Lokalisierung von rRNA-Genorten und Sekundäreinschnürungen beiVicia narbonensis undVicia sativa

Sites of 18/25S RNA genes and those of secondary constrictions have been located in metaphase chromosomes ofV. narbonensis andV. sativa by RNA/DNA in situ hybridization and Feulgen staining. InV. narbonensis the rRNA genes are located in median position on one pair of chromosomes, which is the shortest of all in the genome. InV. sativa rRNA genes are located in two pairs of chromosomes. The two heterologous sites differ markedly in the level of labeling. Strong labeling is found in a submedian position of a short pair of chromosomes. Weaker labeling is found in a median position on the longest pair of chromosomes. InV. narbonensis andV. sativa the position of the grain clusters correlate with the position of the secondary constrictions in chromosomes stained by Feulgen. The implications with respect to karyograms ofV. narbonensis andV. sativa known from the literature are discussed.

     

Evolutionary relations between subtypes of telomere-associated repeats inChironomus

Summary Telomere-associated DNA inChironomus pallidivittatus contains tandemly repeated 340-bp units. We show that they are distributed among several subtypes of which we have characterized two, M1 and D1, with regard to base sequence, homogeneity, and intertelomeric distribution. Each subpopulation is highly homogeneous and the two subtypes have identical consensus sequences throughout 90% of their lengths. In the remaining part the homology is only about 60%. Each subpopulation has its specific intertelomeric distribution and there is no difference in the degree of homogenization within and between telomeres. The repeat unit contains two pairs of subrepeats embedded in linker DNA. This provides a model that makes it possible to relate the two subtypes to each other with regard to evolutionary history. The difference between the two subtypes is due to mutations that have occurred in only one of them, D1, resulting in a decreased similarity between one of its pairs of subrepeats. This type of repeat unit is therefore believed to be derived from the other, M1. The local decrease in similarity between M1 and D1 suggests that homogenization between them occurs by gene conversion.     

Comparison of the reproductive performance of rats at high altitude (3,800m) and at sea level

Estrous cycles and reproductive performance were compared among rats born at high altitude, rats of Berkeley stock transported to 3,800 m, and sea level controls. Disturbances of reproductive function observed in experimental groups were not due to reduced food intake. Estrous cycles of Berkeley stock at 3,800 m were normal, whereas cycles of high altitude native rats were irregular and fertility was impaired. Litter size was reduced in both groups at high altitude with fewer implantation sites than numbers of corpora lutea observed in the Berkeley stock rats at 3,800 m. In the high altitude native animals, numbers of corpora lutea correlated with implantation sites. Placentas from Berkeley stock rats (3,800 m) were heavier than those from the other groups, and fetal hematocrits from these animals were reduced.     

A follow-up study of urinary bladder patients tested for tumour-related lymphocyte-mediated cytotoxicity

Summary A total of 143 patients with transitional cell carcinoma of the urinary bladder were tested for lymphocyte-mediated cytotoxicity against the bladder carcinoma cell line T24. Some of the patients were also tested against MANO (another cell line of transitional cell bladder carcinoma origin), HCV29 (from bladder epithelium, probably transformed in vitro) and/or HT29 (from a colon adenocarcinoma). The patients were divided into a high- or a low-responder group for each cell line. The patients were followed up and the correlation between a high response in the cytotoxicity tests and survival was evaluated using an adaptation of the Mantel-Haenszel statistics. No significant correlation could be demonstrated.     

Up-regulation of uPARAP/Endo180 during culture activation of rat hepatic stellate cells and its presence in hepatic stellate cell lines from different species

Background  

The urokinase plasminogen activator receptor associated protein (uPARAP)/Endo180 is a novel endocytic receptor that mediates collagen uptake and is implicated to play a role in physiological and pathological tissue-remodelling processes by mediating intracellular collagen degradation.     

Seasonal changes in the pituitary gland of the feral hawaiian mongoose (Herpestes auropunctatus)

The Hawaiian mongoose (Herpestes auropunctatus) is a seasonally breeding mammal whose pituitary gland resembles that of other Viverridae. Certain features, such as a prominent pars tuberalis interna and a double-layered pars intermedia forming a cup for the neurohypophysis, are unique. With the light microscope, five different cell types can be recognized in the pars distalis after staining with periodic acid-Schiff (PAS)-orange G. Two types of acidophils are seen, a small yellow-staining cell and a large angular orange cell. Two basophilic cells are also seen, one with fine PAS-positive cytoplasmic granules and the other with coarse PAS-positive granules in the cytoplasm. The last cell type seen is the chromophobe. Differential cell counts indicated an altered distribution of chromophils in the ventral pars distalis of the female mongoose with changing season and reproductive status, but the most striking change was a decreased percentage of basophils in the pars distalis during the nonbreeding season.