Physical mapping of the plastid genome from the chlorophyll c-containing alga,Cryptomonas Φ

Summary A physical map of the circular plastid genome of Cryptomonas has been constructed using the enzymes SacI, BamHI, SmaI, SalI, PstI and XhoI. In addition, fine-structural mapping of the inverted repeat region has been performed using AvaI, BglII, EcoRI and XbaI. The inverted repeat is very small, encompassing no more than 6 kb and containing only genes for the rRNAs. It divides the plastid genome into a small singlecopy region of 12–13 kb which contains genes for phycoerythrin and the 32 kd photosystem II polypeptide, and a large single-copy region of 93–94 kb, giving a total size of 118 kb. The genes for the large subunit of ribulose-1,5-bisphosphate carboxylase (Rubisco) and the beta subunit of ATP synthase CF₁ are encoded in the large single-copy region. The evolutionary significance of the organization of this plastid genome, the first presented from the chlorophyll c-, phycobiliprotein-containing group of algae, is discussed.     

碱性成纤维细胞生长因子对卵巢癌CAOV3细胞cyclin D1及GADDl53表达的影响

目的:研究碱性成纤维细胞生长因子(bFGF)对人卵巢癌CAOV3细胞细胞周期调节蛋白cyclinD1及GADD153表达的影响,探讨bFGF促进人卵巢癌CAOV3细胞增殖、抑制凋亡的信号机制。方法:利用无血清饥饿诱导卵巢癌CAOV3细胞凋亡。分为对照组、bFGF组。分别应用MTT、流式细胞术、琼脂糖凝胶电泳观察25、50、75μg/L bFGF对CAOV3细胞增殖率、细胞周期及细胞凋亡的影响。利用Western blotting检测bFGF对CA-OV3细胞cyclin D1、GADD153以及转录因子(c-Fos、c-Jun)表达的影响。结果:与对照组相比,bFGF呈剂量依赖性加速CAOV3细胞细胞周期进程,促进细胞增殖,抑制饥饿诱导的凋亡(P<0.01);呈时间依赖性促进cyclinD1、c-Fos、c-Jun,抑制GADD153蛋白表达(P<0.01)。结论:bFGF可能通过上调cyclin D1、c-Fos、c-Jun,下调GADD153表达促进细胞增殖,抑制饥饿诱导的卵巢癌CAOV3细胞凋亡。     

Trabecular Shear Stresses Predict <Emphasis Type="Italic">In Vivo</Emphasis> Linear Microcrack Density but not Diffuse Damage in Human Vertebral Cancellous Bone

Linear microcracks and diffuse damage (staining over a broad region) are two types of microscopic damage known to occur in vivo in human vertebral trabecular bone. These damage types might be associated with vertebral failure. Using microcomputed tomography and finite element analysis for specimens of cancellous bone, we estimated the stresses in the trabeculae of human vertebral tissue for inferosuperior loading. Microdamage was quantified histologically. The density of in vivo linear microcracks was, but the diffuse damage area was not, related to the estimates of von Mises stress distribution in the tissue. In vivo linear microcrack density increased with increasing coefficient of variation of the trabecular von Mises stress and with increasing average trabecular von Mises stress generated per superoinferior apparent axial stress. Nonlinear increase in linear crack density, similar to the increase of the coefficient of variation of trabecular shear stresses, with decreasing bone stiffness and bone volume fraction suggests that damage may accumulate rather rapidly in diseases associated with low bone density due to the dramatic increase of shear stresses in the tissue. © 2003 Biomedical Engineering Society. PAC2003: 8719Rr, 8719Xx, 8759Ls, 8759Fm, 8710+e     

GPR34-mediated sensing of lysophosphatidylserine released by apoptotic neutrophils activates type 3 innate lymphoid cells to mediate tissue repair

1. Download : Download high-res image (200KB)
2. Download : Download full-size image

     

Relationship between ROS production, apoptosis and DNA denaturation in spermatozoa from patients examined for infertility

BACKGROUND: The aim of this study was to examine the role of apoptosis and reactive oxygen species (ROS) in inducing DNA damage in ejaculated spermatozoa. METHODS: We examined ejaculated spermatozoa from 31 patients examined for infertility and 19 healthy donors for apoptosis, production of ROS and DNA damage using annexin V binding, chemiluminescence assay and sperm chromatin structure assay. RESULTS: The percentage of spermatozoa that underwent apoptosis in the whole ejaculate and mature fraction was higher in the patients than in the donors (P<0.001 and P=0.009, respectively). Levels of ROS in the whole ejaculate and immature fraction were higher in the patients than in the donors (P=0.002 and P=0.009). Apoptosis was significantly correlated with ROS within patients in the whole ejaculate [r (95% confidence interval)=0.53 (0.19-0.86)] and in the mature [0.71 (0.39-1.00)] and immature spermatozoa [0.75 (0.45-1.00)]. Only apoptosis and the DNA fragmentation index (DFI) were significantly correlated within patients in the whole ejaculate [0.57 (0.18-0.97)]. CONCLUSIONS: DNA damage may be induced by oxidative assault. Apoptosis may not contribute significantly to the DNA damage.     

Genome analysis of dengue type-1 virus isolated between 1990 and 2001 in Brazil reveals a remarkable conservation of the structural proteins but amino acid differences in the non-structural proteins

We have investigated the genetic diversity of dengue type-1 (DEN-1) virus in Brazil. The full nucleotide sequences of three DEN-1 virus isolated from DEN fever (DF) and DEN hemorrhagic fever patients in northeastern Brazil in 1997 (BR/97) and one from a DF patient in the south of Brazil in 2001 (BR/01) were compared to that of the reference strain BR/90 obtained in the city of Rio de Janeiro in 1990. Sequence analysis showed that the structural proteins were remarkably conserved between all isolates. A total of 27 amino acid changes occurred throughout the non-structural proteins. Among them, nine amino acid substitutions were specific of BR/97 and BR/01 isolates, indicating that in situ evolution of these strains had occurred. Within the BR/97 and BR/01 samples, some amino acid substitutions have been previously identified in DEN-1 virus strains sequenced so far, suggesting that recombination events might have occurred.     

Cytogenetics of a new cytotype of African Mus (subgenus Nannomys) minutoides (Rodentia, Muridae) from Kenya: C- and G- banding and distribution of (TTAGGG) n telomeric sequences

We present the results of a cytogenetic study on Mus (Nannomys) minutoides from Kenya by means of C- and G- banding and in-situ fluorescence hybridization (FISH) to localize the telomeric sequences. The karyotype is characterized by the occurrence of several Rb chromosomes Rb(1.X), Rb(1.Y). Rb(2.17), Rb(3.13), Rb(4.10), Rb(5.11), Rb(6.7), Rb(8.12), not previously described for this species. This finding suggests a high level of chromosomal diversification, which means it is possible to consider this cytotype as a new, well-differentiated, chromosomal lineage within the subgenus. The C-banding of the metaphases illustrated conspicuous blocks of centromeric heterochromatin at the paracentromeric regions of all telocentric chromosomes. Centromeric heterochromatin is not visible on all biarmed chromosomes. Following hybridization with telomeric probes, bright interstitial telomeric sequence (ITS) fluorescence signals are evident at the pericentromeric area of all Rb chromosomes, with the exception of Rb(2.17). Considering the localization of the C-positive heterochromatin and of the telomeric sequences, the events leading to the Kenyan cytotype from an all-telocentric condition probably included two steps: first, fusion without loss of heterochromatin and pericentromeric telomeric sequences; second, the reduction of the C-positive satellite DNA followed by the amplification of telomeric sequences in the C-negative paracentromeric region of Rb chromosomes. The presence of a single Rb(2.17) without ITS indicates possible variations of this mechanism.     

Copper and iron-induced oxidative damage in non-tumor bearing LEC rats

The copper and Iron status in the liver of non-tumor bearing Long-Evans Cinnamon (LEC) rats (average age 17 months) was investigated. A direct quantitation of loosely-bound copper and iron was also investigated by using a chelating agent, nitrilotriacetic acid (NTA-chelatable free copper and iron). Besides the total copper and iron contents, the level of NTA-chelatable free copper was also higher in LEC rats than In LEA rats (P<0.05). But for the free iron level there was no signiflcant difference between the two rat groups (P>0.05). The formation of thiobarbituric acid-reactive substances was higher In LEC rats than In LEA rats (P<0.01). The 4–hydroxy-2–nonenal (HNE)-modified proteins were also clearly demonstrated in LEC rat liver. The copper and iron which produced the most important effect In the process of oxidative damage in LEC rats could not be distinguished. Even though free copper, which could induce free radical injuries, was increased in LEC rats, neither tumor-induction nor preneo-plastic lesions in the experimental LEC rats were observed. Therefore it is speculated that the elevation of a free iron is another important factor. Copper and iron, both important translation metals In the body, may participate In the Induction of DNA damage and oncogenesls     

An influenza A(H3) reassortant was epidemic in Australia and New Zealand in 2003

During 2003, Australia and New Zealand experienced substantial outbreaks of influenza. The strain responsible was an A(H3N2) influenza virus described as A/Fujian/411/2002-like, which had circulated as a minor variant in the previous Northern Hemisphere (NH) winter, mainly in Korea and Japan. Early in the year the isolates were very similar to those that had been previously isolated in the NH, however, a reassortant strain emerged early in the New Zealand winter, followed by the appearance of similar viruses in Australia and other regional areas. While the hemagglutinin HA1 sequence of these viruses demonstrated only minor differences from the A/Fujian/411/2002 reference strain, the neuraminidase gene was clearly different from that of other recently circulating H3 viruses and most closely matched an earlier reference strain A/Chile/6416/2001. Three internal genes (NS, NP, M) in the reassortant viruses were also more closely related to the A/Chile/6416/2001 lineage. This reassortant A(H3) virus predominated in Australia and New Zealand in 2003 was also seen in Brazil and Malaysia during 2003 and was widespread in the United States and Europe during their 2003-04 winter. Interestingly most of the strains of A(H3) that were isolated at the beginning of the 2004 winter in Australia, did not have this earlier A/Chile/6416/2001-like neuraminidase but had a neuraminidase that was similar to that of the reference strain A/Fujian/411/2002. This was suggestive of the re-introduction of influenza A(H3) from other countries, however, there was still low level circulation of the reassortant virus in 2004 with isolates detected in Australia and Singapore.     

The chromosome complement ofAcomys spp. (Rodentia,Muridae) from Oursi,Burkina Faso—the ancestral karyotype of thecahirinus-dimidiatus group?

We present here data on chromosome banding analysis (R- and C-bands) ofAcomys sp. (Rodentia, Muridae) from Oursi, Burkina Faso, characterized by 2n=FN=68 and comparison of its banding patterns with those ofAcomys dimidiatus from Saudi Arabia (2n=38, FN=70), studied previously. The study revealed complete homology between acrocentric chromosomes ofAcomys sp. and chromosome arms of 16 pairs of metacentric and two pairs of acrocentric chromosomes ofA. dimidiatus. In addition to monobrachial homology, one tandem translocation accompanied by a centromeric shift was identified in the karyotype of the latter species. The data obtained show that karyotypes of all the species of theAcomys cahirinus-dimidiatus group studied previously may be derived from that ofAcomys sp. from Oursi by means of numerous non-homologous Rb translocations and 1–2 tandem translocations, and thus its karyotype may be considered as ancestral for thecahirinus-dimidiatus group.accepted for publication by M. Schmid