Effect of genotype on duodenal expression of nutrient transporter genes in dairy cows

peer-reviewedBackground Studies have shown clear differences between dairy breeds in their feed intake and production efficiencies. The duodenum is critical in the coordination of digestion and absorption of nutrients. This study examined gene transcript abundance of important classes of nutrient transporters in the duodenum of non lactating dairy cows of different feed efficiency potential, namely Holstein-Friesian (HF), Jersey (JE) and their F1 hybrid. Duodenal epithelial tissue was collected at slaughter and stored at -80°C. Total RNA was extracted from tissue and reverse transcribed to generate cDNA. Gene expression of the following transporters, namely nucleoside; amino acid; sugar; mineral; and lipid transporters was measured using quantitative real-time RT-PCR. Data were statistically analysed using mixed models ANOVA in SAS. Orthogonal contrasts were used to test for potential heterotic effects and spearman correlation coefficients calculated to determine potential associations amongst gene expression values and production efficiency variables. Results While there were no direct effects of genotype on expression values for any of the genes examined, there was evidence for a heterotic effect (P < 0.05) on ABCG8, in the form of increased expression in the F1 genotype compared to either of the two parent breeds. Additionally, a tendency for increased expression of the amino acid transporters, SLC3A1 (P = 0.072), SLC3A2 (P = 0.081) and SLC6A14 (P = 0.072) was also evident in the F1 genotype. A negative (P < 0.05) association was identified between the expression of the glucose transporter gene SLC5A1 and total lactational milk solids yield, corrected for body weight. Positive correlations (P < 0.05) were also observed between the expression values of genes involved in common transporter roles. Conclusion This study suggests that differences in the expression of sterol and amino acid transporters in the duodenum could contribute towards the documented differences in feed efficiency between HF, JE and their F1 hybrid. Furthermore, positive associations between the expression of genes involved in common transporter roles suggest that these may be co-regulated. The study identifies potential candidates for investigation of genetic variants regulating nutrient transport and absorption in the duodenum in dairy cows, which may be incorporated into future breeding programmes

Transcriptome analyses reveal reduced hepatic lipid synthesis and accumulation in more feed efficient beef cattle

peer-reviewedThe genetic mechanisms controlling residual feed intake (RFI) in beef cattle are still largely unknown. Here we performed whole transcriptome analyses to identify differentially expressed (DE) genes and their functional roles in liver tissues between six extreme high and six extreme low RFI steers from three beef breed populations including Angus, Charolais, and Kinsella Composite (KC). On average, the next generation sequencing yielded 34 million single-end reads per sample, of which 87% were uniquely mapped to the bovine reference genome. At false discovery rate (FDR)  2, 72, 41, and 175 DE genes were identified in Angus, Charolais, and KC, respectively. Most of the DE genes were breed-specific, while five genes including TP53INP1, LURAP1L, SCD, LPIN1, and ENSBTAG00000047029 were common across the three breeds, with TP53INP1, LURAP1L, SCD, and LPIN1 being downregulated in low RFI steers of all three breeds. The DE genes are mainly involved in lipid, amino acid and carbohydrate metabolism, energy production, molecular transport, small molecule biochemistry, cellular development, and cell death and survival. Furthermore, our differential gene expression results suggest reduced hepatic lipid synthesis and accumulation processes in more feed efficient beef cattle of all three studied breeds

Does systematic instruction in rhythmic movement influence the speech of the deaf

This paper discusses the influence of rhythm in teaching of hearing impaired children

Plane of nutrition affects the phylogenetic diversity and relative abundance of transcriptionally active methanogens in the bovine rumen

peer-reviewedMethane generated during enteric fermentation in ruminant livestock species is a major contributor to global anthropogenic greenhouse gas emissions. A period of moderate feed restriction followed by ad libitum access to feed is widely applied in cattle management to exploit the animal’s compensatory growth potential and reduce feed costs. In the present study, we utilised microbial RNA from rumen digesta samples to assess the phylogenetic diversity of transcriptionally active methanogens from feed-restricted and non-restricted animals. To determine the contribution of different rumen methanogens to methanogenesis during dietary restriction of cattle, we conducted high-throughput mcrA cDNA amplicon sequencing on an Illumina MiSeq and analysed both the abundance and phylogenetic origin of different mcrA cDNA sequences. When compared to their unrestricted contemporaries, in feed-restricted animals, the methanogenic activity, based on mcrA transcript abundance, of Methanobrevibacter gottschalkii clade increased while the methanogenic activity of the Methanobrevibacter ruminantium clade and members of the Methanomassiliicoccaceae family decreased. This study shows that the quantity of feed consumed can evoke large effects on the composition of methanogenically active species in the rumen of cattle. These data potentially have major implications for targeted CH4 mitigation approaches such as anti-methanogen vaccines and/or tailored dietary management

Assessing aquatic macrophyte recovery responses following lanthanum-modified bentonite applications

Lanthanum – modified bentonite (LMB) has been used successfully in lake restoration projects globally to control phosphorus (P) release from sediments to overlying waters. However, desirable aquatic macrophyte (macrophyte) species recovery following LMB applications, where reported, has been slow or non-existent, despite improvements in water quality. The reasons behind this lack of recovery are unknown. This study is the first comprehensive assessment of macrophyte recovery following sediment capping in lakes and focusses on physical, chemical, and biological constraints which could potentially result in ‘ecological bottlenecks’ to macrophyte reestablishment in lake restoration generally. An assessment of short- (0 – 2 years) and long-term (2 – 10 years) changes in macrophyte composition in lakes following LMB applications revealed that macrophyte communities do not meet European legislative targets, e.g. the Water Framework Directive for good ecological status. Low seedbank viability, dominance of pioneering non-native species and scarcity of external propagule sources may be the main restrictions on macrophyte recovery in LMB treated lakes. A germination trial confirmed that an LMB layer, formed on surface sediments following application, did not impede macrophyte germination success. However, LMB did significantly reduce benthic algal growth which was species-specific. Bioassay experiments revealed that macrophyte species responded differently to LMB under different light conditions. Desirable and non-native invasive species and nationally rare protected species responded in-line with their strategy traits. All species grew when applied with LMB in light conditions, however, all species grew less when applied with LMB in dark conditions. The findings presented demonstrate that additional measures may be required alongside sediment capping to force ecologically recovery, especially where restoration planning is designed to meet ecological targets for desirable vegetation composition. Transplantation of macrophytes may be needed to ensure the establishment of desirable species if viable seedbanks no longer occur following improvements in water quality, or for waterbodies that are isolated from propagule distribution sources, or where pioneering macrophyte species dominate communities

Keeping Up with the Joneses: How Snapchat Stays Relevant

The article we chose from Fortune Magazine is entitled “3,2,1 Countdown to the Snapchat Revolution” and is written by Jessi Hempel, Adam Lashinsky, Marty Jones, and Chanelle Bessette. The article discusses the history of Snapchat and the past and present challenges it has had to face. This ranges from the lawsuit brought by one of the original founders to rejecting an acquisition offer from Facebook of over $3 billion. Big businesses are not apt to jump on the bandwagon for marketing purposes because of their lack of data collection. The discussion varies from what the app actually is, “a disappearing-photo-sending service,” the changing demographics of the users, and how the app has evolved over time

Psychosocial resources underlying disaster survivors' posttraumatic stress symptom trajectories: insight from in-depth interviews with mothers who survived Hurricane Katrina

Background: Weather-related disasters, including hurricanes, are becoming more frequent and severe due to climate change. Vulnerable populations, such as people with low income and racial and ethnic minorities, are particularly prone to increased levels of physical harm and psychiatric adversity from weather-related events.Objectives: We aimed to explore psychosocial resources and coping of survivors with three different posttraumatic stress symptom (PTSS) trajectories (High-Decreasing, Moderate-Decreasing, and High-Stable), after Hurricane Katrina across two different time points: F1 (1-year post-disaster) and F3 (12 years post-disaster).Method: Participants in this multi-method study were part of a larger cohort of the Resilience in Survivors of Katrina (RISK) project. Transcripts of interviews completed at the two time points were analysed using two qualitative methods, combining thematic analysis and narrative analysis, and providing both breadth of perspectives with the depth of specific case studies.Results: Sixteen survivors completed interviews at both F1 and F3. From our in-depth analysis of the data, we derived five inductive themes: 'Hope,' 'Adaptive vs maladaptive avoidance,' 'Emotional delay,' 'Acceptance, Finding Meaning and Being in the Moment,' and 'Coping strategies.' Survivors with High-Decreasing and Moderate-Decreasing PTSS trajectories experienced hope for future, accepted the hurricane and its results, and found efficient ways to cope with their situation. Survivors with High-Stable PTSS trajectories tended to express a lack of hope for future and struggled to be mindful and accept the hurricane and its harm. Unlike survivors with High-Decreasing and Moderate-Decreasing PTSS trajectories, survivors with High-Stable PTSS trajectories also reported less social and family support and faced more discrimination and racism.Conclusion: There are factors beyond individual-level psychosocial resources that may shape post-disaster resilience. When supporting survivors after a weather-related disaster, it is essential to provide ongoing psychological, financial, and physical assistance to bolster these resources

Examination of the molecular control of ruminal epithelial function in response to dietary restriction and subsequent compensatory growth in cattle

Background The objective of this study was to investigate the effect of dietary restriction and subsequent compensatory growth on the relative expression of genes involved in volatile fatty acid transport, metabolism and cell proliferation in ruminal epithelial tissue of beef cattle. Sixty Holstein Friesian bulls (mean liveweight 370 ± 35 kg; mean age 479 ± 15 d) were assigned to one of two groups: (i) restricted feed allowance (RES; n = 30) for 125 d (Period 1) followed by ad libitum access to feed for 55 d (Period 2) or (ii) ad libitum access to feed throughout (ADLIB; n = 30). Target growth rate for RES was 0.6 kg/d during Period 1. At the end of each dietary period, 15 animals from each treatment group were slaughtered and ruminal epithelial tissue and liquid digesta harvested from the ventral sac of the rumen. Real-time qPCR was used to quantify mRNA transcripts of 26 genes associated with ruminal epithelial function. Volatile fatty acid analysis of rumen fluid from individual animals was conducted using gas chromatography. Results Diet × period interactions were evident for genes involved in ketogenesis (BDH2, P = 0.017), pyruvate metabolism (LDHa, P = 0.048; PDHA1, P = 0.015) and cellular transport and structure (DSG1, P = 0.019; CACT, P = 0.027). Ruminal concentrations of propionic acid (P = 0.018) and n-valeric acid (P = 0.029) were lower in RES animals, compared with ADLIB, throughout the experiment. There was also a strong tendency (P = 0.064) toward a diet × period interaction for n-butyric with higher concentrations in RES animals, compared with ADLIB, during Period 1. Conclusions These data suggest that following nutrient restriction, the structural integrity of the rumen wall is compromised and there is upregulation of genes involved in the production of ketone bodies and breakdown of pyruvate for cellular energy. These results provide an insight into the potential molecular mechanisms regulating ruminal epithelial absorptive metabolism and growth following nutrient restriction and subsequent compensatory growth

Effect of dietary restriction and subsequent re-alimentation on the transcriptional profile of bovine jejunal epithelium

peer-reviewedCompensatory growth (CG), an accelerated growth phenomenon which occurs following a period of dietary restriction is utilised worldwide in animal production systems as a management practise to lower feed costs. The objective of this study was to evaluate the contribution of jejunal epithelial to CG in cattle through transcriptional profiling following a period of dietary restriction as well as subsequent re-alimentation induced CG. Sixty Holstein Friesian bulls were separated into two groups; RES and ADLIB, with 30 animals in each. RES animals were offered a restricted diet for 125 days (Period 1) followed by ad libitum feeding for 55 days (Period 2). ADLIB animals had ad libitum access to feed across both periods 1 and 2. At the end of each period, 15 animals from each treatment group were slaughtered, jejunal epithelium collected and RNAseq analysis performed. Animals that were previously diet restricted underwent CG, gaining 1.8 times the rate of their non-restricted counterparts. Twenty-four genes were differentially expressed in RES compared to ADLIB animals at the end of Period 1, with only one gene, GSTA1, differentially expressed between the two groups at the end of Period 2. When analysed within treatment (RES, Period 2 v Period 1), 31 genes were differentially expressed between diet restricted and animals undergoing CG. Dietary restriction and subsequent re-alimentation were associated with altered expression of genes involved in digestion and metabolism as well as those involved in cellular division and growth. Compensatory growth was also associated with greater expression of genes involved in cellular protection and detoxification in jejunal epithelium. This study highlights some of the molecular mechanisms regulating the response to dietary restriction and subsequent re-alimentation induced CG in cattle; however the gene expression results suggest that most of the CG in jejunal epithelium had occurred by day 55 of re-alimentation

Effect of Dietary Restriction and Subsequent Re-Alimentation on the Transcriptional Profile of Bovine Skeletal Muscle

peer-reviewedCompensatory growth (CG), an accelerated growth phenomenon which occurs following a period of dietary restriction is exploited worldwide in animal production systems as a method to lower feed costs. However the molecular mechanisms regulated CG expression remain to be elucidated fully. This study aimed to uncover the underlying biology regulating CG in cattle, through an examination of skeletal muscle transcriptional profiles utilising next generation mRNA sequencing technology. Twenty Holstein Friesian bulls were fed either a restricted diet for 125 days, with a target growth rate of 0.6 kg/day (Period 1), following which they were allowed feed ad libitum for a further 55 days (Period 2) or fed ad libitum for the entirety of the trial. M. longissimus dorsi biopsies were harvested from all bulls on days 120 and 15 of periods 1 and 2 respectively and RNAseq analysis was performed. During realimentation in Period 2, previously restricted animals displayed CG, growing at 1.8 times the rate of the ad libitum control animals. Compensating animals were also more feed efficient during re-alimentation and compensated for 48% of their previous dietary restriction. 1,430 and 940 genes were identified as significantly differentially expressed (Benjamini Hochberg adjusted P < 0.1) in periods 1 and 2 respectively. Additionally, 2,237 genes were differentially expressed in animals undergoing CG relative to dietary restriction. Dietary restriction in Period 1 was associated with altered expression of genes involved in lipid metabolism and energy production. CG expression in Period 2 occurred in association with greater expression of genes involved in cellular function and organisation. This study highlights some of the molecular mechanisms regulating CG in cattle. Differentially expressed genes identified are potential candidate genes for the identification of biomarkers for CG and feed efficiency, which may be incorporated into future breeding programme