Biomedical subjects

J B Marcum

Publications and source records attributed to J B Marcum.

2 recordsLinked to original sources

PubMed1975

Attmepts to induce chromosomal breakage in chicken embryos with Aroclor 1242.

Fertile White Leghorn eggs were injected with Aroclor 1242 and incubated for four to five days. More than 65 percent of the exposed embryos died prior to examination at the end of the incubation period. The five largest pairs of chromosomes from allantoic squashes were examined for the presence of chromosomal breakage in 753 metaphases from PCB-treated eggs and 196 metaphases from controls. Failure to detect chromosomal aberrations in either group indicated that Aroclor 1242, in concentrations of 10 p.p.m. or 20 p.p.m. in the egg, is not an effective clastogen in the chicken embryo.

Allantois↗

PubMedDate not supplied

G-band identification of the chromosomes of sheep.

Peripheral blood cultures were made on 20 Dorset sheep including 16 ewes and 4 rams. Photomicrographs of 100 cells were examined for trypsin-induced G-bands, and the length of each chromosome was measured. The banding patterns of each of the 27 pairs of chromosomes were identified and described, and the results observed in this study were compared with those previously reported. Measurements of all chromosomes in which both members of a homologous pair were identifiable were used to calculate mean relative length. Karyotypes, in which chromosomes were arranged to mean relative length, were prepared and an idiogram illustrating major bands was constructed.

Animals↗