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1.
Ovarian steroids and growth factors are intragonadal modulators which augment a key endpoint of follicle-stimulating hormone (FSH) action in granulosa cells: the induction of aromatase activity. Studies of these paracrine hormones that enhance FSH-stimulated estrogen biosynthesis by cultured rat granulosa cells, have led to the development of a sensitive and specific
bioassay for FSH. This newly developed granulosa cell aromatase bioassay (GAB) allows for the measurement of bioactive FSH levels in serum and urine of humans and animals with various physiological and pathological conditions. These studies have demonstrated that the GAB assay is useful in detecting possible changes in the molecular forms of FSH. The adaptation of this method for urine samples allows for the measurement of bio-FSH levels in situations where venipuncture is not practical or in species for which specific radioimmunoassays are not available. 相似文献
2.
Summary C-band polymorphisms of chromosome 1 can be quantified by Ce bands visualized using oblique epi-illumination. In this paper the polymorphic region of chromosome 9, including variants such as 9qh+, inversions, and translocations, was analyzed in a total of 1860 chromosomes from 20 individuals and 8 fetuses. In this sample we found between zero and five Ce bands on 9q and between zero and four Ce bands on 9p with a maximum of five Ce bands per chromosome. On the basis of these observations at least 19 different polymorphic patterns can be expected theoretically, 15 of which were observed in our sample. Among these, five polymorphic Ce-band classes were distinguishable by the method presented. Considering both homologues, 52=25 quantitatively discernible chromosome 9 pairs may exist. 相似文献
3.
Maria L. Boccia Martin L. Reite Kristine Kaemingk Polly Held Mark L. Laudenslager 《Primates; journal of primatology》1991,32(2):255-263
The social environment affects both behavioral and physiological responses to separation from the mother. Less information
is available on the impact of the social environment on the response to separation in peer-reared infant monkeys. This study
reports the responses of peer-reared pigtail macaque infants to repeated separations, and the impact of social versus isolation
housing during the separation. The responses of two pairs of monkeys were studied during four three-day separations. One of
each pair was housed in isolation during the separation, and the other was with another pair of peers, with whom they had
been living for one month prior to the separation. The isolation-housed peer responded to the separation with behavioral agitation,
but no depression. The socially-housed peer's behavior did not differ from baseline during the separation. During successive
reunions, all the separated monkeys, regardless of housing condition, exhibited declining levels of behaviors related to maintaining
proximity to their attachment figure. Although the number of subjects is small, the results suggest that the presence of social
support, in the form of a familiar peer, can ameliorate the response to separation, and that with repeated separations the
responses of the monkeys changes significantly. 相似文献
4.
Harry Jan Swartz Robert Bors Fouad Mohamed S. Kristine Naess 《Plant Cell, Tissue and Organ Culture》1990,21(2):179-184
Shoot regeneration from Rubus leaves was obtained on a medium containing MS salts, vitamins and sugars, Staba vitamins, casein hydrolysate (100 mg l–1) and 10 M thidiazuron. Shoot regeneration from Malus leaves was obtained on N6 rice anther medium with 5 M thidiazuron. In vitro pretreatment of source shoots with either colchicine or thidiazuron enhanced the organogenic potential of detached leaves of two Rubus hybrids. The response to colchicine was quadratic and occurred at non-mutagenic concentrations (75–250 M). The response to thidiazuron was exponential between 0 and 5 M. When applied as a pretreatment, the effectiveness of several different cytokinins (benzyladenine, thidiazuron, zeatin) at enhancing Malus and Rubus organogenesis was related to the shoot proliferation activity of the cytokinin and to treatment-induced variation in leaf and petiole size.Abbreviations BA
benzyladenine
- 2,4-D
2,4-dichlorophenoxyacetic acid
- IBA
indolebutyric acid
- MS
Murashige & Skoog basal medium devoid of plant growth regulators
- OI
organogenesis-initiating subculture
- PTI
colchicine pretreatment subculture
- PTII
cytokinin pretreatment subculture
- NAA
naphthaleneacetic acid
- TDZ
thidiazuron
- zeatin
trans-zeatin 相似文献
5.
Johnson Kristine; Thornhill Randy; Ligon J. David; Zuk Marlene 《Behavioral ecology》1993,4(3):254-259
We used a breeding design involving 18 sires and 108 dams tostudy the heritabilities of male ornaments in red jungle fowl(Gallus gallus). Ornaments used by females to choose mates showedlow heritabilities, with the exception of comb and wattle measures.The general absence of heritability suggests that a geneticcovariance did not exist at the time of this study between mostmale ornaments and female preferences for those ornaments. Thisresult is contrary to a key prediction of the arbitrary or Fisherianhypothesis of sexual selection. Comb size and color are condition-dependenttraits that reflect short-term changes in health, and comb sizeof males was positively correlated with offspring weight. Ourresults are consistent with the expectation of good-genes hypothesesthat male ornaments reflect the ability of males to withstandenvironmental stresses. 相似文献
6.
Valentina Sora Adrian Otamendi Laspiur Kristine Degn Matteo Arnaudi Mattia Utichi Ludovica Beltrame Dayana De Menezes Matteo Orlandi Ulrik Kristoffer Stoltze Olga Rigina Peter Wad Sackett Karin Wadt Kjeld Schmiegelow Matteo Tiberti Elena Papaleo 《Protein science : a publication of the Protein Society》2023,32(1):e4527
Reliable prediction of free energy changes upon amino acid substitutions (ΔΔGs) is crucial to investigate their impact on protein stability and protein–protein interaction. Advances in experimental mutational scans allow high-throughput studies thanks to multiplex techniques. On the other hand, genomics initiatives provide a large amount of data on disease-related variants that can benefit from analyses with structure-based methods. Therefore, the computational field should keep the same pace and provide new tools for fast and accurate high-throughput ΔΔG calculations. In this context, the Rosetta modeling suite implements effective approaches to predict folding/unfolding ΔΔGs in a protein monomer upon amino acid substitutions and calculate the changes in binding free energy in protein complexes. However, their application can be challenging to users without extensive experience with Rosetta. Furthermore, Rosetta protocols for ΔΔG prediction are designed considering one variant at a time, making the setup of high-throughput screenings cumbersome. For these reasons, we devised RosettaDDGPrediction, a customizable Python wrapper designed to run free energy calculations on a set of amino acid substitutions using Rosetta protocols with little intervention from the user. Moreover, RosettaDDGPrediction assists with checking completed runs and aggregates raw data for multiple variants, as well as generates publication-ready graphics. We showed the potential of the tool in four case studies, including variants of uncertain significance in childhood cancer, proteins with known experimental unfolding ΔΔGs values, interactions between target proteins and disordered motifs, and phosphomimetics. RosettaDDGPrediction is available, free of charge and under GNU General Public License v3.0, at https://github.com/ELELAB/RosettaDDGPrediction . 相似文献
7.
The immunohistochemical occurrence of sarafotoxin (SRTX), a snake venom peptide under strong evolutionary control, was investigated in the pulmonary diffuse neuroendocrine system (PDNES) of newborn cats and rats. By applying the avidin-biotin-peroxidase complex method on serial lung sections, we have demonstrated its distribution and colocalization with different endothelin (ET) isoforms. A light microscopic study revealed apparent immunostaining for SRTX in neuronal components and smooth muscle tissue and in neuroepithelial bodies (NEB), while isolated neuroendocrine cells (NEC) remain unlabelled. Comparison of the SRTX reactivity pattern with that of different ET peptides on adjacent lung sections showed colocalization of SRTX-b with ET-3 in NEB, intrapulmonary ganglion cells and nerve fibres, on the one hand, and with ET-1 in airway and vascular smooth muscle cells, on the other. These findings, in addition to the remarkable functional and structural similarities between SRTX and ET peptides, suggest a common evolutionary origin and biological significance of sarafotoxin and endothelins. Moreover, this is the first time that a toxic peptide has been demonstrated in the PDNES. 相似文献
8.
Brown Arthur V. Aguila Yolanda Brown Kristine B. Fowler William P. 《Hydrobiologia》1997,347(1-3):119-125
We examined macroinvertebrate communities in small(0.1-1.0 m2) pools of intermittent streams (alwayscontainingsome water but without perennial flow) with small watersheds(2-6 ha) subjected to five types of forest harvest to assesspotential impacts of the different harvest methods. Bufferstrips10 m wide were left on each side of the streams. Each harvesttreatment was coupled with a similar unharvested referencestand.An incomplete block design included three 0.05 m2 vacuumsamples from each treatment paired with three from theadjacentreferences. There was a high degree of similarity amongreferencesfor parameters other than taxonomic composition (e.g.macroinvertebrate density, number of species, Shannondiversity,functional groups, etc.). Statistically significantdifferenceswere found between references and treatments and among harvestmethods but the responses varied among response variables(density,Shannon-Weiner diversity, species composition), differentspeciesassemblages (all invertebrates, chironomids,Ephemeroptera-Plecoptera-Trichoptera [EPT], isopods), andfunctional group categories (shredders, collector-gatherers).Wecollected 56 taxa, 7–16 per site, with low communitysimilarity(mean Jaccards=0.18, mean Bray-Curtis percentdissimilarity=81). The most severe harvest treatmentsresultedin the highest diversities of total invertebrates in thesesmallspring pool communities. 相似文献
9.
10.
Expression of HLA-B27 in transgenic mice is controlled by gene(s) mapping between H-2D and H-2L loci 总被引:2,自引:0,他引:2
The level of HLA-B27 transgene expression on the cell surface is dependent on the host H-2 haplotype. Mice homozygous for the H-2
b
, H-2
f
, H-2
f
, H-2
p
, H-2
r
, and H-2
k
haplotypes express B27 at high levels. An intermediate level of B27 expression is observed in H-2
v
mice whereas low levels of B27 are expressed in H-2
q
and H-2
d
mice. The decreased expression of B27 maps to the D region of the major histocompatibility complex. Recombinant strain B10.RKDB (DdLb) mapped the low expression gene centromeric to H-2L. In order to determine the low expression within the H-2D region, the B27 transgene was introduced into B10.D2-H-2
dm1
and BALB/c-H-2
dm2
mice. Expression of B27 in both of these strains was high indicating that neither H-2D
d
nor H-2L
d
is responsible for the low expression. This maps the effect between the H-2D and H-2L loci. In addition, introduction of human 2-microglobulin (2m) into B10.D2-B27 transgenic mice caused a marked enhancement of B27 expression on the cell surface suggesting that the defect in B27 expression in certain haplotypes is due to an inability of B27 to associate with endogenous mouse 2m. We propose that gene(s) mapping between D and L (either D2, D3, D4, or some as yet unidentified gene) may be involved in class I assembly by helping association of 2m with class I. This putative molecule, designated Assembly Enhancer (AE) might have a negative influence in the association between human class II and mouse 2m. 相似文献