Ascertaining the paternal lineage in crossbred calves

Karyotyping is one among the culling parameter used for taking up culling decisions. Cytogenetic screening of breeding bulls has been recommended to screen for chromosomal abnormalities before semen production in artificial insemination. The chromosomal analysis of a Holstein Friesian crossbred bull revealed the presence of acrocentric Y-chromosome, which was further confirmed by CBGbanding. The shape of the Y-chromosome determining that male line used for crossbreeding was from indigenous origin. Karyotyping is a best and reliable technique for the identification of crossbred calves born to the indigenous bulls.

Characterization of a rare short arm heteromorphism of chromosome 22 in a girl with down-syndrome like facies.

Chromosomal heteromorphisms are described as interindividual variation of chromosomes without phenotypic consequence. Chromosomal polymorphisms detected include most regions of heterochromatin of chromosomes 1, 9, 16 and Y and the short arms of all acrocentric chromosomes. Here, we report a girl with Down‑syndrome such as facies and tremendously enlarged short arm of a chromosome 22. Fluorescence in situ hybridization (FISH) with a probe specific for all acrocentric short arms revealed that the enlargement p arms of the chromosome 22 in question contained exclusively heterochromatic material derived from an acrocentric short arm. Parental studies identified a maternal origin of this heteromorphism. Cryptic trisomy 21 of the Down‑syndrome critical region was excluded by a corresponding FISH‑probe. Here, we report, to the best of our knowledge, largest ever seen chromosome 22 short arm, being ~×1.5 larger than the normal long arm.

Chromosomal Instability in peripheral blood lymphocytes in patients with malignancy.

There are lot of studies on the cytogenetic changes in solid tumours but there are very few studies on the cytogenetic changes in peripheral blood by mphosytes in patients with malignancy. In the present study we evaluated peripheral blood lymphocyte cytogenetic changes on short term culture. Twenty four out of 250 patients with various malignancies showed some aberration of karyotypes in peripheral lymphocytes (9-6%) suggesting an underlying genetic instability in these cancer patients or alternatively demonstrating that these changes could be related to exposure to environmental mutagens.

Down Syndrome : Acrocentric Association.

Acrocentric association in Down Syndrome is a widely debated phenomenon. The present study on a total of 68 subjects from South India revealed that the incidence of Down Syndrome is increased with an increased frequency of association of acrocentric chromosomes in their parents.