Early mouse neural stem cells (NSCs) first appear in embryonic day E5.5 and express pluripotency markers Oct4, Sox2, Nanog and early neural marker Sox1. Early NSCs are a good model for understanding the role of various pathways that control initial neural commitment. However, a protocol for differentiation of mouse embryonic stem cells (ESCs) into early NSCs by adherent monolayer culture has not yet been established. Hence, in this study, we identified the combination of growth factors and small molecules that differentiated mouse ESCs into early NSCs and supported their proliferation. Leukaemia inhibitory factor (LIF) was the first factor to be tested and it was found that ESCs can differentiate into early neurogenic lineage in the presence of LIF. However, we found that the induction is weaker in the presence of LIF as compared to cells differentiated in its absence. GSK-3 inhibitor, along with BMP and TGF-β pathway inhibitor (dual SMAD inhibition), are commonly used to sequentially direct ESCs towards NSCs. However, when we used this combination, mouse ESCs failed to differentiate into early NSCs. We observed that by adding Wnt inhibitor to the combination of GSK-3 inhibitor, BMP inhibitor, TGF-β inhibitor and LIF, it was possible to differentiate ESCs into early NSCs. qRT-PCR analysis of early NSCs illustrated that they expressed key pluripotency genes Oct4 and Nanog, albeit at levels lower than non-differentiated ESCs, along with early neural markers Sox1 and Pax6.
Using the fluorescent differential display technique, a special band named Bm541 was identified by screening for differentially expressed genes in the resistant silkworm strain Qiufeng, the susceptible strain Huaba35, and the near isogenic line BC6, which carries the resistant gene to Bombyx mori densonucleosis virus (BmDNV). After applying the 5'RACE technique with specially designed primers, a 1148 bp cDNA clone containing a 387 bp open reading frame (ORF) was obtained. This gene was registered in GenBank under the accession number AY860950. The deduced amino acid sequence showed a 73.1% identity to the protein kinase C inhibitor (PKCI) of Drosophila pseudoobscura. In the deduced sequence of BmPKCI, the histidine triad (HIT) motif, which is essential for PKCI function, and the α-helix region, which is conserved among the PKCI family, were present. The data from quantitative real-time PCR (QRT-PCR) suggest that the expression levels of bmpkci in BC6 and Qiufeng both with BmDNV-Z are significantly higher than those in Huaba35, which indicate that BmPKCI plays a role in resistance to BmDNV-Z.
Type 2 diabetes mellitus (T2DM) is associated with increased fracture risk; the underlying mechanism remains unexplained. This study aimed to investigate the relationships between body composition and bone and glucose metabolism in postmenopausal women wit h T2DM. Dual-energy X-ray absorptiometry was used to measure bone mineral density (BMD) and body composition. A total of 68 postme nopausal women with T2DM and 71 controls were eligible for the study. In contrast to normal BMD in T2DM, a similar prevalence of low-trauma fractures was observed in both groups. T2DM women had significantly higher Trunk fat% and A/G ratio and significantly lower Legs LM% and Legs FM%. Legs LM% was significantly lower in fractured T2DM group and negatively correlated with glycaem ia and HbA1c (p<0.01). Serum osteocalcin was significantly lower in T2DM and inversely correlated with FM%, Trunk FM% and A/G ratio (p<0.01) and positively correlated with Legs FM% and total LM% (p<0.05). In conclusion, abdominal obesity and decrease in mu scle mass may contribute to low bone formation in T2DM women. Further research is needed to unravel underlying pathophysiological mechanisms and to determine whether maintenance of muscle mass, especially in the lower extremities and/or reduction of centra l fat mass can prevent fractures., I. Raška Jr., M. Rašková, V. Zikán, J. Škrha., and Obsahuje bibliografii
European wild rabbit (Oryctolagus cuniculus) is a widely distributed species with a multiple role in both environmental sustainability and local economy. In the current study we examine the body condition of the species in relation to habitat type, age, sex and seasonality on the island of Lemnos. Body condition was assessed based on a visual estimation of the amount of abdominal fat. A high intra-annual variation in the body condition of the species has been observed, which is further affected by sex and age. The species appears to conserve and maintain high levels of energy reserves for two main reasons. The first is to ensure a better reproductive success,
as expressed by the relatively high amount of stored fat reserves at the onset of breeding season, and their depletion during it. The second
is to ensure survival during periods where the shortage of food creates a rather hostile environment, as expressed by the increased level of reserves during summer and their dramatic decrease from late summer until autumn. The temporal fluctuation in energy reserves differs between male and female rabbits, reflecting their temporally different energy demands. Further, differences in body conditions were observed between juvenile and adult individuals, reflecting their different needs in terms of body growth and maintenance. Our results could offer important insights for the development of a time specific management plan and measures to ensure either the control of the population or its conservation.
We assessed five body dimensions and winter coat coloration in a feral population of sika deer. In total, 37 stags and 45 does (age = five years or older) were assessed by sex. Results were compared with those obtained previously from different feral or enclosed populations. Moravian sika deer belong to the group of “nipponoid” forms.
The relationship between possible alterations in the volume or distribution of extracellular fluid and the development of salt hypertension was studied in inbred salt-sensitive (SS/Jr) and salt-resistant (SR/Jr) Dahl rats. Blood pressure, cardiac and renal hypertrophy as well as body fluid volumes were determined in young and adult SS/Jr and SR/Jr rats of both sexes that were subjected to low, normal or high salt intake for various periods of time. Salt hypertension in young salt-sensitive rats fed a 4 % NaCl diet was not accompanied by any substantial intravascular or interstitial expansion as compared to salt-resistant rats that remained normotensive. There was no sex difference in the response of blood pressure or body fluids to high salt intake. Major expansion of plasma and blood volume, which was elicited by 8 % NaCl diet feeding from prepuberty, was not accompanied by a further blood pressure rise (compared to salt hypertensive SS/Jr rats fed 4 % NaCl diet). In conclusions, salt hypertension can occur in Dahl salt-sensitive rats without major salt and water retention. The degree of intravascular expansion is not directly related to blood pressure levels in salt-loaded Dahl rats. A high salt intake seems to exert its hypertensive effects in Dahl rats preferentially by influencing the balance of vasoconstrictor and vasodilator systems rather than by increasing the haemodynamically active intravascular volume.
Variants within the FTO gene are important determinants of body mass index (BMI), but their role in determination of BMI changes after combined dietary/physical ac tivity intervention is unclear. We have analyzed 107 unrelated overweight non-diabetic Czech females (BMI over 27.5 kg/m2 , age 49.2±12.3 years). FTO variants rs17817449 (first intron) and rs17818902 (third intron) were genotyped. The life style mo dification program (10 weeks) consisted of an age- matched reduction of energy intake and exercise program (aerobic exercise 4 times a week, 60 min each). The mean BMI before intervention was 32.8±4.2 kg/m2 and the mean achieved weight loss was 4.8±3.5 kg (5.3±3.5 %, max. -15.5 kg, min. +2.0 kg, p<0. 01). No significant association between BMI decrease and FTO variants was found. Also waist-to-hip ratio, body composition (body fat, water, active tissue), lipid parameters (total, LDL and HDL cholesterol, triglycerides) glucose and hsCRP change s were independent on FTO variants. FTO variants rs17817449 and rs17818902 are not associated with BMI changes after combined short time dietary/physical activity intervention in overweight females., D. Dlouhá ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The effects of body size on mating success and duration of copulation were investigated in Pyrrhocoris apterus. Under laboratory conditions relative mating success of small and large males was investigated in groups of 2 males (majority sex) : 1 female (minority sex). Large males were recorded significantly more often in copulation than small males when the female was large but not when the female was small. This was also the case when the group size was 24 males : 12 females or population density decreased by increasing the area of the experimental arena. In groups of 2females : 1 male, large females were recorded in copulation significantly more often than small females when the male was large but not when the male was small. Proportion of individuals of the minority sex that copulated was similar for males and females, regardless of body size. The average duration of copulation was similar for small and large males, but shorter for small than large females. The difference in the duration of copulation of small and large females was greater when it was with small rather than large males. The prolonged guarding of large females by small males may be explained by a trade-off between increasing the probability of inseminating an uneasily accessible high quality partner and copulating with more females.
The hypothesis that small species of aphidophagous coccinellids need lower aphid population densities for reproduction than large species (Dixon, 2007) was tested in the field. In 2006 we compared seasonal changes in the oviposition behaviour of two coccinellid species regularly found in cereal stands in central Europe, the large Coccinella septempunctata L. and the small Propylea quatuordecimpunctata (L.). Adults of both species were collected at 2-3 day intervals from stands of winter wheat and spring barley, females were allowed to deposit eggs for 24 h following collection and the percentage that laid eggs and the number of eggs were recorded. Both species colonized the cereal crop simultaneously in the middle of May. After colonization of the crop, while the aphid density was still low, few females of C. septempunctata oviposited and laid only a few eggs. Oviposition increased up to a maximum c. 1 month later and was closely associated with prey abundance. Of the females of P. quatuordecimpunctata, whose mass is about one quarter of that of the former species, the percentage ovipositing and number of eggs laid varied less in time and was less associated with prey abundance than in C. septempunctata. As predicted by theory, the small P. quatuordecimpunctata was more effective at exploiting the lower prey densities as it produced proportionally more of its eggs during the early stages of the aphid infestation than the larger C. septempunctata.
The aim of our study was to evaluate the adequacy of a new mapping device for obtaining a reliable set of normal maps characteristic for this approach. We studied body surface isochrone maps of peak R in four healthy adolescent girls using the mapping system CARDIAG 128.1 with 80 unipolar leads placed in a regular grid. The constructed maps were compared with published data using 10 criteria. None of the maps obtained could be regarded as normal. After evaluating the reasons for the "abnormality", we assume that they could be caused mostly by the processing of signals. This fact can be eliminated by improving the existing software.