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91.
92.
L. Austin Doyle Lucinda H. Goldstein Cheryl J. Clingroth Frank Cuttitta 《Analytical biochemistry》1990,190(2):238-243
Recent studies have shown that human cancer cell lines can be adapted to grow in serum-free, unsupplemented RPMI-1640 (RO) medium. We have developed similar techniques to rapidly identify proteins of interest in serum-free conditioned medium (CM) of human lung cancer cell lines. Classic and variant small cell lung cancer (SCLC) lines were adapted to growth in RO medium. CM from each line was concentrated and fractionated on an anion-exchange column of a fast protein liquid chromatography system. Concentrates of each fraction were loaded onto lanes of minigels of an automated electrophoresis system. Analysis of the chromatograms reveals peaks seen only in CM of the classic SCLC lines. Electrophoretic analysis of the fractions containing these peaks reveal protein bands distinguishing between the subtypes of human SCLC. One protein was purified to homogeneity with subsequent reversed-phase chromatography and identified by protein microsequencing as histone H2B. These automated techniques have general use in the rapid identification of CM proteins associated with the differentiation or progression of the many types of neoplastic cells which can be adapted to growth in RO medium. 相似文献
93.
Using the adsorption theory of chemical kinetics, a new equation concerning the growth of single populations is presented: or in its integral form: This equation attempts to explain the relationship between population increment and limiting resources. It can be reduced to either the logistic or exponential equation under two extreme conditions. The new equation has three parameters, Xm, X′m and μc, each of which has ecological significance. concerns the efficiency of nutrient utilization by an organism. Its value is between zero and one. With ratios approaching unity, the efficiency is high; lower ratios indicate that population increment is quickly restricted by limiting resources. μc, is a velocity parameter lying between μe, (exponential growth) and μL (logistic growth), and is dependent on the value of . From μc we can predict the time course of population incremental velocity (), and can observe that it is not symmetrical, unlike that derived from the logistic equation. At the maximum velocity of the population increment predicted from the new equation is twice that of the logistic equation.Population growth in nature seems to support the new equation rather than the logistic equation, and it can be successfully fitted by means of a least square method. 相似文献
94.
Summary Healthy pecan, Caryaillinoensis (Wang) Koch, tissue was obtained from an 8-year-old grafted Cherokee tree. Dormant buds were gathered and stored until spring
growth. After rigorous surface sterilization, halves of both stored and freshly harvested dormant buds and of actively growing
shoots were plated onto sterile PDA. Corresponding halves wre fixed in FAA and processed for scanning electron microscopy
(SEM). All plated dormant buds (both stored and freshly harvested) showed presence internally of a fungus, and SEM studies
revealed hyphalike strands similar to those of the isolated fungi within cells of those buds. The spring flush was sterile
in culture, and strands were absent in SEM studies. 相似文献
95.
Estrogen dependent ciliogenesis in the chick oviduct 总被引:1,自引:0,他引:1
Both the hormone dependency and the morphological details of estrogen-dependent ciliogenesis in the shell gland of the chick oviduct were investigated. Ciliogenesis was initiated on day 3 of estrogen treatment, and progressively more cells became differentiated until, on day 10, 55% ciliation occurred with 17-estradiol (1 mg/day) and 75% ciliation occurred with diethylstilbestrol (1 mg/day). Simultaneous administration of progesterone with diethylstilbestrol (1 mg each/day for 10 days) caused a 50% depression in the number of ciliated cells on day 10. The rate of ciliogenesis was found to be affected by progesterone and the type of estrogen administered. The minimum stimulatory dose of estradiol was found to be between 0.01 mg/day and 0.05 mg/day. Ciliogenic cells were first recognized by the appearance of pro-basal bodies in the apical portion of the cell. Pro-basal body maturation and cilium formation were the same as those described for the chick trachea. Ciliogenesis in the chick was found to be homologous to estrogen-dependent ciliogenesis in various mammalian oviducts. 相似文献
96.
Jing Fu Xinglin Zhang Jiaming Liu Xudong Gao Juan Bai Yueling Hao Hongchang Cui 《The Plant journal : for cell and molecular biology》2021,107(4):1029-1039
Root growth relies on both cell division and cell elongation, which occur in the meristem and elongation zones, respectively. SCARECROW (SCR) and SHORT-ROOT (SHR) are GRAS family genes essential for root growth and radial patterning in the Arabidopsis root. Previous studies showed that SCR and SHR promote root growth by suppressing cytokinin response in the meristem, but there is evidence that SCR expressed beyond the meristem is also required for root growth. Here we report a previously unknown role for SCR in promoting cell elongation. Consistent with this, we found that the scr mutant accumulated a higher level of reactive oxygen species (ROS) in the elongation zone, which is probably due to decreased expression of peroxidase gene 3, which consumes hydrogen peroxide in a reaction leading to Casparian strip formation. When the oxidative stress response was blocked in the scr mutant by mutation in ABSCISIC ACID 2 (ABA2) or when the redox status was ameliorated by the upbeat 1 (upb1) mutant, the root became significantly longer, with longer cells and a larger and more mitotically active meristem. Remarkably, however, the stem cell and radial patterning defects in the double mutants still persisted. Since ROS and peroxidases are essential for endodermal differentiation, these results suggest that SCR plays a role in coordinating cell elongation, endodermal differentiation, redox homeostasis and oxidative stress response in the root. We also provide evidence that this role of SCR is independent of SHR, even though they function similarly in other aspects of root growth and development. 相似文献
97.
Taxonomy and phylogeny of Ceriporia (Polyporales,Basidiomycota) with an emphasis of Chinese collections 总被引:1,自引:0,他引:1
Bi-Si Jia Li-Wei Zhou Bao-Kai Cui Bernard Rivoire Yu-Cheng Dai 《Mycological Progress》2014,13(1):81-93
Ceriporia accommodates a kind of wood-inhabiting polypores producing resupinate basidiocarps and causing a white rot. More than 30 species of this genus have been described; however, only a few species were referred to molecular phylogeny. In this study, a total of 203 specimens of Ceriporia were studied morphologically, and the ITS and/or nLSU regions from 42 samples, representing 18 species, were sequenced for phylogenetic analysis. Based on both morphological and phylogenetic analyses, three new species of Ceriporia, C. bubalinomarginata, C. pseudocystidiata and C. variegata, are described and illustrated. An annotated identification key is provided for all 20 species of this genus thus far known in China. Our phylogeny shows that (1) Ceriporia is not monophyletic, (2) C. spissa and C. viridans as morphologically circumscribed are polyphyletic, (3) C. inflata is retained for both C. inflata and C. jiangxiensis, and (4) presence or absence of hymenial cystidia is not a useful character in delimiting species relationships in Ceriporia. 相似文献
98.
Caitlin A. O'Connell Tri Wahyu Susanto Cheryl D. Knott 《American journal of primatology》2020,82(11):e23058
The primate adolescent period is characterized by a series of changes in physiology, behavior, and social relationships. Orangutans have the slowest life history and the longest period of dependency of all primates. As members of a semisolitary species with high levels of sexual coercion, adolescent female orangutans face a unique combination of challenges when achieving independence from their mother. This study examined the mating behavior of adolescent female orangutans and compared it with that of adult females to assess whether mating behavior reflects distinct strategies at these different points in the life cycle. Data were collected in Gunung Palung National Park on the island of Borneo over 20 years. Mating events from adolescent (n = 19) and adult females (n = 26) were scored and compared. Adolescent female mating events had significantly higher mating scores (indicating more proceptivity) than those of adult females (β = 1.948, p = .001). Adolescent females also engaged in elaborate sociosexual interactions with different flanged males, behaviors that were never observed during mating events of adult females. These interactions involved characteristic behavior on the part of both the adolescent females and the flanged males. Given these findings and the documentation of similar accounts of adolescent female–flanged male mating from the island of Sumatra, we propose that adolescent female orangutans display distinctive behavioral repertoires throughout the genus Pongo which serves to overcome male ambivalence toward nulliparous females, establish familiarity, and evaluate coercive tendencies in flanged males. We suggest that these behavioral patterns are an integral part of female social development in a female philopatric, but highly dispersed species where consistent social support is absent after ranging independence is achieved. 相似文献
99.
100.
Bo‐Wen Gu Lian‐Mei Tan Cui‐Jun Zhang Xiao‐Mei Hou Xue‐Wei Cai She Chen Xin‐Jian He 《植物学报(英文版)》2020,62(11):1703-1716
Imitation Switch (ISWI) chromatin remodelers are known to function in diverse multi‐subunit complexes in yeast and animals. However, the constitution and function of ISWI complexes in Arabidopsis thaliana remain unclear. In this study, we identified forkhead‐associated domain 2 (FHA2) as a plant‐specific subunit of an ISWI chromatin‐remodeling complex in Arabidopsis. By in vivo and in vitro analyses, we demonstrated that FHA2 directly binds to RLT1 and RLT2, two redundant subunits of the ISWI complex in Arabidopsis. The stamen filament is shorter in the fha2 and rlt1/2 mutants than in the wild type, whereas their pistil lengths are comparable. The shorter filament, which is due to reduced cell size, results in insufficient pollination and reduced fertility. The rlt1/2 mutant shows an early‐flowering phenotype, whereas the phenotype is not shared by the fha2 mutant. Consistent with the functional specificity of FHA2, our RNA‐seq analysis indicated that the fha2 mutant affects a subset of RLT1/2‐regulated genes that does not include genes involved in the regulation of flowering time. This study demonstrates that FHA2 functions as a previously uncharacterized subunit of the Arabidopsis ISWI complex and is exclusively involved in regulating stamen development and plant fertility. 相似文献