When sex determination in a species is predominantly genetic but environmentally reversible, exposure to (anthropogenic) changes in the environment can lead to shifts in a population's sex ratio. Such scenarios may be common in many fishes and amphibians, yet their ramifications remain largely unexplored. We used a simple model to study the (short-term) population consequences of environmental ...

The purpose of the in vitro chromosomal aberration test is to identify agents that cause structural chromosome aberrations in cultured mammalian cells (1)(2)(3). Structural aberrations may be of two types, chromosome or chromatid. With the majority of chemical mutagens, induced aberrations are of the chromatid type, but chromosome-type aberrations also occur. An increase in polyploidy may indic...

The mammalian in vivo chromosome aberration test is used for the detection of structural chromosome aberrations induced by the test substance to the bone marrow cells of animals, usually rodents (1)(2)(3)(4). Structural chromosome aberrations may be of two types, chromosome or chromatid. An increase in polyploidy may indicate that a chemical has the potential to induce numerical aberrations. Wi...

During male meiosis, the X and Y chromosomes are transcriptionally silenced, a process termed meiotic sex chromosome inactivation (MSCI). Recent studies have shown that the sex chromosomes remain substantially transcriptionally repressed after meiosis in round spermatids, but the mechanisms involved in this later repression are poorly understood. Mice with deletions of the Y chromosome long arm...

It has long been appreciated that tumor cells carry chromosomal aberrations (1). Deviation from the paired ordering of autosomes and sex chromosomes by either increasing or decreasing the copy number of a given chromosome, is referred to as aneuploidy. Errors in the faithful segregation of chromosomes during mitotic or meiotic cell division play a crucial role in the generation of chromosomal a...

Oculo-auriculovertebral dysplasia (Goldenhar) is a congenital syndrome. Its phenotype differs from craniofacial anomalies to cardiac, vertebral or central nervous system defects. This syndrome is rare and its etiology is not apparent yet. Pericentric inversion of chromosome 9 is one of the most common structural balanced chromosomal aberrations with its incidences 15% to 25%. Herein we present ...

Across human cultures and mammalian species, sex differences can be found in the expression of aggression and parental nurturing behaviors: males are typically more aggressive and less parental than females. These sex differences are primarily attributed to steroid hormone differences during development and/or adulthood, especially the higher levels of androgens experienced by males, which are ...

This paper reports on results of intracytoplasmic sperm injection (ICSI) in patients in whom constitutional or secondary chromosome aberrations were detected in the male and/or female partner. Out of 434 couples treated by ICSI (590 cycles), 16 couples (3.7%) were affected by constitutional chromosome aberrations and 96 (22.1%) by secondary chromosome aberrations. Constitutional chromosome aber...

The frequency of chromosomal aberrations was studied in the peripheral blood lymphocytes of 65 radiology technologists CRT) working at hospitals chronically exposed to x-rays. Although film dosimetry did not show the maximal annual permitted dose in any of the examined subjects, cytogenetic analysis detected fairly high levels of chromosomal aberrations in R T compared to unexposed controls...

Background: To evaluate the effects of hyperthermia (HT) on the frequency of chromosomal aberrations induced by a low dose of neutron or γ-rays in human peripheral blood lymphocytes. Materials and Methods: Blood samples were exposed to HT (41.5°C for 30 and 60min, 43°C for 15 and 30min), 10 cGy neutron or γ-rays, HT + neutron/γ, and neutron/γ + HT. After standard cell culture, harvestin...