Hindgut Research Articles

Intra-amniotic delivery of tropomodulin 3 rescues cell apoptosis induced by miR-200b-3p upregulation via non-canonical nuclear factor kappa B pathways in ethylene thiourea induced anorectal malformations fetal rat

Ethylene thiourea (ETU), a metabolite of the fungicide ethylene bisdithiocarbamate (EBDC), has received great concern because of its harmful effects. ETU-induced anorectal malformations (ARMs) in rat models have been reported and widely used in the study of ARMs embryogenesis. Dysplasia of the lumbosacral spinal cord (LSSC), pelvic floor muscles (PFMs), and hindgut (HG) during intrauterine life affects postoperative defecation in patients with ARMs. However, the underlying toxic effects of ETU and pathological mechanisms in the three defecation-related tissues of fetuses with ARMs have not been reported. Thus, this study aimed to elucidate the molecular mechanisms involved in ARMs, with a focus on the dysregulation of miR-200b-3p and its downstream target tropomodulin 3 (TMOD3). The mRNA and protein levels of miR-200b-3p and TMOD3 in LSSC, PFMs, and HG of fetal rats with ARMs were evaluated by reverse transcription quantitative polymerase chain reaction and Western blotting (WB) on embryonic day 17 (E17). Further, a dual-luciferase reporter assay confirmed their targeting relationship. Gene silencing and overexpression of miR-200b-3p and TMOD3 were performed to verify their functions in HEK-293 T cells. Fetal rats with ARMs also received intra-amniotic microinjection of Ad-TMOD3 on E15, and key molecules in nuclear factor kappa (NF-κB) signaling and apoptosis were evaluated by WB on E21. Abnormally high levels of miR-200b-3p inhibited TMOD3 expression by binding with its 3′-untranslated region, leading to the activation of the non-canonical NF-κB signaling pathway, which is critical in the maldevelopment of LSSC, PFMs, and HG in ARMs rats. Furthermore, miR-200b-3p triggered apoptosis by directly targeting TMOD3. Notably, intra-amniotic Ad-TMOD3 microinjection revealed that the upregulation of TMOD3 expression mitigates the effects of miR-200b-3p on the activation of non-canonical NF-κB signaling and apoptosis in fetal rat model of ARMs. A novel miR-200b-3p/TMOD3/non-canonical NF-κB signaling axis triggered the massive apoptosis in LSSC, PFMs, and HG of ARMs, which was restored by the intra-amniotic injection of Ad-TMOD3 during embryogenesis. Our results indicate the potential of TMOD3 as a treatment target to restore defecation.

Differential expression of neuropeptide F in the digestive organs of female freshwater prawn, Macrobrachium rosenbergii, during the ovarian cycle

Neuropeptide F is a key hormone that controls feeding in invertebrates, including decapod crustaceans. We investigated the differential expression of Macrobrachium rosenbergii neuropeptide F (MrNPF) in the digestive organs of female prawns, M. rosenbergii, during the ovarian cycle. By using RT-qPCR, the expression of MrNPF mRNA in the esophagus (ESO), cardia (CD), and pylorus (PY) of the foregut (FG) gradually increased from stage II and peaked at stage III. In the midgut (MG), hindgut (HG), and hepatopancreas (HP), MrNPF mRNA increased from stage I, reaching a maximal level at stage II, and declined by about half at stages III and IV (P < 0.05). In the ESO, CD, and PY, strong MrNPF-immunoreactivities were seen in the epithelium, muscle, and lamina propria. Intense MrNPF-ir was found in the MG cells and the muscular layer. In the HG, MrNPF-ir was detected in the epithelium of the villi and gland regions, while MrNPF-ir was also more intense in the F-, R-, and B-cells in the HP. However, we found little colocalization between the MrNPF and PGP9.5/ChAT in digestive tissues, implying that most of the positive cells might not be neurons but could be digestive tract-associated endocrine cells that produce and secrete MrNPF to control digestive organ functions in feeding and utilizing feed. Taken together, our first findings indicated that MrNPF was differentially expressed in digestive organs in correlation with the ovarian cycle, suggesting an important link between MrNPF, the physiology of various digestive organs in feeding, and possibly ovarian maturation in female M. rosenbergii.

Replacing fishmeal with salmon hydrolysate reduces the expression of intestinal inflammatory markers and modulates the gut microbiota in Atlantic salmon (Salmo salar)

The feed legislation allows the use of fish protein hydrolysates in feed for the same species in which it came from, since enzymatic hydrolysis degrades the proteins and eliminates potential prions, which have caused disease in mammals, but not in fish. In this trial, we investigated the effects of partially replacing dietary fishmeal (FM) with salmon protein hydrolysate (FPH) on the intestinal gene expression and microbiota. Atlantic salmon post smolts were either fed a control diet containing 30% fishmeal (FM), a 20% FM diet with 9% salmon hydrolysate (FPH-09) or a 10% FM diet with 18% salmon hydrolysate (FPH-18), until doubling of weight. Gene expression analysis by RNA sequencing of pyloric caeca (PC), midgut (MG) and hindgut (HG) revealed a downregulation of immunological genes involved in inflammation in the intestine of FPH-18 fed salmon compared to salmon fed the FM control. The gene expression of paralogous peptide transporters (PepT) was analyzed by real time quantitative PCR in PC, anterior midgut (AMG), posterior midgut (PMG) and HG of salmon fed all the three diets. The PepT1b paralog had highest relative expression levels in PC and AMG, suggesting that PepT1b is most important for peptide uptake in the anterior intestine. PepT1a was also mainly expressed in the PC and AMG, but at lower levels than PepT1b and PepT2b in the AMG. The PepT2b paralog had high levels of expression in AMG, PMG and HG indicating that it contributed significantly to peptide uptake in the posterior part of the gastrointestinal tract. The gut microbiota in the mucosa and digesta of the MG and HG, were dominated by the phyla Cyanobacteria and Proteobacteria, but also Firmicutes were present. The only dietary effect on the microbiota was the higher prevalence of the phyla Spirochaetes in the mucosa of FPH-18 fed salmon compared to the FM fed salmon. In conclusion, replacing FM with salmon hydrolysate reduced the expression of inflammatory markers in the Atlantic salmon intestine suggesting improved health benefits. The reduced inflammation may be related to the reduced FM content, potentially bioactive peptides in the hydrolysate and/or the altered gut microbial composition.

Microencapsulation technology for delivery of enzymes in ruminant feed.

The ruminant digestive system is uniquely designed to make efficient use of high-fibre feed, including forages. Between 40 to 100% of the ruminant diet consists of forages which are high in fibre and up to 70% of this may remain undigested in the ruminant gut, with substantial impact on feed utilisation rate and productivity and the economic and environmental sustainability of livestock production systems. In ruminants, feed costs can make up to 70% of the overall cost of producing an animal product. Increasing feed utilisation efficiency, i.e., more production with less feed lowers feeding costs and improves livestock economic viability. Strategies for improving nutrient utilisation in animal feed has been investigated over the years. Incorporation of fibre digesting enzymes in the feed to facilitate the digestion of the residual fibre in hind gut is one of the proposed strategies. However, delivering such enzymes to the hind gut in active state is challenging due to the unfavourable biochemical environment (pH, microbial proteases) of ruminant's gastrointestinal tract. This review discusses the potential application of microencapsulation for protected and targeted delivery of enzymes into the hind gut of ruminants.

Variations of intact phospholipid compositions in the digestive system of Antarctic krill, Euphausia superba, between summer and autumn.

The biochemical composition of Antarctic krill, Euphausia superba, is largely determined by their feeding behaviour. As they supply energy for animals of a higher trophic level and are also commercialized for human consumption, the interest in research on the species is high. Lipids, especially phospholipids, make up a high proportion of dry weight in krill. Seasonal changes are well documented in the fingerprint of free fatty acids analysed after hydrolysis of phospholipids, but the underlying intact polar lipids are rarely considered. In this study, we evaluated the compositions of intact phospholipids (IPLs) in the stomach, digestive gland and hind gut of Antarctic krill caught in summer and autumn at the Antarctic Peninsula region. Using high-resolution mass spectrometry, the fatty acid composition of 179 intact phospholipids could be resolved. Most IPLs were phosphatidylcholines, followed by phosphatidylethanolamines. Several very long chain polyunsaturated fatty acids up to 38:8, which have not been reported in krill before, were identified. The composition shifted to higher molecular weight IPLs with a higher degree of unsaturation for summer samples, especially for samples of the digestive gland. The data supplied in this paper provides new insights into lipid dynamics between summer and autumn usually described by free fatty acid biomarkers.

PSII-26 Feeding Behavior and Feed Conversion in Roughage-Lacking Diets Containing Ionized Amino Acids as Antibiotic Alternative

Abstract To improve animal performance there has been an increase of starch amounts in the ruminant diets; however, feeding high-grain diets can induce metabolic disturbs, needs to include antibiotics in the diet to avoid acidosis and control the growth of lactic acid producing microorganism. In this study was used ionized amino acids to replace monensin and withdraw all forage of diet. Twenty-four Nellore young bulls were allocated into two groups. The first group was fed with high-grain diet containing Brachiaria brizantha hay (15% of DM) and sodium monensim (120 mg/d). The second group was fed with high-grain diet without forage and without antibiotics, containing 82 mg/kg of ionized amino acids (no-forage diet, MJ Nutricao Animal). The feeding lasted 100 d before slaughter, at the end of period l rumen fluid was collected for VFA and lactic acid measurements. The Penn State Particle Separator has been used to monitor feeding sorting, the dry matter intake (DMI) was monitored daily in GrowSafe system and body weight (BW) was measured monthly. A completely randomized design was used. In the forage plus monensin diet the animals sorted larger particle (7.8 to 19 and &amp;gt; 19 mm), the proportion of larger particles decrease after feeding, the proportion of particles from 1.7 to 7.8 mm increased and there was no effect on smaller particles (&amp;lt; 1.7 mm). The animals feeding with no-forage diet avoided the whole cottonseed, the proportion of particles from 1.7 to 7.8 mm decreased and smaller particles (&amp;lt; 1.7 mm) did not change, before or after feeding (Table 2). The feeding behavior was changed; there were visits in the Growsafe feeder, the visits were faster and there was greater consumption per visit, in no-forage diet (Table 1). However, there were greater concentrations of propionic acid (50.9 vs 16.0 mM), smaller acetic:propionic ratio (1.1 vs 3.4), a trend to increased lactic acid (0.3 vs 0.2 mM), and the pH decreased in no-forage diet (6.29 vs 6.68), reducing the DMI (2 vs 2.5% of BW). There was a trend to reduce the BWG (1.7 vs 2.0 kg/d) in no-forage diet. There was no difference in feed conversion (6.43 in forage diet vs 6.08 no forage diet). In conclusion, the faster starch consumption of no-forage diet can induce greater propionic acid concentration, reducing DMI, on the other hand, the no-forage diet representing advantage to become the management of feedlot diets easier, allowing supply concentrate with less frequency, reducing dependence of forage production on farm, with the same feed conversion, without use of antibiotics. We hypothesize that fast passage rate reduces the hind gut starch digestibility, thus, further investigation can include supplies to improve alfa-amylase, to achieve even better feed conversion.

Time from feeding impacts farmed Atlantic salmon (Salmo salar) gut microbiota and faecal score

In intensive Atlantic salmon aquaculture, faecal score potentially serves as a generalised indicator of gut microbiome diversity and composition and as a proxy for gut transit time. There is also the possible application to detect dysbiosis. The utility of using faecal scoring for assessing commercially farmed fish populations may, however, be impacted by rapid temporal changes in digestive status following feeding that, as yet, has not been considered. To help inform sampling strategies and better understand the utility of faecal scoring for farmed fish, this study documented Atlantic salmon faecal scores and gut bacterial 16S rRNA amplicon sequence profiles over 24 h following a feeding event. Samples were collected from two marine cohorts of salmon in different seasons (summer and winter), and comparisons were also made between non-destructive stripped hindgut faeces (HS) and destructive sampling of hindgut digesta (HD) and hind gut mucosa (HM). Average hindgut faecal scores and microbiome diversity were largely consistent over a normal (6 to 8 h) sampling day in winter, but were much more variable in summer, potentially associated with faster faecal passage and dynamic gut microbial changes in the hours after feeding. HS samples were determined to be a valid non-destructive method to obtain material for assessing the diversity and composition of transient bacterial communities in the distal intestine. For an accurate representation of both the transient and resident bacterial communities, both sample types should be considered. It is recommended that studies comparing treatment cohorts, or between individuals in large sample sets, should be designed to capture temporal and seasonal effects that are associated with changes in digestive status and gut microbiome.

A unique case of commensalism: The beaver beetle Platypsyllus castoris (Leiodidae, Coleoptera) and its morphological adaptations.

Platypsyllus castoris is closely associated with beavers and displays a unique set of structural specializations. We document the morphology of adults with modern techniques, and interpret evolutionary changes linked with the specific life style. The small subfamily Platypsyllinae has evolved an entire suite of features correlated with a more or less close association with mammals, for instance a flattened body, a dorsal cephalic shield, flightlessness, eye reduction, and depigmentation. Within this small group, Platypsyllus displays numerous autapomorphic features, correlated with a close association with the beaver. Essential is a combination of mechanical stabilization and firm anchorage on the host, and efficient forward movement in the fur. Exo- and endoskeletal structures of the head and thorax are reinforced by vertical cuticular columns and by an array of internal ridges. The antennae are shortened and strongly modified, the mandibles distinctly reduced and flattened, unsuitable for cutting, scraping or grinding. The musculature of the mouthparts is simplified, whereas an enhanced set of prepharyngeal and pharyngeal dilators forms an efficient sucking pump. The prothoracic musculature is strongly developed. In contrast, the pterothoracic muscle system is distinctly simplified, even though leg muscles are strongly developed. Using the legs, the flattened beetles move sideways through the dense fur of the beaver, using posteriorly directed groups of setae and ctenidia to prevent being pushed backwards by the densely arranged hairs. In contrast to the anterior body, the cuticle of the abdomen is thin, and the entire tagma flexible, with thin layers of segmental muscles. The hind gut is not connected with the mid gut. The beetles probably consume liquid, possibly with emulgated minute skin debris. As the morphology of the mouthparts excludes damage to the skin of the host, the association should not be addressed as ectoparasitic but as commensalism.

Studies on Synergistic Effects of Different Bio-Active Chemicals on Nuclearpolyherosis (Grasserie Disease) of Silkworm, Bombyx mori Linnaeus

Purpose: Larval hind gut of multivoltine breed silk worm Bombyx mori L. (Nistari) was studied in both favourable and unfavourable rearing seasons after Grasserie caused by Bombyx mori Nuclearpolyherosis Virus (BmNPV) using Histological Analysis, Scanning Electron Microscopy and Transmission Electronic Microscopy.&#x0D; Methodology: Chemical treatments using various bio active chemicals: Curcumin, Allicin and Azadirachtin were administered to minimize the extent of damage.&#x0D; Findings: The present study clearly indicates that Azadirachtin is more effective in comparison to its other counterparts and it is the major finding of this extensive study.&#x0D; Unique Contribution to Theory, Policy and Practice: The uniqueness of this type of bio chemical control of Grasserie disease which is not only a cost effective and eco-friendly technique, but also it is less hazardous and simple controlling procedure of Grasserie. Therefore, this extensive study may help the stakeholders to step ahead on the progression of sustainable agriculture while avoiding crop loss by means of cost-effective pathogen management technology.

Leidynema bestium sp. n. (Oxyuridomorpha: Thelastomatidae) an intestinal parasite of blaberid cockroaches from Yaroslavl Zoo, Russia

A new species of thelastomatid Leidynema bestium sp. n. is described from the hind gut lumen of the cockroaches Diploptera punctata (Eschscholtz, 1922) and Elliptorhina chopardi (Lefeuvre, 1966). The new species is characterized by a combination of morphological features: presence of lateral alae in both sexes with posterior margin of alae in females not ending in the shape of a spike; longitudinal striation of the anteriormost annuli in males; four male genital papillae, equatorial position of vulva. In the cladogram inferred from analysis of D2-D3 segment of LSU rDNA L. bestium sp. n. demonstrates a position independent of the Leidynema species with known sequences of this taxonomic marker near the basal node for this genus.

The digestive tract sections of the sea cucumber Isostichopus badionotus reveal differences in composition, diversity, and functionality of the gut microbiota.

For the first time, this study analyses the composition and diversity of the gut microbiota of Isostichopus badionotus in captivity, using high-throughput 16S rRNA sequencing, and predicts the metagenomic functions of the microbiota. The results revealed a different composition of the gut microbiota for the foregut (FG) and midgut (MG) compared to the hindgut (HG), with a predominance of Proteobacteria, followed by Actinobacteria, Bacteroidetes, and Firmicutes. The FG and MG demonstrated a greater bacterial diversity compared to the HG. In addition, a complex network of interactions was observed at the genus level and identified some strains with probiotic and bioremediation potentials, such as Acinetobacter, Ruegeria, Streptococcus, Lactobacillus, Pseudomonas, Enterobacter, Aeromonas, Rhodopseudomonas, Agarivorans, Bacillus, Enterococcus, Micrococcus, Bifidobacterium, and Shewanella. Predicting metabolic pathways revealed that the bacterial composition in each section of the intestine participates in different physiological processes such as metabolism, genetic and environmental information processing, organismal systems, and cellular processes. Understanding and manipulating microbe--host-environment interactions and their associated functional capacity could substantially contribute to achieving more sustainable aquaculture systems for I. badionotus.

Developmental Alterations of Colonic microRNA Profiles Imply Potential Biological Functions in Kid Goats.

Simple SummaryThe colon plays a crucial role in the fermentation and utilization of cell wall carbohydrates, cellulose, and hemicellulose in ruminants. MicroRNAs have been reported to be involved in regulating the gastrointestinal development and maintaining intestinal homeostasis of mammals. In this study, we first reveal the microRNA expression profiles in the colon of kid goats. Meanwhile, we found that targeted genes of DEmiRNAs were highly enriched for the prevention of microbial invasion via the Erbb−MAPK network while targeted genes of HEmiRNAs contributed to the permeable barrier maintenance and surveillance of cell damage. Additionally, more than half of the microRNAs showed a developmentally dynamic expression in the colon of kid goats. This study disclosed microRNA-based biological functions in the regulation of colon development in ruminants.The colon is a crucial digestive organ of the hind gut in ruminants. The bacterial diversity and mucosal immune maturation in this region are related to age. However, whether the microRNA expression in the colon of goats is affected by age is still unclear. In the current study, we analyzed the transcriptomes of colon microRNAs during preweaning (Day 10 and Day 25) and postweaning (Day 31). A total of 1572 microRNAs were identified in the colon tissues. Of these, 39 differentially expressed microRNAs (DEmiRNAs) and 88 highly expressed microRNAs (HEmiRNAs) were screened. The target genes regulated by the DEmiRNAs and HEmiRNAs were commonly enriched in the MAPK signaling pathway, Wnt signaling pathway, Hippo signaling pathway, cell adhesion molecules, focal adhesion, and adherens junction. Remarkably, the targeted genes of the DEmiRNAs were highly enriched for the prevention of microbial invasion via the Erbb−MAPK network while the targeted genes of HEmiRNAs contributed to the permeable barrier maintenance and cell damage surveillance. Additionally, there were eight different expression profiles of 87 dynamic miRNAs, in which approximately half of them were affected by age. Taken together, our study reveals the different roles of DEmiRNAs, HEmiRNAs, and dynamic microRNAs in the development of the colon and gives new insights into the regulatory mechanism of colon development in goats.

A rectal duplication cyst with rectovaginal fistula: A case report

Alimentary tract duplications (ATD's) are rare congenital anatomical abnormalities. They have an incidence of 1 in 4500 live births and can occur anywhere throughout the digestive tract from the oropharynx to the anus. ATD's occurs most commonly in the midgut (56%), less commonly in the foregut (33%) and even more rare in the hind gut (11%). Rectal duplications are the least common among other alimentary tract duplications, forming only 4% of them. Typically, they are cystic masses, slightly more common in males and they can present in the newborns period or any time later in childhood and even adulthood. We describe a case of an adolescent female presenting with long standing constipation since birth associated with painful defecation and offensive stool odor, abdominal pain and distention. She recently noticed stool in the vagina at the time of defecation. Patient was admitted to our medical center for further investigations and underwent colonoscopy. The study showed two pouches in the rectum, one with blind end and ulcer with suspected fistula opening, and the other lumen continues to the cecum. Abdomen and pelvic CT with rectal contrast was also done, showing a huge recto-sigmoid duplication cyst compressing the native rectum. Evidence of contrast in the vagina was also seen. Decision for surgery was then made. The procedure commenced laparoscopically, showing a huge duplication cyst starting at the distal part of sigmoid and extending downward distally to the rectum. Severe adhesions and edema was also encountered (frozen pelvis) which forced us to convert to open surgery. It was not possible therefore, to perform complete excision of the cyst without risking to damage the rectum and surrounding structures, which will increase the morbidity significantly in our case. Moreover, the fistula was not seen from this approach, as it was very low. We eventually performed a near total cystectomy with the sigmoid attached to it, joined the common wall of the remaining of the cyst and the native rectosigmoid using endo-GIA staplers. We decided to exteriorize the proximal colon as end colostomy. Subsequently, the fistula was taken down trans -vaginally by the gynecology team as a second procedure . A third procedure was performed 6 months later, a laparotomy was performed, the colostomy was taken down and primary anastomosis was performed. No immediate postoperative complications were seen and the patient was discharged in good general condition. This is a unique case as it is a case of a huge rectosigmoidal duplication cyst that was discovered in a female at an adolescent age, causing severe adhesions and chronic inflammations in the pelvis which led to a rectovaginal fistula and made complete resection impossible without converting the surgery into a major surgery with risk of morbidity and long term sequela. As the condition is considered benign, the medical literature is usually against performing a major surgery that can be harmful to the patient like a very low anterior resection to excise the duplication cyst as it is acceptable to perform partial excision with unification the two lumens together which was performed in our case. This case is an example of multistage and multidisciplinary procedure to treat a rare duplication cyst anomaly.

149 Effect of Dietary Structural Fiber and Fermentable Protein on Growth Performance in Post-Weaning Pigs

Abstract Excessive protein fermentation in the hind gut is harmful to piglet gut health. Addition of fermentable fiber has been used as a mitigating strategy. However, the impact of structural fiber (STR) and its interactive effect with fermentable protein (FP) are less studied. In the present study, in a 2 x 2 factorial arrangement setting, 240 weaned pigs with initial body weight of 6.9 ± 1.1 kg (6 mixed sex pigs/pen, 10 pens/treatment) were allotted in a randomized complete block design to 1 of the following diets: low STR, low FP (control); low STR, high FP; high STR, low FP or high STR, high FP diet. A standard corn-soy based nursery diet was used as control. The treatment diets were supplemented with either oat hulls to increase STR or canola meal to increase FP level. Experimental diets were fed during the first 3 weeks post-weaning and followed by a common diet for the rest of nursery phase. Data was analyzed by general linear model in R. In summary, STR significantly increased average daily gain (ADG) during week 1 (P &amp;lt; 0.05) and in the entire nursery phase (P = 0.01) and tended to increase average daily feed intake (ADFI) during these periods (P &amp;lt; 0.10) (Table 1). Interaction effect tended to be different (P &amp;lt; 0.10) on ADG and ADFI during week 3 post-weaning, with pigs fed with high STR, high FP diet having higher ADG and ADFI numerically compared with the same level FP but lower STR treatment. An interaction effect was observed on gain:feed (G:F) for entire nursery phase (P = 0.05), where high STR, low FP diet resulted in numerically highest G:F. Conclusively, high STR improves performance during entire nursery phase and when dietary FP is high, increasing STR may alleviate the negative impact on performance.

Simultaneous Single-Cell Genome and Transcriptome Sequencing of Termite Hindgut Protists Reveals Metabolic and Evolutionary Traits of Their Endosymbionts.

ABSTRACTSome of the protist species which colonize the hindguts of wood-feeding Reticulitermes termites are associated with endosymbiotic bacteria belonging to the genus Endomicrobium. In this study, we focused on the endosymbionts of three protist species from Reticulitermes flavipes, as follows: Pyrsonympha vertens, Trichonympha agilis, and Dinenympha species II. Since these protist hosts represented members of different taxa which colonize separate niches within the hindguts of their termite hosts, we investigated if these differences translated to differential gene content and expression in their endosymbionts. Following assembly and comparative genome and transcriptome analyses, we discovered that these endosymbionts differed with respect to some possible niche-specific traits, such as carbon metabolism. Our analyses suggest that species-specific genes related to carbon metabolism were acquired by horizontal gene transfer (HGT) and may have come from taxa which are common in the termite hind gut. In addition, our analyses suggested that these endosymbionts contain and express genes related to natural transformation (competence) and recombination. Taken together, the presence of genes acquired by HGT and a putative competence pathway suggest that these endosymbionts are not cut off from gene flow and that competence may be a mechanism by which members of Endomicrobium can acquire new traits.IMPORTANCE The composition and structure of wood, which contains cellulose, hemicellulose, and lignin, prevent most organisms from using this common food source. Termites are a rare exception among animals, and they rely on a complex microbiota housed in their hindguts to use wood as a source of food. The lower termite, Reticulitermes flavipes, houses a variety of protists and prokaryotes that are the key players in the disassembly of lignocellulose. Here, we describe the genomes and the gene expression profiles of five Endomicrobium endosymbionts living inside three different protist species from R. flavipes. Data from these genomes suggest that these Endomicrobium species have different mechanisms for using carbon. In addition, they harbor genes that may be used to import DNA from their environment. This process of DNA uptake may contribute to the high levels of horizontal gene transfer noted previously in Endomicrobium species.

Chemosensory Proteins (CSPs) in the Cotton Bollworm Helicoverpa armigera

Simple SummaryThe insect chemosensory system is crucial in regulating insect behaviors. Chemosensory proteins (CSPs) are a family of small, soluble proteins conventionally known to transport odorant molecules in insect chemosensory system. Besides chemosensation, CSPs have been reported to play important roles in development, nutrient metabolism, and insecticide resistance. Therefore, identification and characterization of previously unknown CSPs will be valuable for further investigation of this protein family. The cotton bollworm, Helicoverpa armigera (Hübner) is among the most serious insect pests in various agricultural and horticultural crops. In this study, 27 CSP genes were identified from H. armigera genome and transcriptome sequences, and their expression patterns were further examined by using transcriptomic data obtained from different tissues and stages. The results demonstrate that H. armigera CSP genes are highly expressed in both chemosensory and non-chemosensory tissues. Moreover, a new recombinant expression method was developed that can significantly increase H. armigera CSP expression levels as soluble proteins in Escherichia coli. This study improves our understanding of insect CSPs and developed a new approach to highly express recombinant CSPs, which can be expanded to examine CSPs in other species for functional characterization.Chemosensory proteins (CSPs) are a family of small, soluble proteins that play a crucial role in transporting odorant and pheromone molecules in the insect chemosensory system. Recent studies reveal that they also function in development, nutrient metabolism and insecticide resistance. In-depth and systematic characterization of previously unknown CSPs will be valuable to investigate more detailed functionalities of this protein family. Here, we identified 27 CSP genes from the genome and transcriptome sequences of cotton bollworm, Helicoverpa armigera (Hübner). The expression patterns of these genes were studied by using transcriptomic data obtained from different tissues and stages. The results demonstrate that H. armigera CSP genes are not only highly expressed in chemosensory tissues, such as antennae, mouthparts, and tarsi, but also in the salivary glands, cuticle epidermis, and hind gut. HarmCSP6 and 22 were selected as candidate CSPs for expression in Escherichia coli and purification. A new method was developed that significantly increased the HarmCSP6 and 22 expression levels as soluble recombinant proteins for purification. This study advances our understanding of insect CSPs and provides a new approach to highly express recombinant CSPs in E. coli.

An X-ray micro-computer tomography study of the Malpighian tubules of the Blue Bottle Blow Fly (Calliphora vomitoria) Diptera: Calliphoridae

Malpighian tubules are the insect equivalent of mammalian kidneys and normally drain into the gut at the junction between the mid and hind gut. The Malpighian tubules of the fruit fly Drosophila melanogaster are increasingly being used as a model for studying human renal tract development, histology, nephrolithiasis and urolithiasis. In the present study we report when using X-ray micro-computer tomography techniques, the larval, intrapuparial and adult stages of the larger Calliphora vomitoria can contain large amounts of calcium-rich concretions which are tightly packed in the lumen of both anterior Malpighian tubules. We show that it is feasible to utilise these calcium-rich concretions as a form of marking agent to delineate the various developmental stages of the Malpighian tubules including the crucial phase when the Malpighian tubules reconnect with the hind gut. In the majority of cases during the intrapuparial period the ureters of the Malpighian tubules did not start to re-canalise and thus reconnect with the developing hind gut until the 7th day of the 10-11 day. Just prior to ecdysis, virtually all the radio-opaque concretions in the Malpighian tubules had emptied into the hind gut and had then been completely excreted by the time the imago emerged from its puparium. In contrast, we show that in flies developing from larvae previously stained by ingesting Rhodamine B, a known substrate for both the Multi Xenobiotic Resistance and Multi Drug Resistant membrane transport systems, the efficiency with which these calcium-rich concretions are excreted by the imago as it emerges from its intrapuparial period can be significantly impaired. Therefore, it might be useful to include C. vomitoria as a model when studying renal tract development and urolithiasis using X-ray micro-computer tomography.

Ruminal and Fecal Bacteriome of Dairy Calves Fed Different Levels and Sources of NDF.

Simple SummaryThe present study aimed to characterize and understand how the gastrointestinal microbiome (in rumen and feces) of pre-weaning dairy calves is affected by feeding a starter concentrate with two levels of fiber and the inclusion of hay in the diet. Another study objective was to verify if the effects on the microbiome remained after weaning. The ruminal bacteriome was not affected by levels or sources of fiber. The fecal bacteriome was affected by age and diet. The inclusion of hay affected the fecal microbial diversity.A starter concentrate containing different levels and sources of NDF can modify the gastrointestinal bacteriome. This study evaluated 18 Holstein calves housed in un-bedded suspended individual cages, fed one of three treatments: 22NDF: a conventional starter containing 22% NDF (n = 7); 31NDF: a starter with 31% NDF, replacing part of the corn by soybean hull (n = 6); and 22Hay: diet 22NDF plus coast-cross hay ad libitum (n = 5). All animals received 4 L of milk replacer daily, weaned at 8th week of age, and housed in wood shelters until week 10. To evaluate the bacteriome, the bacterial community of ruminal fluid and fecal samples was determined by sequencing V3 and V4 region amplicons of the 16S rRNA gene. Bacterial diversity in rumen was not affected by diet or age. The phyla Firmicutes and Bacteroidota, and Prevotella’ genus were the most abundant in ruminal fluid and fecal samples. In feces, the α-diversity indices were higher for 22Hay. All indices were significantly affected by age. We believe that the ruminal bacteriome was affected by basal diet components, but not affected by NDF levels or sources. The supply of hay was effective in modifying the fecal bacteriome of dairy calves due to hind gut fermentation.

Effects of corn stalk inclusion and tylosin on performance, rumination, ruminal papillae morphology, and gut pathogens associated with liver abscesses from finishing beef steers

To reduce prevalence of liver abscesses in finishing beef steers, we must evaluate the possibility of pathogens originating from the hind gut as well as the rumen. We hypothesized that pathogens promoting liver abscess formation are located throughout the gut, and increased dietary roughage levels could improve gut integrity over time. Two hundred sixty-three crossbred beef steers (BW = 258 ± 29 kg) were used in a randomized complete block design with 7-8 hd/pen (8 pens/treatment) using a 2 × 2 factorial treatment structure. Steers received steam-flaked corn-based diets with 5 or 15% corn stalk (CS) inclusion (dry matter basis, DMB) and with (TYL) or without (NTYL) tylosin (7.9 g/T; DMB). Half of the pens in each treatment remained on feed for the entire experiment duration (Exp 1) whereas the remaining half were designated for serial slaughter (Exp 2). Steers were fed each day at 0700 h for an average of 220 d (heavy block = 175 d, light block = 233 d). For Exp 2, eight steers were slaughtered on d 0 to obtain initial tissue samples and thereafter one pen/treatment was slaughtered every 56 d. During serial slaughter, dorsal and ventral sac rumen tissue samples were collected for histopathological evaluation along with ruminal, ileal, and colonic tissues for bacterial isolation. Data were analyzed using mixed models; pen was the experimental unit for performance outcomes and individual animal was the experimental unit for bacterial isolation and histopathological data. No interaction (P ≥ 0.40) between tylosin and CS inclusion was detected for ADG or final BW. Interactions were detected for DMI and G:F; both outcomes were similar when tylosin was included in the diet, however both outcomes differed notably without tylosin. Perimeter and length of ventral rumen papillae decreased (P ≤ 0.01) as DOF increased. In contrast, dorsal rumen papillae perimeter and length increased through d112 and then decreased through d231. Corn stalk inclusion rate did not affect the incidence of bacterial species isolated from the ruminal (P = 0.38), ileal (P > 0.15), or colonic (P > 0.37) epithelial tissues. Cattle consuming the TYL diets tended to have decreased (P = 0.06) presence of ileal Fusobacterium necrophorum subsp. necorphorum and increased (P = 0.07) rates of ruminal Salmonella enterica compared to NTYL. Prolonged consumption of a finishing diet, regardless of CS or TYL inclusion, seemed to be the major source of change in rumen epithelial tissue morphology.

Protease Complex Reduces Potentially Pathogenic Microbial Populations in the Ileum While Optimizing Performance of Broiler Chickens

A 42-day trial was conducted to assess the effects of a dietary protease on growth performance and ileum population of selected bacteria in broiler chickens fed standard diets and diets deficient in crude protein and digestible amino acids (CP/AA, ~5%) or apparent metabolizable energy (AME, 50 kcal/kg) or both. Reducing CP/AA and AME negatively affected average daily weight gain (ADG, <I>P</I> < 0.05) and feed conversion ratio (FCR, <I>P</I> < 0.05). Dietary protease improved BW at 42-d (<I>P</I> = 0.021, linear effect) of birds fed both standard and nutrient deficient diets but improved FCR (<I>P</I> = 0.0002) was only observed when supplemented to the standard diet. Serum protein concentration was not affected by the level of CP/AA and AME but decreased linearly with the level of protease (<I>P</I> = 0.02). Numbers of <i>Escherichia coli</i>¸ <i>Salmonella</i> spp. and <i>Clostridium perfringens</i> increased (<I>P</I> = 0.0001) with the decrease of dietary CP/AA and AME. In contrast, the numbers of studied bacteria linearly decreased (<I>P</I> = 0.0001) with dietary protease level. Dietary protease was found to decrease the numbers of <i>Clostridium perfringens</i> (<I>P</I> = 0.0001) when supplemented to either low CP/AA or low AME diets. It can be concluded that protease supplementation sustained the harvesting biomass in the experimental birds fed lower nutrient density diets and decreased the numbers of resident bacteria in the hind gut, some of which might be potential pathogens. Hence, the study documented not only the nutrient sparing effects but also the extra-proteinaceous effect in terms of gut health of dietary protease in broiler chickens.