Chromosome analysis of preimplantation embryos after cadmium treatment of oocytes at meiosis I

Female mice were given a single subcutaneous injection of cadmium chloride (1.5 mg or 3.0 mg/kg body weight) at the metaphase I stage of oogenesis. The incidences of blastocysts with trisomies and triploidies were significantly increased in the cadmium-treated groups. Chromosome analysis of preimplantation embryos may be one of the useful in vivo methods for screening for chromosome anomalies induced in mammalian germ cells.     

Vero—E_6细胞染色体的扫描电镜观察

气干法制备的Vero-E_6细胞染色体标本,采用锇酸-鞣酸-镀膜技术,扫描电镜检查。结果:染色体呈现三维立体圆柱形;未染色或常规Giemsa染色的标本,染色体表面光滑,经胰酶-G分带处理的标本,表面则有纤维丝;着丝粒位于凹陷中,界限清楚;染色体的臂显现弹簧样螺旋结构。环形螺旋的凹沟,相当于光镜检查G带的暗带。     

Phenotypic changes associated with DYNACTIN-2 (DCTN2) over expression characterise SJSA-1 osteosarcoma cells

DYNACTIN-2 (DCTN2) localises to chromosome 12q13-q15, a region prone to stable amplification in several cancers. Transient DCTN2 overexpression has a significant impact on cellular phenotype primarily due to disruption of the DYNEIN-dynactin motor. Changes reported include alterations of microtubule-directed movement of molecular (e.g. TP53) and organelle (e.g. Golgi) cargoes towards the nucleus, centrosome biology, cellular movement and mitosis with a potential predisposition to mitotic block and polyploidy. These changes would be expected to be of relevance to carcinogenesis. To investigate this, we report the first study of DCTN2 genomic amplification and sustained DCTN2 overexpression in cancer cells. QFMPCR was employed to characterise the extent of chromosome 12q13-q15 amplicons in SJSA-1, SJRH30, U373MG and CCF-STTG1 cancer cells. DCTN2 amplification was present in SJSA-1, U373MG and SJRH30 cells, yet was incomplete at the 5'-end in SJRH30 cells. Only SJSA-1 cells were characterised by DCTN2 overexpression on Western blot analyses. Microscopy studies distinguished SJSA-1 cells by greater DCTN2 immunofluorescence and diminished centrosome and 58K protein Golgi-marker focus compared to SJRH30 cells. Indirect evidence derived from the published work of others indicated that TP53 transport into the nucleus was unimpaired. Furthermore, we observed that SJSA-1 cells were easy to propagate. In conclusion, persistent DCTN2 overexpression can be tolerated in SJSA-1 cancer cells despite phenotypic abnormalities predicted from transient overexpression studies. This preliminary study does not support a major role for DCTN2 overexpression in carcinogenesis, although further studies would be necessary to confirm this.     

Rats with inherited stress-induced arterial hypertension (ISIAH strain) display specific quantitative trait loci for blood pressure and for body and kidney weight on chromosome 1

1. The aim of the present study was to scan chromosome 1 in the hypertensive 'inherited stress-induced arterial hypertension' (ISIAH) rat strain for the quantitative trait loci (QTL) that control basal and stress-induced arterial blood pressure (ABP) levels and weight traits. 2. Two F(2) populations of 3-4- and 6-month-old male rats derived from a cross between the normotensive Wistar albino Glaxo (WAG) and hypertensive ISIAH rats were used in the search for the QTL. To identify the QTL for blood pressure (basal and under stress) and weight traits (bodyweight, as well as the weight of the adrenals, kidney and heart), 12 polymorphic markers covering a span of 234.6 Mb on chromosome 1 were analysed. 3. In 3-4-month-old rats, QTL were found for bodyweight in the vicinity of the D1Rat76 marker (230.6 Mb; P = 0.0019; logarithm of odds (LOD) score 3.23) and for relative kidney weight in the vicinity of the D1Rat117 marker (219.3 Mb; P = 0.000992; LOD score 3.41). No QTL for blood pressure were detected on chromosome 1 in the 3-4-month-old population. 4. In 6-month-old rats, a QTL for basal ABP in the region spanning 168.0-250.4 Mb, with two peaks around the markers D1Rat168 (204.8 Mb; P = 0.00087; LOD score 3.42) and D1Rat76 (P = 0.0006; LOD score 3.34), was described. A novel QTL was found in the D1Rat54-D1Rat168 region for stress-induced blood pressure (P = 0.0014; LOD score 3.08). 5. The results provide support for the existence of age-dependent differences in the genetic control of ABP and weight traits. Chromosome 1 was characterized by four QTL: for bodyweight and relative kidney weight in 3-4-month-old F(2) (ISIAH yen WAG) rats and basal ABP and ABP under emotional (restraint) stress conditions in 6-month-old F(2) rats. The QTL for stress-induced ABP seems to be novel and specific to the ISIAH rat strain.     

Humans as reservoir for enterotoxin gene--carrying Clostridium perfringens type A

We found a prevalence of 18% for enterotoxin gene-carrying (cpe+) Clostridium perfringens in the feces of healthy food handlers by PCR and isolated the organism from 11 of 23 PCR-positive persons by using hydrophobic grid membrane filter-colony hybridization. Several different cpe genotypes were recovered. The prevalence was 3.7% for plasmidial IS1151-cpe, 2.9% for plasmidial IS1470-like-cpe, 0.7% for chromosomal IS1470-cpe, and 1.5% for unknown cpe genotype. Lateral spread of cpe between C. perfringens strains was evident because strains from the same person carried IS1470-like cpe but shared no genetic relatedness according to pulsed-field gel electrophoresis analysis. Our findings suggest that healthy humans serve as a rich reservoir for cpe+ C. perfringens type A and may play a role in the etiology of gastrointestinal diseases caused by this organism. The results also indicate that humans should be considered a risk factor for spread of C. perfringens type A food poisoning and that they are a possible source of contamination for C. perfringens type A food poisoning.     

Klinefelter syndrome and two fragile X chromosomes

Two fragile X chromosomes were found in 20% of the cells in a moderately mentally retarded patient with Klinefelter syndrome.     

武汉钴源事故受照者照后10年染色体畸变观察结果

本文报道事故发生后10年观察的结果。采用分析稳定性畸变的方法, 在所分析的720个中期分裂细胞中, 仅见到4个非稳定性畸变细胞, 而稳定性畸变细胞有16个。畸变类型主要是相互易位和缺失。此外, 还观察到原先受照剂量较大的8例, 畸变率相应也高。与此同时, 采用FPG法作了细胞周期的观察以及SeE频率的测定, 与对照组相比没有发现早先受此剂量水平的照射, 对细胞周期和对SCE有何影响。     

Human chromosome heteromorphisms in American blacks: II. Higher incidence of pericentric inversions of secondary constriction regions (h)

Eighty normal American blacks were studied by the CBG technique (C-bands by barium hydroxide using Giemsa) for estimation of size and inversion heteromorphisms of chromosomes 1, 9, and 16, and the data were compared to those of whites using subjectively defined criteria. Size and inversion heteromorphisms were classified into 5 levels. The frequencies of size heteromorphisms of chromosomes 1 and 16 were 10.63% and 6.88%, respectively, which are not significantly different from those of a normal population of whites. A higher incidence of size heteromorphisms for chromosome 9 was noted in whites (47.5% vs 30%). The frequencies of inversion heteromorphism of chromosomes 1, 9, and 16 were 17.5%, 21.9%, and 0.0%, respectively. Overall, 61 chromosomes were found to have an inversion. Of these, 28 were in chromosome 1, and 33 were in chromosome 9. A higher incidence of inversion heteromorphisms of chromosomes 1 and 9 was noted in American blacks, while no inversions were found in chromosome 16 in either population. A significant association of increased size of the h region with inversion (r = 0.99 P < 0.01) is demonstrated, ie, enlarged h regions have a higher frequency of inversions.     

Meiotic consequences of pericentric inversions of chromosome 13

A case is presented demonstrating meiotic consequences of inheritance of a pericentric inversion, inv(13)(p13q21), and suggesting, together with other similar reports reviewed, that certain manifestations (highly arched palate, long philtrum, polydactyly, microphthalmia, and capillary hemangiomata) result from duplication of the distal 13q while others (cleft lip/palate, scalp defects, congenital heart disease) result from duplication of the proximal 13q.