Digestive physiology,metabolism and methane production of captive Linné's two‐toed sloths (Choloepus didactylus)          下载免费PDF全文

C. Vendl  S. Frei  M. T. Dittmann  S. Furrer  C. Osmann  S. Ortmann  A. Munn  M. Kreuzer  M. Clauss 《Journal of animal physiology and animal nutrition》2016,100(3):552-564

Sloths are renowned for their low metabolic rate, low food intake and low defecation frequency. We investigated factors of digestive physiology and energy metabolism in four captive individuals (mean body mass 10.0 ± SD 3.7 kg) of a hitherto mostly unstudied sloth species, Linné's two‐toed sloth (Choloepus didactylus), in a 2‐week digestion recording and 23‐h respiration experiment on animals fed a standard zoo diet of vegetables and starchy components. Dry matter intake, defecation frequency and particle mean retention time (MRT) in the gastrointestinal tract (GIT) were 12 ± 3 g/(kg^0.75 day), once every 5 days and >140 h in three individuals, but 53 g/(kg^0.75 day), daily and 82 h in one individual that was apparently compensating for a period of weight loss prior to the experiment. In all animals, solute marker was eliminated at a faster rate than the particle marker, indicating ‘digesta washing’ in the sloths’ GIT. The overall metabolic rate calculated from oxygen consumption matched the metabolisable energy intake in three individuals [173 ± 22 vs. 168 ± 44 kJ/(kg^0.75 day)] but not in the fourth one [225 vs. 698 kJ/(kg^0.75 day)], supporting the interpretation that this animal was replenishing body stores. In spite of the low food intake and the low‐fibre diet (209 ± 26 g neutral detergent fibre/kg dry matter), methane production was rather high accounting for 9.4 ± 0.8% of gross energy intake (2.7% in the fourth individual), which exceeded literature data for ruminants on forage‐only diets. These results corroborate literature reports on low intake, low defecation frequency, low metabolic rate and long MRT in other sloth species. The long MRT is probably responsible for the comparatively high methane production, providing more opportunity for methanogenic archaea than in other non‐ruminant mammals to produce significant amounts of methane.  相似文献   

Genetic variation of seedling traits responded to brassinosteroid and gibberellin inhibitors in maize (Zea mays) doubled haploid lines     

Kun Hu  Ying Xie  Chenglai Wu  Ursula K. Frei  Thomas Lübberstedt 《Plant Breeding》2020,139(5):870-882

The purpose of this study was to examine the genotypic variation in maize doubled haploid (DH) lines response to brassinosteroid and gibberellin inhibitors. Plant responses to hormone inhibitors were determined in growth chamber experiments using germination paper for three different seedling treatments: application of propiconazole (Pcz), uniconazole (Ucz) or water (control). Mesocotyl length (ML) was more sensitive to hormone inhibitors, especially to the Ucz treatment, than other seedling traits. ML was significantly correlated with other traits in the Ucz treatment. All the seedling traits showed moderate-to-high broad sense heritability values, ranging from 0.39 to 0.82. The Euclidian genetic distances of inbred line pairs ranged from 1.27 to 19.94, indicating there was a high level of variability across the maize DH lines used in this study. DH lines with extreme MLs were identified, which can provide valuable breeding resources for improving abiotic stress tolerance, and for further genetic studies.  相似文献   

Correction to: Molecular analysis indicates high levels of carabid weed seed consumption in cereal fields across Central Europe     

Frei  Britta  Guenay  Yasemin  Bohan  David A.  Traugott  Michael  Wallinger  Corinna 《Journal of pest science》2022,95(1):541-542

Journal of Pest Science -  相似文献   

Inhibition of low-density lipoprotein oxidation by carnosine histidine     

Decker EA  Ivanov V  Zhu BZ  Frei B 《Journal of agricultural and food chemistry》2001,49(1):511-516

Carnosine is a beta-alanylhistidine dipeptide found in skeletal muscle and nervous tissue that has been reported to possess antioxidant activity. Carnosine is a potential dietary antioxidant because it is absorbed into plasma intact. This research investigated the ability of carnosine to inhibit the oxidation of low-density lipoprotein (LDL) in comparison to its constituent amino acid, histidine. Carnosine (3 microM) inhibited Cu2+-promoted LDL (20 of protein/mL) oxidation at carnosine/copper ratios as low as 1:1, as determined by loss of tryptophan fluorescence and formation of conjugated dienes. Carnosine (6 microM) lost its ability to inhibit conjugated diene formation and tryptophan oxidation after 2 and 4 h of incubation, respectively, of LDL with 3 microM Cu2+. Compared to controls, histidine (3 microM) inhibited tryptophan oxidation and conjugated diene formation 36 and 58%, respectively, compared to 21 and 0% for carnosine (3 microM) after 3 h of oxidation. Histidine was more effective at inhibiting copper-promoted formation of carbonyls on bovine serum albumin than carnosine, but carnosine was more effective at inhibiting copper-induced ascorbic acid oxidation than histidine. Neither carnosine nor histidine was a strong inhibitor of 2,2'-azobis(2-amidinopropane) dihydrochloride-promoted oxidation of LDL, indicating that their main antioxidant mechanism is through copper chelation.  相似文献   

Newsgathering     

Hirschberg E  Joseph Fu SC  Frisell WR  Farber E  Potter VR  Rusch HP  Saffiotti U  Shimkin MB  Brennan MJ  Nowell PC  Creech HJ  Taylor RM  Schabel FM  Frei E  Lepage GA  Weinhouse S  Hall TC 《Science (New York, N.Y.)》1972,176(4041):1288-1289

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Protease inhibitors from lung, secretions and blood in horses and cattle: a comparative study on endogenous, predisposing factors of chronic obstructive lung disease]     

R von Fellenberg  H Minder  C Wegmann  F Frei 《Schweizer Archiv für Tierheilkunde》1979,121(7):355-365

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Application of doubled haploids for target gene fixation in backcross programmes of maize     

Thomas Lübberstedt  Ursula K. Frei 《Plant Breeding》2012,131(3):449-452

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Aspects of fusion combining ability of dihaploidSolanum tuberosum L.: influence of the cytoplasm     

Ursula Frei  Marietta Stattmann  A. Lössl  G. Wenzel 《Potato Research》1998,41(2):155-162

Summary Creation from 4x hybrid clones from protoplast fusion of 2x clones of potato was evaluated. Besides combined nuclear genomes, composition of the cytoplasm significantly influenced the phenotypic traits of hybrid clones. To ascertain the influence of parental cytoplasm on the success of protoplast fusion and regeneration of hybrid plants, data from 74 fusion combinations of 50 dihaploid clones were analyzed. The majority of dihaploid breeding clones belonged to the cytoplasm types Wα, Tβ and Wγ. When the closely related mt types α, β and γ were used, fusion combinations had a better combining ability compared with more distantly related cytoplasms δ and ⃛. Fusions containing the same mitochondrial type (homofusions) were not superior to closely related mitochondrial types. However, homofusions of cytoplasm type Wα yielded significantly more hybrids than homofusions of type Tβ. In general, parental cytoplasm types had little impact on the fusion combining behaviour. Thus the cytoplasm type of the fusion parents is not a suitable marker for predicting the combining ability in protoplast fusion experiments.  相似文献   

Validation of two models for self‐incompatibility in autotetraploid perennial ryegrass using high resolution melting‐based markers     

Andrea Arias Aguirre  Bruno Studer  Javier Do Canto  Ursula Frei  Thomas Lübberstedt 《Plant Breeding》2014,133(6):765-770

Perennial ryegrass (Lolium perenne L.) displays a two‐locus gametophytic self‐incompatibility (SI) system that remains intact at the tetraploid level. Two models are plausible for SI in autotetraploids. In Model I: both alleles at the S locus and both at the Z locus in diploid pollen matching the female genotype results in incompatibility. In Model II: only one allele at S and one at Z locus in diploid pollen matching the female results in incompatibility. The goals were to determine which of the models best explains SI in our autotetraploid ryegrass population and to evaluate the efficiency of high‐resolution melting (HRM) genotyping for discriminating different iso‐allelic genotypes. The progeny of a cross between two autotetraploids was characterized with three HRM‐based markers co‐segregating with Z. Segregation ratios were used to make inferences about the mode of action of the SI system. The observed segregation differed significantly (P < 0.001) from the expected under Model I, but not from the expected under Model II (P = 0.463). Thus, Model II explains SI in this population, and HRM is an efficient tool to distinguish different iso‐allelic genotypic classes.  相似文献   

Chemistry. Selective hydrocarbon oxidation in zeolites     

Frei H 《Science (New York, N.Y.)》2006,313(5785):309-310

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