Biomaterial Database

Classification of X-ray-induced Robertsonian fusion-like configurations in mouse splenocytes. 1996

J J Boei, and A T Natarajan

Department of Radiation Genetics and Chemical Mutagenesis, Leiden University, The Netherlands.

A characteristic karyotypic feature of mouse chromosomes is the presence of large blocks of heterochromatin in the vicinity of the centromeres. Breakage inside this centromeric heterochromatin might result in the formation of abnormal chromosomes, very similar to the metacentric chromosomes derived from Robertsonian fusion. X-rays are very efficient in inducing these Robertsonian fusion-like configurations (RLC) in cultured mouse splenocytes. Observed frequencies of these RLC increase in a linear-quadratic manner with dose. Two types of RLC were found. The first type (approximately 70% of induced RLC) has heterochromatin only in the middle of the chromosome and appears as a metacentric chromosome, whereas the other type (approximately 30%) has a heterochromatic block inside the chromosome arm (and has the appearance of a dicentric chromosome). Induced RLC are difficult to classify as either a stable or unstable aberration, based only on traditional cytogenetic techniques such as C-banding. Here we describe a cytogenetic approach to achieving better insight into the molecular organization of RLC. We utilized two-colour fluorescence in situ hybridization (FISH) using a combination of mouse minor satellite DNA probe and telomeric probe. Over 90% of RLC did not have detectable minor satellite arrays inside the interstitial heterochromatin. Consequently, most of the RLC of the first type should be classified as acentric fragments and those of the second type as translocations. The chance of inducing true Robertsonian fusions in mouse splenocytes by X-rays is < 2.5% based on the total RLC observed.

UI	MeSH Term	Description	Entries
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D002503	Centromere	The clear constricted portion of the chromosome at which the chromatids are joined and by which the chromosome is attached to the spindle during cell division.	Centromeres
D002869	Chromosome Aberrations	Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.	Autosome Abnormalities,Cytogenetic Aberrations,Abnormalities, Autosome,Abnormalities, Chromosomal,Abnormalities, Chromosome,Chromosomal Aberrations,Chromosome Abnormalities,Cytogenetic Abnormalities,Aberration, Chromosomal,Aberration, Chromosome,Aberration, Cytogenetic,Aberrations, Chromosomal,Aberrations, Chromosome,Aberrations, Cytogenetic,Abnormalities, Cytogenetic,Abnormality, Autosome,Abnormality, Chromosomal,Abnormality, Chromosome,Abnormality, Cytogenetic,Autosome Abnormality,Chromosomal Aberration,Chromosomal Abnormalities,Chromosomal Abnormality,Chromosome Aberration,Chromosome Abnormality,Cytogenetic Aberration,Cytogenetic Abnormality
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013154	Spleen	An encapsulated lymphatic organ through which venous blood filters.
D014965	X-Rays	Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.	Grenz Ray,Grenz Rays,Roentgen Ray,Roentgen Rays,X Ray,X-Ray,Xray,Radiation, X,X-Radiation,Xrays,Ray, Grenz,Ray, Roentgen,Ray, X,Rays, Grenz,Rays, Roentgen,Rays, X,X Radiation,X Rays,X-Radiations
D017404	In Situ Hybridization, Fluorescence	A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.	FISH Technique,Fluorescent in Situ Hybridization,Hybridization in Situ, Fluorescence,FISH Technic,Hybridization in Situ, Fluorescent,In Situ Hybridization, Fluorescent,FISH Technics,FISH Techniques,Technic, FISH,Technics, FISH,Technique, FISH,Techniques, FISH
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus