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Feed efficiency is one of the economically important traits for the cattle industry that affects profit (feed costs) and the environment (production of manure and methane). Due to that feed efficiency is driven by multi-factors, mechanisms contributing to the animal to animal variation in this trait have not been well defined, limiting the development of precision feeding strategies to improve the herd production efficiency. Rumen microbial fermentation and volatile fatty acids (VFA) production have been recently reported to be associated with cattle feed efficiency, however the roles of rumen epithelial function in feed efficiency are less studied although the rumen epithelium has an important function in VFA absorption and metabolism which can affect host feed efficiency. Rumen epithelium is colonized with a diverse microbial population, termed epimural microbiota, which has proposed functions in tissue development, barrier and inflammation, urea transport, and oxygen scavenging, suggesting that they can affect rumen epithelial functions and subsequently cattle feed efficiency. Especially, prospective functions of epimural microbiota, enhanced rumen immunity and increased rumen epithelial thickness, might contribute to less nutritional requirement for tissue recuperation. Thus, the understanding of the functions of rumen epithelium, epimural microbiota, and rumen epithelial host-microbe interactions is essential to identify their roles in contributing to feed efficiency. In this review, we will focus on to date research findings on the structure of rumen epithelium, epimural microbiota, and epithelial host-microbe interactions together with their functions and how these are associated with feed efficiency, aiming to provide insights on future directions to study rumen epithelial host-microbe interactions and improve the rumen functions in cattle.

Our objective was to evaluate the effect of colostrum feeding times on genome-wide gene expression of neonatal calves. In total, twenty-seven calves were assigned to three colostrum feeding treatments: within 45 min (TRT0h, n = 9), 6 h (TRT6h, n = 9) and 12 h (TRT12h, n = 9). Ileum tissues were collected at 51 h and transcriptomic analysis was conducted. Uniquely expressed genes were identified in TRT0h group with enriched "Antigen Presentation" function. Meanwhile, the weighted gene co-expression network analysis (WGCNA) identified four significant gene modules (|correlation| > 0.50 and P ≤ 0.05). In particular, Turquoise gene module with the enriched "Cadherin binding involved in cell-cell adhesion" and "Cell-cell adherences junction" GO terms were significantly correlated with Faecalibacterium prausnitzii (R = -0.70, P < 0.01) and Bifidobacterium (R = -0.55, P < 0.01). Our findings suggest feeding colostrum without delay could stimulate the expression of genes involved in immune function development related to host response and microbial colonization in neonatal claves.

Protein-lipid composite nanoparticles featuring three-layer structure (protein layer, α-tocopherol layer and phospholipid layer) and an inner aqueous compartment have been developed recently as a delivery system for hydrophilic nutraceuticals. These composite nanoparticles overcome many shortfalls of sole protein or lipid nanoparticles, however, exhibited poor stability during storage and high burst release in the intestinal environment. In this study, the performance of these nanoparticles was improved by modifying the protein outer layer through succinylation. The increased surface charge and spatial extension of succinate chain on nanoparticle surface improved the nanoparticle stability in both physiological buffer and water. The crosslinking by succinate minimized the leakage of vitamin B12 to 4.5% during one month of storage. Moreover, succinylation slowed down pancreatic digestion of the protein shell, leading to a sustainable release within 10 h in the simulated intestinal fluid. Also, the modified nanoparticle increased the uptake efficiency of vitamin B12 over 20 folds and demonstrated a good mucoadhesive capacity. The in vivo efficacy study showed that the modified nanoparticle could correct a vitamin B12 deficiency in a rat model more efficiently than a free vitamin B12 supplement.

The production of adequate and nutritious animal proteins for the increasing human population is an urgent global task. Therefore, enhancing the efficiency and sustainability of food animal production requires advanced analytical techniques. We propose the concept of “feedomics” for food animal research, an emerging field using omics technologies, to understand and uncover the mechanisms involved in many biological processes that determine animal productivity, product quality, and health as a result of the interactions among feed, environment, animal genetics, physiology, and its symbiotic microbiota. In this review, we summarize the findings to date based on the omics approaches including (meta)genomics, epigenomics, (meta)transcriptomics, proteomics, and metabolomics in food animal species and consider how these can be used to understand the processes from the “gate” to “plate”. We also highlight future directions for applying feedomics in fundamental and practical studies to improve the quantity, quality, safety and functional properties of food animal products.

The purpose of this work was to better understand the interactions between oat protein (OPI) and shellac to form oat protein-shellac based gels at near neutral pH as carrier to protect and deliver sensitive bioactive compounds. There were moderate interactions between OPI and shellac with a binding constant (Ka) of 2.088 × 103 M−1 via hydrophobic interactions and hydrogen bonding as revealed by Isothermal Titration Calorimeter (ITC) and Fourier Transform Infrared Spectroscopy (FTIR). Such interactions allowed the formation of a gel-like mixture with good compatibility that only one endothermic peak and Tg value for OPI-shellac mixture as demonstrated by differential scanning calorimetry (DSC) analysis. Novel core (OPI)-shell (OPI-shellac mixture) beads were then developed by a cold-gelation method at near neural pH and ambient temperature. The optimized samples possessed a homogeneous, smooth and integrated shell structure. This structure could effectively restrict the swelling of the shell and prevent premature diffusion of the contained riboflavin. Also, this structure could efficiently protect the survival of L. acidophilus as 85.5% and the activity of amylase as 80.0% in the harsh environment of simulated gastric fluids after 1 h. When transferred to a simulated intestinal tract, riboflavin and L. acidophilus were sustainably released. Since the beads are easily prepared using a simple extrusion method at near neutral pH and ambient temperature, they are excellent candidates for natural delivery systems for sensitive bioactive compounds in the food and biomedical industries.

Characterizing ruminal parameters in the context of sampling routine and feed efficiency is fundamental to understand the efficiency of feed utilization in the bovine. Therefore, we evaluated microbial and volatile fatty acid (VFA) profiles, rumen papillae epithelial and stratum corneum thickness and rumen pH (RpH) and temperature (RT) in feedlot cattle. In all, 48 cattle (32 steers plus 16 bulls), fed a high moisture corn and haylage-based ration, underwent a productive performance test to determine residual feed intake (RFI) using feed intake, growth, BW and composition traits. Rumen fluid was collected, then RpH and RT logger were inserted 5.5±1 days before slaughter. At slaughter, the logger was recovered and rumen fluid and rumen tissue were sampled. The relative daily time spent in specific RpH and RT ranges were determined. Polynomial regression analysis was used to characterize RpH and RT circadian patterns. Animals were divided into efficient and inefficient groups based on RFI to compare productive performance and ruminal parameters. Efficient animals consumed 1.8 kg/day less dry matter than inefficient cattle (P⩽0.05) while achieving the same productive performance (P⩾0.10). Ruminal bacteria population was higher (P⩽0.05) (7.6×1011 v. 4.3×1011 copy number of 16S rRNA gene/ml rumen fluid) and methanogen population was lower (P⩽0.05) (2.3×109 v. 4.9×109 copy number of 16S rRNA gene/ml rumen fluid) in efficient compared with inefficient cattle at slaughter with no differences (P⩾0.10) between samples collected on-farm. No differences (P⩾0.10) in rumen fluid VFA were also observed between feed efficiency groups either on-farm or at slaughter. However, increased (P⩽0.05) acetate, and decreased (P⩽0.05) propionate, butyrate, valerate and caproate concentrations were observed at slaughter compared with on-farm. Efficient had increased (P⩽0.05) rumen epithelium thickness (136 v. 126 µm) compared with inefficient cattle. Efficient animals also spent 318% and 93.2% more time (P⩽0.05) in acidotic (4.14% v. 1.30%) (pH⩽5.6) and optimal (5.6

The objective of the present experiment was to determine if carcass quality and fatty acid profiles of longissimus thoracis (LT) and hamburger would be affected by feeding steers extruded flaxseed on its own followed by hay (non-TMR) compared to when hay and extruded flaxseed were fed together (TMR). Forty-eight steers in six pens were assigned to TMR or non-TMR for an average of 242 days. Dry matter intake was lower for non-TMR versus TMR steers (10.56 vs. 11.42 kg/d; P = 0.02), but final live weight (610 ± 0.50 kg) and average daily gain (1.18 ± 0.02 kg/d) did not differ. Compared to TMR, feeding non-TMR enriched LT and hamburger with α-linolenic acid (ALA; 18:3n-3) by 14%, vaccenic acid (VA; t 11–18:1) by 44%, rumenic acid (RA; c 9, t 11–18:2) by 40%, and conjugated linolenic acid (CLnA) by 58%. Overall, feeding extruded flaxseed separately from hay in a non-TMR was more effective at enhancing deposition of ALA, VA, RA and CLnA in beef.

The purpose of this study was to evaluate the effect of different doses of 3-nitrooxypropanol (NOP) to a backgrounding diet on methane (CH4) emissions using the in vitro rumen simulation technique (Rusitec). 3-Nitrooxypropanol is an enzymatic inhibitor that has consistently reduced CH4 emissions in sheep, dairy and beef cattle (up to 59% reduction on a long term basis). Two Rusitec apparatuses each equipped with 8 fermenters were used in a completely randomized block design with 2 blocks (apparatus) and 4 treatments: 0, 5, 10 and 20 mg of NOP. Within each apparatus, 2 fermenters were randomly assigned to a treatment. Treatments were supplied daily with 10 g of diet (6 g of barley silage, 3.5 g of barley grain and 0.5 g of supplement; dry matter [DM] basis). The experiment included an adaptation period without treatment supplementation (8 days) and a treatment period (7 days) with NOP addition. 3-Nitrooxypropanol did not affect dry matter (DMD; P = 0.79) or organic matter disappearance (OMD; P = 0.50) but reduced CH4 production (mL g−1 DM) by up to 86.2% (P 0.12); however, that for methanogens in the solid phase was reduced (P

In the current study barley protein hydrolysate was cationized using polyethyleneimine and the physicochemical and antimicrobial properties of the modified peptides were investigated. Degree of substitution and zeta potential analysis verified the high proportion of positively charged components. Antimicrobial assay showed that cationized peptides effectively inhibited non-beneficial bacterial growth ( Escherichia coli JM109 and Micrococcus luteus (ATCC 4698)) at low concentration (98–195 μg/mL), while higher concentration levels (390–1560 μg/mL) were required to inhibit the growth of beneficial lactic acid bacteria ( Lactobacillus reuteri (ATCC 23272) and Lactococcus lactis MG 1363). Structural studies revealed the unordered open structures as the major structural elements of cationized peptides which resulted in conformational flexibility. Highly exposed hydrophobic segments accompanied by the chain flexibility could positively contribute to adsorption and penetration of cationized peptides into bacterial membrane. These unique structural characteristics of barley proteins in combination with positively charged side chains confer potential antimicrobial activity to barley-derived peptides which can be applied to enhance the shelf life stability of food, feed and other products.

The objective of this study was to evaluate the effects of ammonia and amino acids (AA) supplementation on activities of ruminal enzymes involved in ammonia assimilation. In addition, the temporal changes of ruminal bacterial populations and enzyme activities during in vitro incubation were investigated. Rumen fluid from four ruminally fistulated goats was used in a 3×3 factorial arrangement of treatments with ammonia equivalent to 1, 4, and 15 mM ammonium chloride (NH4Cl), and with an added AA mixture (containing 992 g casein acid hydrolysate plus 1.4 g l -cysteine plus 8.68 g l -tryptophan) at 0, 1, and 15.5 g/L in the in vitro culture solution. Both ammonia and AA supplementation increased (P

An in vitro batch culture study was conducted to investigate (1) 13 C-labeled methane (CH 4 ) production efficiency (PE) which was produced from the reduction of 13 C-labeled sodium bicarbonate (NaH 13 CO 3 ) in media; and (2) the effects of NaHCO 3 and hydrogen (H 2 ) additions on ruminal fermentation, CH 4 production and methanogenic populations in a 4 × 3 factorial design with lucerne hays as substrates. Factors were NaH 13 CO 3 concentration in media (0, 11.9, 23.8 or 47.6 μmol/ml) and H 2 volume in headspace (0, 36 or 60 ml). The 13 CH 4 PE produced from NaH 13 CO 3 was linearly increased ( P 2 addition, but quadratically decreased ( P 13 CO 3 addition. Moreover, addition of H 2 quadratically increased ( P 4 production, apparent dry matter degradability (ADMD), total volatile fatty acids (VFA), molar proportion of acetate and populations of Methanosarcina barkeri ( M. barkeri ), Methanosphaera stadtmanae ( M. stadtmanae ), Methanobrevibacter ruminantium M1 ( M. ruminantium ) and Methanobrevibacter smithii (M. smithii ). Quadratic effects ( P 4 production, populations of M. barkeri , M. stadtmanae , M. ruminantium and M. smithii in response to NaHCO 3 addition. Additionally, the addition of NaHCO 3 linearly increased ( P M. barkeri was increased ( P = 0.023) by incubation time with the highest value being at 24 h, but no differences were observed for the M. stadtamanae , M. ruminantium and M. smithii gene copy numbers among the incubation time points. These results demonstrate that both CO 2 and H 2 concentrations affect methanogenesis in the rumen. Furthermore, the present study suggests that headspace hydrogen and media bicarbonate play roles in regulating feed fermentation, CH 4 production and methanogenic populations in vitro .

Information is rapidly accumulating regarding the role of miRNAs as key regulators of immune system development and function. It is also increasingly evident that miRNAs play an important role in host-pathogen interactions through regulation of both innate and acquired immune responses. Little is known, however, about the specific role of miRNAs in regulating normal development of the mucosal immune system, especially during the neonatal period. Furthermore, there is limited knowledge regarding the possible role the commensal microbiome may play in regulating mucosal miRNAs expression, although evidence is emerging that a variety of enteric pathogens influence miRNA expression. The current review focuses on recent information that miRNAs play an important role in regulating early development of the bovine mucosal immune system. A possible role for the commensal microbiome in regulating mucosal development by altering miRNA expression is also discussed. Finally, we explore the potential advantages of using the newborn calf as a model to determine how interactions between developmental programming, maternal factors in colostrum, and colonization of the gastrointestinal tract by commensal bacteria may alter mucosal miRNA expression and immune development. Identifying the key factors that regulate mucosal miRNA expression is critical for understanding how the balance between protective immunity and inflammation is maintained to ensure optimal gastrointestinal tract function and health of the whole organism.

Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne's disease (JD), a chronic granulomatous intestinal inflammation of ruminants. Current diagnostic tools lack sensitivity to detect JD early in infection; therefore, alternatives are desired. The objective was to identify potential biomarkers in whole blood of high- and low-dose (LD) MAP-challenged Holstein-Friesian calves 3 months after inoculation. Infected calves were designated MAP-positive using the IFN-γ release assay. Differential expression of transcripts in whole blood was compared between non-infected controls and HD, as well as LD calves, using the Affymetrix(®) GeneChip(®) Bovine Genome Array. Microarray data were analyzed using RMA and PLIER algorithms; 296 transcripts were differentially expressed (17 had ≥ 1.5 fold change). The HD and LD calves had differential gene expression profiles for up to 80% of differentially expressed genes. Pathway analyses using Ingenuity Pathway Analysis (IPA(®)) indicated inhibition of several defence mechanisms, including apoptosis, leukocyte and lymphocyte trafficking, overall repression of gene expression and potentially hydrogen peroxide production in macrophages. Further validation using qPCR verified increased expression of CD46, ICOS, and CEP350, but decreased expression of CTLA4, YARS, and PARVB in infected calves. Additionally, a comparison of seropositive and seronegative infected calves identified transcripts predictive of seroconversion. We concluded that IL6ST/gp130 and CD22 may have important roles in the induction of antibodies against MAP. Putative biomarkers of early MAP infection with roles in immune responses were identified; in addition, the importance of infective dose on biomarkers was determined.

The primary aim of this study was to determine regional and age-dependent expression patterns of Toll-like receptors (TLRs), peptidoglycan recognition protein 1 (PGLYRP1), and β-defensin in rumen, jejunum, ileum, cecum and colon of 3 week (n=8) and 6 month old (n=8) calves. The expression of most TLRs was significantly down-regulated throughout the gastrointestinal tract (GIT) with increasing age. TLR10 expression was significantly higher in ileum than all other gut regions, irrespective of age. TLR2 and TLR4 expression were significantly higher in the cecum and colon of 6 month old calves. Furthermore, expression of β-defensin, and PGLYRP1 was only detectable in 6 month old calves. The expression of TLRs was positively or negatively correlated with population of total bacteria and/or lactic acid bacteria depending on the GIT region. These observations indicate that innate immune responses to commensal microflora may vary significantly throughout the GIT and with age changes.

It is well known that egg storage reduces embryo performance, but the fundamental reasons for reduced embryo quality remain unclear. The objective of this study was to investigate possible cellular and molecular mechanisms that might reduce embryo quality after egg storage. Broiler hatching eggs were obtained from the Ross 308 broiler strain, divided into 2 groups, and stored (4 and 14 d) under the same temperature and humidity conditions. Samples of the eggs were used to assess embryo quality by determining daily embryo weight (wet and dry) from 4 to 21 d of incubation. To understand possible cellular and molecular mechanisms that might affect embryo quality, blastoderms (unincubated embryos) were isolated from a sample of eggs from each storage group, dissociated into single cells, and subjected to flow cytometry analysis to differentiate between viable, apoptotic, and necrotic cell populations. Quantitative real-time PCR analysis was used to compare the expression of selected apoptotic genes (Bcl-2 homologous antagonist/killer gene, Bcl-2-associated X gene, Bcl-2-related ovarian killer gene, B-cell lymphoma 2 gene, and B-cell lymphoma xL gene) in blastoderms and embryos (6 d old after incubation). Data were analyzed by the MIXED model procedure of SAS (SAS Institute, Cary, NC), with significance set at P ≤ 0.05. After covariance analysis of initial egg weights, the results showed decreased daily embryo weights (wet and dry), an indication of decreased embryo quality that could affect hatch quality. In addition, a decrease in blastodermal cell viability was associated with an increased percentage of apoptotic cell deaths (P < 0.0001). Expression of pro-apoptotic genes (Bcl-2 homologous antagonist/killer gene, Bcl-2-associated X gene, and Bcl-2-related ovarian killer gene) were upregulated at the blastodermal level as the storage duration increased, but all genes were downregulated after 6 d of incubation. This suggests that an increase in egg storage duration could activate mechanisms of apoptotic cell death at the blastodermal level, which may be one of the molecular mechanisms that leads to reduced daily embryonic weight during incubation. Experimental controls capable of reducing the cellular and molecular mechanisms of egg storage should be used to increase embryo quality.

Condensed tannins (CT) and corn distillers grains from ethanol production have the potential to reduce enteric CH4 production from ruminants because of their anti-microbial properties and high lipid contents, respectively. However, their effects on the community of rumen methanogens in cattle rumens have not been investigated. Our objective was to evaluate effects of dry corn distillers grain with solubles (DDG) and CT from Acacia mearnsii added to the diet of cattle on rumen methanogens using PCR denaturing gradient gel electrophoresis (PCR-DGGE) and quantitative real time (qRT)-PCR. Eight ruminally cannulated beef heifers were used in a replicated 4 × 4 Latin square design with four 35 d periods. Diets were (g DDG dry matter [DM]/kg DM): control (Ctrl; 0 DDG), 200 DDG, 400 DDG and 400 DDG plus 25 g CT (400 DDG + CT). Rumen digesta samples were collected before feeding on d 25 and 28 of each period from 4 sites in the rumen. Total DNA extracted from rumen digesta samples (i.e., 0.5 ml liquid + 0.5 g solid pooled by heifer for each period) was used to generate amplicons of partial 16S rRNA genes. The PCR products obtained were subjected to PCR-DGGE. Detectable methanogenic PCR-DGGE profiles from periods 1 and 2 clustered while periods 3 and 4 formed a second cluster. A total of 25 distinct PCR-DGGE bands were identified, of which 16 bands were successfully cloned and sequenced. The sequences of 11 bands had 97–100% similarity with Methanobrevibacter sp., and this was supported by clustering of 10 of these bands with this species upon phylogenetic analysis of the sequences. The remaining bands clustered with Methanosphaera stadmanae. Although no effect of diet on total methanogenic PCR-DGGE profiles occurred, the proportion of bands 4, 5, 6, 7, 9 and 11 increased and bands 16 and 18 decreased with increased DDG in the diet. Bands 13 and 19 were in all diets except 400 DDG + CT. Quantitative RT-PCR analysis revealed that the copy numbers of total methanogenic 16S rRNA gene did not differ among diets. Findings from PCR-DGGE and qRT-PCR analysis suggest that inclusion of DDG or a mixture of DDG and CT altered the diversity of rumen methanogens without affecting total methanogen associated 16S rRNA copy numbers thereby indicating that copy numbers of particular species of methanogens may be required to explain the altered diversity of rumen methanogens. This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.

Methanogenesis provides a means of H2 disposal and a mechanism to maintain low partial H2 pressure in the rumen, a prerequisite for efficient ruminal fermentation. As methanogens possess stringent requirements for cultivation, only a few species have been successfully isolated from the rumen and cultured. Culture independent molecular based approaches have provided new insight into the diversity, prevalence and role of methanogens within the overall rumen microbial community. In addition, recent developments in next generation sequencing technology have enabled the ruminal microbial community to be investigated at a metagenomic level, providing information to explore the structure, function and metabolic diversity of microbial communities. This review summarizes existing molecular technologies utilized in studies of ruminal methanogens by outlining their advantages and limitations, and introduces future applications of next generation sequencing approaches for studying the ecology of ruminal methanogens. These approaches could provide new understanding of the mechanisms of methanogenesis, as well as interactions of methanogens with other members of the rumen microbial community. An understanding of the fundamental role of methanogens in ruminal CH4 production would provide insight into methods of curtailing emissions of this greenhouse gas from ruminants. This article is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors; K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.

In this study, non-transformed progeny adipofibroblasts, derived from mature adipocyte dedifferentiation, was used as a novel in vitro model to study adipogenic gene expression in cattle. Adipofibroblasts from dedifferentiated mature perimuscular fat (PMF) tissue were cultured with differentiation stimulants until the cells exhibited morphological differentiation. Treated cells were harvested from day 2 to 16 for RNA extraction, whereas control cells were cultured without addition of stimulants. Results from time course gene expression assays by quantitative real-time PCR revealed that peroxisome proliferator-activated receptor gamma (PPAR-gamma), sterol regulatory element binding protein 1 (SREBP-1) and their six down-stream genes were co-expressed at day 2 post-differentiation induction. When compared to other adipogenesis culture systems, the adipogenic gene expression of bovine PMF adipofibroblasts culture was different, especially to the rodent model. Collectively, these results demonstrated PPAR-gamma and SREBP-1 cooperatively play a key role to regulate the re-differentiation of bovine adipofibroblasts, during early conversion stages in vitro.

The world's oceans are iron-deficient environments and there is little knowledge available regarding iron uptake by marine sponges. To understand iron-related biofunctions in marine organisms, iron-binding natural compounds from marine sponges were investigated. Here we reported a natural compound haliclonamide A and its analogue haliclonamide B were isolated from the marine sponge Haliclona sp. and their structures were investigated by spectroscopic analysis. The structure of haliclonamide A was determined to consist of novel cyclic peptides containing oxazole and methyloxazoline rings. Mass spectra revealed that these two compounds formed a 1:1 stable complex with trivalent iron but not with divalent iron. EPR analysis showed that these compounds will bind with Fe(III) and Cr(III) specifically, but will not bind to other cation ions such as Cu2+, Zn2+, Co2+, Ni2+, Al3+, and Ti3+. The binding constant of compound-iron complex was 10(19) which is lower than the binding constant of siderophores. The Fe(III) concentration in this sponge tissue was shown to be 10 and 100 times higher than the other sponge tissues and seawater. This indicated the sponge Haliclona sp. may possibly uptake iron through nonsiderophore metal-binding peptides haliclonamides A and B. It also suggests that iron uptake activity of marine organisms may occur through nonsiderophore metal-binding peptides in natural ocean.

Adipose tissue contains a large portion of stem cells. These cells appear morphologically like fibroblasts and are primarily derived from the stromal cell fraction. Mature (lipid-filled) adipocytes possess the ability to become proliferative cells and have been shown to produce progeny cells that possess the same morphological (fibroblast-like) appearance as the stem cells from the stromal fraction. A closer examination of mature adipocyte-derived progeny cells may prove to be an emerging area of growth/metabolic physiology that may modify present thinking about adipose tissue renewal capabilities. Knowledge of these cells may also prove beneficial in cell-based therapies for tissue repair, regeneration, or engineering.

The Ni(III) complex of bleomycin (BLM) reacts with guanine residues of the oligomer duplex only under high salt condition (4.5 M NaCl) where the (dC-dG)6 sequence exists as the isolated Z-form segment. In addition, the (dC-dG)n inserts were subcloned into a plasmid so that reactivity of the BLM-Ni(III) complex with restriction fragments could be examined. Results are reported for two fragments: an EcoRI-DdeI fragment in which the (dC-dG)n insert is flanked at the 5' end by a segment of B-DNA and a HindIII-DdeI fragment in which the (dC-dG)n fragment is embedded at both ends by stable B-DNA forming segments. The BLM-Ni(III) complex does not bind to (dC-dG)5 sequence of pBRZ10 DNA fragment under any conditions, but to several guanine residues of (dC-dG)8 and (dC-dG)12 sequences of pBRZ16 and pBRZ24 DNA fragments in 4.5 M NaCl solution. In the fragments of pBRZ16 and pBRZ24 DNAs, the BLM-Ni(III) complex reacts with most of guanine bases of (dC-dG)8 and (dC-dG)12.

Molecular mechanisms of peroxisome proliferator activated receptors (PPARs) are being defined rapidly, as illustrated by the volume of papers published. Much of the research is directed towards a clinical end-point/application; however, the non-homogeneous nature of adipose depots in laboratory animals is spurring similar research in domestic meat animals (such as beef cattle). Moreover, the size of adipose depots in meat animals remains an attractive feature for using them to obtain cells for PPAR research. Examination of meat-animal depot-specific PPAR moieties may provide novel information about adipocyte regulation that might be extrapolated to all animals.