The effects of a radiomimetic chemical, bleomycin (BLM), on meiotic chromosomes was evaluated in mice. hromosome aberrations were analyzed at meiotic metaphase I, and damage to the synaptonemal complex was analyzed in meiotic prophase cells. n the metaphase aberration studies, an...

The effects of a radiomimetic chemical, bleomycin (BLM), on meiotic chromosomes was evaluated in mice. Chromosome aberrations were analyzed at meiotic metaphase I, and damage to the synaptonemal complex was analyzed in meiotic prophase cells. In the metap...

Artificially induced intersyngenic crosses in Paramecium caudatum can produce viable and fertile hybrids. When F(1) hybrids of double E mating type (Mt(1)/Mt(3) or Mt(12)/Mt(3)) were crossed with mating type O (mt/mt), aberrant segregants of double E and single O type were produced. This segregation was not explained by ordinary equal or unequal crossing over. Breeding ...

We have developed a protocol for the identification of aberrant chromosome behavior during human male meiosis up to metaphase of the secondary spermatocyte. Histological evaluation by the Johnsen score of a testicular biopsy was combined with immunofluorescence of first meiotic prophase spermatocytes, using antibodies against ...

Reaction mechanisms involved in the induction of chromosome aberrations by ionizing radiation are reviewed. Topics discussed include chromosome and chromated type aberrations; the exchange hypothesis; chromosome stickiness and sub-chromated aberrations; the relation between aberration structure and the ...

Synaptonemal complex analysis provides a unique means of visualizing the behavior of meiotic chromosomes. The technique has been applied to the study of normal karyotypes and mutant stocks of mice. Recent work demonstrating the usefulness of SC analysis for the detection of chromosome damage suggests its potential application in a variety of mechanistic ...

Artificially induced intersyngenic crosses in Paramecium caudatum can produce viable and fertile hybrids. When F₁ hybrids of double E mating type (Mt¹/Mt³ or Mt¹²/Mt³) were crossed with mating type O (mt/mt), aberrant segregants of double E and single O type were ...

BackgroundAgave tequilana Weber var. azul, is the only one variety permitted by federal law in M�xico to be used for tequila production which is the most popular contemporary alcoholic beverage made from agave and recognized worldwide. Despite the economic, genetic, and ornamental value of the plant, it has not been subjected to detailed cytogenetic research, which could lead to a better ...

Meiotic non-disjunction is thought to occur in 10-20% of all human oocytes, making this the most common genetic abnormality in our species. Aberrant recombination has been implicated in the genesis of these errors; however, direct studies of the meiotic process have been hampered by the lack of material and appropriate technology. We ...

The mechanisms by which chemically induced lesions in the chromosomes of mammalian germ cells are actually converted to aberrations and transmitted to progeny are very complex and little understood. An attempt is made to explain how dominant-lethal mutati...

Chromosome aberrations are a major component of radiation or chemically induced genetic damage in mammalian germ cells. The types of aberration produced are dependent upon the mutagen used and the germ-cell stage treated. For example, in male meiotic and ...

The mechanisms by which chemically induced lesions in the chromosomes of mammalian germ cells are actually converted to aberrations and transmitted to progeny are very complex and little understood. An attempt is made to explain how dominant-lethal mutations and heritable translocations are produced from chemical treatment of meiotic and postmeiotic germ ...

Data are compared from an analysis of chromosome mutations arising spontaneously in Tradescantia paludosa and the frequency of micronuclei induced in meiotic cells of Tradescantia by doses of x radiation ranging from 0.3 to 6.0 r. It is suggested that the possibility of unexpectedly high meiotic sensitivity should be taken into account in setting ...

Monosomics lack a pairing partner in each meiotic cell, and genes on an entire chromosome are present in the hemizygous condition. We have isolated monosomics for chromosomes 1, 2, 3, 4, 6, 7, 8, 9, and 10 in Zea mays utilizing a recently-discovered system. This is the only series of this type that has been recovered in any diploid organism. The monosomic plants are ...

A study of the effects of gamma irradiation on oats and wheat, especially Triticum vulgare variety Shinchunaga, showed many morphologic and physiologic mutants in the X/sub 2/ and the later generations of the irradiated wheat. From the genetic behavior of the mutant characters, it is assumed that most of them were induced through chromosome ...

Monosomics lack a pairing partner in each meiotic cell and genes on an entire chromosome are present in the hemizygous condition. Monosomics for chromosomes 1, 2, 3, 4, 6, 7, 8, 9, and 10 in Zea mays were isolated utilizing a recently-discovered system. This is the first time that a series of this type has been recovered in any diploid organism. The monosomic plants are ...

The application for a Research Contract to the US Atomic Energy Commission of February, 1970 proposed to isolate as many as possible to the 10 maize monosomic types and to characterize them by studying: (1) the cytology of meiosis, (2) the cytological behavior of monosomic chromosomes in meiosis, (3) the effect of monosomy on recombination in heterozygous bivalents, and (4) ...

Meiosis, a specialized cell division with a single cycle of DNA replication round and two consecutive rounds of nuclear segregation, allows for the exchange of genetic material between parental chromosomes and the formation of haploid gametes. The structural maintenance of chromosome (SMC) proteins aid manipulation of chromosome structures inside cells. Eukaryotic SMC complexes include cohesin, ...

Synaptonemal complex aberrations can provide a sensitive measure of chemical-specific alterations to meiotic chromosomes. Mitomycin C, cyclophosphamide, amsacrine, ellipticine, colchicine, vinblastine sulfate, and cis-platin exposures in mice have been sh...

Synaptonemal complex aberrations can provide a sensitive measure of chemical-specific alterations to meiotic chromosomes. Mitomycin C, cyclophosphamide, amsacrine, ellipticine, colchicine, vinblastine sulfate, and cis-platin exposures in mice have been shown to cause various patt...

This {open_quotes}Letter to the Editor{close_quotes} discusses the implications of meiotic versus somatic chromosomal aberrations and how this corresponds to the discussion of trisomy 22, including the survival time of the patient. 5 refs.

During meiosis, accurate segregation of intact chromosomes is essential for generating healthy gametes. Defects in recombination and/or chromosome synapsis activate the pachytene checkpoint, which delays meiotic cell cycle progression to avoid aberrant chromosome segregation and formation of defective gametes. Here, we characterize the role of the ...

Meiotic restitution is considered to be a common mechanism of polyploidization in plants and hence is one of the most important processes in plant speciation. Meiotic behaviour of plant chromosomes is influenced by both genetic and environmental factors. In this study, the meiotic behaviour of cereal crops was investigated, which ...