Characteristics of chromosome of teratocarcinoma and its influence elements

AIM:To investigate the characteristics of chromosome of teratocarcinoma and its influence elements.METHODS:We used the methods of G-banded karyotype analysis,DNA basic sequence analysis and Western blot and the others,and studied the chromosome karyotype and the status of p53 gene of teratocarcinoma PA-1 cell line which had been cultured for 407-445 passages for 20 years. RESULTS: More than 80% PA-1 cells still maintained the near-diploid karyotype,after passage 30 the cells appeared with M1 and M2 chromosomal markers because of a balanced translocation between chromosomes 15 and 20. DNA directional sequence analysis of RP-PCR products revealed that there were both wild and mutated band (p53 codon 239 mutation), Western blot did not detect mutational p53 gene protein,while p21 protein expression lower than that in normal human fibroblasts. CONCLUSION:Missense mutation of one of the p53 allele gene of PA-1 cells in human teratocarcinoma was detected after cultured for more than twenty years, which was not sufficient to induce the instability of the chromosome of cell line.     

西镇牛的染色体研究

对２１头西镇牛的染色体核型、Ｇ带、Ｃ带及Ａｇ－ＮＯＲｓ进行了研究。结果表明，西镇牛公牛的核型为６０，ｘｙ，，母牛为６０，ｘｘ。Ｙ染色体近端着丝点染色体。     

Karyotype Variation within Some Natural Populations of Sulla (Hedysarum coronarium L., Fabaceae) in Algeria

As a part of the characterization and the valorization of plant genetic resources of fodder and pastoral interest in Algeria, a cytogenetic study was undertaken for nine natural populations of Hedysarum coronarium L. originating from North-East Algeria. The chromosomic characterization was realized throughout the mitosis, the C-banding and the meiosis analysis. Ecological factors (altitude and rainfall) of the originating environment of the different populations were considered in this study. Six Algerian populations present the stable chromosome number, usually observed in this species (2n = 16), whereas three others present two numbers. The first number (2n = 2x = 16), previously cited by other authors throughout the world, and the second one (2n = 2x = 18) is newly observed within Hedysarum coronarium L. Both mitotis ans meiosis confirmed these numbers. The chromosomes are median and the karyotype is primitive in terms of form and size. The C-banding method showed off three types of bands (telomeric, intercalary, centromeric). The originating environment seems to have an effect on the existing variability in Hedysarum coronarium L.     

斑茅染色体和植物学性状观察研究

 通过对采自滇、蜀、藏、陕、赣、鄂、闽、粤、桂、琼等10个省(区)的35份斑茅无性系的染色体数目和植物学性状观察,发现染色体数目有2n=40和2n=60两种类型。其中2n=40类型的斑茅只有3个无性系,分别采自云南和西藏。采自其它省(区)的32个无性系都属于2n=60这种类型。     

茶树染色体技术研究

介绍了茶树有丝分裂染色体核型、C带、G带、银染与小孢子减数染色体的制片技术及其关键步骤,其中包括作者创新的高温G带诱导系列法和小孢子染色体改良涂片法。所有这些技术的特点是制片成功率高,稳定性好,技术不复杂。此外,还介绍了观察染色体数目的简易方法。     

百合染色体细胞学研究进展

百合属绝大多数种是2n=24的二倍体,其核型具有稳定性,一般为3B型,存在少数多倍化现象,但广泛存在B染色体,百合染色体核型的差异正是环境因素和结构变异共同作用的结果。通过百合属C-带带型中单套染色体条带数及特征染色体可以清晰地区分形态学相似的百合属植物,但采用尿素法进行G带带纹的鉴定有更高的分辨率。原位杂交技术已运用于百合属植物的区分和杂种后代的鉴定,而GISH较FISH更适用于杂种百合的鉴定。     

东北梅花鹿染色体R分带的研究

[目的]研究东北梅花鹿染色体R带核型,为梅花鹿的遗传变异、基因定位等提供参考。[方法]采用外周血细胞培养,过量胸腺嘧啶脱氧核苷阻断法使细胞分裂同步化,用RBG显带方法来研究东北梅花鹿中期染色体R带核型。[结果]梅花鹿单倍体染色体显带数目达400条。No1、No2、No3、No4、X染色体和Y染色体的R带和高分辨G带几乎完全是相反的;除了No21、No24、No28末端浅染外,其他的末端均为阳性深染带。[结论]RBG显带方法能使东北梅花鹿中期染色体显示出典型的R带带型。     

家猪染色体Q-和G-及C-分带的多态性

对杜洛克、巴克夏、关中黑和八眉猪的Q-、G-和C-分带的多态性作了祥细的比较分析。发现Q-,G-分带在品种、个体及同源染色体间有多态性。随着染色体的伸长和带纹的进一步精细,多态性表现的愈多愈明显;C-分带的多态性在品种、个体、细胞及同源染色体间广泛存在,同源染色体间C-带多态性具品种特征和个体特征。此外,发现家猪染色体中存在“额外”G-带和“额外”浅染区现象。     

Karyotypic studies in wild germplasm of <Emphasis Type="Italic">Arachis</Emphasis> (Leguminosae)

The karyomorphology for eight diploid species of Arachis belonging to three sections has been described for the first time, Sect. Extranervosae: A. macedoi (2n = 20m) and A. retusa (2n = 14m + 6sm); Sect. Heteranthae: A. sylvestris (2n = 16m + 4sm); Sect. Procumbentes: A. chiquitana (2n = 18m + 2sm); Sect. Arachis: A. cruziana (2n = 18m + 2sm), A. herzogii (2n = 18m + 2sm), A. simpsonii (2n = 20m) and A. williamsii (2n = 20m). A pair of satellited chromosomes was observed in all species. A chromosomes were found in A. chiquitana, A. herzogii and A. simpsonii. Karyotypic differences between sections were observed, but not enough to establish a characteristic karyotype pattern for each section. However, the species may be differentiated by the presence of A chromosomes, the type and position of satellites, and the karyotype formulae. These results are discussed with regard to karyotype evolution in Arachis to contribute to understanding the role of chromosome changes in the evolution of the genus.     

The microsatellite instability and loss of heterozygosity in head and neck squamous cell carcinomas

AIM:To examine the microsatellite instability (MSI) and loss of heterozygosity (LOH) in head and neck squamous cell carcinomas (HNSCC). METHODS: 36 cases of HNSCC were analyzed with 15 microsatellite markers from chromosome 3,5,6,8,9,13,17 and 18. RESULTS: Among the 36 cases of HNSCC, 27.8%(10/36)of samples showed MSI in one to eight microsatellite markers. High frequent MSI occurred at D17S520(22.9%), D6S105(16.7%)and D8S264(13.9%). LOH was detected on the site of 9p21-p22 and 3p14. No correlations were found between allelic instability and grade or stage of the tumor. CONCLUSION: Our data suggest that MSI is a common genetic change in HNSCC. Tumor suppressor genes related to HNSCC may harbor at chromosome 9p21-p22 and 3p14 regions.