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41.
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小麦Kr基因在小麦与玉米或鸭茅状摩擦禾杂交中的失活 总被引:2,自引:0,他引:2
用37个小麦(Triticumaestivum)品种(系)为母本,分别与黑麦(Secalecereale)、球茎大麦(Hordeumbulbosum)、玉米(Zeamays)和鸭茅状摩擦禾(Tripsacumdactyloides)杂交,比较其亲和性,小麦和玉米或鸭茅状摩擦禾杂交比小麦与黑麦或球茎大麦杂交的亲和性显著提高。携带着显性Kr1和Kr2基因的小麦品种Hope与黑麦杂交,不能形成胚,而与玉米及鸭茅状摩擦禾杂交时,成胚率分别达16.00%和32.50%。表明控制小麦与黑麦及球茎大麦杂交亲和性的Kr基因系统在小麦与玉米及小麦与鸭茅状摩擦禾属间杂交中失活。讨论了还存在有其它控制小麦属间杂交亲和性的遗传调控系统的可能性。 相似文献
43.
Nm23 is a family of genes encoding the nucleoside diphosphate (NDP) kinase, which functions in a wide variety of biological processes, including growth, development, differentiation and tumor metastasis. In this study, a novel nm23 gene, designated as Mrnm23, was identified from the freshwater giant prawn Macrobrachium rosenbergii. The full-length cDNA was 776 bp in length, encoding for a protein of 176 amino acids with one typical NDP kinase domain that harbored all the crucial residues for nucleotide binding and enzymatic activity. Like human novel nm23-H1B, the putative protein contained a unique 21-amino-acid NH2-terminal extension as compared to human nm23 (nm23-H1) homologs. Further, 3 extra amino acid residues prolonged the COOH-terminus. The Mrnm23 was ubiquitously expressed in all tissues examined, including androgenic gland, gill, heart, liver, muscle, ovary, and testis. In situ hybridization to gonad sections indicated that the Mrnm23 mRNA was localized in the cytoplasm of cup-base of differentiating spermatids, in the spike of the umbrella-shaped spermatozoa and in the cytoplasm of the early previtellogenic oocytes, suggesting that the Mrnm23 has potential roles in spermiogenesis and early differentiation of oocyte. 相似文献
44.
Yifeng Miao Yongming Qiu Yuchang Lin Zengli Miao Jing Zhang Xiaojie Lu 《Molecular biology reports》2011,38(5):3235-3242
Pyruvate, an endogenous metabolite of glycolysis, is an anti-toxicity agent. Recent studies have suggested possible roles
for pyruvate in protecting CNS neurons from excitotoxic and metabolic insults. Utilizing cultures derived from embryonic rat
cortex, the studies presented in this paper indicate that an astroglia-mediated mechanism is involved in the neuroprotective
effects of pyruvate against glutamate toxicity. Glutamate-induced toxicity could be reversed by pyruvate in a mixed culture
of cortex cells. Importantly, in pure neuronal cultures from the same tissue, pyruvate failed to protect against glutamate
toxicity. Addition of astroglia to the pure neuronal cultures restores the ability of pyruvate to protect neurons from glutamate-induced
toxicity. Our results further suggest that pyruvate can induce glia to up-regulate the synthesis of glutathione (GSH), an
antioxidant that protects cells from toxins such as free radicals. Taken together, our data suggest that astroglia in mixed
cultures are essential for mediating the effects of pyruvate, revealing a novel mechanism by which pyruvate, an important
intermediate of tricarboxylic acid cycle in the body, may act to protect neurons from damage during insults such as brain
ischemia. 相似文献
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The Xenopus tadpole is able to regenerate its tail, including skin, muscle, notochord, spinal cord and neurons and blood vessels. This process requires rapid tissue growth and morphogenesis. Here we show that a focus of apoptotic cells appears in the regeneration bud within 12 h of amputation. Surprisingly, when caspase-3 activity is specifically inhibited, regeneration is abolished. This is true of tails both before and after the refractory period. Programmed cell death is only required during the first 24 h after amputation, as later inhibition has no effect on regeneration. Inhibition of caspase-dependent apoptosis results in a failure to induce proliferation in the growth zone, a mispatterning of axons in the regenerate, and the appearance of ectopic otoliths in the neural tube, in the context of otherwise normal continued development of the larva. Larvae amputated during the refractory stage exhibit a much broader domain of caspase-3-positive cells, suggesting a window for the amount of apoptosis that is compatible with normal regeneration. These data reveal novel roles for apoptosis in development and indicate that a degree of apoptosis is an early and obligate component of normal tail regeneration, suggesting the possibility of the existence of endogenous inhibitory cells that must be destroyed by programmed cell death for regeneration to occur. 相似文献
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In order to investigate the levels of genetic diversity of the endangered species Kirengeshoma palmata (Saxifragaceae), four extant populations were sampled and analyzed using inter-simple sequence repeats (ISSR) markers. We expected a low genetic diversity level, but our results revealed a high level of intraspecific genetic diversity, probably resulting from this species being in a refuge during the last glaciation (at population level: P = 63.25%, Ae = 1.47, HE = 0.26 and HO = 0.37; at species level: P = 79.00%, A = 1.5538, HT = 0.2586 and Hsp = 0.3104). A low level of genetic differentiation among populations was detected based on Nei's genetic diversity analysis (16.69%) and AMOVA (19.36%). Populations shared high levels of genetic identity. Insect pollination and seed dispersal by wind may have facilitated extensive gene flow and are likely responsible for this present structure of genetic variation. 相似文献
50.
Yingwei Qiu Xiaofei Lv Huanhuan Su Guihua Jiang Junzhang Tian Fuzhen Zhuo Lujun Han Xuelin Zhang 《PloS one》2013,8(11)