A mutation in the myostatin gene increases muscle mass and enhances racing performance in heterozygote dogs

Double muscling is a trait previously described in several mammalian species including cattle and sheep and is caused by mutations in the myostatin (MSTN) gene (previously referred to as GDF8). Here we describe a new mutation in MSTN found in the whippet dog breed that results in a double-muscled phenotype known as the “bully” whippet. Individuals with this phenotype carry two copies of a two-base-pair deletion in the third exon of MSTN leading to a premature stop codon at amino acid 313. Individuals carrying only one copy of the mutation are, on average, more muscular than wild-type individuals (p = 7.43 × 10⁻⁶; Kruskal-Wallis Test) and are significantly faster than individuals carrying the wild-type genotype in competitive racing events (Kendall's nonparametric measure, τ = 0.3619; p ≈ 0.00028). These results highlight the utility of performance-enhancing polymorphisms, marking the first time a mutation in MSTN has been quantitatively linked to increased athletic performance.     

Placental metabolite profiles in late gestation for healthy mice

Metabolomics - The study of lipoprotein metabolism at the population level can provide valuable information for the organisation of lipoprotein related processes in the body. To use this...     

Engineering the acceptor substrate specificity in the xyloglucan endotransglycosylase TmXET6.3 from nasturtium seeds (Tropaeolum majus L.)

Plant Molecular Biology - The knowledge of substrate specificity of XET enzymes is important for the general understanding of metabolic pathways to challenge the established notion that these...     

Feeding ecological knowledge: the underutilised power of faecal DNA approaches for carnivore diet analysis

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The db mutation improves memory in younger mice in a model of Alzheimer's disease

Alzheimer's disease (AD) is the most common age-related neurodegenerative disease, while obesity is a major global public health problem associated with the metabolic disorder type 2 diabetes mellitus (T2DM). Chronic obesity and T2DM have been identified as invariant risk factors for dementia and late-onset AD, while their impacts on the occurrence and development of AD remain unclear. As shown in our previous study, the diabetic mutation (db, Lepr^db/db) induces mixed or vascular dementia in mature to middle-aged APP^ΔNL/ΔNL x PS1^P264L/P264L knock-in mice (db/AD). In the present study, the impacts of the db mutation on young AD mice at 10 weeks of age were evaluated. The db mutation not only conferred young AD mice with severe obesity, impaired glucose regulation and activated mammalian target of rapamycin (mTOR) signaling pathway in the mouse cortex, but lead to a surprising improvement in memory. At this young age, mice also had decreased cerebral Aβ content, which we have not observed at older ages. This was unlikely to be related to altered Aβ synthesis, as both β- and γ-secretase were unchanged. The db mutation also reduced the cortical IL-1β mRNA level and IBA1 protein level in young AD mice, with no significant effect on the activation of microglia and astrocytes. We conclude that the db mutation could transitorily improve the memory of young AD mice, a finding that may be partially explained by the relatively improved glucose homeostasis in the brains of db/AD mice compared to their counterpart AD mice, suggesting that glucose regulation could be a strategy for prevention and treatment of neurodegenerative diseases like AD.     

Measurement of fecal steroids in the black rhinoceros (Diceros bicornis) using group-specific enzyme immunoassays for 20-oxo-pregnanes

The metabolism and excretion of progesterone in different animal species results in several fecal 5-reduced progesterone metabolites (pregnanes), which in recent studies were quantified using progesterone antibodies. To increase the accuracy of fecal 20-oxo-pregnane evaluations in the black rhinoceros, enzyme immunoassays (EIA) using antibodies against 5α-pregnane-3β-ol-20-one 3HS:BSA (5α-20-one EIA) and 5β-pregnane-3α-ol-20-one 3HS:BSA (5β-20-one EIA) were developed. The assays showed high crossreactivities with pregnanes containing a 20-oxo group and are referred to as group-specific; results of these assays were compared with an EIA using an antibody against 6HS-progesterone (4-ene-20-one EIA). Fecal samples of both subspecies of the black rhinoceros (Diceros bicornis michaeli, n = 5, and Diceros bicornis minor, n = 1) during pregnancy were collected 1–3 times/week. HPLC separation showed three major immunoreactive fecal 20-oxo-pregnane peaks; their elution profiles and different crossreactivities in the three EIAs provided strong evidence that these peaks are 5α-pregnane-3, 20-dione, 5α-pregnane-3α-ol-20-one, and 5α-pregnane-3β-ol-20-one. Pregnane values in the pregnant animals continuously increased between months 3–7 and were significantly (P < 0.01) elevated above the levels of nonpregnant animals (0.2 μg/g) by week 11. During months 6–13 concentrations in the 5α-20-one and in the 5β-20-one EIA (5–11 μg/g) were significantly (P < 0.01) higher than in the 4-ene-20-one EIA (1.5–3 μg/g). In conclusion, the immunoreactive fecal 20-oxo-pregnane metabolites in the black rhinoceros are determined more accurately with antibodies against pregnane-20-one-C3 conjugates, as compared with a progesterone antibody. © 1996 Wiley-Liss, Inc.