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EN
Spermatozoa were present in the cauda epididymidis of male Rickett's big-footed bat, Myotis ricketti, from late September to early April but absent from the testes from mid November until late August. Males thus store spermatozoa in the cauda epididymidis for 4.5–6.5 months of the year. Assessments of sperm motility, movement pattern and computer-assisted sperm analysis (CASA) were carried out on spermatozoa which had been stored for over 3.5 months in the cauda epididymidis. The motility of sperm stored for the same period of time and taken from a male which died over 9 h before assessment was 86%. Four kinds of culture media were screened for their suitability for future studies of sperm motility, and a low calcium minimal capacitation medium and a hamster fertilization medium were selected. Serum testosterone (T) concentration increased dramatically in September and began to fall in October, before returning to baseline for the remainder of winter. These results indicate that high levels of T are required for spermatogenesis and spermiogenesis but not for sperm storage.
EN
We studied the link between abscisic acid (ABA), auxin, MAPK (mitogen-activated protein kinase) signaling, and the cell cycle in cadmium (Cd)-stressed rice (Oryza sativa L. cv. Zhonghua No. 11) roots. ABA can partially compensate for root growth inhibition and counteract over-accumulation of auxin caused by Cd. GUS staining of rice plants harboring DR5-GUS showed that ABA affects auxin distribution in Cd-stressed roots. Detection using DRB (5,6-dichlorobenzimidazole 1-β-ᴅ-ribofuranoside, an RNA synthesis inhibitor), MG132 (a protein degradation inhibitor), BFA (brefeldin A, a protein transport inhibitor), and TIBA (2,3,5-triiodobenzoic acid, a polar auxin transport inhibitor) revealed that ABA regulates the distribution of auxin via transcription, protein degradation, and transport pathways under Cd stress. Several genes related to ABA and MAPK, key components of the auxin signaling pathway, and the cell cycle were differentially regulated by Cd plus ABA vs. Cd plus tungstate (TS) (a ABA biosynthesis inhibitor) at 7 days or 11 days of treatment in roots, indicating that ABA levels affect the transcription of these genes, and that these genes are differentially regulated by ABA in rice seedlings at different developmental stages. Furthermore, the expression of some of these genes differed between Cd + ABA/TS-treated plants and plants treated with TS or ABA alone, suggesting that ABA signaling serves specific functions in the regulation of gene expression under Cd stress. Overall, these results suggest that ABA coordinates auxin and MAPK signaling and the cell cycle in response to Cd stress. The ABA signal transduction pathways in Cd-stressed rice plants are discussed.
EN
A combined approach using molecular and morphological data has revealed that the taxon Myotis taiwanensis, which until now has been usually considered as a subspecies of Myotis adversus, should be reinstated as a full species, as originally described by Ärnbäck-Christie-Linde (1908) from Takao, Anping, Tainan, Formosa (= southern Taiwan). In our genetic analysis using two nuclear DNA segments of protein kinase C iota (PRKCI) and ubiquitin specific peptidase 9 (Usp9x), X-linked genes, together with two mitochondrial genes, i.e., nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1) and cytochrome b (Cyt b), we demonstrate that M. taiwanensis is closely related to M. pilosus, and largely divergent from two subspecies of M. adversus. Our analysis further shows that M. taiwanensis differs considerably from M. adversus in external and dental features. New records of M. taiwanensis from Shandong and Anhui provinces in eastern China are presented.
EN
This paper describes the feeding behaviour ofRousettus leschenaulti Desmarest, 1820 on lychees, the preferred cultivated food of this bat in captive conditions. We found that feeding comprised 25–30% of the total activity of these animals in a flight cage and that feeding durations were not significantly different between two sexes. To evaluate the role of odor and vision in foraging behaviour, we provided animals with artificial lychees, real lychees and artificial lychees soaked in the juice of real lychees and we recorded the number of feeding approaches to the different “fruit” types. The results indicated that bats approached real fruit significantly more than artificial fruit, and that the number of approaches to the soaked artificial fruit was also significantly higher than to the unsoaked artificial fruit. There were no significant differences between sexes in approach rates to any “fruit” type. We discuss the role of different sensory cues in the foraging behaviour of these bats and emphasize that the olfactory cue is important in detecting food resources and discriminating between different kinds of food items.
EN
MicroRNAs (miRNAs) regulate gene expression by inhibiting translation or targeting messenger RNA (mRNA) for degradation in a posttranscriptional fashion. In this study, we show that ectopic expression of miR-34a-5p reduces the mRNA and protein levels of Krüppel-like factor 4 (KLF4). We also demonstrate that miR-34a targets the 3′-untranslated mRNA region of KLF4 and show that overexpression of miR-34a induces a significant level of apoptosis in BNL CL.2 cells exposed to doxorubicin or 10 Gy X-ray. Our data suggest that the effects of miR-34a on apoptosis occur due to the downregulation of KLF4.
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