Texas AgriLife Research

About: Texas AgriLife Research is a based out in . It is known for research contribution in the topics: Population & Forage. The organization has 577 authors who have published 769 publications receiving 18041 citations.

Cellulosic biofuel contributions to a sustainable energy future: Choices and outcomes

Abstract: Cellulosic crops are projected to provide a large fraction of transportation energy needs by mid-century. However, the anticipated land requirements are substantial, which creates a potential for environmental harm if trade-offs are not sufficiently well understood to create appropriately prescriptive policy. Recent empirical findings show that cellulosic bioenergy concerns related to climate mitigation, biodiversity, reactive nitrogen loss, and crop water use can be addressed with appropriate crop, placement, and management choices. In particular, growing native perennial species on marginal lands not currently farmed provides substantial potential for climate mitigation and other benefits.

Pathogenesis and immunobiology of brucellosis: review of Brucella-host interactions.

Abstract: This review of Brucella–host interactions and immunobiology discusses recent discoveries as the basis for pathogenesis-informed rationales to prevent or treat brucellosis. Brucella spp., as animal pathogens, cause human brucellosis, a zoonosis that results in worldwide economic losses, human morbidity, and poverty. Although Brucella spp. infect humans as an incidental host, 500,000 new human infections occur annually, and no patient-friendly treatments or approved human vaccines are reported. Brucellae display strong tissue tropism for lymphoreticular and reproductive systems with an intracellular lifestyle that limits exposure to innate and adaptive immune responses, sequesters the organism from the effects of antibiotics, and drives clinical disease manifestations and pathology. Stealthy brucellae exploit strategies to establish infection, including i) evasion of intracellular destruction by restricting fusion of type IV secretion system-dependent Brucella-containing vacuoles with lysosomal compartments, ii) inhibition of apoptosis of infected mononuclear cells, and iii) prevention of dendritic cell maturation, antigen presentation, and activation of naive T cells, pathogenesis lessons that may be informative for other intracellular pathogens. Data sets of next-generation sequences of Brucella and host time-series global expression fused with proteomics and metabolomics data from in vitro and in vivo experiments now inform interactive cellular pathways and gene regulatory networks enabling full-scale systems biology analysis. The newly identified effector proteins of Brucella may represent targets for improved, safer brucellosis vaccines and therapeutics.

Rumen Bacterial Diversity Dynamics Associated with Changing from Bermudagrass Hay to Grazed Winter Wheat Diets

Abstract: Rumen bacterial communities in forage-fed and grazing cattle continually adapt to a wide range of changing dietary composition, nutrient density, and environmental conditions. We hypothesized that very distinct community assemblages would develop between the fiber and liquid fractions of rumen contents in animals transitioned from bermudagrass hay diet to a grazed wheat diet. To address this hypothesis, we designed an experiment utilizing a 16S-based bTEFAP pyrosequencing technique to characterize and elucidate changes in bacterial diversity among the fiber and liquid rumen fractions and whole rumen contents of 14 (Angus × Hereford) ruminally cannulated steers sequentially fed bermudagrass hay (Cynodon dactylon; 34 days) and grazing wheat forage (28 days). Bermudagrass hay was a conserved C4 perennial grass lower in protein and higher in fiber (11% and 67%, respectively) content than grazed winter wheat (Triticum aestivum), a C3 annual grass with higher protein (20%) and a large (66%) soluble fraction. Significant differences in the OTU estimates (Chao1, Ace, and Rarefaction) were detected between fractions of both diets, with bermudagrass hay supporting greater diversity than wheat forage. Sequences were compared with a 16S database using BLASTn and assigned sequences to respective genera and genera-like units based on the similarity value to known sequences in the database. Predominant genera were Prevotella (up to 33%) and Rikenella-like (up to 28%) genera on the bermudagrass diet and Prevotella (up to 56%) genus on the wheat diet irrespective of the fractions. Principle component analyses accounted for over 95% of variation in 16S estimated bacterial community composition in all three fractions and clearly differentiated communities associated with each diet. Overall, bermudagrass hay diets clustered more clearly than wheat diets. These data are the first to explore bacterial diversity dynamics in a common population of animals in response to contrasting grass forage diets.

National Beef Quality Audit-2000: survey of targeted cattle and carcass characteristics related to quality, quantity, and value of fed steers and heifers.

Abstract: The National Beef Quality Audit-2005 assessed the current status of quality and consistency of US fed steers and heifers Hide colors or breed type were black (563%), red (186%), Holstein (79%), gray (60%), yellow (49%), brown (30%), white (23%), and brindle (10%) Identification method and fre- quency were lot visual tags (632%), individual visual tags (387%), metal-clip tags (118%), electronic tags (35%), bar-coded tags (03%), by other means (25%), and without identification (97%) Brand frequencies were no (613%), 1 (351%), and 2 or more (36%), and brands were located on the butt (265%), side (74%), and shoulder (12%) There were 223% of cattle with- out horns, and the majority of those with horns (522%) were between 254 and 127 cm in length Percentages of animals with mud or manure on specific body loca- tions were none (258%), legs (614%), belly (559%), side (226%), and top-line (100%) Permanent incisor number and occurrence were zero (822%), 1 (52%), 2 (99%), 3 (04%), 4 (12%), 5 (01%), 6 (03%), 7 (00%), and 8 (07%) Most carcasses (648%) were not bruised, 258% had one bruise, and 94% had multiple bruises Bruise location and incidence were round (106%), loin (326%), rib (195%), chuck (270%), and brisket, flank, and plate (103%) Condemnation item and incidence were liver (247%), lungs (115%), tripe (116%), heads (60%), tongues (97%), and carcasses (00%) Car- cass evaluation revealed these traits and frequencies: steer (637%), heifer (362%), bullock (005%), and cow (004%) sex classes; dark-cutters (19%); A (971%), B (17%), and C or older (12%) overall maturities; and native (909%), dairy-type (83%), and Bos indicus (08%) estimated breed types Mean USDA yield grade (YG) traits were USDA YG (29), HCW (3599 kg), adjusted fat thickness (13 cm), LM area (864 cm 2 ), and KPH (23%) The USDA YG were YG 1 (165%), YG 2 (363%), YG 3 (331%), YG 4 (118%), and YG 5 (23%) Mean USDA quality grade traits were USDA quality grade (Select 90 ), marbling score (Small 32 ), over- all maturity (A 64 ), lean maturity (A 57 ), and skeletal ma- turity (A 68 ) Marbling score distribution was Slightly Abundant or greater (27%), Moderate (43%), Modest (144%), Small (345%), Slight (412%), and Traces or less (29%) This information helps the beef industry measure progress and provides a benchmark for future educational and research activities

Population- and genome-specific patterns of linkage disequilibrium and SNP variation in spring and winter wheat (Triticum aestivum L.)

Abstract: Background: Single nucleotide polymorphisms (SNPs) are ideally suited for the construction of high-resolution genetic maps, studying population evolutionary history and performing genome-wide association mapping experiments. Here, we used a genome-wide set of 1536 SNPs to study linkage disequilibrium (LD) and population structure in a panel of 478 spring and winter wheat cultivars (Triticum aestivum) from 17 populations across the United States and Mexico. Results: Most of the wheat oligo pool assay (OPA) SNPs that were polymorphic within the complete set of 478 cultivars were also polymorphic in all subpopulations. Higher levels of genetic differentiation were observed among wheat lines within populations than among populations. A total of nine genetically distinct clusters were identified, suggesting that some of the pre-defined populations shared significant proportion of genetic ancestry. Estimates of population structure (FST) at individual loci showed a high level of heterogeneity across the genome. In addition, seven genomic regions with elevated FST were detected between the spring and winter wheat populations. Some of these regions overlapped with previously mapped flowering time QTL. Across all populations, the highest extent of significant LD was observed in the wheat D-genome, followed by lower LD in the A- and B-genomes. The differences in the extent of LD among populations and genomes were mostly driven by differences in long-range LD ( > 10 cM). Conclusions: Genome- and population-specific patterns of genetic differentiation and LD were discovered in the populations of wheat cultivars from different geographic regions. Our study demonstrated that the estimates of population structure between spring and winter wheat lines can identify genomic regions harboring candidate genes involved in the regulation of growth habit. Variation in LD suggests that breeding and selection had a different impact on each wheat genome both within and among populations. The higher extent of LD in the wheat D-genome versus the A- and B-genomes likely reflects the episodes of recent introgression and population bottleneck accompanying the origin of hexaploid wheat. The assessment of LD and population structure in this assembled panel of diverse lines provides critical information for the development of genetic resources for genome-wide association mapping of agronomically important traits in wheat.