A new solid-phase support for oligonucleotide synthesis.

An alternative solid support for oligonucleotide synthesis was developed by coupling a polymer colloid to a modified polyethylene filter disc. The functions on the polymer colloid not used for attachment to the surface were derivatized with a Jeffamine diamine and loaded with appropriate deoxynucleoside succinates. The performance of this support system was evaluated and compared to existing resins.

Changes in melanin granules in the fox due to coat color mutations.

Hair samples from 11 different coat color phenotypes of the fox (Vulpes vulpes) were examined microscopically to determine the effects of several mutations on melanin granule color and distribution. Standard silver (b/b) causes the production of eumelanin rather than the phaeomelanin produced in wild-type red fox. Fromm brown (bf/bf) and Collicott brown (cb/cb) change the shape of the granules and convert eumelanin to brown and dark brown, respectively. The color dilution of Eastern Pearl (pe/pe) and Mansfield Pearl (pm/pm) is caused by clumping of granules in specific manners. Hairs from animals expressing more than one mutant gene, such as Amber (b/b pe/pe bf/bf), show the color and distribution of granules expected from interactions of independent loci.

Orthotopic ovarian transplantation in young and aged CBA mice.

Reproductive and hormonal changes associated with CBA mice which were orthotopically transplanted with ovaries from young or aged CBA mice were studied. Reproductive decline was defined by the number of mice mating and the number of implantation sites and resorptions in pregnant mice. A high percentage of resorptions was observed in aged mice receiving ovaries from young mice. An increase in the number of resorptions and a decrease in the number of implantation sites was observed in young mice transplanted with aged ovaries. Concentrations of LH, FSH and Prl were analyzed by radioimmunoassay from plasma of pregnant and nonpregnant transplanted mice, ovariectomized and sham-operated controls. Young ovariectomized mice had elevated concentrations of LH and FSH when compared to sham-operated controls. No differences were noted between the aged ovariectomized mice although the gonadotrophin levels in these animals were higher than those in comparable young groups. The highest LH and lowest FSH concentrations were found in young to young transplanted mice. The Prl concentrations in transplanted mice did not vary between groups. These data suggest that the hypothalamic-hypophyseal complex is functioning adequately in all transplanted groups and age-related changes in the ovary and uterus are responsible for embryonic mortality.

Post-meiotic cell mediation of behavior in progeny of male rats treated with cyclophosphamide.

Transmission of the effects of paternal pre-fertilization exposure to a genotoxic drug being manifested in the F1 progeny is well established using the traditional rodent dominant lethal protocol [7]. More recently, the induction of genotoxic effects in the F1 progeny following chronic paternal exposure prior to fertilization has been described in rats using behavioral testing as an endpoint [1]. In our initial study, male F344 adult rats were treated chronically with 10 mg/kg cyclophosphamide (CP) or saline for 5 weeks (5 days of daily treatment and 2 days of rest). The present study describes the behavior of progeny whose fathers were treated with a single intraperitoneal injection of 10 mg/kg CP and mated at different times post-injection. This design showed that post-meiotic germ cells are the most sensitive to the effects of CP as seen by behavioral testing of the F1 progeny.

Active avoidance behavior in the F1 progeny of male rats exposed to cyclophosphamide prior to fertilization.

The acquisition and extinction of a one-way active avoidance task was studied in 30 day old F1 progeny of male rats previously exposed to either acute or chronic treatment with cyclophosphamide (CP) prior to breeding with normal females. Chronic treatment (10 mg/kg/day x 5 days x 5 weeks) was given to adult F344 males followed by subsequent breeding with normal females (CP-S). Separate groups of males were given a single CP injection (10 mg/kg) and breeding with normal females was done at 7-9, 14-16 and 28-30 days following the CP treatment. F1 progeny of males exposed to chronic CP or to a single CP treatment when bred 7-9 (females only) and 14-16 days post exposure (males and females) took significantly longer to reach the criterion for extinction. These progeny also responded significantly faster during extinction than progeny of the saline treated males. These findings support our earlier evidence of behavioral anomalies induced in the F1 progeny of male rats exposed to CP prior to breeding and that this effect reflects damage in post-meiotic germ cells.

SCE and UDS studies in a family with retinoblastoma: a case study.

The frequencies of both spontaneous and mitomycin C (MMC)-induced sister chromatid exchanges (SCE) were analyzed in mixed lymphocyte cultures from a kindred with retinoblastoma. Both the affected daughter and male proband, as well as two normal controls, were studied. No differences were observed in the spontaneous or in the MMC-induced SCE frequencies obtained from the peripheral lymphocytes of these patients compared to the normal controls. Unscheduled DNA synthesis (UDS) was observed in the lymphocytes treated with varying concentrations of both MMC and M-methyl-N-nitro-N-nitrosoguanidine (MNNG). Whereas no differences were observed in the rate of [3H]thymidine incorporation in the retinoblastoma-derived lymphocytes exposed to MMC when compared to the controls, differences were seen in the response to MNNG. Our data suggest that cells from these retinoblastoma patients respond like normal cells to damage induced by MMC, but that they are unable to repair damage induced by MNNG.

Mutagenicity studies of vinyl chloride.

Mutagenicity studies in both man and in test organisms clearly demonstrate positive mutagenic activity of vinyl chloride. In terms of the mutagenicity studies using a variety of in vitro procedures covering both eukaryotes and prokaryotes, positive effects were found. Cytogenetic in vivo studies in animals and in humans indicate not only somatic mutations, but also germinal effects with this chemical.

Etiology, role and detection of chromosomal aberrations in man.

Genetic aberrations play a major role in human disease. They are responsible for a number of birth defects and have been identified as an important cause of much prenatal mortality. Approximately one-half of all conceptuses, for example, have been estimated not to survive to term, and some die so early that they are not even detected by the mother. Not all genetic anomalies appear at birth, however, since a number may result postnatally from environmental agents that have caused single cell mutations (which might develop into a human tumor), and yet others may require a second mutational event and appear even later. Thus, the industrial environment poses special hazards, to both female and male workers, because of the risks of induction of cancer, as well as of impairment of reproductive ability. Industrial cytogenetic monitoring, as a form of preventive medicine, is now possible. This review discusses many of the causes and types of genetic damage and the current cytogenetic techniques, as well as their use in industrial monitoring.

Cyclophosphamide-induced spermatogenic effects detected in the F1 generation by behavioral testing.

Fischer 344 male rats were treated with cyclophosphamide (10 milligrams per kilogram of body weight) for 5 weeks and subsequently mated to females previously treated with saline or cyclophosphamide. The F1 progeny of the cyclophosphamide-treated males exhibited behavior deficits when compared to controls. These data could indicate a chemically induced genetic effect manifested by behavioral alterations.

A novel ATP-driven glucose transport system in Escherichia coli.

In Escherichia coli wild-type cells and in ATPase-deficient cells (unc mutants), glucose was found to be transported mainly by an ATP-driven system. The evidence is based on experiments involving interference at different sites of energy metabolism with the use of uncouplers, arsenate, and starved cells. Furthermore, addition of succinate to starved cells increased glucose uptake only in the wild-type cells, where ATP could be regenerated. Glucose transport was also ATP-dependent in cells deficient in methyl-beta-galactoside transport (a system that carries glucose specificity). It was found to be shock-sensitive in all strains tested. The NOVEL ATP-driven glucose transport is a high-affinity (Km 3-10 microM) and high-capacity (V 240-330 Mmol . min-1 . mg cell protein-1) uptake system.

Maternal age related pre- and post-implantation fetal mortality: a strain survey.

Pre and post-implantation mortality were examined as a function of maternal aging in six inbred mouse strains. These strains were chosen to evaluate the effects of altered immunity (A/J and NZB/J) and premature reproductive aging (CBA). The decline in litter size observed with maternal aging does not appear to be the result of a decrease in the number of ova produced. The frequency of both pre- and post-implantation mortality increases with maternal age in all strains examined. Although the highest levels of pre- and post-implantation mortality were found in the NZB/J strain, which features altered immune responses, results from the A/J females, which also display immune dysfunction were at the other end of the spectrum. Thus, no consistant relationship was seen between altered immune function and fetal mortality. The CBA strain which is characterized by premature reproductive decline and marked maternal age-related fetal aneuploidy also demonstrated high levels of pre- and post-implantation mortality, even in the young maternal age range.

Genetic Map of Bacteriophage phiX174.

Bacteriophage phiX174 temperature-sensitive and nonsense mutations in eight cistrons were mapped by using two-, three-, and four-factor genetic crosses. The genetic map is circular with a total length of 24 x 10(-4)wt recombinants per progeny phage. The cistron order is D-E-F-G-H-A-B-C. High negative interference is seen, consistent with a small closed circular deoxyribonucleic acid molecule as a genome.