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51.
Effects of parental body condition and size on reproductive success in a tenebrionid beetle with biparental care 总被引:1,自引:0,他引:1
Abstract. 1. The beetle Parastizopus armaticeps (Coleoptera: Tenebrionidae) inhabits the Kalahari desert of southern Africa, constructs breeding burrows after rainfall, and shows extensive biparental care. Previous work has shown that it is predominantly male size, not female size, that determines breeding success; however, in the field these beetles show size assortative mating. This might obscure or override effects of female size on reproduction. Moreover, the inaccessibility of the breeding burrows makes it impossible to test effects of female and male size on offspring development and survival before adulthood. 2. To disentangle the effects of male and female length, body mass, and body condition on reproductive success, males and females were paired randomly in small breeding cages in the laboratory (n = 887 breeding pairs). The construction of the breeding cages allowed a clear view of the brood chamber contents at each stage in offspring development. Larva, pupa, and imago numbers and development were monitored daily, and imago mass at hatching from the pupa (hatchlings), offspring mass, and offspring body length at complete exoskeleton melanisation (juveniles) were determined. 3. There was a weak positive correlation between body condition and body length for females only. Breeding chronology was related to male body condition: males in better condition were fast to start and finish a breeding bout. Males in better condition produced heavier hatchlings and juveniles, and larger‐sized males produced larger‐sized juveniles. In contrast, numbers of larvae and juveniles produced were determined mainly by female length and body condition: larger females in better condition hatched more larvae and produced more offspring. 4. The results suggest that male size and condition will be the most important determinant of reproductive success under relatively dry conditions, when burrow length is critical for reproductive success. Female size might be more important for the pair's reproductive success under wet breeding conditions, when burrow length is less critical for successful reproduction. 相似文献
52.
rRNA mutants in the yeast peptidyltransferase center reveal allosteric information networks and mechanisms of drug resistance 总被引:1,自引:1,他引:0
To ensure accurate and rapid protein synthesis, nearby and distantly located functional regions of the ribosome must dynamically communicate and coordinate with one another through a series of information exchange networks. The ribosome is ~2/3 rRNA and information should pass mostly through this medium. Here, two viable mutants located in the peptidyltransferase center (PTC) of yeast ribosomes were created using a yeast genetic system that enables stable production of ribosomes containing only mutant rRNAs. The specific mutants were C2820U (Escherichia coli C2452) and Ψ2922C (E. coli U2554). Biochemical and genetic analyses of these mutants suggest that they may trap the PTC in the ‘open’ or aa-tRNA bound conformation, decreasing peptidyl-tRNA binding. We suggest that these structural changes are manifested at the biological level by affecting large ribosomal subunit biogenesis, ribosomal subunit joining during initiation, susceptibility/resistance to peptidyltransferase inhibitors, and the ability of ribosomes to properly decode termination codons. These studies also add to our understanding of how information is transmitted both locally and over long distances through allosteric networks of rRNA–rRNA and rRNA–protein interactions. 相似文献
53.
Migl Vai
iukyn Jonas
iauka Rasa
kien Lidija Vertelkait Sigut Kuusien 《Physiologia plantarum》2019,165(1):114-122
The research aim was to assess the effects of the plant hormone abscisic acid (ABA) and the growth regulator paclobutrazol (PBZ) on root system development during the in vitro culture of different birch and aspen genotypes. The studied genotypes involved two aspen (Populus tremula and Populus tremuloides × P. tremula) and two silver birch (Betula pendula) trees, with one of the birches characterized by its inability to root in vitro. For experiments, apical shoot segments were cultured on nutrient medium enriched with either ABA or PBZ. Additionally, the analysis of the endogenous hormones in shoots developed on hormone‐free medium was conducted by high‐performance liquid chromatography. The endogenous concentration of auxin indole‐3‐acetic acid was much higher in the aspens than that in the birches, while the highest concentration of ABA was found in the root‐forming birch. The culturing of this birch genotype on medium enriched with ABA resulted in an increased root length and a higher number of lateral roots without any negative effect on either shoot growth or adventitious root (AR) formation, although these two processes were largely inhibited by ABA in the aspens. Meanwhile, PBZ promoted AR formation in both aspen and birch cultures but impaired secondary root formation and shoot growth in birches. These results suggest the use of ABA for the in vitro rooting of birches and PBZ for the rooting of aspens. 相似文献
54.
Restriction endonuclease BpuJI specific for the 5'-CCCGT sequence is related to the archaeal Holliday junction resolvase family 下载免费PDF全文
Sukackaite R Lagunavicius A Stankevicius K Urbanke C Venclovas C Siksnys V 《Nucleic acids research》2007,35(7):2377-2389
Type IIS restriction endonucleases (REases) recognize asymmetric DNA sequences and cleave both DNA strands at fixed positions downstream of the recognition site. REase BpuJI recognizes the asymmetric sequence 5′-CCCGT, however it cuts at multiple sites in the vicinity of the target sequence. We show that BpuJI is a dimer, which has two DNA binding surfaces and displays optimal catalytic activity when bound to two recognition sites. BpuJI is cleaved by chymotrypsin into an N-terminal domain (NTD), which lacks catalytic activity but binds specifically to the recognition sequence as a monomer, and a C-terminal domain (CTD), which forms a dimer with non-specific nuclease activity. Fold recognition approach reveals that the CTD of BpuJI is structurally related to archaeal Holliday junction resolvases (AHJR). We demonstrate that the isolated catalytic CTD of BpuJI possesses end-directed nuclease activity and preferentially cuts 3nt from the 3′-terminus of blunt-ended DNA. The nuclease activity of the CTD is repressed in the apo-enzyme and becomes activated upon specific DNA binding by the NTDs. This leads to a complicated pattern of specific DNA cleavage in the vicinity of the target site. Bioinformatics analysis identifies the AHJR-like domain in the putative Type III enzymes and functionally uncharacterized proteins. 相似文献
55.
Abdominal adiposity change in white and black midlife women: The study of women's health across the nation 下载免费PDF全文
56.
Simanavicius Martynas Tamosiunas Paulius Lukas Petraityte-Burneikiene Rasa Johne Reimar Ulrich Rainer G. Zvirbliene Aurelija Kucinskaite-Kodze Indre 《Applied microbiology and biotechnology》2018,102(1):185-198
Applied Microbiology and Biotechnology - Hepatitis E is a globally distributed human disease caused by hepatitis E virus (HEV). In Europe, it spreads through undercooked pork meat or other products... 相似文献
57.
Sūdžius J Baranauskienė L Golovenko D Matulienė J Michailovienė V Torresan J Jachno J Sukackaitė R Manakova E Gražulis S Tumkevičius S Matulis D 《Bioorganic & medicinal chemistry》2010,18(21):7413-7421
A series of 4-[N-(substituted 4-pyrimidinyl)amino]benzenesulfonamides were designed and synthesised. Their binding potencies as inhibitors of selected recombinant human carbonic anhydrase (hCA) isozymes I, II, VII, and XIII were measured using isothermal titration calorimetry and the thermal shift assay. To determine the structural features of inhibitor binding, the crystal structures of several compounds in complex with hCA II were determined. Several compounds exhibited selectivity towards isozymes I, II, and XIII, and some were potent inhibitors of hCA VII. 相似文献
58.
Jonas Schmidt-Chanasit Sandra Essbauer Rasa Petraityte Kumiko Yoshimatsu Kirsten Tackmann Franz J. Conraths Kestutis Sasnauskas Jiro Arikawa Astrid Thomas Martin Pfeffer Jerrold J. Scharninghausen Wolf Splettstoesser Matthias Wenk Gerald Heckel Rainer G. Ulrich 《Journal of virology》2010,84(1):459-474
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Vida Mildaziene Rasa Baniene Ausra Marcinkeviciute Zita Nauciene Alvydas Kalvenas Aurelijus Zimkus 《Molecular and cellular biochemistry》1997,174(1-2):67-70
We show that tetraphenylphosphonium inhibits oxidation of palmitoylcarnitine, pyruvate, malate, 2-oxoglutarate and glutamate in heart mitochondria in the range of concentration (1–5 µM) commonly used for the determination of mitochondrial membrane potential. The inhibition of 2-oxoglutarate (but not other substrate) oxidation by tetraphenylphosphonium is dependent on the concentration of 2-oxoglutarate and on extramitochondrial free calcium, and the kinetic plots are consistent with a mixed type of inhibition. Our results indicate that tetraphenylphosphonium interacts with enzymes, specifically involved in the oxidation of 2-oxoglutarate, most possibly, 2-oxoglutarate dehydrogenase. 相似文献