Autofluorescence excitation‐emission matrices as a quantitative tool for the assessment of meat quality

Commercially produced meat is currently graded by a complex and partly subjective multiparameter methodology; a quantitative method of grading, using small samples would be desirable. Here, we investigate the correlation between commercial grades of beef and spectral signatures of native fluorophores in such small samples. Beef samples of different commercial grades were characterized by fluorescence spectroscopy complemented by biochemical and histological assessment. The excitation‐emission matrices of the specimens reveal five prominent native autofluorescence signatures in the excitation range from 250 to 350 nm, derived mainly from tryptophan and intramuscular fat. We found that these signatures reflect meat grade and can be used for its determination.      

The four hexamerin genes in the honey bee: structure,molecular evolution and function deduced from expression patterns in queens,workers and drones

Background  

Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens.     

Development and characterization of a synthetic promoter for selective expression in proliferating endothelial cells

BACKGROUND: Systemic administration of non-viral gene therapy provides better access to tumors than local administration. Development of a promoter that restricts expression of cytotoxic proteins to the tumor vasculature will increase the safety of the system by minimizing expression in the non-dividing endothelial cells of the vasculature of non-target tissues. METHODS: Cell cycle promoters were tested for selective expression in dividing cells vs. non-dividing cells in vitro and promoter strength was compared to the cytomegalovirus (CMV) promoter. Successful promoter candidates were tested in vivo using two proliferating endothelium mouse models. Ovarectomized mice were injected with estradiol prior to lipoplex administration and expression levels were measured in the lungs and uterus 4 days after administration. The second model was a subcutaneous tumor model and expression levels were measured in the lungs and tumors. For both animal models, expression levels from the proliferating endothelium promoter were compared to that obtained from a CMV promoter. RESULTS: The results showed that the Cdc6 promoter yielded higher expression in proliferating vs. non-proliferating cells. Secondly, promoter strength could be selectively increased in endothelial cells by the addition of a multimerized endothelin enhancer (ET) to the Cdc6 promoter. Thirdly, comparison of expression levels in the lungs vs. uterus in the ovarectomized mouse model and lungs vs. tumor in the mouse tumor model showed expression was much higher in the uterus and the tumor than in the lungs for the ET/Cdc6 promoter, and expression levels were comparable to that of the CMV promoter in the hypervascularized tissues. CONCLUSIONS: These results demonstrate that the combination of the endothelin enhancer with the Cdc6 promoter yields selective expression in proliferating endothelium and can be used to express cytotoxic proteins to treat vascularized tumors.     

Status of complete proteome analysis by mass spectrometry: SILAC labeled yeast as a model system

Background  

Mass spectrometry has become a powerful tool for the analysis of large numbers of proteins in complex samples, enabling much of proteomics. Due to various analytical challenges, so far no proteome has been sequenced completely. O'Shea, Weissman and co-workers have recently determined the copy number of yeast proteins, making this proteome an excellent model system to study factors affecting coverage.     

Optical imaging of luminescence for in vivo quantification of gene electrotransfer in mouse muscle and knee

Background  

Optical imaging is an attractive non-invasive way to evaluate the expression of a transferred DNA, mainly thanks to its lower cost and ease of realization. In this study optical imaging was evaluated for monitoring and quantification of the mouse knee joint and tibial cranial muscle electrotransfer of a luciferase encoding plasmid. Optical imaging was applied to study the kinetics of luciferase expression in both tissues.     

Increased shear stress with upregulation of VEGF-A and its receptors and MMP-2, MMP-9, and TIMP-1 in venous stenosis of hemodialysis grafts

Venous injury and subsequent venous stenosis formation are responsible for hemodialysis graft failure. Our hypothesis is that these pathological changes are in part related to changes in wall shear stress (WSS) that results in the activation of matrix regulatory proteins causing subsequent venous stenosis formation. In the present study, we examined the serial changes in WSS, blood flow, and luminal vessel area that occur subsequent to the placement of a hemodialysis graft in a porcine model of chronic renal insufficiency. We then determined the corresponding histological, morphometric, and kinetic changes of several matrix regulatory proteins including VEGF-A, its receptors, matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1, and TIMP-2. WSS was estimated by obtaining blood flow and luminal vessel area by performing phase-contrast MRI with magnetic resonance angiography in 21 animals at 1 day after graft placement and prior to death on day 3 (n = 7), day 7 (n = 7), and day 14 (n = 7). At all time points, the mean WSS at the vein-to-graft anastomosis was significantly higher than that at the control vein (P < 0.05). WSS had a bimodal distribution with peaks on days 1 and 7 followed by a significant reduction in WSS by day 14 (P < 0.05 compared with day 7) and a decrease in luminal vessel area compared with control vessels. By day 3, there was a significant increase in VEGF-A and pro-MMP-9 followed by, on day 7, increased pro-MMP-2, active MMP-2, and VEGF receptor (VEGFR)-2 (P < 0.05) and, by day 14, increased VEGFR-1 and TIMP-1 (P < 0.05) at the vein-to-graft anastomosis compared with control vessels. Over time, the neointima thickened and was composed primarily of alpha-smooth muscle actin-positive cells with increased cellular proliferation. Our data suggest that hemodialysis graft placement leads to early increases in WSS, VEGF-A, and pro-MMP-9 followed by subsequent increases in pro-MMP-2, active MMP-2, VEGFR-1, VEGFR-2, and TIMP-1, which may contribute to the development of venous stenosis.     

Morphological and biochemical responses of selected germplasm of tobacco to soil inoculation with Pythium aphanidermatum

The effect of inoculation with Pythium aphanidermatum was studied on total phenol (TP), salicylic acid (SA), chlorophylls and carotenoid contents of leaves and plant growth characteristics of five tobacco cultivars, namely RK-10 P3, RK-12 P3, RK-13 P4, RK-18 P8 and RK-26 P3, to assess cultivar response at biochemical and morphological levels. Root rot measured at 0–5 scale was 2.66 on cv. RK-10 P3, followed by 2. 33 on cv. RK-18 P8, 1.33 on cv. RK-26 P3 and 1.0 on cv. RK-13 P4. The cv. RK-12 P3 did not develop measurable root rot. The rhizosphere population of root rot fungus increased over time, being highest on the cv. RK-10 P3 (P ≤ 0.001), followed by cvs. RK-18 P8, RK-26 P3, RK-13 P4 and RK-12 P3. Inoculation with the fungus resulted in 5% (cv. RK-10 P3), 10.3% (cv. RK-18 P8, P ≤ 0.05), 10.9% (cv. RK-26 P3, P ≤ 0.05), 16.4% (cv. RK-13 P4, P ≤ 0.01) and 41.5% (cv. RK-12 P3, P ≤ 0.001) increase in the TP content of leaves. SA concentration in tobacco leaves increased marginally (0.8%–3%) in cvs. RK-10 P3, RK-18 P8 and RK-26 P3, but considerably (16%–17%, P ≤ 0.01) in cv. RK-13 and RK-12 P3 in comparison to uninoculated plants. Total chlorophyll content of leaves in response to inoculation with P. aphanidermatum decreased by 27% and 23% in tobacco cvs. RK-10 P3 and RK-18 P8 (P ≤ 0.001) and 17.6 (P ≤ 0.01) and 10.6% (P ≤ 0.05) in cv. RK-26 P3 and RK-13 P4, respectively. Reduction in chlorophylls a and b was 20% and 15% in cv. RK-10 P3 and 20% and 11% in cv. RK-18 P8. Total carotenoid contents of tobacco leaves decreased significantly in cvs. RK-10 P3 and RK-18 P8 (P ≤ 0.05). Significant and greater decrease in plant growth variables was recorded in the cultivars in which increase in TP and SA was lower and decrease in chlorophyll and carotenoids was greater. This study has revealed that greater synthesis of TP and SA may provide resistance in tobacco plants against P. aphanidermatum. The cv. RK-12 P3, in which greatest increase in the SA (17%) and TP (41.5%) was recorded, did not exhibit a significant decrease in plant growth variables and leaf pigments (P ≤ 0.05).     

Compositional studies and biological activities of some mash bean (Vigna mungo (L.) Hepper) cultivars commonly consumed in Pakistan

Background

In recent years, the desire to adopt a healthy diet has drawn attention to legume seeds and food products derived from them. Mash bean is an important legume crop used in Pakistan however a systematic mapping of the chemical composition of mash bean seeds is lacking. Therefore seeds of four mash bean (Vigna mungo (L.) Hepper, family Leguminoseae) cultivars (NARC-Mash-1, NARC-Mash-2, NARC-Mash-3, NARC-Mash-97) commonly consumed in Pakistan have been analyzed for their chemical composition, antioxidant potential and biological activities like inhibition of formation of advanced glycation end products (AGE) activity and tyrosinase inhibition activity.

Results

The investigated cultivars varied in terms of biochemical composition to various extents. Mineral composition indicated potassium and zinc in highest and lowest amounts respectively, in all cultivars. The amino acid profile in protein of these cultivars suggested cysteine is present in lowest quantity in all cultivars while fatty acid distribution pattern indicated unsaturated fatty acids as major fatty acids in all cultivars. All cultivars were found to be rich source of tocopherols and sterols. Fourier transform infrared spectroscopy (FTIR) fingerprints of seed flour and extracts indicated major functional groups such as polysaccharides, lipids, amides, amines and amino acids. Results indicated that all investigated cultivars possessed appreciable antioxidant potential.

Conclusions

All cultivars are rich source of protein and possess sufficient content of dietary fiber, a balanced amino acid profile, low saturated fatty acids and antioxidant capacity that rationalizes many traditional uses of seeds of this crop besides its nutritional importance. The collected data will be useful for academic and corporate researchers, nutritionists and clinical dieticians as well as consumers. If proper attention is paid, it may become an important export commodity and may fetch considerable foreign exchange for Pakistan.     

Genome-wide association study of reproductive traits in Nellore heifers using Bayesian inference

Background

An important goal of Zebu breeding programs is to improve reproductive performance. A major problem faced with the genetic improvement of reproductive traits is that recording the time for an animal to reach sexual maturity is costly. Another issue is that accurate estimates of breeding values are obtained only a long time after the young bulls have gone through selection. An alternative to overcome these problems is to use traits that are indicators of the reproductive efficiency of the herd and are easier to measure, such as age at first calving. Another problem is that heifers that have conceived once may fail to conceive in the next breeding season, which increases production costs. Thus, increasing heifer’s rebreeding rates should improve the economic efficiency of the herd. Response to selection for these traits tends to be slow, since they have a low heritability and phenotypic information is provided only later in the life of the animal. Genome-wide association studies (GWAS) are useful to investigate the genetic mechanisms that underlie these traits by identifying the genes and metabolic pathways involved.

Results

Data from 1853 females belonging to the Agricultural Jacarezinho LTDA were used. Genotyping was performed using the BovineHD BeadChip (777 962 single nucleotide polymorphisms (SNPs)) according to the protocol of Illumina - Infinium Assay II ® Multi-Sample HiScan with the unit SQ ™ System. After quality control, 305 348 SNPs were used for GWAS. Forty-two and 19 SNPs had a Bayes factor greater than 150 for heifer rebreeding and age at first calving, respectively. All significant SNPs for age at first calving were significant for heifer rebreeding. These 42 SNPs were next or within 35 genes that were distributed over 18 chromosomes and comprised 27 protein-encoding genes, six pseudogenes and two miscellaneous noncoding RNAs.

Conclusions

The use of Bayes factor to determine the significance of SNPs allowed us to identify two sets of 42 and 19 significant SNPs for heifer rebreeding and age at first calving, respectively, which explain 11.35 % and 6.42 % of their phenotypic variance, respectively. These SNPs provide relevant information to help elucidate which genes affect these traits.