Fe2+ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe2+ requirement in nori had not been seen. Porphyra yezoensis cells were separat...Fe2+ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe2+ requirement in nori had not been seen. Porphyra yezoensis cells were separated enzymatically and cultured in a series of sterilized seawater media containing various concentra- tions of Fe2+. The growth development and cell were investigated in this work. Through this experiment, two biologically-meant concentration scales were found, one is low concentrations, 12.1–102.1 μg/L, 10–100 times than that in seawater, favoring the development of isolated cells of Porphyra and the other was high concentra- tions, more than 10mg/L inhibiting the cell growth, leading to the deformity and shrinkage of the cells. At the concentration of 50 mg/L, the cells stopped growing and died eventually.展开更多
Total DNA is isolated from Porphyra cells which have been prepared from sea snail enzyme digests of Porphyra thalli. The crude extracts of total DNA are rapidly purified with Wizard DNA Clean-up resin by using modifie...Total DNA is isolated from Porphyra cells which have been prepared from sea snail enzyme digests of Porphyra thalli. The crude extracts of total DNA are rapidly purified with Wizard DNA Clean-up resin by using modified washing solution. DNA bands are clearly observed in the restriction endonuclease patterns of P. yezoensis and P. haitanensis total DNAs. Both P. yezoensis and P. haitanensis have specific DNA bands in the restriction patterns of EcoRI, PastI and HaeIII. According to the band pattern of total DNA, the discrimination between P. yezoensis and P. haitanensis is very easy especially in the restriction pattern of HaeIII. The comparative results indicate that the band pattern of total DNA is a new type and reliable DNA marker for identification and classification of Porphyra species.展开更多
This study on the cytological changes of the body wall,aspiratory intestine and crissal bursa in Urechis unicinctus by light microscope (LM) and transmission electron microscope (TEM) showed that the difference betwee...This study on the cytological changes of the body wall,aspiratory intestine and crissal bursa in Urechis unicinctus by light microscope (LM) and transmission electron microscope (TEM) showed that the difference between the body wall and the natural environment rich in H 2S was not obvious; that the wall color of the aspiratory intestine in H 2S rich environment changed from normal semitransparency to dark brown; that its epithelia were disassembled and the electron density of its cytoplasm matrix was lower; and that in H 2S rich environment many basophilic granules occurred in the epithelia of the crissal bursa. Granules with single membrane and myelinefingure were found with TEM.展开更多
The rare males occurring in low numbers in populations of Artemia parthenogenetica may arise from the fusion of two haploid X cells after the second meiotic division. There is no unanimous overview concerning the role...The rare males occurring in low numbers in populations of Artemia parthenogenetica may arise from the fusion of two haploid X cells after the second meiotic division. There is no unanimous overview concerning the role and ability of these asexually produced males to hybridize with bisexual females. Bowen et al. first succeeded in crossing 4 rare males originated from India, Japan and France with females of A. franciscana and A. urmiana. In that study, fertilization was confirmed by Mendelian segregation patterns of展开更多
基金This work was supported by the NSFC (No. 40206019).
文摘Fe2+ acted as an accessorial factor for many cellular enzymatic reactions is very important for seaweed growth and development, but the Fe2+ requirement in nori had not been seen. Porphyra yezoensis cells were separated enzymatically and cultured in a series of sterilized seawater media containing various concentra- tions of Fe2+. The growth development and cell were investigated in this work. Through this experiment, two biologically-meant concentration scales were found, one is low concentrations, 12.1–102.1 μg/L, 10–100 times than that in seawater, favoring the development of isolated cells of Porphyra and the other was high concentra- tions, more than 10mg/L inhibiting the cell growth, leading to the deformity and shrinkage of the cells. At the concentration of 50 mg/L, the cells stopped growing and died eventually.
文摘Total DNA is isolated from Porphyra cells which have been prepared from sea snail enzyme digests of Porphyra thalli. The crude extracts of total DNA are rapidly purified with Wizard DNA Clean-up resin by using modified washing solution. DNA bands are clearly observed in the restriction endonuclease patterns of P. yezoensis and P. haitanensis total DNAs. Both P. yezoensis and P. haitanensis have specific DNA bands in the restriction patterns of EcoRI, PastI and HaeIII. According to the band pattern of total DNA, the discrimination between P. yezoensis and P. haitanensis is very easy especially in the restriction pattern of HaeIII. The comparative results indicate that the band pattern of total DNA is a new type and reliable DNA marker for identification and classification of Porphyra species.
文摘This study on the cytological changes of the body wall,aspiratory intestine and crissal bursa in Urechis unicinctus by light microscope (LM) and transmission electron microscope (TEM) showed that the difference between the body wall and the natural environment rich in H 2S was not obvious; that the wall color of the aspiratory intestine in H 2S rich environment changed from normal semitransparency to dark brown; that its epithelia were disassembled and the electron density of its cytoplasm matrix was lower; and that in H 2S rich environment many basophilic granules occurred in the epithelia of the crissal bursa. Granules with single membrane and myelinefingure were found with TEM.
基金the National Natural Science Foundation of China.
文摘The rare males occurring in low numbers in populations of Artemia parthenogenetica may arise from the fusion of two haploid X cells after the second meiotic division. There is no unanimous overview concerning the role and ability of these asexually produced males to hybridize with bisexual females. Bowen et al. first succeeded in crossing 4 rare males originated from India, Japan and France with females of A. franciscana and A. urmiana. In that study, fertilization was confirmed by Mendelian segregation patterns of
