Adaptive responses by mouse fetus to a maternal HLE diet by downregulating SREBP1: a microarray- and bio-analytic-based study

Maternal diet has long been recognized as a significant factor affecting offspring development and health, but the target genes affected by a maternal high-lipid diet are currently unknown. In this study, the gene expression profile of neonatal mouse liver was analyzed using gene chips to identify genes with significant up- or downregulated expression levels due to maternal high-fat diet during gestation. Real-time PCR and Western blotting were used to measure key genes selected using microarray. Serum lipid, glucose, and insulin levels in adult offspring from dams fed with chow or a high-lipid diet were measured using commercial kits. Results indicate that the expression of genes involved in cholesterol and fatty acid synthesis were significantly inhibited, while the expression of genes involved in glycolysis were significantly decreased by maternal high-lipid diet during gestation. SREBP1 might be the key gene regulating genes involved in fatty acid, glucose, and cholesterol metabolism in response to a maternal high-fat diet.     

Effect of modified meridic diet on the development and growth of tomato fruitworm Helicoverpa armigera (Lepidoptera: Noctuidae)

The efficacy of one new modified and two old meridic diets on Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) for rearing six successive generations was studied. Duration of larval development for insects fed on the modified diet was considerably shortened as most of them went through only five stadia before pupation, while the per cent pupation and per cent eclosion were relatively higher than on other diets. The lowest pupal mortality (6.33 ± 0.13%) was recorded in the F₁ generation reared on the modified diet, whereas the highest pupal mortality (19.49 ± 0.15%) was observed in insects reared on a natural diet in the F₆ generation. Blending of chickpea Cicer arietinum L. and red kidney bean Phaseolus vulgaris L. flours with tomato paste proved highly favorable for adult reproduction. These results suggest that the vitality of the tomato fruitworm did not decline obviously after rearing on a modified diet for several generations.     

Substantial contribution of invertebrates to the diet of a winter seed‐eater,the reed bunting Emberiza schoeniclus,wintering in a sewage farm in south‐western Poland

We investigated whether the winter diet of a typical seed‐eating bird is hard‐wired in the context of evolutionary hypothesis for granivory. We examined the diet composition of ‘a small‐billed form’ of the reed bunting Emberiza schoeniclus wintering in a sewage farm in south‐western Poland (Central Europe), where unfrozen wastewater provides various groups of invertebrate prey. The analysis of droppings (N = 151) collected from four different feeding grounds located in reedbeds and grasslands inundated with waste‐water showed the substantial contribution of invertebrates in the diet of reed buntings. Across four sample areas, the frequency of invertebrates in faecal samples ranged between 37% to 80%. In total, we identified 194 animal prey, mainly spiders Araneae (53% of all identified invertebrate prey), and several taxa of Coleoptera (43%). Among plant food (N = 8357 identified items), the most numerous were shells of weed seeds, namely Amaranthus sp. (56.8%), Urtica dioica (22.6%), and Chenopodium sp. (19.6%). Our results showed that, during winter, the reed bunting is not an obligatory seed‐eater. This species may exploit both animal and plant food; hence, our results indicate that the reed buntings wintering in temperate Europe may feed more opportunistically than was previously assumed. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 108 , 429–433.     

The effects of a low-carbohydrate ketogenic diet and a low-fat diet on mood, hunger, and other self-reported symptoms

Objective: To investigate the effects of weight loss diets on mood, food cravings, and other self‐reported symptoms. Research Methods and Procedures: Mood and other symptoms were evaluated by participant self‐report using the Atkins Health Indicator Test (AHIT) in individuals undergoing weight loss following either a low‐carbohydrate, ketogenic diet (LCKD) or a low‐fat diet (LFD). Participants were 119 overweight community volunteers randomized to an LCKD or an LFD. An additional 51 participants who had completed an earlier trial contributed data for the psychometric analyses but were not included in the prospective analyses. Self‐reported symptom levels on seven scales factor‐analytically derived from the AHIT (negative affect, fatigue, somatic symptoms, physical effects of hunger, insomnia, hunger, and stomach problems) were acquired during 12 visits. Results: After adjusting for the change in BMI over the course of the trial, participants experienced significant improvements in most symptoms regardless of diet. Diet group × visit interactions were observed for negative affect [F(9,803) = 2.30, p = 0.015] and hunger [F(9,803) = 3.62, p < 0.0002]. Examination of means indicated that the LCKD group reported less negative affect and hunger, compared with the LFD group. Discussion: Regardless of diet, participants experienced significant improvement in a broad range of symptoms. Symptoms of negative affect and hunger improved to a greater degree in patients following an LCKD compared with those following an LFD. Whether these symptom changes explain the greater short‐term weight loss generally experienced by LCKD followers deserves further research.     

Resource sharing among cod, haddock, saithe and pollack on a herring spawning ground

Cod Gadus morhua , haddock Melanogrammus aeglefinus , pollack Pollachius pollachius and saithe Pollachius virens were abundant fishes on herring Clupea harengus spawning grounds o. southwestern Norway. Their diets were species specific and ontogenetic changes were similar to patterns observed in other areas, indicating both inter- and intraspecific resource sharing. However, strong interspecific diet overlap occurred when cod and pollack preyed upon sandeel Ammodytes marinus , and when all the gadoids fed on herring eggs during the herring spawning season in the spring. These prey items were very abundant and the extensive diet overlap may not reflect strong competitive interaction.     

Food and feeding habits of the African catfish Clarias gariepinus (Burchell, 1822) (Pisces: Clariidae) in Lake Koka,Ethiopia

The food and feeding habits of Clarias gariepinus (Burchell, 1822) were studied in Lake Koka, Ethiopia, in May 2011 (dry month) and September 2011 (wet month). Three hundred and thirty eight nonempty stomach samples were analysed using frequency of occurrence and volumetric methods of analysis. Detritus, insects, macrophytes, zooplankton and fish were the dominant food categories by occurrence, and they occurred in 79.6%, 63.6%, 63.0%, 56.2% and 15.4% of the stomachs, respectively. Volumetrically, the above food items comprised 24.3%, 14.1%, 14.5%, 19.3% and 21.8% of the total volume of food categories. Phytoplankton and gastropods were of low importance, and they occurred in 28.7% and 8.6% of the stomachs, respectively. Their volumetric contributions were 3.2% and 2.8% of the total volume of food categories. During the dry month, fish, zooplankton, insects and detritus were important food categories, while during the wet month detritus, macrophytes, insects and gastropods were important. Smaller catfish diets were dominated by detritus, macrophytes and insects, whereas larger catfish shifted to fish and zooplankton. Based on the results, C. gariepinus was found to be omnivorous in its feeding habits in Lake Koka.     

High-sucrose diet exposure is associated with selective and reversible alterations in the rat peripheral taste system

Download : Download video (7MB)     

On the relationship of dental microwear to dental macrowear

Dental microwear analysts have demonstrated that hard diets leave numerous microscopic pits on occlusal surfaces. The relationship between occlusal pitting and gross macrowear, however, is not well known. The current study seeks to elucidate the relationship between dental microwear and macrowear by determining if microscopically pitted teeth are associated with greater expressions of macrowear. This study examined microwear and macrowear on mandibular second molars from 60 prehistoric adult Native Americans representing three dietary regimes (foraging, mixed economy, and agriculture). Initially, two dental microwear feature variables were studied: percentage of pits and mean scratch width. Standard macrowear scores ranged from 4 to 40. ANOVAs suggested that neither of the microwear variables was affected by age or sex, but age affected macrowear scores. Because of this, the sample had a balanced number of young and old adults (i.e., those below and above skeletal age 35). A Pearson's correlation showed no covariation between scratch width and the percentage of pits. Regression analysis indicated that macrowear was not a function of the percentage of pits. However, a significant positive relationship was found between dental macrowear and scratch width. A post priori test found a significant negative relationship between macrowear and the total number of scratches. It is concluded, then, that wide scratches remove more enamel and dentin than do numerous pits, although both cause dental wear. It is suggested here that the term “abrasive” be used to describe those microwear profiles that lead to heavy macrowear and have relatively wide scratches. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.     

Diet and feeding habits of predatory fishes upstream and downstream of a low-level weir

A study investigating the influence of a low-level weir on the diets of three migratory percithyid species was undertaken on the Murrumbidgee River, Australia. A combination of fish community sampling and stomach flushing determined that Yanco Weir substantially impacted upon the abundance and feeding habits of golden perch Macquaria ambigua , Murray cod Maccullochella peelii peelii and trout cod Maccullochella macquariensis . The relative abundance of all three species was significantly greater downstream of the weir, where individuals attempting upstream migrations were obstructed. In areas of fish aggregations, some species displayed altered feeding strategies and exploited different prey taxa upstream and downstream of the weir. Diet overlap, and the proportion of individuals with empty stomachs, was also substantially greater from downstream zones. These results suggest that competition among species may be greater in areas of increased predator abundance and some species could be partitioning resources to minimize competitive interactions. Reducing accumulations of predatory species, by providing suitable fish passage facilities, would be an effective means to prevent such trophic interactions occurring at other low-level weirs.     

The feeding relationships of the larger fish species in a Scottish sea loch

Patterns within a fish assemblage have been examined from catches obtained over a period of 17 months using fixed nets and rod and line sampling. A total of 19 species were caught with summer samples dominated by dab and saithe and winter samples by whiting. Cod were caught regularly throughout the year. Catches at the study site of dab and whiting occurred mainly at night but for cod and saithe catches occurred throughout the day. There was no indication ofa crepuscular or tidal rhythm for any species. Differences between our own observations and those from other published studies lead us to conclude that no species-specific generalizations about feeding periodicities can be made. Feeding patterns are more likely to be determined by site-specific features of particular habitats and their associated prey and predator assemblages.
Examination of stomach contents data using a variety of methods indicates that conclusions are highly dependent on the form of the resource matrix used. However, our analyses indicate that during summer cod and dab feed on a much narrower range of prey than saithe and that there is significant overlap in their diets if a resource matrix based on percentage occurrence of prey species is used. Nevertheless, most diet overlap values for the species examined were low (between 0.1 and 0.2) suggesting that competition for food is unlikely. To date, no experiments have been performed to test the hypothesis that cod and dab compete for food.     

Diet comparison between pelagic and demersal whiting in the North Sea

Pelagic North Sea whiting Merlangius merlangus preyed upon (pelagic) sprat and sandeel, while demersal whiting preyed upon (demersal) Norway pout and herring. Values of diet breadth were low for both feeding groups using Levin's index. Diet overlaps within layers were low ( D <0·25), while the between layer food overlap was moderate ( D =0·25–0·74) to high ( D >0·74) using Schoener's index. Selection of prey was density dependent. However, prey size also played an important role. The diet of whiting shifted from amphipods and mysids to fish with increasing predator length, and the length of prey consumed increased significantly with length of whiting. The fact that the stomach contents differed between the feeding groups demonstrates the need for a sampling design that includes both pelagic and demersal habitats when trying to quantify the diet of whiting.     

Distinct Genetic and Functional Traits of Human Intestinal Prevotella copri Strains Are Associated with Different Habitual Diets

1. Download high-res image (150KB)
2. Download full-size image

     

Niche Differentiation and its Relationship with Food Abundance and Vegetation Complexity in Four Frugivorous Bat Species in Southern Mexico

Species can co‐exist within a community when their use of limiting resources is differentiated. To test whether differentiation facilitates coexistence, we quantified differences and overlap in habitat use, fruit consumption, morphological characteristics, and the relationship with vegetation structure for two pairs of ecologically similar frugivorous bat species, Carollia sowelli and C. perspicillata, and Artibeus jamaicensis and A. lituratus. In Carollia sowelli and C. perspicillata, differences in body mass and wing aspect ratio were not reflected in differences in fruit or habitat use (diet overlap, 96 percent; habitat overlap, 98 percent). However, the capture rate of Carollia sowelli positively correlated with canopy openness, and that of C. perspicillata positively correlated with tree height. Body mass and wing characteristics of Artibeus species suggested a greater maneuverability for A. jamaicensis. Also, more A. jamaicensis individuals were captured feeding on Ficus spp., while Artibeus lituratus preferred fruits of the early successional tree Cecropia. However, both habitat overlap and diet overlap were higher than by chance (diet overlap, 75 percent; habitat overlap, 92 percent). The co‐existence of the four bat species in the study area may be facilitated by the abundance of the food resources forming part of the diets of both Carollia species, by the morphological differences between the Artibeus species, which allow the differentiation of foraging behavior in relation to fruit consumption, and by the structural characteristics of the vegetation.     

Effect of the Japanese diet during pregnancy and lactation or post-weaning on the risk of metabolic syndrome in offspring

We examined the effects on offspring of ingestion of the 1975 Japanese diet during pregnancy and lactation and after weaning in mice. Pregnant dams were divided into groups that were fed the Japanese diet or a control diet and raised until offspring were weaned. The offspring after weaning were further divided into groups that were raised on the Japanese diet or the control diet. Ingestion of the Japanese diet after weaning suppressed accumulation of visceral fat in offspring, and reduced the amount of lipids in serum and liver. This effect was weakened if the Japanese diet was only ingested during pregnancy and lactation. Therefore, it was suggested that ingestion of the Japanese diet of mothers during pregnancy and lactation weakens the lipid accumulation inhibitory effect of the Japanese diet in children.     

Management of dietary essential metals (iron,copper, zinc,chromium and manganese) by Wistar and Zucker obese rats fed a self-selected high-energy diet

The balances and content of essential elements (iron, copper, zinc, chromium and manganese) in the body of Wistar, Zucker lean and Zucker obese rats fed a reference or cafeteria diet from day 30 to 60 after birth have been studied. Intestinal iron absorption compensated for low iron content of the cafeteria diet and the extra needs of growth and fat deposition. It can be assumed that the altered energy regulation processes that afflict the genetically obese rat are not directly related to altered iron metabolism. Obese Zucker rats had lower copper tissue concentrations than lean rats, but when fed a cafeteria diet the differences between Zucker rats strains disappear. This cannot be traced to large differences in diet copper concentration. A low diet availability of zinc—such as that of cafeteria-fed fa/fa rats—is easily compensated for by increasing absorption. So, as a consequence, we can conclude that genetic obesity did not impair zinc absorption. There was no deficit of zinc in any of the groups studied; the rats have enough capacity to extract zinc within a wide range of dietary concentrations. The absorption of dietary chromium was inversely proportional to its concentration. The ability to extract chromium from the diet and the very low urinary losses are a consequence of its scarcity in most dietary items. Despite wide variations in the manganese of the diets, the absorption rates were practically unchanged except for obese rats fed the cafeteria diet. It seems that this low absorptive capacity is enough to supply the rat with the manganese it needs, since a sizeable—but subjected to 8-fold-span variations-proportion is lost in the urine. This alone points towards a considerable excess of manganese in both diets studied. Obesity does not have a significant effect on the abilities to absorb and retain minerals, since these processes were more related to dietary availability. Management of essential metals by obese rats depends whether this condition is genetic or induced by diet. Most of the differences observed can be related to differences in diet concentration, to the excess fat content or different metabolic attitude to use substrates of obese animals. The data presented show that the cafeteria diet used adequately serves the mineral needs of the rat, since the rat adapts its absorbing and retaining strategies to match the dietary availability of these minerals.     

Comparison of Fat Storage between Fischer 344 and Obesity‐Resistant Lou/C Rats Fed Different Diets**

Objective: We aimed to characterize further the Lou/C (LOU) and Fischer 344 (F344) rat strains for nutritional traits to validate their use as contrasting strains for molecular genetic studies. Research Methods and Procedures: Five batches of LOU and F344 rats were used to measure caloric intake, weight gain, and body composition when fed a chow diet, a self‐selection diet (together with the study of preferences for macronutrients), hypercaloric diets, and a chow diet in a cold environment. Results: Despite a higher caloric intake when fed a chow diet, LOU rats showed a lower weight gain, final body weight, and percentage of fat tissue, together with a higher percentage of carcass weight, than F344 rats. When fed a self‐selection diet, LOU males ingested less protein and more fat than F344 males, and the reverse was observed for females. In this condition, feed efficiency was reduced in LOU but increased in F344 rats compared with the chow diet. Diet‐induced obesity was observed in F344 rats but not in LOU rats fed hypercaloric diets. In a cold environment, both LOU and F344 rats displayed an increased percentage of brown adipose tissue compared with control groups, together with a higher caloric intake. Discussion: The study shows robust nutritional differences between the LOU rat, a lean strain with a low feed efficiency and resistant to diet‐induced obesity, and the contrasting F344 rat strain. It also shows the interest in these strains for studying the genetic components of resistance to obesity.     

Some microbial contaminants and control agents in a diet and larvae of Heliothis spp

Sixteen tests were conducted with four antimicrobial agents that are routinely incorporated into lepidopterous larval diets for bacterial and fungal inhibition. The agents tested in all possible combinations were benomyl, chlortetracycline, sorbic acid, and methyl P-hydroxybenzoate. Those combinations that contained benomyl and sorbic acid in the formula were effective in complete microbial suppression during the larval portion of the 35-day testing period. Insect development in plastic cups of test diets with benomyl and sorbic acid averaged 97 and 93% pupation and adult emergence, respectively. The 12 tests that did not contain benomyl and sorbic acid were contaminated with some of the following fungi: Aspergillus niger, A. flavus, Rhizopus nigricans, Cladosporium, Fusarium, yeasts, or the bacterium, Bacillus subtilis. Microorganisms in Heliothis spp. larvae from mass-rearing diets were tested, examined, and identified. Bacteria recovered from laboratory-reared Heliothis larvae included Pseudomonas aeruginosa, P. maltophilia, Micrococcus luteus, α-hemolytic Streptococcus, Serratia marcescens, and S. rubidaea. Tests were conducted with sensi-discs for the selection of antimicrobials to arrest contamination in the larval digestive systems.