Recent evidence suggests that fructose consumption is associated with weight gain, fat deposition and impaired cognitive function. However it is unclear whether the detrimental effects are caused by fructose itself or by the concurrent increase in overall energy intake. In the present study we examine the impact of a fructose diet relative to an isocaloric glucose diet in the absence of overfeeding, using a mouse model that mimics fructose intake in the top percentile of the USA population (18% energy). Following 77 days of supplementation, changes in body weight (BW), body fat, physical activity, cognitive performance and adult hippocampal neurogenesis were assessed. Despite the fact that no differences in calorie intake were observed between groups, the fructose animals displayed significantly increased BW, liver mass and fat mass in comparison to the glucose group. This was further accompanied by a significant reduction in physical activity in the fructose animals. Conversely, no differences were detected in hippocampal neurogenesis and cognitive/motor performance as measured by object recognition, fear conditioning and rotorod tasks. The present study suggests that fructose per se, in the absence of excess energy intake, increases fat deposition and BW potentially by reducing physical activity, without impacting hippocampal neurogenesis or cognitive function.

A detailed morphometric study of the basilar membrane was made from serial sections and graphic reconstructions of the cochlea of three little brown bats. Four distinct morphometric changes were observed within the basilar membrane. First, between 0-1.4 mm from the basal end of the cochlea, there is a rapid increase in width and cross-sectional area of the basilar membrane. Secondly, between 1.4-2.5 mm, there is little change in width of the basilar membrane (its cross-sectional area is at its greatest in this region). Thirdly, between 2.7-3.1 mm, there is a sudden decrease in cross-sectional area concomitant with an increase in the width of the basilar membrane. Finally, between 3.1 mm and the apex, there is a gradual decrease in cross-sectional area concomitant with an increase in the width of the basilar membrane. The magnitudes of the cross-sectional areas of the scalae media and vestibuli decrease from base to apex, but this is not true for the scala tympani. The cross-sectional area of the scala tympani appears to decrease from the base to 0.7 mm, then it increases up to 1.4 mm, and then it decreases to the apex. These morphometric changes in the basilar membrane of the little brown bat are compared to those in other echolocating and non-echolocating mammals. The significance of these changes is discussed in relation to the range of hearing in the little brown bat.

Many artisanal meat professionals believe that the microbial populations on the outer crust of dry-aged beef contribute to variation in sensory profiles; however, to date there is minimal information about the microbes themselves that grow on commercially produced dry-aged beef. The microbiome of dry-aged beef bone-in strip loins (Institutional Meat Purchase Specifications #175) from 5 commercial dry aging facilities, including one utilizing ultraviolet light treatment, were surveyed to assess the microbial populations residing on and within each subprimal. Each strip loin was sampled at multiple spatial locations and depths, and the microbial sequences present in the samples were identified using a nextgeneration sequencing approach. Insufficient microbial DNA was isolated from ultraviolet-light-treated strip loins, indicating that this treatment eliminates all or most microbial growth on the meat. Sequencing results indicated that each establishment was producing meat with different microbial communities, based on Permutational Multivariate Analysis of Variance (P < 0.01) and clustering in the Principal Coordinates Analysis plot of Jaccard distances. The position on strip loins from which samples were taken had negligible influence on microbial community structure. Aging facility, and the relative unique environmental conditions within, was determined to be the only observed driver of community structure. Notable operational taxonomic units (OTUs) detected included the spoilage-associated bacterium Pseudomonas fragi and the fungal species Debaryomyces udenii and Penicillium polonicum. An OTU identified as Mucor sp. PG272 was found to be present in over 75% of all samples. This OTU may represent a species similar to Thamnidium, a mold that has been associated with product quality. This study established a general core microbiome for dry-aged beef observed in commercial facilities, variations of which may—as future research could indicate—contribute to distinct sensory properties.

No abstract

A SNP (IGF2 G3072A) within intron 3 of disrupts a binding site for the repressor zinc finger BED-type containing 6 (ZBED6), leading to increased carcass lean yields in pigs. However, the relative contributions of prenatal as opposed to postnatal increased IGF2 expression are unclear. As muscle fiber number is set at birth, prenatal and neonate skeletal muscle development is critical in determining mature growth potential. Therefore, the objectives of this study were to determine the contributions of hyperplasia and hypertrophy to increased muscle mass and to delineate the effect of the mutation on the expression of myogenic genes during prenatal and postnatal growth. Sows (IGF2 A/A) were bred to a single heterozygous (IGF2 A/G) boar. For fetal samples, sows were euthanized at 60 and 90 d of gestation (d60 and d90) to obtain fetuses. Male and female offspring were also euthanized at birth (0d), weaning (21d), and market weight of approximately 130 kg (176d). At each sampling time, the LM, psoas major (PM), and semitendinosus (ST) muscles were weighed. Samples of the LM were used to quantify the expression of IGF family members, myogenic regulatory factors (MRF), myosin heavy chain isoforms, and growth factors, myostatin, and . Liver samples were used to quantify and expression. At 176d, weights of LM, PM, and ST muscles were all increased approximately 8% to 14% (P < 0.01) in pigs with paternal A (A(Pat)) alleles compared with those with paternal G (G(Pat)) alleles. Additionally, total muscle fiber number in the ST at 176d tended to be greater (P = 0.10), whereas muscle fiber cross-sectional area tended to be reduced ( P= 0.08) in A(Pat) pigs compared with G(Pat) pigs. In addition to the expected 2.7- to 4.5-fold increase (P ≤ 0.02) in expression in the LM in A(Pat) compared with G(Pat) pigs at postnatal sampling times (21d and 176d), IGF2 expression was also increased (P ≤ 0.06) 1.4- to 1.5-fold at d90 of gestation and at birth. At d90, expression of myogenic factor 5 (MYF5), a MRF expressed in proliferating myoblasts, in the LM was greater (P = 0.01) in A (Pat) pigs than in G(Pat) pigs. Interestingly, at 21d hepatic expression was greater (P = 0.01), whereas expression decreased (P = 0.01) in A(Pat) pigs compared with G(Pat) pigs; however, there were no differences (P ≥ 0.18) in hepatic expression between genotypes at 0d and 176d. These data suggest that prenatal hyperplasia of muscle fibers stimulated by increased IGF2 expression may contribute to increased muscle mass of A(Pat) pigs.