Recombinant inversion chromosomes in phenotypically normal chickens

Some progeny resulting from interbreeding of individuals heterozygous for a pericentric inversion of chromosome 1 in the chicken have the two complementary types of recombinant chromosomes arising from a single crossing-over within the inverted segment. These individuals are capable of reproduction. Their progeny can have one or the other of the two recombinant chromosomes or, if crossing-over occurs, either a normal or an inversion chromosome.

Differential induction of sister chromatid exchange by chemical carcinogens in lymphocytes cultured from patients with solid tumors

Three carcinogens with different requirements for activation were used to generate sister chromatid exchange (SCE) in cultured lymphocytes from 22 untreated patients with solid tumors. These data were compared to SCEs produced by incubating lymphocytes, from 44 normal persons, with the same carcinogens. In vitro treatments with butadiene epoxide (0.125 micrograms/ml) show no significant differences in the SCEs generated. However, in vitro treatment with mitomycin-C (0.04 micrograms/ml) did induce significant differences (p less than 0.05) in the distribution of the SCE scores. Treatment of the cultured cells with benzo(a)pyrene (10 micrograms/ml), a carcinogen requiring extensive metabolic activation, significantly (p less than 0.001) altered the distribution of the SCEs generated in vitro. The SCE data suggest that metabolic activities play an important role in the processing of carcinogens in solid tumor patients.

Cytogenetic evidence for premeiotic transformation of human testicular cancers

To determine the point at which transformation of the germ cell occurs during meiosis in nonseminomatous testicular cancer, the sex chromosome compositions of 15 cell lines derived from primary tumors or metastases of 12 patients with testicular cancer were analyzed by trypsin G-banding analysis and Y-body staining. The simultaneous existence of both X- and Y-chromosomes in a single cell has been confirmed in 14 cell lines. This suggests that transformation of the cell occurs before the first meiotic division because it is known that segregation of X- and Y-chromosomes occurs during the first meiotic division. An incidental finding was the presence of Barr bodies in some cell lines containing more than one X-chromosome, which is consistent with the known primitive nature of testicular cancer and its ability to differentiate independently from the male host.

The tadpole-shaped structures in human non-necrotizing granulomas

We scrutinized the secondary lysosomal vesicle of the epitheloid cell from 9 patients whose biopsy specimens show multiple non-necrotizing granulomas by light microscopy (LM). In 4 of the 9 patients, we found tadpole-shaped structures (TSS) approximately tenfold larger than the size of the mycobacteriophage by transmission electron microscopy (TEM). In addition, we used a plasma etching method on epon-embedded tissue and successfully demonstrated the stereoscopic appearance of the TSS by scanning electron microscopy (SEM). The identified TSS were further analyzed with an X-ray energy dispersive spectrometer for their microchemistry. The TSS appeared to be integral structures by TEM and SEM and did not contain any nonbiologic elements when analyzed with the X-ray energy dispersive spectrometer. Their location as well as their morphologic features and microchemistry suggested that the TSS are a microorganism and related to the formation of the granulomas in our 4 patients.

Alcohol dehydrogenase in Drosophila: isolation and characterization of messenger RNA and cDNA clone

The mRNA for alcohol dehydrogenase (ADH) in D. melanogaster has been identified by translation in a cell-free system. The in vitro synthesized polypeptide, specifically precipitated by anti-ADH antibody, has identical subunit molecular weight (25,000 daltons) and tryptic peptide profile to the in vivo synthesized ADH. The poly A containing ADH-mRNA has been purified by specific precipitation of ADH-polysomes using anti-ADH antibody and S. aureus. Transformation of E. coli with the dA-tailed ADH-mRNA-complementary DNA hybrid annealed to the dT-tailed pBR322 yielded one plasmid which has been identified as the ADH-cDNA clone. The identification involved hybridization selection of ADH-mRNA and in vitro translation, in situ hybridization to the Adh locus on salivary gland polytene chromosomes and DNA sequencing. This ADH-cDNA plasmid contains 349 bases of the C-terminal protein coding and 180 bases of the 3' untranslated region.

The induction and detection of diploid spermatozoa in Gallus domesticus

Colcemid at the dose level of 0.37 mg/kg/day was injected intraperitoneally to 3 sexually active chicken males for 3 consecutive days. 10-12 days after the first colcemid injection, 14-25% of the sperm population in the semen samples from the treated males was found to be diploid in DNA content by flow microfluorometric analysis. Cytogeneic and developmental analyses on early embryos indicate that, during the process of spermatogenesis, the male germ cells are most susceptible to colcemid treatment 10-12 days prior to the maturation of the spermatozoa which is equivalent to the primary through secondary spermatocyte stages in chicken males. By the application of an extremely unequal chromosomal translocation as a cytological marker of parentage, it is confirmed that the diploid sperm induced are capable of uniting with a normal haploid or diploid egg to produce a triploid or tetraploid zygote.

Cytogenetic evidence for the absence of an inactivated X chromosome in a human female (XX) breast carcinoma cell line

Barr body staining procedures were applied directly to the chamber slide cultures of female amniotic cells. WI38 fibroblasts, normal female kidney cells, and a human breast carcinoma cell line, Elco. A high frequency of Barr bodies was found in all the normal female control cells; however, no Barr bodies were observed in the Elco cells. By trypsin G-banding analysis, two normal X chromosomes were identified in all Elco cells. The late DNA replication pattern of the cell line was then studied with the terminal BrdU pulse method. Both X chromosomes in the Elco cell line were found to be euchromatic with a characteristic R-banding pattern; no late-replicating X chromosome was observed. The absence of both a Barr body and a late-replicating heterocyclic X chromosome provides strong cytogenetic evidence that an inactivated X chromosome is absent in the human breast carcinoma cells bearing two X chromosomes.

Nonrandom abnormalities in chromosome 1 in human testicular cancers

Trypsin G banding was performed on metaphase chromosomes from 14 cell lines derived from primary tumors or metastases of 11 patients with testicular cancer. Most of the cell lines, 11 of 14, have a modal number between 51 and 61. All lines have numerical and structural changes involving chromosome 1 with trisomy of the q arm being the common aberration. Break points in chromosome 1 were nonrandom, being concentrated in the regions of p12, q12, p36, and p22, which resulted in morphologically identical marker chromosomes in different cases. These changes probably are not artifacts of cell culture. In one instance, three lines derived from the same patient, one from tissue removed at operation, and two from separate metastases removed at autopsy nearly 3 years later after unsuccessful radiotherapy and chemotherapy had identical chromosome compositions. In another case, lines derived from a primary tumor and a metastasis from the same patient also had identical marker chromosomes. The consistent involvement of chromosome 1 in aberrations may be associated with the highly malignant nature of testicular cancers.

Induction of heteroploidy in Gallus domesticus

Intraperitoneal colcemid injection at the dose level of 0.37 mg/kg applied 3-4 h before the first oviposition produces a high frequency of triploids among the second oviposition eggs laid the first day after colcemid treatment. The triploids, mostly 3A-ZZW type, appear to be as developmentally compatible as contemporary diploids at both embryonic and hatching level. No other kinds of heteroploids besides triploids were found at hatching time even though a high frequency was observed in 24-h embryos.

Optical Somatic Cell Counting and Total Protein Analysis in a Dairy Herd Improvement Program 1

Milk sample preparation for Optical Somatic Cell Counter II operation was simplified by using a diluter to add fixative, mix, and dilute samples. Potassium dichromate preservative tablets produced a mean increase of 7,000 in somatic cell counts in fresh milk. Samples held at 20-23 C beyond 2 days or at 4-7 C beyond 4 days showed a reduction in somatic cell count. The mean somatic cells in 3 Holstein herds tested over a 6-month period was 3.8 × 10⁵/ml. A 22-month survey of 52.6 thousand Utah Dairy Herd Improvement samples which were shipped under ambient conditions and then held at 5 C until tested, indicated 75% below 400,000 and 2.7% above 1.6 million somatic cells/ml. Casein, noncasein protein, total protein, fat and milk weight data were also obtained on the three herds. Multiple correlations were obtained. The best correlations suggested that testing for total protein and somatic cells in a central laboratory would estimate casein and noncasein protein. Such tests are most valuable for the cheese industry.