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91.
Chromosomal localization of uroplakin genes of cattle and mice 总被引:2,自引:0,他引:2
Anne M. Ryan James E. Womack Jun Yu Jun-Hsiang Lin Xue-Ru Wu Tung-Tien Sun Virginia Clarke Peter D'Eustachio 《Mammalian genome》1993,4(11):656-661
The asymmetric unit membrane (AUM) of the apical surface of mammalian urinary bladder epithelium contains several major integral membrane proteins, including uroplakins IA and IB (both 27 kDa), II (15 kDa), and III (47 kDa). These proteins are synthesized only in terminally differentiated bladder epithelial cells. They are encoded by separate genes and, except for uroplakins IA and IB, appear to be unrelated in their amino acid sequences. The genes encoding these uroplakins were mapped to chromosomes of cattle through their segregation in a panel of bovine x rodent somatic cell hybrids. Genes for uroplakins IA, IB, and II were mapped to bovine (BTA) Chromosomes (Chrs) 18 (UPK1A), 1 (UPK1B), and 15 (UPK2), respectively. Two bovine genomic DNA sequences reactive with a uroplakin III cDNA probe were identified and mapped to BTA 6 (UPK3A) and 5 (UPK3B). We have also mapped genes for uroplakins 1A and II in mice, to the proximal regions of mouse Chr 7 (Upk1a) and 9 (Upk2), respectively, by analyzing the inheritance of restriction fragment length variants in recombinant inbred mouse strains. These assignments are consistent with linkage relationships known to be conserved between cattle and mice. The mouse genes for uroplakins IB and III were not mapped because the mouse genomic DNA fragments reactive with each probe were invariant among the inbred strains tested. Although the stoichiometry of AUM proteins is nearly constant, the fact that the uroplakin genes are unlinked indicates that their expression must be independently regulated. Our results also suggest likely positions for two human uroplakin genes and should facilitate further analysis of their possible involvement in disease. 相似文献
92.
Yung-Chieh Tsai Tian-Ni Kuo Yu-Ying Chao Pei-Rong Lee Ruei-Ci Lin Xiao-Yi Xiao Bu-Miin Huang Chia-Yih Wang 《Journal of cellular biochemistry》2023,124(1):89-102
Testes control the development of male reproductive system. The testicular interstitial Leydig cells (Leydig cells) synthesize testosterone for promoting spermatogenesis and secondary sexual characteristics. Type A platelet-derived growth factor (PDGF-AA) is one of the most important growth factors in regulating Leydig cell growth and function. Knockout of PDGF-AA or its congenital receptor PDGFR-α leads to poor testicular development caused by reducing Leydig cell numbers, supporting PDGF-AA/PDGFR-α signaling regulates Leydig cell development. Primary cilium is a cellular antenna that functions as an integrative platform to transduce extracellular signaling for proper development and differentiation. Several receptors including PDGFR-α are observed on primary cilia for initiating signaling cascades in distinct cell types. Here we showed that PDGF-AA/PDGFR-α signaling promoted Leydig cells growth, migration, and invasion via primary cilia. Upon PDGF-AA treatment, AKT and ERK signaling were activated to regulate these cellular events. Interestingly, active AKT and ERK were detected around the base of primary cilia. Depletion of ciliary genes (IFT88 and CEP164) alleviated PDGF-AA-activated AKT and ERK, thus reducing Leydig cell growth, migration, and invasion. Thus, our study not only reveals the function of PDGF-AA/PDGFR-α signaling in maintaining testicular physiology but also uncovers the role of primary cilium and downstream signaling in regulating Leydig cell development. 相似文献
93.
Dr. Wei Huang Dr. Huixian Ye Prof. Xiaodan Li Dr. Yuntong Li Prof. Junyue Lin 《化学与生物多样性》2023,20(6):e202201246
Rational design of high-efficiency N-heterocyclic carbene (NHC) palladium catalyst is of great importance to modern organic synthesis, especially in chemical and pharmaceutical industries. Herein, we fabricate a polymer network containing N-heterocyclic carbene palladium (PNNHC-Pd) catalytic active sites via an immobilization process. The N-heterocyclic carbene palladium can serve as a promising linkage of polymer network as well as an effective catalytic active site owing to its structural preference and strong σ-donating ability with palladium species. The results display that N-heterocyclic carbene palladium disperses homogeneously in polymer network, thus rendering PNNHC-Pd excellent catalytic activity, high stability and superior reusability in palladium-catalyzed Suzuki–Miyaura coupling reaction in aqueous medium. This work provides a new insight into the development of heterogenization of homogeneous catalysts based on polymer network. 相似文献
94.
95.
Richard Shine Lin Schwarzkopf 《Evolution; international journal of organic evolution》1992,46(1):62-75
Life history theory suggests that the optimal evolved level of reproductive effort (RE) for an organism depends upon the degree to which additional current reproductive investment reduces future reproductive output. Future reproduction can be decreased in two ways, through (i) decreases in the organism's survival rate, and/or (ii) decreases in the organism's growth (and hence subsequent fecundity). The latter tradeoff–that is, the “potential fecundity cost”—should affect the evolution of RE only in species with relatively high survival rate, a relatively high rate of fecundity increase with body size, or a relatively high reproductive frequency per annum. Unless these conditions are met, the probable benefit in future fecundity obtained from decreasing present reproductive output is too low for natural selection to favor any reduction in RE below the maximum physiologically possible. Published data on survival rate, reproductive frequency and relative clutch mass (RCM) suggest that many lizard species fall well below the level at which natural selection can be expected to influence RE through such “potential fecundity” tradeoffs. Hence, the relative allocation of resources between growth and reproduction is unlikely to be directly optimized by natural selection in these animals. Instead, energy allocation should influence the evolution of RE only indirectly, via effects on an organism's probability of survival during reproduction. Survival costs of reproduction may be the most important evolutionary determinants of RE in many reptiles, and information on the nature and extent of such costs is needed before valid measures of reptilian RE can be constructed. 相似文献
96.
97.
Processing of global and local properties——An analysis with event-related brain potentials 总被引:3,自引:1,他引:2
The different processing of global and local properties of compound visual stimuli was studied with event-related brain potentials (ERPs) in the present experiment. It was found that, compared with the identification of global properties, the discrimination of local properties elicited longer RTs, lower accuracies, increased amplitudes of P1, decreased amplitudes of N1, and longer latencies of N2 and P3. The conflict of global and local properties increased the amplitudes of P2, decreased the amplitudes of P3, and prolonged latencies of N2 and P3. These results indicated that the advantage of global processing occurs at an early perceptual stage, and the attentional mechanisms for global and local processing may be different. 相似文献
98.
We compared the pattern of 3-phosphorylated phosphoinositides produced by confluent 3T3-L1 preadipose cells upon exposure to growth factors that either induce differentiation (insulin, insulin-like growth factor-1) or do not (platelet-derived growth factor). Following addition of insulin or insulin-like growth factor-1, PI(3,4,5)P3 rapidly rose, on average, to levels tenfold over basal. PI(3,4)P2 either did not change (after insulin) or slightly increased (1.5 fold). Time course studies with insulin demonstrated that the rise in PI(3,4,5)P3 peaked by 1 minute, and levels then remained steady over 30 minutes. Dose-response experiments showed that insulin at a concentration of 1 nM was sufficient for the PI(3,4,5)P3 response. Insulin failed to increase PI(3,4)P2 at any of the time points or at any of the doses used. In contrast, after addition of platelet-derived growth factor, both PI(3,4)P2 and PI(3,4,5)P3 rose concurrently and to comparable extents. These data suggest that one possible mechanism contributing to insulin/insulin-like growth factor-1-induced 3T3-L1 preadipose cell differentiation is a distinct pattern of 3-phosphorylated phosphoinositide accumulation, defined by a prominent increase in PI(3,4,5)P3 with no (in the case of insulin), or a minimal (in the case of IGF-1), rise in PI(3,4)P2. 相似文献
99.
第四纪甲虫的研究在国外已开展多年,形成了一套完整的方法,而在我国几乎为一空白。第四纪甲虫研究方法一般包括如下几个步骤:野外采样,实验室分离,标本保存,标本鉴定,结果分析。第四纪甲虫研究的意义主要表现在如下三个方面:重建古气候、恢复昆虫地理史和第四纪考古。 相似文献
100.
冬小麦根表面氧化还原活力的研究 总被引:4,自引:1,他引:3
证实了两个不同品种的冬小麦根系表面存在着氧化NADH和还原K3Fe(CN)6的氧化的活力。还原铁氰化物活力在PH5.5到8.5范围内随着PH值升高而增大,温度在15℃到45℃范围内随温度升高还原活力增强,45℃达最高值,55℃时活力急剧下降。 相似文献