Ograniczanie wyników

Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 39

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  Rattus norvegicus
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Developmental stability analysis was conducted for three strains of laboratory rat Rattus norvegicus Berkenhout, 1769 and their hybrids. Developmental stability was estimated by fluctuating asymmetry of 20 characters of skull morphology. A decrease was revealed in fluctuating asymmetry for the inbred strains and for the hybrids of genetically different strains. There were not any differences in fluctuating asymmetry between the homo- and heterozygotes for the separate locus. This support the hypothesis of the dependence of developmental stability on general genetic coadaptation.
Arthropods obtained on Rattus norvegicus from Wrocław in 2003-2004 were studied. Also based on literature all arthropods occurring on this host in Poland are mentioned: 3 species of Anoplura, 12 species of Siphonaptera and at least 44 species of Acari. Arthropod communities and dynamic structure of arthropods for brown rat from Poland are given.
Two from three brown rats (Rattus norvegicus) catched in Milanówek near Warsaw, and one catched in the centre of Warsaw were infected with Trypanosoma lewisi. The morphometric features of trypanosomes were in accordance with the features of T. lewisi gived by other authors. This is first note about infection of free living rats with T. lewisi in Poland.
Developmental stability of the progeny of pregnant female rats Rattus norvegicus Berkenhout, 1769 kept under different conditions was studied. In two experimental groups, females were exposed to social stress by keeping them in crowded cages at different stages of pregnancy, from the 1st to the 15th and from the 16th to the 21th days, respectively. In the control group, pregnant females were kept under normal conditions. Fluctuating asymmetry of 20 skull characters (number of foramina for small blood vessels and nerves) was used as a measure of developmental stability. Variance of the difference in foramen number between the left and right sides of the skull (1-r) as well as mean number of asymmetrical traits per individual revealed an increase of fluctuating asymmetry in both experimental groups compared with the control group. These results imply the deterioration of developmental stability under impact of social stress.
Characteristics of 64 possible tandem trinucleotide repeats (TSSR) from Homo sapiens (hs), Mus musculus (mm) and Rattus norvegicus (rn) genomes are presented. Comparative analysis of TSSR frequency depending on their repetitiveness and similarity of the TSSR length distributions is shown. Comparative analysis of TSSR sequence motifs and association between type of motif and its length (n) using ρ-coefficient method (quantitatively measuring the association between variables in contingency tables) is presented. These analyses were carried out in the context of neurodegenerative diseases based on trinucleotide tandems. The length of these tandems and their relation to other TSSR is estimated. It was found that the higher repetitiveness (n) the lower frequency of trinucleotides tandems. Differences between genomes under consideration, especially in longer than n=9 TSSR were discussed. A significantly higher frequency off A- and T-rich tandems is observed in the human genome (as well as in human mRNA). This observation also applies to mm and rn, although lower abundant in proportion to human genomes was found. The origin of elongation (or shortening) of TSSR seems to be neither frequency nor length dependent. The results of TSSR analysis presented in this work suggest that neurodegenerative disease-related microsatellites do not differ versus the other except the lower frequency versus the other TSSR. CAG occurs with relatively high frequency in human mRNA, although there are other TSSR with higher frequency that do not cause comparable disease disorders. It suggests that the mechanism of TSSR instability is not the only origin of neurodegenerative diseases.
16
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Zwierzęce modele schizofrenii

67%
Demodex ratticola was recorded in the brown rat Rattus norvegicus from northern Poland. It is a skin mite specific to this host, previously recorded only in the Czech Republic. D. ratticola was found at a prevalence 65.0% and mean intensity 12.7 in skin samples taken from the regions of lips, nose and chin. Furthermore, three other species from the family of Demodecidae were recorded, including Demodex nanus found in skin samples from different parts of the body and characterised by the highest parameters of infestation (100.0%, 25.2), D. ratti (50.0%, 3.3) found in the head skin and D. norvegicus (30.0%, 3.5) found in the genital and anal regions. The identified demodectic mites did not cause any pathological symptoms in rats.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.