Use Of Chromosomes Research Articles

Leveraging Active Learning to Establish Efficient In Vitro Transcription and Translation from Bacterial Chromosomal DNA.

Gene expression is a fundamental aspect in the construction of a minimal synthetic cell, and the use of chromosomes will be crucial for the integration and regulation of complex modules. Expression from chromosomes in vitro transcription and translation (IVTT) systems presents limitations, as their large size and low concentration make them far less suitable for standard IVTT reactions. Here, we addressed these challenges by optimizing lysate-based IVTT systems at low template concentrations. We then applied an active learning tool to adapt IVTT to chromosomes as template DNA. Further insights into the dynamic data set led us to adjust the previous protocol for chromosome isolation and revealed unforeseen trends pointing at limiting transcription kinetics in our system. The resulting IVTT conditions allowed a high template DNA efficiency for the chromosomes. In conclusion, our system shows a protein-to-chromosome ratio that moves closer to in vivo biology and represents an advancement toward chromosome-based synthetic cells.

Reviews in plant cytogenetics

Reviews in plant cytogenetics

The use of chromosomes in paternity actions

The authors performed paternity investigations for many years by the order of the court and on this basis they give expert opinion in discussed paternity cases. In recent years opinion was given with the help of chromosome studies in cases where neither blood group nor anthropology investigations were decisive. From a couple of hundred persons the thickening of the heterochromatic part of the chromosomes studied by C-band methods is evaluated (1, 9, 16, Y) and (within this) the occurrence of total or partial inversion is observed. The frequency of polymorphism was studied among the chromosomes investigated by the C-band technique. From these data the authors aimed at deducing exact relationship: and forming the most exact possible expert's opinion in this problem which is of social significance as well.

Transfer of murine leukaemia and murine sarcoma virus genetic information by transfection with isolated metaphase chromosomes.

Chromosome-mediated transfer of murine leukaemia (MuLV) and murine sarcoma (MuSV) virus genetic information to uninfected recipient cells was investigated. Metaphase chromosomes from AKR MuLV-infected SC-1 mouse cells were incubated with NIH/3T3 cells. After several passages (1 to 3 weeks), infectious virions exhibiting reverse transcriptase activity and the characteristic host range of ecotropic, N-tropic AKR virus appeared in the supernatant fluids of the treated cells. Restriction endonuclease analysis of genomic DNA from transfected cells indicated that AKR proviral DNA was associated with the high molecular weight DNA of the host. These results demonstrate that the AKR MuLV genome can be stably transferred to uninfected recipient cells via isolated metaphase chromosomes. Although AKR virions are not able to infect heterologous cells, chromosome-mediated transfection resulted in the establishment of productive AKR MuLV infection in mink cells. Thus, the use of chromosomes to transfer virus genes can circumvent the natural host restriction barrier. In other experiments, it was shown that normal NIH/3T3 cells were transformed after exposure to metaphase chromosomes isolated from an MuSV-infected, non-producer line. Foci were detected 14 to 21 days after chromosome treatment and were shown to contain true viral transformants since transforming virus was produced after superinfection with MuLV.

The Significance of Chromosome Numbers in Ferns

The Significance of Chromosome Numbers in Ferns

Karyotypes of the Six Species of Frogs (GenusRana) Endemic to the Ryukyu Islands

Karyotypes of Rana narina, R. ishikawae, R. subaspera, R. holsti, R. okinavana, and R. namiyei were analyzed by making use of chromosomes from bone marrow cells. The first five species have 13 pair...

Pitfalls in the use of chromosome aberration analysis for biological radiation dosimetry.

The use of chromosomes as biological radiation dosimeters is a well-established and valuable technique, especially when physical methods are inadequate or not available. This technique has also been used in studies of lymphocyte kinetics (Sharpe, Dolphin, Dawson and Field, 1967; 1968). Peripheral blood lymphocytes are stimulated in culture to go into division and then arrested in mitosis with Colcemid. Radiation damage can be seen in the metaphase chromosomes and the amount of damage can be related to the dose of radiation (Bender and Gooch, 1962).

A pollen grain squash technique for Saccharum and related genera.

Anthers collected between 9 and 10 AM were treated for 1 hr at 26-28 C with a 0.5% solution of colchicine, washed for 2-4 min in water, placed in 0.002 M 8-hydroxyquinoline for 1 hr, washed in water for 10 min and fixed in: methanol, 60 ml; chloroform, 30 ml; distilled water, 20 ml; picric acid, 1 gm and mercuric chloride 1 gm, for 24 hr. After washing they were hydrolysed in 1 N HCl for 15 min at 60 C, stained in leuco basic fuchsin for 30 min, then smeared on a slide in a drop of acetocarmine. The slides were sealed, stored overnight, the paraffin was removed, and the slide passed through a 1:1 mixture of n-butyl alcohol and acetic acid, then through pure n-butyl alcohol and mounted in Canada balsam. The significant features of this procedure are: (1) use of chromosomes in the haploid condition for karyotype analysis, (2) better exaggeration of constrictions for easier interpretation of chromosome types and (3) good spreading in plants with a large chromosome number.