Codominant expression of genes coding for different sets of inducible salivary polypeptides associated with parotid hypertrophy in two inbred mouse strains

Abstract

Experimental mouse parotid hypertrophy has been associated with the expression of a number of isoproterenol-induced salivary proline-rich polypeptides (IISPs). Mouse salivary proline-rich proteins (PRPs) have been mapped both to chromosomes 6 and 8. Recently, mice of two inbred strains (A/Snell and A. Swiss) have been found to differ drastically in the IISPs. In this study, mice of both strains were used for cross-breeding experiments addressed to define the pattern of inheritance of the IISP phenotype and to establish whether the IISPs are coded on a single or on several chromosomes. The IISP phenotype of individual mice was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of whole saliva collected after three daily stimulations by isoproterenol. Parental A/Snell and A. Swiss mice were homogeneous for distinctive strain-associated IISP-patterns. First filial generation (F1) mice obtained from the cross of A/Snell with A. Swiss mice expressed with no exception both the A/Snell and A. Swiss IISPs (coexpression). In the second filial generation (F2) both parental IISP phenotypes reappeared together with a majority of mice expressing the F1-hybrid phenotype (1:2:1 ratio). Backcrosses of F1 x A/Snell and F1 x A. Swiss produced offsprings displaying the F1 and the corresponding parental phenotypes with a 1:1 ratio. No recombinants were observed among F2 mice or among mice resulting from backcrosses. Thus, genes coding for the IISPs that are expressed differentially in both mouse strains are located on the same chromosome, probably at the same locus (alleles) or at quite closely linked loci (nonalleles).

Induction of salivary polypeptides associated with parotid hypertrophy by gallotannins administered topically into the mouse mouth

“…Another main characteristic of the present study is that the expression of IISP polypeptides was assessed by analyzing saliva rather than salivary glands [Muenzer et al, 1979a; Mehansho et al, 1983, 1985, 1987; López Solís et al, 1993]. Under this approach, early expression (within 2–3 days) of a specific group of IISP polypeptides was readily defined on the basis that the polypeptide background of murine saliva is certainly much lower than the polypeptide background observed in the electrophoretic fractionation of salivary gland homogenates [López Solís et al, 2003b; López Solís and Kemmerling, 2005].…”

“…That cellular and glandular response has been associated with the induction, accumulation, and secretion of a group of salivary proline‐rich proteins [Muenzer et al, 1979a,b; López Solís et al, 1987, 1989]. In mouse, the assessment of isoproterenol‐induced salivary proline‐rich polypeptides (IISPs) in saliva, rather than in salivary glands, has allowed a much earlier recognition of the trophic response of parotid acinar cells [López Solís et al, 1989, 2003a,b; López Solís and Kemmerling, 2005]. In effect, IISP polypeptides can be detected in saliva as early as 24 h after a single intraperitoneal administration of the powerful sialotrophic β‐adrenoceptor agonist isoproterenol whereas protocols to induce salivary gland hypertrophy are currently based on recurrent administrations of the same agonist for several days or weeks [Muenzer et al, 1979a,b; Humphreys‐Beher et al, 1987a; Ann et al, 1987; Li et al, 1997].…”

Aversive Effect of Tannic Acid on Drinking Behavior in Mice of an Inbred Strain: Potential Animal Model for Assessing Astringency

“…Mice of the A/Snell strain, which have been inbred for over 50 years in our laboratory, were used in most of the experiments. 25 Tannic Acid (TA). Tannic acid from nut galls of Quercus infectoria (Sigma Chemical Co., St. Louis, MO), a yellowish-brown powder comprising 7% water, 0.3% ash, <0.004% metal impurities (as Pb), and <3 ppm arsenic, was further characterized by reversed-phase HPLC-DAD and spectral analysis.…”

“…Saliva from A/Snell mice was collected after pilocarpine stimulation, as described elsewhere. 25 Aliquots of saliva were mixed in Eppendorf tubes with series of growing concentrations of TA solutions (water served as control) and incubated for 5 min at room temperature. Microliter aliquots of the salivaÀTA mixtures were placed on a cellulose membrane, allowed to dry spontaneously, fixed in 5% trichloroacetic acid, washed in 80% ethanol, stained for protein in 0.25% Coomassie blue for 20 min, and washed exhaustively with 7% acetic acid.…”