Plant intraspecific functional trait variation is related to within‐habitat heterogeneity and genetic diversity in Trifolium montanum L.

Intraspecific trait variation (ITV), based on available genetic diversity, is one of the major means plant populations can respond to environmental variability. The study of functional trait variation and diversity has become popular in ecological research, for example, as a proxy for plant performance influencing fitness. Up to now, it is unclear which aspects of intraspecific functional trait variation (iFD_CV) can be attributed to the environment or genetics under natural conditions. Here, we examined 260 individuals from 13 locations of the rare (semi‐)dry calcareous grassland species Trifolium montanum L. in terms of iFD_CV, within‐habitat heterogeneity, and genetic diversity. The iFD_CV was assessed by measuring functional traits (releasing height, biomass, leaf area, specific leaf area, leaf dry matter content, F_v/F_m, performance index, stomatal pore surface, and stomatal pore area index). Abiotic within‐habitat heterogeneity was derived from altitude, slope exposure, slope, leaf area index, soil depth, and further soil factors. Based on microsatellites, we calculated expected heterozygosity (H_e) because it best‐explained, among other indices, iFD_CV. We performed multiple linear regression models quantifying relationships among iFD_CV, abiotic within‐habitat heterogeneity and genetic diversity, and also between separate functional traits and abiotic within‐habitat heterogeneity or genetic diversity. We found that abiotic within‐habitat heterogeneity influenced iFD_CV twice as strong compared to genetic diversity. Both aspects together explained 77% of variation in iFD_CV ( = .77, F_{2, 10} = 21.66, p < .001). The majority of functional traits (releasing height, biomass, specific leaf area, leaf dry matter content, F_v/F_m, and performance index) were related to abiotic habitat conditions indicating responses to environmental heterogeneity. In contrast, only morphology‐related functional traits (releasing height, biomass, and leaf area) were related to genetics. Our results suggest that both within‐habitat heterogeneity and genetic diversity affect iFD_CV and are thus crucial to consider when aiming to understand or predict changes of plant species performance under changing environmental conditions.     

Frequency of large granular lymphocytes in peripheral blood of healthy persons and breast cancer patients

Summary The frequency of large granular lymphocytes (LGL) in the peripheral blood of healthy persons (n=56) and breast cancer patients (31 cases with stage-I and -II disease and 42 cases with stage-III and -IV disease) was studied. The frequency of LGL in peripheral blood was significantly depressed in cancer patients, and particularly in patients with advanced breast cancer.     

Social behavior in a captive chimpanzee (Pan troglodytes) group

A group of captive chimpanzees, consisting of one adult male and three mother/infant pairs, was systematically observed over a 15-month period. Over 200 hr of data were collected, using both sequential and time sampling techniques, and compared to the available data on wild chimps. Unlike many captive groups, most behavior patterns were remarkably similar, both qualitatively and quantitatively, to that of wild chimpanzees including: play, grooming, infant sexual development, tool use, food sharing, prosocial partner preferences, and aggressive displays.     

Complementary Roles of the Hippocampus and the Dorsomedial Striatum during Spatial and Sequence-Based Navigation Behavior

We investigated the neural bases of navigation based on spatial or sequential egocentric representation during the completion of the starmaze, a complex goal-directed navigation task. In this maze, mice had to swim along a path composed of three choice points to find a hidden platform. As reported previously, this task can be solved by using two hippocampal-dependent strategies encoded in parallel i) the allocentric strategy requiring encoding of the contextual information, and ii) the sequential egocentric strategy requiring temporal encoding of a sequence of successive body movements associated to specific choice points. Mice were trained during one day and tested the following day in a single probe trial to reveal which of the two strategies was spontaneously preferred by each animal. Imaging of the activity-dependent gene c-fos revealed that both strategies are supported by an overlapping network involving the dorsal hippocampus, the dorsomedial striatum (DMS) and the medial prefrontal cortex. A significant higher activation of the ventral CA1 subregion was observed when mice used the sequential egocentric strategy. To investigate the potential different roles of the dorsal hippocampus and the DMS in both types of navigation, we performed region-specific excitotoxic lesions of each of these two structures. Dorsal hippocampus lesioned mice were unable to optimally learn the sequence but improved their performances by developing a serial strategy instead. DMS lesioned mice were severely impaired, failing to learn the task. Our data support the view that the hippocampus organizes information into a spatio-temporal representation, which can then be used by the DMS to perform goal-directed navigation.     

Dimeric chromenes and mixed dimers of a chromene with euparin from Encelia canescens

The investigation of Encelia canescens afforded, in addition to several known compounds, four new dimeric p-hydroxyacetophenone derivatives, two epimeric chromene dimers and two epimeric mixed dimers of euparin and encecalin. Furthermore, derivatives of tremetone and of encecalin were present. The structures were elucidated hy high field ¹H NMR spectroscopy.     

Obesity-inducing lesions of the central nervous system alter leptin uptake by the blood-brain barrier.

Leptin regulates body adiposity by decreasing feeding and increasing thermogenesis. Obese humans and some obese rodents are resistant to peripherally administered leptin, suggesting a defect in the transport of leptin across the blood-brain barrier (BBB). Defective transport of exogenous leptin occurs in some models of obesity, but in other models transport is normal. This shows that factors other than obesity are associated with impairment of leptin transport across the BBB. In order to further investigate these factors, we determined leptin transport in rats made obese by lesioning of the ventromedial hypothalamus (VMH), paraventricular nucleus (PVN), or posterodorsal amygdala (PDA). These regions all contain leptin receptors and lesions there induce obesity and hyperleptinemia and alter the levels of many feeding hormones which might participate in leptin transporter regulation. We measured the uptake of radioactively labeled leptin by the BBB by multiple-time regression analysis which divides uptake into a reversible phase (Vi, e.g., receptor/transporter binding to the brain endothelial cell) and an irreversible phase (Ki, complete transport across the BBB). Leptin uptake was not affected in rats with VMH lesions. No significant change occurred in the entry rate (Ki) for any group, although Ki declined by over 35% in rats with PVN lesions. Decreased uptake was observed in rats with PVN lesions and with PDA lesions. This was primarily due to a reduced Vi (about 21% for the PDA). This decreased uptake is most likely explained by decreased binding of leptin to the brain endothelial cell, which could be because of decreased binding by either receptors or transporters. This suggests that some of the feeding hormones controlled by the PVN and PDA may participate in regulating leptin uptake by the BBB.     

Synthesis of a 3-methyluridine phosphoramidite to investigate the role of methylation in a ribosomal RNA hairpin.

The synthesis of a 5'-O-BzH-2'-O-ACE-protected-3-methyluridine phosphoramidite is reported [BzH, benzhydryloxy-bis(trimethylsilyloxy)silyl; ACE, bis(2-acetoxyethoxy)methyl]. The phosphoramidite was employed in solid-phase RNA synthesis to generate a series of RNA hairpins containing single or multiple modifications, including the common nucleoside pseudouridine. Three 19-nucleotide hairpin RNAs that represent the 1920-loop region (G(1906)-C(1924)) of Escherichia coli 23S ribosomal RNA were generated. Modifications were present at positions 1911, 1915, and 1917. The stabilities and structures of the three RNAs were examined by using thermal melting, circular dichroism, and NMR spectroscopy     

The karyotype of Alligator mississippiensis,and chromosomal mapping of the ZFY/X homologue,Zfc

Comparative mapping studies of X-linked genes in mammals have provided insights into the evolution of the X chromosome. Many reptiles including the American alligator, Alligator mississippiensis, do not appear to possess heteromorphic sex chromosomes, and sex is determined by the incubation temperature of the egg during embryonic development. Mapping of homologues of mammalian X-linked genes in reptiles could lead to a greater understanding of the evolution of vertebrate sex chromosomes. One of the genes used in the mammalian mapping studies was ZFX, an X-linked copy of the human ZFY gene which was originally isolated as a candidate for the mammalian testis-determining factor (TDF). ZFX is X-linked in eutherians, but maps to two autosomal locations in marsupials and monotremes, close to other genes associated with the eutherian X. The alligator homologue of the ZFY/ZFX genes, Zfc, has been isolated and described previously. A detailed karyotype of A. mississippiensis is presented, together with chromosomal in situ hybridisation data localising the Zfc gene to chromosome 3. Further chromosomal mapping studies using eutherian X-linked genes may reveal conserved chromosomal regions in the alligator that have become part of the eutherian X chromosome during evolution.