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11.
12.
Menstrual-cycle phase and sexual behavior in semi-free-ranging stumptail macaques (Macaca arctoides)
The sexual behavior and female reproductive cycles of a group of island-dwelling stumptail macaques (Macaca arctoides)were monitored over a 6-month period, yielding 530 observation hr and 268 copulations. Compared to nondominant males, the
dominant male copulated at a relatively high rate throughout the cycle, but largely with one high-ranking female. The non-dominant
males copulated most frequently at midcycle. Female presenting was highest at midcycle, but only to the dominant male. Cross-study
discrepancies may be due to different observation methods and restricted environmental conditions that mask female-initiated
sexual behavior. The more naturalistic setting of this study allowed for a fuller expression of proceptivity. Contrary to
some previous conclusions, present findings suggest that both hormonal and socioenvironmental factors influence the patterns
of sexual behavior found in stumptail macaque colonies. 相似文献
13.
Acquisition of phosphorus and copper by VA-mycorrhizal hyphae and root-to-shoot transport in white clover 总被引:17,自引:0,他引:17
White clover (Trifolium repens L.) plants were grown in a calcareous soil in pots with three compartments, a central one for root growth and two outer ones
for growth of vesicular-arbuscular (VA) mycorrhizal (Glomus mosseae [Nicol. & Gerd.] Gerdemann & Trappe) hyphae (hyphal compartments). Phosphorus (P) was applied at three levels (0, 20 and
50 mg kg−1 soil) in the outer compartments in mycorrhizal treatments. Root and shoot dry weight were increased in mycorrhizal plants
with hyphal access to outer compartments. Growth of the mycorrhizal hyphae in the outer compartments was not significantly
affected by variation in P level in these compartments. However, both concentration and amount of P in roots and shoots sharply
increased with increasing P supply in the outer (hyphal) compartments. With increasing P levels the calculated delivery of
P by the hyphae from the outer compartments increased from 34% to 90% of total P uptake.
Hyphal access to the outer compartments also significantly increased both concentration and quantity of Cu in the plants.
The calculated delivery of Cu by the hyphae from the outer compartments ranged from 53% to 62% of total Cu uptake, irrespective
of the P levels and the amounts of P taken up and transported by the hyphae. However, the distribution of Cu over roots and
shoots was largely dependent on P levels. With increase in P level in the outer compartments the calculated hyphal contribution
to the total amount of Cu in the shoots increased from 12% to 58%, but decreased in the roots from 75% to 46%.
In conclusion, uptake and transport by VA-mycorrhizal hyphae may contribute substantially not only to P nutrition, but also
to Cu nutrition of the host. 相似文献
14.
Cytogenetic and molecular characterization of a newly established neuroblastoma cell line LS 总被引:2,自引:0,他引:2
Günter Rudolph Karin Schilbach-Stückle Rupert Handgretinger Peter Kaiser Horst Hameister 《Human genetics》1991,86(6):562-566
Summary A new human neuroblastoma cell line (LS) that originated from an abdominal tumor of a 16-month-old girl is presented; it was classified, according to Evans, as being stage III. Morphological (dense-core particles) and biochemical characteristics (dopamine--hydroxylase, acetylcholinesterase, neuron-specific-enolase) confirmed the diagnosis. In addition to a slightly variable modal chromosome number of 48 or 49 (because of marker-chromosomes and autosomal trisomies), cytogenetic analysis revealed two constantly appearing chromosomes with homogeneously stained regions (HSR's). The karyo-type remained constant over 50 passages in vitro [49,XX, –12,+der5, + 17,+mar1,+mar2]. Double minutes were a rare phenomenon and appeared only in a few metaphases. In situ hybridization showed that some of the HSR's consisted of amplified N-myc copies. The distribution of the N-myc copies according to in situ hybridization signals along the HSR's was compared with the data of Southern and Northern blotting analyses. 相似文献
15.
We have previously shown linear and circular splicing intermediates resembling intermediates that result from self-splicing of ribosomal precursor RNA of Tetrahymena to be present in mitochondrial RNA. Here we show that splicing of yeast mitochondrial precursor RNA also occurs in vitro in the absence of mitochondrial proteins. The large ribosomal RNA gene, consisting of the intron and part of the flanking exon regions, was inserted behind the SP6 promoter in a recombinant plasmid and was transcribed in vitro. The resulting RNA shows self-catalyzed splicing via incorporation of GTP at the 5'-end of the excised intron, 5'- to 3'-exon ligation, and intron circularization. When purified mitochondrial RNA is incubated under similar conditions with alpha-32P-GTP, the excised ribosomal intron RNA is also labeled, as well as several other RNA species. Some of these RNAs are derived from excised introns from the multiply split gene coding for cytochrome oxidase subunit I. 相似文献
16.
Siegbahn Nils Mosbach Klaus Grodzki Karola Zocher Rainer Madry Norbert Kleinkauf Horst 《Biotechnology letters》1985,7(5):297-302
Summary The multienzyme enniatin synthetase was covalently immobilized to N-hydroxysuccinimide activated agarose. The stability of the immobilized enzyme at 25°C was enhanced compared to the soluble enzyme. Immobilization experiments also indicated that the enniatins are synthesized by a single molecule and thus do not require interactions of several enzyme molecules. 相似文献
17.
Barbara Siemieniako Ewa M. Rakowicz-Szulczyńska Antoni Horst 《Molecular and cellular biochemistry》1985,65(2):131-141
Non-histone chromatin proteins synthesized during chicken embryonic liver development were labeled with [3H]tryptophan and [3H]methionine and characterized by electrophoresis. During embryonic development protein/DNA ratio in chromatin was low (1.30-1.62) but synthesis of non-histone protein was high. Especially one characteristic fraction K (MW 18 000), tightly bound with DNA was preferentially associated with DNAase II sensitive, active transcribed sequences. In 7-day old and adult chicken synthesis of all non-histone proteins was low, fraction K was absent or synthesized only in small amounts in association with non-active sequences, however protein/DNA ratio in chromatin was high (2.30-2.33). 相似文献
18.
Summary DNA haplotype constellations of the β-globin gene cluster have been analyzed in German families with hemoglobinopathies (Hb
Freiburg, Hb K?ln, Hb Presbyterian) and β-thalassemias. The polymorphis patterns obtained were compared to those found in
families from Greece, Italy, and Turkey affected by β-thalassemia syndromes. With the combined analysis of seven restriction
site polymorphisms a DNA-diagnostic prediction for additional offspring could be made with an overall frequency of 75% in
the four ethnic groups. 相似文献
19.
20.
Raif G. Vasilov Alfred Hahn Horst Mölders Jon J. van Rood Martijn Breuning Hidde L. Ploegh 《Immunogenetics》1983,17(4):333-356
Class I antigens were isolated by immunoprecipitation from cell extracts prepared from mitogenically stimulated and internally radiolabeled peripheral blood lymphocytes (PLBs). The precipitating antibodies used are monomorphic and recognize a determinant on the heavy chain of HLA-A, B, C antigens regardless of their allelic specificities when complexed with
2m, or determinants on
2m itself. Comparison of class I molecules isolated from 25 different homozygous typing cels (HTC) and analyzed by two-dimensional (2-D) gel electrophoresis allowed the identification of those HLA-A,13 locus specificities most common in the European Caucasoid population. Class I antigens isolated from HTC that are HLA identical are biochemically indistinguishable also. Evidence was obtained for the expression of additional class I antigens besides the HLA-A, B, C locus products: for some haplotypes, up to six class I genes may be active in mitogenically activated PBLs. No differences in molecular weight and isoelectric point of the class I heavy chains were observed between the antigens recognized by W6/32, the anti-heavy chain reagent, and anti-
2m reagents. The nature of the mitogenic stimulus, i. e., pokeweed mitogen or phytohemagglutinin, was irrelevant with respect to the class I antigens isolated by this method. Using the HTCs as reference, a panel of HLA-B27 positive heterozygous cells was analyzed. Two types of HLA-B27 antigens, distinct by CML typing were represented. These two forms differed also in their biochemical properties. In addition, we obtained evidence for the existence of an A2 variant. This finding was likewise confirmed by CML typing. 相似文献