Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Records 1 - 20 / 415

  • help
  • print

    Print search results

  • export
    A maximum of 250 titles can be exported. Please, refine your queryYou can also select and export up to 30 titles via your marked list.
  • alert
    We will mail you new results for this query: q=Knol
Check title to add to marked list
Mechanistic study on trophic interaction between mucosal keystone species and butyrogenic gut commensals
Chia, L.W. ; Hornung, B.V.H. ; Aalvink, S. ; Schaap, P.J. ; Vos, W.M. de; Knol, J. ; Belzer, C. - \ 2018
PRJEB20031 - ERP022138 - Akkermansia muciniphilaAkkermansia muciniphila
Host glycans are paramount in regulating the symbiotic relationship between humans and their gut bacteria. The constant flux of host-secreted mucin at the mucosal layer creates a steady niche space for bacteria colonization. Mucin, characterized by complex molecular structure, exerts selective nutritional pressure for mucin-degrading bacteria. Mucin degradation by keystone species subsequently drives the local trophic chain and shapes mucosal microbial assembly a.k.a. mucobiome. This study investigates mucin-driven trophic interaction between the specialized mucin-degrader, Akkermansia muciniphila and butyrogenic gut commensals. Co-cultures of A. muciniphila with non-mucolytic butyrogens (Anaerostipes caccae and Eubacterium hallii) were grown in minimal media supplemented with pure mucin. Metabolites (HPLC) and meta-transcriptome (RNA-seq) were studied. Mucin degradation by A. muciniphila produced mucin-derived monosaccharides and metabolites (galactose, fucose, mannose, GlcNAc and acetate) for the growth of butyrogens (A. caccae and E. hallii) resulted in 2mM butyrate production. Interestingly, co-culture of A. muciniphila with E. hallii demonstrated mutual relationship, in which pseudovitamin B12 production by E. hallii facilitated propionate production by A. muciniphila. Cobalamin-dependent methylmalonyl-CoA mutase genes (Amuc_1983 and Amuc_1984) were upregulated in A. muciniphila monoculture, indicated the attempt by A. muciniphila to activate propionate production pathway by synthesizing more key catalytic enzymes. Differential analysis (DESeq2) showed the presence of butyrogens resulted in an altered transcriptional profile of A. muciniphila. E. hallii in particular, incurred high functional impact on A. muciniphila gene expression. Mucosal subpopulation driven by A. muciniphila could result in butyrate and propionate production. Deciphering the underlying mechanism of this microbial tropism is crucial for the understanding of mucosal health and pathophysiology.
Aged mice display altered numbers and phenotype of basophils, and bone marrow-derived basophil activation, with a limited role for aging-associated microbiota
Beek, Adriaan A. Van; Fransen, Floris ; Meijer, Ben ; Vos, Paul de; Knol, Edward F. ; Savelkoul, Huub F.J. - \ 2018
Immunity and Ageing 15 (2018)1.
Aging - Basophils - Bone marrow - Immunity - Microbiota - Spleen

Background: The influence of age on basophils is poorly understood, as well as the effect of aging-associated microbiota on basophils. Therefore, we studied the influence of aging and aging-associated microbiota on basophil frequency and phenotype, and differentiation from basophil precursors. Results: Basophils became more abundant in bone marrow (BM) and spleens of 19-month-old mice compared with 4-month-old mice. Aged basophils tended to express less CD200R3 and more CD123, both in BM and spleen. Differences in microbiota composition with aging were confirmed by 16S sequencing. Microbiota transfers from young and old mice to germ-free recipients revealed that CD11b tended to be lowered on splenic basophils by aging-associated microbiota. Furthermore, abundance of Alistipes, Oscillibacter, Bacteroidetes RC9 gut group, and S24-7 family positively correlated and CD123 expression, whereas Akkermansia abundance negatively correlated with basophils numbers. Subsequently, we purified FcϵRIα+CD11c-CD117- BM-derived basophils and found that those from aged mice expressed lower levels of CD11b upon stimulation. Higher frequencies of IL-4+ basophils were generated from basophil precursors of aged mice, which could be reproduced in basophils derived from germ-free recipients of aging-associated microbiota. Conclusions: Collectively, these results show the influence of aging on basophils. Furthermore, this study shows that aging-associated microbiota altered activation of BM-derived basophils in a similar fashion as observed in BM-derived basophils from aged mice.

Corrigendum: Fecal microbial composition associated with variation in feed efficiency in pigs depends on diet and sex
Verschuren, Lisanne M.G. ; Calus, Mario P.L. ; Jansman, Alfons J.M. ; Bergsma, Rob ; Knol, Egbert F. ; Gilbert, Hélène ; Zemb, Olivier - \ 2018
Journal of Animal Science 96 (2018)9. - ISSN 0021-8812 - p. 4013 - 4013.
The potential role of gut microbiota and its modulators in the management of propionic and methylmalonic acidemia
Burlina, Alberto ; Tims, Sebastian ; Spronsen, Francjan van; Sperl, Wolfgang ; Burlina, Alessandro P. ; Kuhn, Mirjam ; Knol, Jan ; Rakhshandehroo, Maryam ; Coşkun, Turgay ; Singh, Rani H. ; MacDonald, Anita - \ 2018
Expert Opinion on Orphan Drugs 6 (2018)11. - p. 683 - 692.
methylmalonic acid - microbiota - prebiotic - probiotic - Propionic acid

Introduction: Propionic and methylmalonic acidemia (PA/MMA) are rare inborn errors of metabolism characterized by accumulation of propionyl CoA and/or methylmalonyl CoA, resulting in potentially serious metabolic crises and clinical complications. The gut microbiota contributes a significant proportion of total propionate production and provides a potentially modifiable target. Empiric use of oral antibiotics to reduce propionate production is a common approach but is hampered by possible drug resistance, perturbation of normal gut microbiota, and toxicity. Moreover, constipation, associated with low fiber intake, inadequate fluid intake, low gut motility, and other factors, is a chronic problem in this patient population and may influence propionate production. Newer management techniques that reduce the burden of propionate and address these clinical challenges are needed. Areas covered: This paper summarizes the potential contribution of gut-related factors in PA/MMA and considers modifying gut microbiota as a management approach. Expert opinion: Dietary management of PA/MMA may be improved by specific prebiotics that modify gut microbiota to stabilize or possibly reduce PA production.

Making the Arctic predictable : the changing information infrastructure of Arctic weather and sea ice services
Knol, Maaike ; Arbo, Peter ; Duske, Paula ; Gerland, Sebastian ; Lamers, Machiel ; Pavlova, Olga ; Sivle, Anders Doksæter ; Tronstad, Stein - \ 2018
Polar Geography 41 (2018)4. - ISSN 1088-937X - p. 279 - 293.
Arctic - information infrastructure - polar prediction - sea ice - shipping - weather

This paper explores the changing infrastructure around weather and sea ice information provisioning for Arctic marine areas. Traditionally, the most important providers of operational information on sea ice and weather conditions are the national sea ice and meteorological services. More recently, the community of Arctic information providers has become more heterogeneous with the establishment of numerous collaborative platforms. Three case studies will enhance our understanding of current developments (BarentsWatch, Polar View and Arctic Web). We analyze their organization and funding structures, the types of services they develop, and their target groups. Based upon these cases, we discuss the information infrastructure’s dynamics and underlying drivers of change. Apart from an expected need for customized services due to changing Arctic activity patterns, new initiatives arise due to a combination of (1) progress in information and communication technology, (2) a need to enhance interoperability of data systems, (3) and a desire to improve customized data conveyance from provider to user. The paper concludes with a discussion of the implications of the changing Arctic information infrastructure and defines directions for further research.

Sex differences in lipid metabolism are affected by presence of the gut microbiota
Baars, Annemarie ; Oosting, Annemarie ; Lohuis, Mirjam ; Koehorst, Martijn ; Aidy, Sahar El; Hugenholtz, Floor ; Smidt, Hauke ; Mischke, Mona ; Boekschoten, Mark V. ; Verkade, Henkjan J. ; Garssen, Johan ; Beek, Eline M. van der; Knol, Jan ; Vos, Paul de; Bergenhenegouwen, Jeroen van; Fransen, Floris - \ 2018
Scientific Reports 8 (2018)1. - ISSN 2045-2322

Physiological processes are differentially regulated between men and women. Sex and gut microbiota have each been demonstrated to regulate host metabolism, but it is unclear whether both factors are interdependent. Here, we determined to what extent sex-specific differences in lipid metabolism are modulated via the gut microbiota. While male and female Conv mice showed predominantly differential expression in gene sets related to lipid metabolism, GF mice showed differences in gene sets linked to gut health and inflammatory responses. This suggests that presence of the gut microbiota is important in sex-specific regulation of lipid metabolism. Further, we explored the role of bile acids as mediators in the cross-talk between the microbiome and host lipid metabolism. Females showed higher total and primary serum bile acids levels, independent of presence of microbiota. However, in presence of microbiota we observed higher secondary serum bile acid levels in females compared to males. Analysis of microbiota composition displayed sex-specific differences in Conv mice. Therefore, our data suggests that bile acids possibly play a role in the crosstalk between the microbiome and sex-specific regulation of lipid metabolism. In conclusion, our data shows that presence of the gut microbiota contributes to sex differences in lipid metabolism.

A synbiotic mixture of scGOS/lcFOS and Bifidobacterium breve M-16V increases faecal Bifidobacterium in healthy young children
Kosuwon, P. ; Lao-Araya, M. ; Uthaisangsook, S. ; Lay, C. ; Bindels, J. ; Knol, J. ; Chatchatee, P. - \ 2018
Beneficial Microbes 9 (2018)4. - ISSN 1876-2883 - p. 541 - 552.
Bifidobacterium - Gut microbiota - Healthy toddlers - Stool consistency - Synbiotic

Little is known about the impact of nutrition on toddler gut microbiota. The plasticity of the toddler gut microbiota indicates that nutritional modulation beyond infancy could potentially impact its maturation. The objective of this study was to determine the effect of consuming Young Child Formula (YCF) supplemented with short chain galactooligosaccharides and long chain fructooligosaccharides (scGOS/lcFOS, ratio 9:1) and Bifidobacterium breve M-16V on the development of the faecal microbiota in healthy toddlers. A cohort of 129 Thai children aged 1-3 years were included in a randomised controlled clinical study. The children were assigned to receive either YCF with 0.95 g/100 ml of scGOS/lcFOS and 1.8×107 cfu/g of B. breve M-16V (Active-YCF) or Control-YCF for 12 weeks. The composition and metabolic activity of the faecal microbiota, and the level of secretory immunoglobulin A were determined in the stool samples. The consumption of Active-YCF increased the proportion of Bifidobacterium (mean 27.3% at baseline to 33.3%, at week 12, P=0.012) with a difference in change from baseline at week 12 between the Active and Control of 7.48% (P=0.030). The consumption of Active-YCF was accompanied with a more acidic intestinal milieu compared to the Control-YCF. The pH value decreased statistically significantly in the Active-YCF group from a median of 7.05 at baseline to 6.79 at week 12 (P < 0.001). The consumption of Active-YCF was associated with a softer pudding-like stool consistency compared to the Control-YCF. At week 6 and week 12, the betweengroup difference in stool consistency was statistically significant (P=0.004 and P < 0.001, respectively). A Young Child Formula supplemented with scGOS/lcFOS and B. breve M-16V positively influences the development of the faecal microbiota in healthy toddlers by supporting higher levels of Bifidobacterium. The synbiotic supplementation is also accompanied with a more acidic intestinal milieu and softer stools.

Weighted single-step GWAS and gene network analysis reveal new candidate genes for semen traits in pigs
Marques, Daniele B.D. ; Bastiaansen, John W.M. ; Broekhuijse, Marleen L.W.J. ; Lopes, Marcos S. ; Knol, Egbert F. ; Harlizius, Barbara ; Guimarães, Simone E.F. ; Silva, Fabyano F. ; Lopes, Paulo S. - \ 2018
Genetics, Selection, Evolution 50 (2018)1. - ISSN 0999-193X

Background: In recent years, there has been increased interest in the study of the molecular processes that affect semen traits. In this study, our aim was to identify quantitative trait loci (QTL) regions associated with four semen traits (motility, progressive motility, number of sperm cells per ejaculate and total morphological defects) in two commercial pig lines (L1: Large White type and L2: Landrace type). Since the number of animals with both phenotypes and genotypes was relatively small in our dataset, we conducted a weighted single-step genome-wide association study, which also allows unequal variances for single nucleotide polymorphisms. In addition, our aim was also to identify candidate genes within QTL regions that explained the highest proportions of genetic variance. Subsequently, we performed gene network analyses to investigate the biological processes shared by genes that were identified for the same semen traits across lines. Results: We identified QTL regions that explained up to 10.8% of the genetic variance of the semen traits on 12 chromosomes in L1 and 11 chromosomes in L2. Sixteen QTL regions in L1 and six QTL regions in L2 were associated with two or more traits within the population. Candidate genes SCN8A, PTGS2, PLA2G4A, DNAI2, IQCG and LOC102167830 were identified in L1 and NME5, AZIN2, SPATA7, METTL3 and HPGDS in L2. No regions overlapped between these two lines. However, the gene network analysis for progressive motility revealed two genes in L1 (PLA2G4A and PTGS2) and one gene in L2 (HPGDS) that were involved in two biological processes i.e. eicosanoid biosynthesis and arachidonic acid metabolism. PTGS2 and HPGDS were also involved in the cyclooxygenase pathway. Conclusions: We identified several QTL regions associated with semen traits in two pig lines, which confirms the assumption of a complex genetic determinism for these traits. A large part of the genetic variance of the semen traits under study was explained by different genes in the two evaluated lines. Nevertheless, the gene network analysis revealed candidate genes that are involved in shared biological pathways that occur in mammalian testes, in both lines.

Comparative genomics and genotype-phenotype associations in Bifidobacterium breve
Bottacini, Francesca ; Morrissey, Ruth ; Esteban-Torres, Maria ; James, Kieran ; Breen, Justin van; Dikareva, Evgenia ; Egan, Muireann ; Lambert, Jolanda ; Limpt, Kees van; Knol, Jan ; O'Connell Motherway, Mary ; Sinderen, Douwe van - \ 2018
Scientific Reports 8 (2018)1. - ISSN 2045-2322

Bifidobacteria are common members of the gastro-intestinal microbiota of a broad range of animal hosts. Their successful adaptation to this particular niche is linked to their saccharolytic metabolism, which is supported by a wide range of glycosyl hydrolases. In the current study a large-scale gene-Trait matching (GTM) effort was performed to explore glycan degradation capabilities in B. breve. By correlating the presence/absence of genes and associated genomic clusters with growth/no-growth patterns across a dataset of 20 Bifidobacterium breve strains and nearly 80 different potential growth substrates, we not only validated the approach for a number of previously characterized carbohydrate utilization clusters, but we were also able to discover novel genetic clusters linked to the metabolism of salicin and sucrose. Using GTM, genetic associations were also established for antibiotic resistance and exopolysaccharide production, thereby identifying (novel) bifidobacterial antibiotic resistance markers and showing that the GTM approach is applicable to a variety of phenotypes. Overall, the GTM findings clearly expand our knowledge on members of the B. breve species, in particular how their variable genetic features can be linked to specific phenotypes.

Follicular development of sows at weaning in relation to estimated breeding value for within-litter variation in piglet birth weight
Costermans, N.G.J. ; Teerds, K.J. ; Keijer, J. ; Knol, E.F. ; Koopmanschap, R.E. ; Kemp, B. ; Soede, N.M. - \ 2018
Animal (2018). - ISSN 1751-7311 - 10 p.
lactation - litter uniformity - metabolism - reproduction - sows

In this study we aimed to identify possible causes of within-litter variation in piglet birth weight (birth weight variation) by studying follicular development of sows at weaning in relation to their estimated breeding value (EBV) for birth weight variation. In total, 29 multiparous sows (parity 3 to 5) were selected on their EBV for birth weight variation (SD in grams; High-EBV: 15.8±1.6, N=14 and Low-EBV: −24.7±1.5, N=15). The two groups of sows had similar litter sizes (15.7 v. 16.9). Within 24 h after parturition, piglets were cross-fostered to ensure 13 suckling piglets per sow. Sows weaned 12.8±1.0 and 12.7±1.0 piglets, respectively, at days 26.1±0.2 of lactation. Blood and ovaries were collected within 2 h after weaning. The right ovary was immediately frozen to assess average follicle size and percentage healthy follicles of the 15 largest follicles. The left ovary was used to assess the percentage morphologically healthy cumulus-oocyte complexes (COCs) of the 15 largest follicles. To assess the metabolic state of the sows, body condition and the circulating metabolic markers insulin, IGF1, non-esterified fatty acid, creatinine, leptin, urea and fibroblast growth factor 21 were analysed at weaning. No significant differences were found in any of the measured follicular or metabolic parameters between High-EBV and Low-EBV. A higher weight loss during lactation was related to a lower percentage healthy COCs (β= −0.65, P=0.02). Serum creatinine, a marker for protein breakdown, was negatively related to average follicle size (β= −0.60, P=0.05). Backfat loss during lactation was related to a higher backfat thickness at parturition and to a higher average follicle size (β=0.36, P<0.001) at weaning. In conclusion, we hypothesise that modern hybrid sows with more backfat at the start of lactation are able to mobilise more energy from backfat during lactation and could thereby spare protein reserves to support follicular development.

Cross-feeding interactions of gut symbionts driven by human milk oligosaccharidesand mucins
Chia, Loo Wee - \ 2018
Wageningen University. Promotor(en): Jan Knol, co-promotor(en): Clara Belzer. - Wageningen : Wageningen University - ISBN 9789463438476 - 187
Gastrointestinal function and microbiota development in preterm infants
Zwittink, Romy D. - \ 2018
Wageningen University. Promotor(en): Jan Knol, co-promotor(en): Clara Belzer. - Wageningen : Wageningen University - ISBN 9789463432757 - 164
Enhancing the Saliency of climate services for marine mobility sectors in European Arctic seas (SALIENSEAS) : Stakeholder Advisory Group workshop report
Lamers, M.A.J. ; Knol, Maaike ; Müller, Malte ; Blair, Berill ; Jeuring, J.H.G. ; Rasmussen, Till ; Sivle, Anders - \ 2018
Wageningen : - 28 p.
SALIENSEAS brings together a team of social and natural scientists, metocean service personnel, and end-users, with the aim to 1). Better understand the mobility patterns, constraints, challenges, decision-making contexts and information needs of end-users in different European Arctic marine sectors; 2). Develop and apply participatory tools for co-producing salient weather and sea ice services with Arctic marine end-users, and 3). Co-develop user-relevant and sector specific weather and sea ice services and dissemination systems dedicated to Arctic marine end-users tailored to key social, environmental and economic needs. This report provides an overview of the activities and discussions that took place during the first SALIENSEAS Stakeholder Advisory Group (SAG) workshop, held on 25 January 2018 at UiT The Arctic University of Norway in Tromsø, Norway. Participants of the SAG represented a wide variety of perspectives and needs related to maritime activities in the European Arctic, including expedition cruising, ice pilotage, ice breaking, fishing and hunting, and shipping. During this participatory workshop participants reflected on important information needs pertinent to planning and operations in their sectors. The core purpose of the workshop was twofold: 1) to identify the most pressing issues around metocean information availability and access, in terms of sector-specific needs to increase safety and efficiency of operations; and 2) to formulate a plan for efficient and relevant data collection from end users.
Fecal microbial composition associated with variation in feed efficiency in pigs depends on diet and sex
Verschuren, Lisanne M.G. ; Calus, Mario P.L. ; Jansman, Alfons J.M. ; Bergsma, Rob ; Knol, Egbert F. ; Gilbert, Hélène ; Zemb, Olivier - \ 2018
Journal of Animal Science 96 (2018)4. - ISSN 0021-8812 - p. 1405 - 1418.
Diet - Fecal microbiome - Feed efficiency - Pig - Sex
Dietary fiber content and composition affect microbial composition and activity in the gut, which in turn influence energetic contribution of fermentation products to the metabolic energy supply in pigs. This may affect feed efficiency (FE) in pigs. The present study investigated the relationship between the fecal microbial composition and FE in individual growing-finishing pigs. In addition, the effects of diet composition and sex on the fecal microbiome were studied. Fecal samples were collected of 154 grower-finisher pigs (3-way crossbreeds) the day before slaughter. Pigs were either fed a diet based on corn/soybean meal (CS) or a diet based on wheat/barley/by-products (WB). Fecal microbiome was characterized by 16S ribosomal DNA sequencing, clustered by operational taxonomic unit (OTU), and results were subjected to a discriminant approach combined with principal component analysis to discriminate diets, sexes, and FE extreme groups (10 high and 10 low FE pigs for each diet by sex-combination). Pigs on different diets and males vs. females had a very distinct fecal microbiome, needing only 2 OTU for diet (P = 0.020) and 18 OTU for sex (P = 0.040) to separate the groups. The 2 most important OTU for diet, and the most important OTU for sex, were taxonomically classified as the same bacterium. In pigs fed the CS diet, there was no significant association between FE and fecal microbiota composition based on OTU (P > 0.05), but in pigs fed the WB diet differences in FE were associated with 17 OTU in males (P = 0.018) and to 7 OTU in females (P = 0.010), with 3 OTU in common for both sexes. In conclusion, our results showed a diet and sex-dependent relationship between FE and the fecal microbial composition at slaughter weight in grower-finisher pigs.
A synbiotic-containing amino-acid-based formula improves gut microbiota in non-IgE-mediated allergic infants
Candy, David C.A. ; Ampting, Marleen T.J. Van; Oude Nijhuis, Manon M. ; Wopereis, Harm ; Butt, Assad M. ; Peroni, Diego G. ; Vandenplas, Yvan ; Fox, Adam T. ; Shah, Neil ; West, Christina E. ; Garssen, Johan ; Harthoorn, Lucien F. ; Knol, Jan ; Michaelis, Louise J. - \ 2018
Pediatric Research 83 (2018)3. - ISSN 0031-3998 - p. 677 - 686.
BackgroundPrebiotics and probiotics (synbiotics) can modify gut microbiota and have potential in allergy management when combined with amino-acid-based formula (AAF) for infants with cow's milk allergy (CMA).MethodsThis multicenter, double-blind, randomized controlled trial investigated the effects of an AAF-including synbiotic blend on percentages of bifidobacteria and Eubacterium rectale/Clostridium coccoides group (ER/CC) in feces from infants with suspected non-IgE-mediated CMA. Feces from age-matched healthy breastfed infants were used as reference (healthy breastfed reference (HBR)) for primary outcomes. The CMA subjects were randomized and received test or control formula for 8 weeks. Test formula was a hypoallergenic, nutritionally complete AAF including a prebiotic blend of fructo-oligosaccharides and the probiotic strain Bifidobacterium breve M-16V. Control formula was AAF without synbiotics.ResultsA total of 35 (test) and 36 (control) subjects were randomized; HBR included 51 infants. At week 8, the median percentage of bifidobacteria was higher in the test group than in the control group (35.4% vs. 9.7%, respectively; P<0.001), whereas ER/CC was lower (9.5% vs. 24.2%, respectively; P<0.001). HBR levels of bifidobacteria and ER/CC were 55% and 6.5%, respectively.ConclusionAAF including specific synbiotics, which results in levels of bifidobacteria and ER/CC approximating levels in the HBR group, improves the fecal microbiota of infants with suspected non-IgE-mediated CMA.
Genetic correlations between feed efficiency traits, and growth performance and carcass traits in purebred and crossbred pigs
Godinho, R.M. ; Bergsma, R. ; Silva, F.F. ; Sevillano, C.A. ; Knol, E.F. ; Lopes, M.S. ; Lopes, P.S. ; Bastiaansen, J.W.M. ; Guimarães, S.E.F. - \ 2018
Journal of Animal Science 96 (2018)3. - ISSN 0021-8812 - p. 817 - 829.
Breeding program - Carcass traits - Feed efficiency - Genetic correlations - Growing-Finishing pigs - Growth
Selection for feed efficiency (FE) is a strategy to reduce the production costs per unit of animal product, which is one of the major objectives of current animal breeding programs. In pig breeding, selection for FE and other traits traditionally takes place based on purebred pig (PB) performance at the nucleus level, while pork production typically makes use of crossbred animals (CB). The success of this selection, therefore, depends on the genetic correlation between the performance of PB and CB (rpc) and on the genetic correlation (rg) between FE and the other traits that are currently under selection. Different traits are being used to account for FE, but the rpc has been reported only for feed conversion rate. Therefore, this study aimed 1) to estimate the rpc for growth performance, carcass, and FE traits; 2) to estimate rg between traits within PB and CB populations; and 3) to compare three different traits representing FE: feed conversion rate, residual energy intake (REI), and residual feed intake (RFI). Phenotypes of 194,445 PB animals from 23 nucleus farms, and 46,328 CB animals from three farms where research is conducted under near commercial production conditions were available for this study. From these, 22,984 PB and 8,657 CB presented records for feed intake. The PB population consisted of five sire and four dam lines, and the CB population consisted of terminal cross-progeny generated by crossing sires from one of the five PB sire lines with commercially available two-way maternal sow crosses. Estimates of rpc ranged from 0.61 to 0.71 for growth performance traits, from 0.75 to 0.82 for carcass traits, and from 0.62 to 0.67 for FE traits. Estimates of rg between growth performance, carcass, and FE traits differed within PB and CB. REI and RFI showed substantial positive rg estimates in PB (0.84) and CB (0.90) populations. The magnitudes of rpc estimates indicate that genetic progress is being realized in CB at the production level from selection on PB performance at nucleus level. However, including CB phenotypes recorded on production farms, when predicting breeding values, has the potential to increase genetic progress for these traits in CB. Given the genetic correlations with growth performance traits and the genetic correlation between the performance of PB and CB, REI is an attractive FE parameter for a breeding program.
Relationship between the estimated breeding values for litter traits at birth and ovarian and embryonic traits and their additive genetic variance in gilts at 35 days of pregnancy
Silva, Carolina L.A. da; Mulder, Han A. ; Broekhuijse, Marleen L.W.J. ; Kemp, Bas ; Soede, Nicoline M. ; Knol, Egbert F. - \ 2018
Frontiers in Genetics 9 (2018)APR. - ISSN 1664-8021
Corpora lutea weight - Embryo - Gilts - Ovulation rate - Precision phenotyping
We investigated (1) the relationship between the estimated breeding values (EBVs) for litter traits at birth and ovulation rate (OR), average corpora luteal weight, uterine length and embryonic survival and development traits in gilts at 35 days of pregnancy by linear regression, (2) the genetic variance of OR, average corpora lutea (CL) weight, uterine length and embryonic survival and development traits at 35 days of pregnancy, and (3) the genetic correlations between these traits. Landrace (n = 86) and Yorkshire × Landrace (n = 304) gilts were inseminated and slaughtered at 35 days of pregnancy. OR was assessed by dissection of the CL on both ovaries. Individual CL was weighed and the average CL weight calculated. The number of embryos (total and vital) were counted and the vital embryos were individually weighed for calculation of within litter average and standard deviation (SD) of the embryo weight. Length of the uterine implantation site of the vital embryos was measured and the average per gilt calculated. Results suggests that increasing the EBV for total number of piglets born would proportionally increase OR and number of embryos, while decreasing the average CL weight. On the contrary, increasing the EBV for average piglet birth weight and for within litter birth weight standard deviation would increase the average CL weight. There was no relationship between the EBVs for BW and for BWSD and vital embryonic weight at 35 days of pregnancy. OR, average CL weight, number of embryos, average weight and implantation length of the vital embryos had all moderate to high heritabilities, ranging from 0.36 (±0.18) to 0.70 (±0.17). Thus, results indicate that there is ample genetic variation in OR, average CL weight and embryonic development traits. This knowledge could be used to optimize the balance between selection for litter size, average piglets birth weight and within litter birth weight uniformity.
Relations between ovarian & embryonic traits in pigs : effects of genetic selection for litter traits at birth
Lima Alvares Da Silva, Carolina - \ 2018
Wageningen University. Promotor(en): Bas Kemp, co-promotor(en): Nicoline Nieuwenhuizen-Soede; E.F. Knol. - Wageningen : Wageningen University - ISBN 9789463438858 - 196
Specific synbiotics in early life protect against diet-induced obesity in adult mice
Mischke, Mona ; Arora, Tulika ; Tims, Sebastian ; Engels, Eefje ; Sommer, Nina ; Limpt, Kees van; Baars, Annemarie ; Oozeer, Raish ; Oosting, Annemarie ; Bäckhed, Fredrik ; Knol, Jan - \ 2018
Diabetes, Obesity & Metabolism 20 (2018)6. - ISSN 1462-8902 - p. 1408 - 1418.
Body composition - Dietary intervention - Insulin resistance - Liver - Mouse model - Obesity therapy
Aims: The metabolic state of human adults is associated with their gut microbiome. The symbiosis between host and microbiome is initiated at birth, and early life microbiome perturbation can disturb health throughout life. Here, we determined how beneficial microbiome interventions in early life affect metabolic health in adulthood. Methods: Postnatal diets were supplemented with either prebiotics (scGOS/lcFOS) or synbiotics (scGOS/lcFOS with Bifidobacterium breve M-16V) until post-natal (PN) day 42 in a well-established rodent model for nutritional programming. Mice were subsequently challenged with a high-fat Western-style diet (WSD) for 8 weeks. Body weight and composition were monitored, as was gut microbiota composition at PN21, 42 and 98. Markers of glucose homeostasis, lipid metabolism and host transcriptomics of 6 target tissues were determined in adulthood (PN98). Results: Early life synbiotics protected mice against WSD-induced excessive fat accumulation throughout life, replicable in 2 independent European animal facilities. Adult insulin sensitivity and dyslipidaemia were improved and most pronounced changes in gene expression were observed in the ileum. We observed subtle changes in faecal microbiota composition, both in early life and in adulthood, including increased abundance of Bifidobacterium. Microbiota transplantation using samples collected from synbiotics-supplemented adolescent mice at PN42 to age-matched germ-free recipients did not transfer the beneficial phenotype, indicating that synbiotics-modified microbiota at PN42 is not sufficient to transfer long-lasting protection of metabolic health status. Conclusion: Together, these findings show the potential and importance of timing of synbiotic interventions in early life during crucial microbiota development as a preventive measure to lower the risk of obesity and improve metabolic health throughout life.
Deciphering the trophic interaction between Akkermansia muciniphila and the butyrogenic gut commensal Anaerostipes caccae using a metatranscriptomic approach
Chia, Loo Wee ; Hornung, Bastian V.H. ; Aalvink, Steven ; Schaap, Peter J. ; Vos, Willem M. de; Knol, Jan ; Belzer, Clara - \ 2018
Antonie van Leeuwenhoek: : Nederlandsch tijdschrift voor hygiëne, microbiologie en serologie 111 (2018)6. - ISSN 0003-6072 - p. 859 - 873.
Butyrate - Cross feeding - Keystone species - Microbiome - Mucin - Transcriptional regulation - Verrucomicrobia
Host glycans are paramount in regulating the symbiotic relationship between humans and their gut bacteria. The constant flux of host-secreted mucin at the mucosal layer creates a steady niche for bacterial colonization. Mucin degradation by keystone species subsequently shapes the microbial community. This study investigated the transcriptional response during mucin-driven trophic interaction between the specialised mucin-degrader Akkermansia muciniphila and a butyrogenic gut commensal Anaerostipes caccae. A. muciniphila monocultures and co-cultures with non-mucolytic A. caccae from the Lachnospiraceae family were grown anaerobically in minimal media supplemented with mucin. We analysed for growth, metabolites (HPLC analysis), microbial composition (quantitative reverse transcription PCR), and transcriptional response (RNA-seq). Mucin degradation by A. muciniphila supported the growth of A. caccae and concomitant butyrate production predominantly via the acetyl-CoA pathway. Differential expression analysis (DESeq 2) showed the presence of A. caccae induced changes in the A. muciniphila transcriptional response with increased expression of mucin degradation genes and reduced expression of ribosomal genes. Two putative operons that encode for uncharacterised proteins and an efflux system, and several two-component systems were also differentially regulated. This indicated A. muciniphila changed its transcriptional regulation in response to A. caccae. This study provides insight to understand the mucin-driven microbial ecology using metatranscriptomics. Our findings show that the expression of mucolytic enzymes by A. muciniphila increases upon the presence of a community member. This could indicate its role as a keystone species that supports the microbial community in the mucosal environment by increasing the availability of mucin sugars.
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.