有关发酵过程营养剂和代谢产物可靠的在线监控系统的研制 第一部分:系统设计和设备配制

生物工程研究的飞速发展,更加需要发酵系统具有综合性的测定、精良完备的控制。对优化细菌、酵母和哺乳动物细胞的发酵条件,并且获得产物最大量而言,发酵过程的自动控制是至关重要的。为此目的,必须获取有关基质和产物连续的信息,而具有流动注射分析（FIA）功能的在线采样系统为此提供了可能的解决途径和办法。目前,在线采样、FIA和发酵数据处理的计算机控制系统的发展已引起人们的关注。然而,绝大多数商品成套装备操作复杂、适用性差且昂贵,总是无法满足生物工程科学家的需要。此项新的控制技术的开发要求汇集程序设计、电子学…     

原癌基因c-myc、c-H-ras、c-sis在小鼠卵巢和睾丸中的转录表达研究

以地高辛标记c-myc、c-H-ras、c-sis基因作探针,利用组织切片原位杂交的方法,检测了昆明种小鼠5周龄、10周龄和孕期卵巢,以及1天龄、5周龄和10周龄睾丸,初步研究了这3种原癌基因在生殖腺中的转录表达及其可能的功能作用。结果显示:(1)c-myc基因在孕鼠卵巢的个别卵泡的卵泡细胞中有强转录信号,但在3组卵巢的卵母细胞中及3组睾丸切片中均未见杂交信号。(2)c-H-ras基因在孕鼠卵巢黄体中有较强转录表达,但在3组卵巢的卵母细胞中及3组睾丸切片中均无杂交信号,(3)c-sis基因在10周龄睾丸曲细精管的精原细胞层和精母细胞有强转录表达,而在1天龄、5周龄睾丸及3组卵巢切片中均无杂交信号。上述结果表明:c-myc基因可能与精子发生和卵子的发育关系不大,但可能与卵泡的退化有关;c-H-ras基因可能与精子发生和卵子的发育关系也不大,但可能与妊娠黄体的形成有关;c-sis基因可能与卵子的发育无关,但可能与精子的发生密切相关。 Abstract:Using in Site Hybridization on tissue section of ovary from 5 weeks old,10 weeks old and pregnant Kunming mice,and test is from one-day old,5 weeks old,and 10 weeks old Kunming mice,we prelimmaily studied the expression and function of the proto-oncogenes c-myc,c-H-ras and c-sis.The results are as follows:(1)The strong expression of c-myc gene was found in follicular epithelium of some follicles of ovary from pregnant mice,and was not found in the oocytes of three groups of female mice and testes of three groups of male mice.(2)The strong expression of c-H-ras was observed in corpus luteum of ovary of pregnant mice,but it was not observed in any germ cells of all three groups of female mice and male mice.(3)The strong expression of c-sis gene was found in spermatogomia and spermatocytes of mature male mice,but it was not found in any germ cells of one day old and immature male mice and three groups of femala mice.These results showed that there might be no relationships between the expression of c-myc gene and spermatogenesis or oocyteatogenesis,but the expression of c-myc gene probably related to the cells degeneration of follicle;the expression of c-H-ras gene hadn’t a bearning on oogenesis and spermatogenesis,but probably related to the genesis of corpus luteum of corpus luteum of pregnant mice;the expression of c-sis gene there might be no related to the oogenesis and sperm maturation,but probably promoted the division of spermatogonim.     

Preliminarily functional analysis of a cloned novel human gene ADAM29

ADAM is a family of type I integral membrane proteins which are characterized by sharing a disintegrin and metalloprotease domain and involved in many important physiological processes such as fertilization, neurogenesis and inflammatory response. A novel human ADAM gene--ADAM29, which was cloned in our laboratory, is exclusively expressed in human testis and contains a potential fusion domain. A full-length cDNA of ADAM29 was obtained by using multiple-step PCR. Phylogenetic tree of known mammalian ADAMs specifically expressed in testis was reconstructed. Polyclonal antiserum was raised by immunizing the rabbits with sub-peptide of ADAM29 (Leu268-Asp374) as immunogen. The result of immunohistochemical test on human testis showed that ADAM29 is expressed in different stages of spermatogenesis and in interstitial cells. ADAM29 may play a certain role in the signal transduction during the maturation of testis-associated cells.     

Comparing the frequencies of restriction fragment length polymorphisms for dystrophin gene in Chinese with those from Japanese and Caucasian populations

The restriction fragment length polymorphisms distribution and frequency of dystrophin gene in Chinese were studied by using 14 subclones of the entire 14kb cDNA for the dystrophin as hybridization probes. Allelic fragments were detected in hybridization patterns of PvuⅡ/la, Taq Ⅰ/2b-3, Taq Ⅰ/5b-7, and Xba Ⅰ/10. Among them, the allelic fragments (26kb and 3.8kb) in PvuⅡ/2b-3 pattern and the allelic fragments (10.0kb and 8.4kb) in Taq Ⅰ/5b-7 patterns had never been reported previously. Compared with the data from Caucasians and Japanese, it indicated that there was a significant difference (P<0.01) of the allelic fragment frequency in Taq Ⅰ/2b-3 and Xba Ⅰ/10 patterns between Chinese and Caucasians. The frequencies of allelic fragments A2 (5.6kb) in Taq Ⅰ/8 and A2 (10.Tkb) in EcoR Ⅴ/9 were high in Caucasians, yet had not been detected in Chinese, the differences were also highly significant. But in Chinese and Caucasians, the B1B2 allelic frequencies in Taq Ⅰ/5b-7 are the same. As to the frequency of the allelic fragments A1A2 and B1B2 in Pvu Ⅱ/la, there was no significant difference between Chinese and Japanese.     

DNA Polymorphism Among Yewei B, V20B, and Oryza minuta J. S. Presl. ex C. B. Presl

The new cytoplasmic male sterile （CMS） line Yewei A and its maintainer line Yewei B, with better agronomic characteristics, have been developed from a mutant of V20B （a rice maintainer line） through transformation of genomic DNA of wild rice （Oryza minuta J. S. Presl. ex C. B. Presl.）. Analysis of molecular markers, DNA sequences, and Southern blot revealed that high DNA polymorphism exists between the mutant and its receptor, indicating that the special DNA fragment from O. minuta may be integrated into the genome of Yewei B. Therefore, transformation of genomic DNA from distant relatives to the plant of a target receptor may open an avenue for creating a new rice germplasm.     

Identification and Validation of Single Nucleotide Polymorphisms in Poplar Using Publicly Expressed Sequence Tags

By using assembled expressed sequence tags （ESTs） from 14 different eDNA libraries that contain 84 132 sequences reads, 556 Populus candidate single nucleotide polymorphisms （SNPs） were identified. Because traces were not available from dbEST （http：//www.ncbi.nlm.nih.gov/dbEST/index.html）, stringent filters were used to identify reliable candidate SNPs. Sequences analysis indicated that the main types of substitutions among candidate SNPs were A/G and T/C transitions, which accounted for 22.0% and 30.8%, respectively. One hundred and ten candidate SNPs were tested. As a result, 38 candidate SNPs were confirmed by directed sequencing of PCR products amplified from six different individuals. Thirteen new SNPs in intron regions were found and multiple SNPs were found to be located in both intron and exon regions of four contigs. Heterozygosis was found in all 47 candidate sites and five SNP sites were heterozygous in all six samples. This is the first report of SNP identification in a tree species which reveals that assembled ESTs from multiple libraries of the public database may provide a rich source of comparative sequences for an SNP search in the poplar genome.     

Discovery of a Homolog of Siderophilin in a Plant

Members belonging to the siderophilin family are iron-binding and iron-transporting proteins, which includes transferrin and lactoferrin. They have only been found in animals previously. If siderophilin could be found in and isolated from a plant, its production and subsequent extensive application could be increased. The present study is the first to report the discovery of a homolog of siderophilin in a plant. In order to purify antifreeze proteins from Ammopiptanthus mongolicus （Maxim.） Cheng f., the authors processed the proteins from the leaves using techniques such as column chromatography using DEAE-Cellulose-52, gel filtration via Sephacryl S-100 HR medium, hydrophobic interaction chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mass spectroscopy was performed on the three proteins purified and the sequence of one of the proteins （containing 32 amino acids） was found to have 97% homology with the corresponding part of one type of human lactoferrin. Moreover, one of the two peptides belongs to an iron-binding domain. So, it is possible that siderophilin also exists in plants and plays a role as an antibacterial and antifungal, among other actions.     

Effects of Logging on the Genetic Diversity of Quercus tiaoloshanica Chun et Ko in a Tropical Montane Forest of Hainan Island, Southern China

Quercus tiaoloshanica Chun et Ko, which has a narrow range of distribution, is one of the important endemic species of the tropical montane rain forest on Hainan Island, southern China. Long-term logging and habitat destruction have resulted in population decline and distribution retreat of Q. tiaoloshanica. To determine the impact of logging on the genetic diversity of Q. tiaoloshanica, the authors investigated the genetic structures using amplified fragment length polymorphism markers in four regenerated stands after logging and in one unlogged stand. Compared with the unlogged stand, the effective number of alleles per locus dropped by 1.0% in selective logging stands and by 2.0% in clear logging stands, corresponding to reductions of 3.8% and 5.2%, respectively, in mean Nei＇s gene diversity and 2.9% and 3.5%, respectively, in mean Shannon diversity index. No substantial genetic erosion was detected in any of the regenerated stands owing to the high tree density and high heterogeneity of the Q. tiaoloshanica stands investigated. Meanwhile, there was no natural regeneration of the species observed in a Dacrydium pierrei Hickel plantation 700 m away from the regenerated stands, suggesting the limited ability of seed dispersal of Q. tiaoloshanica. Clear logging should be undertaken cautiously because the total number of plant species dropped by 15.2% in the clear-logged stands compared with the unlogged stand. To conserve the genetic diversity of this species, as well as the plant biodiversity of tropical forests, the habitats of Q. tiaoloshanica should be protected against exploitation in terms of agricultural or other forms of land use, and some mature trees should be preserved as seed sources to maintain an adequate regeneration base for this species in the management of logging.