Fish ponds on farms

Johnson, Robert S.; Stapleton, Mortimer Freeman

doi:10.5962/bhl.title.36140

Cited by 48 publications

(77 citation statements)

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“…The question has been raised (10) as to whether the figures given for our historical control, which were also cited in an earlier paper on ENU results (1), might have included some preexisting mutants. In response, it can be pointed out that, not only in the historical control, but in all our past and current experiments with the specific-locus method, the number of offspring raised from each wild-type parent is more than adequate to determine that this parent is not heterozygous at any ofthe specific loci and, therefore, that it is not carrying a preexisting mutation at these loci.…”

Section: Resultsmentioning

confidence: 99%

Dose--response curve for ethylnitrosourea-induced specific-locus mutations in mouse spermatogonia.

Russell¹,

Hunsicker²,

Raymer³

et al. 1982

Proc. Natl. Acad. Sci. U.S.A.

112

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The extreme mutagenic effectiveness ofN-ethyl-N-nitrosourea in the mouse has permitted the accumulation of the most extensive dose-response data yet obtained for chemical induction of specific-locus mutations in spermatogonia. In the lower portion of the curve, below a dose of 100 mg/kg, the data fall statistically significantly below a maximum likelihood fit to a straight line. Independent evidence indicates that, over this dose range, ethylnitrosourea reaches the testis in amounts directly proportional to the injected dose. It is concluded that, despite the mutagenic effectiveness of ethylnitrosourea, the spermatogonia are apparently capable of repairing at least a major part of the mutational damage when the repair process is not swamped by a high dose. This finding is important both in basic studies on the mutagenic action of chemicals in mammals and in risk estimation.In 1979, it was shown (1) with the specific-locus method that N-ethyl-N-nitrosourea (ENU) is, by more than an order ofmagnitude, a more effective mutagen in mouse spermatogonia than any other compound tested. It was pointed out that ENU could, therefore, serve as a model chemical in exploring, with relative ease, the various factors-such as dose, dose fractionation, sex, and cell stage-that might affect mutagenic action. Preliminary findings on the effects of these and other factors have been reported (2-7). A more detailed dose-response curve than that obtained for any other compound tested for transmitted mutations in the mouse is now available and is presented here.MATERIALS AND METHODS ENU (purchased from Bio-Clinical Laboratories, Bohemia, NY) was dissolved in phosphate buffer (8) adjusted to pH 6. The dose injected intraperitoneally was matched to the body weight of the animal by adjusting the volume of solution injected, which approximated 1 ml for all doses. Wild-type (101 x C3H)F1 male mice 11.5-14.5 wk old were injected with a single dose. The experiment was done in two series, the first with doses of 100, 150, 200, and 250 mg/kg, and the second, 11 wk later, with doses of 25, 50, 75, and 100 mg/kg. The same crystalline batch of ENU, kept in a dessicator under refrigeration, was used throughout but, to check for deterioration of the chemical or other change in the conditions, the 100-mg/kg dose was included in both series. All injections were completed within 2 hr after the chemical was dissolved. The injected males were mated to females of our standard specific-locus test strain (T), which is homozygous for seven marker genes (9). Each male was mated to a group of either two or four females and moved to a new group of females each week. After each 7-wk period, the males were rotated back to the original group offemales to start the cycle over again. All the offspring reported here came from conceptions occurring more than 7 wk after injection, thus ensuring that they were derived from cells that had been exposed to the chemical in spermatogonial stem-cell stage. The offspring were scored for mutations at the seven loci. RES...

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Section: Resultsmentioning

confidence: 99%

Dose--response curve for ethylnitrosourea-induced specific-locus mutations in mouse spermatogonia.

Russell¹,

Hunsicker²,

Raymer³

et al. 1982

Proc. Natl. Acad. Sci. U.S.A.

112

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“…To date, 40 induced and 9 spontaneous mutations have been found, and 45 of the total mutations have been compared with the available electrophoretic markers found in the common inbred strains (7). None of the 45 characterized mutations involves a switch to an alternative form characteristic of any alleles found among inbreds, in contrast to the prediction by Fitch and Atchley (1).…”

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confidence: 96%

“…Approximately one-half of the induced and spontaneous mutations are nulls (7). Null mutations are most efficiently distinguished at loci for which allelic differences exist in the two parental strains.…”

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confidence: 99%

“…Two categories of loci are represented in the electrophoretic analysis (7); loci that are homozygous for the same apparent allelic form in both strains and loci that show electrophoretic differences between the strains. In the former category are Pgm-2, Pgd, Pep-7, Ldh-i, Ldh-2, Es-2, Mpi, Trf, Pep-2, Npi-i, Sod-i, Pep-i, and Gpd-X; and in the latter, Idh-1, Pep-3, Car-2, Gpd-i, Pgm-i, Ggc, Hba, Hbb, Gpi-i, Es-i, Mod-i, Pgm-3, Sep-i, Acy-i, Es-3, and Pre-l.…”

mentioning

confidence: 99%

“…The most recent list of mouse loci (4) for the direct measurement of mutation rates in strains C57BL/6J and DBA/2J (7). In analysis for mutations, mice of the different strains are mated, offspring obtained, tissues removed surgically, and electrophoresis performed on the tissue homogenates.…”

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confidence: 99%

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Rapid Mutations in Mice?

JOHNSON¹,

AQUADRO²,

SKOW³

et al. 1985

Science

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Personality profiles of the morbidly obese

1989

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Personality characteristics of 150 morbidly obese patients (100 pounds or more over ideal weight) were investigated. The patients were given the Minnesota Multiphasic Personality Inventory (MMPI) and a new, self‐report personality disorder inventory. The study attempted to determine whether particular personality variables could predict success or failure at weight loss six months post‐surgery. Multivariate analyses of variance revealed no significant differences on any of the personality variables when the patients were divided into “good,” “fair,” and “poor” success categories. Rank order MMPI scale profiles and personality disorder profiles are presented and implications discussed.

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Fish ponds on farms

Cited by 48 publications

References 0 publications

Dose--response curve for ethylnitrosourea-induced specific-locus mutations in mouse spermatogonia.

Dose--response curve for ethylnitrosourea-induced specific-locus mutations in mouse spermatogonia.

Rapid Mutations in Mice?

Personality profiles of the morbidly obese

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