This Article Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints, Permissions and Rights Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by ROLLINS, W. C. Articles by COLE, H. H. Search for Related Content PubMed PubMed Citation Articles by ROLLINS, W. C. Articles by COLE, H. H.

THE RELATIVE IMPORTANCE OF GENETIC AND ENVIRONMENTAL FACTORS IN DETERMINING THE PRECISION OF GONADOTROPHIN ASSAY

From the Division of Animal Husbandry, University of California at Davis Davis

Abstract

AT PRESENT, the assay of gonadotrophin must be based on some biological response. According to Bliss (1950), "The inherent precision of the assay may be increased principally by reducing the standard deviations about the dosage response line and less frequently by increasing the slope without change in the standard deviation". This paper is concerned with determining to what extent individual variation can be decreased by the use of highly inbred animals as compared to random bred (non-inbred) animals. Furthermore, the influence of certain environmental factors on the standard deviation has been studied.

MATERIALS AND METHODS

Immature female rats stemming from the Long-Evans strain were used; one strain was random bred and the other was the result of 15 or more generations of close inbreeding. The first 3 generations were the result of sire-daughter matings whereas later generations resulted from brother-sister matings. All of the inbred animals stemmed from a single brother-sister mating in the eighth generation of inbreeding.1 A test for isogeneity of the inbred animals will be described later.

Footnotes

¹ Calculating Wright’s (1922) Coefficients of Inbreeding and Relationship it was found that the degree of inbreeding was greater than 97 per cent, the relationship within litters was greater than 99 per cent, and the relationship between litter was greater that 94 per cent. The theoretical implication of the high values of these coefficients of inbreeding and relationship is that the genetic variance had been essentially removed from this inbred colony of rats.

² We wish to express our appreciation to Dr. Erwin Schwenk of Schering Corporation, Bloomfield, N. J. for supplying extract 35-D testing 1000 I.U. per mg.

Received April 22, 1952.

This article has been cited by other articles:

				J. L. Spearow and M. Barkley Genetic Control of Hormone-Induced Ovulation Rate in Mice Biol Reprod, October 1, 1999; 61(4): 851 - 856. [Abstract] [Full Text]