observed in numbers of MG or proventriculus infections, or in the number and type of developmental forms produced. Female flies tended to produce foregut migratory forms later than males, but this had no detectable impact on the number of SG infections. The sex difference was not apparent until the final stage of SG invasion and colonisation, showing that the SG environment differs between male and female flies. Comparison of G. m. morsitans with G. pallidipes showed a similar, though less pronounced, sex difference in susceptibility, but additionally revealed very different levels of trypanosome resistance in the MG and SG. While G. pallidipes was more refractory to MG infection, a very high proportion of MG infections led to SG infection in both sexes. It appears that the two fly species use different strategies to block trypanosome infection: G. pallidipes heavily defends against initial establishment in the MG, while G. m. morsitans has additional measures to prevent trypanosomes colonising the SG, particularly in female flies. We conclude that the tsetse-trypanosome interface works differently in G. m. morsitans and G. pallidipes.

III-2. カキの腸内細菌によるノロウイルス感染症の抑止

III-2. カキの腸内細菌によるノロウイルス感染症の抑止

EFFECT OF SECONDARY METABOLITES FROM THREE ENTOMOPATHOGENIC FUNGI ON THE COTTON LEAF WORM, SPODOPTERA LITTORALIS (BOISD.)

Three entomopathogenic fungi isolates, i. e., Beauveria bassiana, Paecilomyces fumosoroseus and Metarhizium anisopliae were used as biological control agents against the Egyptain cotton leaf worm, Spodoptera littoralis (Boisd.), which represent the most severe destructive cotton pest in Egypt and many other countries. The entomopathogenic fungi were inoculated YES medium, incubation period was carried out for 19 days at pH 5.4 and 28 – 30oC. After incubation period, the mats of the fungi were removed and YES broth was mixed individually with chloroform/methanol (2:1, v/v). The mixture was shaken vigorously in a separating funnel and left to settle down forming a dense lower aqueous layer containing the secondary metabolites. Extracted metabolites were then concentrated by using a speed vacuum device (Maxi Dry Plus) to a volume of 1 ml. Virulence of B. bassiana, M. anisopliae and P. fumosoroseus was investigated against 1st instar larvae of the cotton leaf worm S. littoralis. Results obtained revealed that the three metabolites (toxins) were toxic to the 1st instar larvae of S. littoralis. The most effective toxin was M. anisopliae (84.92 %) followed by P. fumosoroseus (66.32%) and B. bassiana (62.65 %). On the other hand, LT50 values in days for M. anisopliae were 8.5414, 6.4808, 4.7721, 3.7211, while for P. fumosoroseus they were 11.0488, 7.7757, 6.4998, 5.1703 and for B. bassiana they were 10.4380, 8.3415, 6.8299, 5.6922 in relation to the concentrations 25, 50, 75, 100% respectively. Treatment of S. littoralis 4th instars with LC50 of the metabolic fungal toxins caused complete disruption of endocuticle of the resulting late 6th instars. Meanwhile, it caused exfoliation of the mid gut epithelium from the underlying circular muscle fibers, leaving a large vacuole or space, disruption of both the peritrophic membrane and columnar cells, beside high vacuolization and collapsing of the fat body.

Expression of recombinant HAO3 from an Iranian isolate of Hyalomma anatolicum anatolicum in Pichia pastoris and evaluation of its antigenicity

Hyalomma anatolicum anatolicum tick is considered as one of the main problem of ruminants’ productivity in endemic countries such as parts of Africa, the Middle East and India. The disease is economically important and hence, its control and eradication is a priority. This problem reinforces the need for alternative approach like vaccine to control tick infestations instead of continuous application of acaricide which led to the natural selection of the acaricide-resistant ticks. Therefore, the present study provided evidence for the construction of transformant containing the chromosomally integrated multi-copy expression cassettes of HAO3, its successful and efficient expression in Pichia pastoris yeast and purification of the secreted protein by ultrafiltration (UF) system in a high level yield and purity.The result of antigenicity assay for the rHAO3 protein pointed well toward its capability for the elicitation of antibody response in immunized rabbits. Interestingly, the results indicated that the expressed HAO3 protein reacted well with mid gut antigen (MGAg) and rBm86 (Gavac) antisera in ELISA and western blot assays making it evident that the epitopes present in expressed protein are well recognized by the antibodies against MGAg and rBm86 proteins. Moreover, the presence of cross-reactive epitopes between rHAO3 protein with its native antigen from mid gut cells was also determined.

Carnobacterium maltaromaticum vs. Vibrio (Listonella) anguillarum in the midgut of Atlantic cod (Gadus morhua L.): an ex vivo study

The present investigation addresses whether the midgut (MG) of Atlantic cod (Gadus morhua L.) is an infection route for Vibrio (Listonella) anguillarum serotype 02 β and if Carnobacterium maltaromaticum, a probiotic bacterium, can out-compete the pathogen and modulate the autochthonous MG microbiota. This was investigated by using an ex vivo method the intestinal sac, utilized previously in studies on Atlantic cod and Atlantic salmon (Salmo salar L.). Exposure of the MG to V. (L.) anguillarum did not reveal any cell damage indicating that the MG does not appear to be an infection route for V. (L.) anguillarum in healthy Atlantic cod. This finding together with previous observations on Atlantic cod and Atlantic salmon indicate that intestine as an infection route might vary between these two species. When the MG was exposed to C. maltaromaticum, no cell damage or cellular disruptions were observed. As budding from the apices of microvilli was observed in all treatments exposed to bacteria, we suggest that budding might be involved in the primary barrier against bacterial infection. However, to clarify this hypothesis, further studies are needed. Exposure of the MG to the probiotics and pathogenic bacteria indicated that C. maltaromaticum, to some extent, is able to out-compete V. (L.) anguillarum but the topic merits further investigation. Analysis of the MG microbiota after sterile saline solution and bacterial exposure indicates that bacteria related to Staphylococcus sciuri belong to the autochthonous gut microbiota in Atlantic cod.

Validation and application of Drosophila melanogaster as an in vivo model for the detection of double strand breaks by neutral Comet assay

Comet assay under neutral conditions allows detection of DNA double-strand breaks (DSBs), which has consequence to genome instability and carcinogenesis. The present study aims to validate the neutral Comet assay for genotoxicity assessment in Drosophila melanogaster (Oregon R +) with three well known DSBs inducers i.e. cyclophosphamide (CP), bleomycin (BLM), cisplatin (CPT) and subsequently its efficacy in detecting DSBs in the organism exposed to a well known environmental chemical, chromium [Cr(VI)]. Third instar larvae of D. melanogaster were fed different concentrations of BLM, CPT and CP (50.0–200.0 μg/ml) or Cr(VI) (5.0–20.0 μg/ml) mixed standard Drosophila food for 48 h. Neutral Comet assay was performed in cells of mid gut and brain from control and treated larvae. Our results show a dose-dependent increase in the migration of DNA in cells of the exposed organisms. A comparison among DNA lesions per mole number of the test chemical in the exposed groups showed that both BLM and CPT induce more DSBs than CP. Interestingly, Cr(VI) at 20.0 μg/ml was found to induce significantly increased ( p < 0.001) DSBs in the exposed organism as compared to the control. The study while validating neutral Comet assay in D. melanogaster suggests its use for in vivo assessment of environmental chemical induced DSBs.

Characterisation of a novel paralog of scavenger receptor class B member I (SCARB1) in Atlantic salmon (Salmo salar)

BackgroundRed flesh colour is a unique trait found in some salmonid genera. Carotenoid pigments are not synthesized de novo in the fish, but are provided by dietary uptake. A better understanding of the molecular mechanisms underlying the cellular uptake and deposition of carotenoids could potentially be used to improve the low muscle deposition rate that is typically found in farmed Atlantic salmon. In addition, from an evolutionary point of view, the establishment and maintenance of this trait is still poorly understood. It has been demonstrated in several species that scavenger receptor class B, member 1 (SCARB1) is involved in intestinal absorption of carotenoids, which makes this gene a possible source of genetic variation in salmonid flesh pigmentation.ResultsIn this study, a novel paralog of SCARB1 (SCARB1-2) was detected through screening for genetic variation in Atlantic salmon SCARB1. Full length SCARB1-2 encodes a protein with 89% identity to Atlantic salmon SCARB1, except for the C-terminal cytoplasmic tail that shows only 12% identity. The most prominent site of SCARB1 mRNA expression was in the mid gut, while a five-fold lower level was detected in Atlantic salmon skeletal muscle and liver. The SCARB1-2 mRNA was equally expressed in liver, muscle and mid gut, and at a lower level than SCARB1 mRNA. A total of seven different SCARB1-2 alleles comprising repetitive enhancer of zeste motifs (EZH2) were identified in the founding parents of a resource Atlantic salmon population. We mapped the SCARB1-2 paralog to a region on Atlantic salmon chromosome 1, containing a putative QTL for flesh colour. Addition of the SCARB1-2 marker increased the significance of this QTL, however the large confidence interval surrounding the QTL precludes confirmation of SCARB1-2 as a causative gene underlying variation in this trait.ConclusionWe have characterised a novel paralog of SCARB1 (SCARB1-2), have mapped it to Atlantic salmon chromosome 1 and have described its expression in various tissues. Mapping with SCARB1-2 alleles added further evidence for a QTL affecting flesh colour on this chromosome, however further studies are needed to confirm a functional role for this gene in flesh colour pigmentation.

Metastatic Carcinoid from a Nodule Localized by Complete Double-Balloon Enteroscopy: A Small Lesion with Big Potential

Purpose: Carcinoid tumors are rare, slow growing tumors originating from enterochromaffin cells. They generally do not become symptomatic until already metastasized while the primary tumor is still small with the most common site of origin being the small bowel. Double-balloon enteroscopy (DBE) is increasingly becoming an important part of the diagnostic algorithm of primary small bowel neuroendocrine tumor (NET) localization, especially since their surgical excision leads to a better prognosis, even in metastasized NET. A 55-year-old Caucasian woman was diagnosed as having metastatic well-differentiated neuroendocrine tumor lesions of the liver positive for chromogranin and synaptophysin in 2009 per liver biopsy after initially presenting with unexplained fevers and abdominal pain since 2005 but no carcinoid syndrome symptoms. As part of the search for her primary tumor she underwent endoscopic ultrasound of the pancreas and esophagogastroduodenoscopy at our institution. This demonstrated no pancreatic mass but three hepatic hilar and periportal lymph nodes were consistent with benign lymphoid tissue. A MRI of the abdomen and pelvis revealed innumerable arterial enhancing nodules and masses in all segments of the liver consistent with metastatic disease. The largest lesion was in the dome of the liver at the left hepatic lobe, measuring 3.6 cm x 3.5 cm. Additionally, a wireless capsule enteroscopy (WCE) and CT chest were negative. Of note, chromogranin A, serotonin, pancreastatin, pancreatic polypeptide, and gastrin levels were within normal limits. She then underwent a retrograde DBE to the point of maximal insertion, which was the proximal ileum. At the level of the distal ileum there was a 3 mm yellowish nodule removed in one pass. There were no other lesions seen, and the pathology was consistent with a submucosal carcinoid strongly positive for chromogranin, synaptophysin; histochemical stains were positive for Fontana and Grimelius, consistent with mid-gut origin; and the Ki67 proliferation marker was positive in less than 1% of cells. She then underwent an oral DBE to evaluate for other multifocal carcinoid mid gut lesions and the enteroscope was advanced all the way to the cecum with no other lesions identified. An exploratory laparotomy was subsequently performed in order to evaluate for a possible primary tumor; however, despite the small bowel being run in its entirety four times there was neither a macroscopic nor histologic abnormality identified, including in eight regional lymph nodes. This case highlights the metastatic potential of a smaller ileal lesion than has been previously reported in the literature per DBE despite negative imaging, WCE, and exploratory laparotomy.

Entomotoxic action of Sambucus nigra agglutinin i in Acyrthosiphon pisum aphids and Spodoptera exigua caterpillars through caspase‐3‐like‐dependent apoptosis

In this project, the toxicity and mechanism of action of the ricin-B-related lectin SNA-I from elderberry (Sambucus nigra) in the pea aphid (Acyrthosiphon pisum) and the beet armyworm (Spodoptera exigua), two important pest insects in agriculture, were studied. SNA-I is a chimeric lectin belonging to the class of ribosome-inactivating proteins and consists of an A-chain with N-glycosidase activity and a carbohydrate-binding B-chain. Incorporation of 2 mg/ml of SNA-I in the diet of neonates and adults of A. pisum caused 40-46% mortality within 2 days, while in third instars of S. exigua, the larval biomass was significantly reduced by 12% after feeding for 3 days on a diet containing 5 mg/g of SNA-I. Interestingly, extracts of the (mid)gut of treated A. pisum and S. exigua demonstrated DNA fragmentation and this was accompanied with an increase in caspase-3-like activity. The involvement of cell death or apoptosis in the entomotoxicity of SNA-I through induction of caspase-3-like activity was also confirmed by addition of the permeable caspase-3 inhibitor III in the diet, leading to a rescue of the treated aphid neonates. Finally, similar to the chimeric lectin SNA-I, the hololectin SNA-II, consisting of two carbohydrate-binding B-chains caused high mortality to neonate A. pisum aphids with an LC₅₀ of 1.59 mg/ml, suggesting that the entomotoxic action of the lectins under study mainly relies on their carbohydrate-binding activity.