Developmental Patterns of Catechol-O-Methyltransferase in Genetically Different Rat Strains: Enzymatic and Immunochemical Studies

Abstract: Catechol- O -methyltransferase (COMT) activity in the liver and kidneys of adult Fischer-344 (F-344) rats is only half of that in the same organs of Wistar-Furth (W-F) rats. The trait of low COMT activity in these animals is inherited in an autosomal recessive fashion. A comprehensive study of patterns of change in COMT activity during growth and development was performed to determine whether "temporal gene" effects might play a role in the inherited differences in enzyme activity present in adult animals. The COMT activity expressed per mg protein in liver and kidneys of newborn F-344 rats is only 50–60% of that in the same organs of W-F animals. The liver and the kidneys of newborn rats of both strains have COMT activity an order of magnitude higher than those in brain, heart, or blood. In addition, in both strains there are much larger increases in liver and kidney COMT activities during growth and development (5–10 fold) than in blood, brain, or heart (one- to twofold). Immunotitration with antibodies against rat COMT demonstrates that differences in immunoreactive COMT parallel differences in COMT activity, both between strains and within strains during growth and development. However, when the temporal patterns of change in enzyme activities in the liver and the kidneys of the two strains of rat are compared at multiple times during growth and development, no differences in the patterns are present. These results make it unlikely that temporal gene effects can explain the inherited differences in COMT activity in liver and kidneys of F-344 and W-F rats.     

Salt marsh harvest mouse demography and habitat use in the Suisun Marsh,California

We undertook a 2-year (2002–2004) mark–recapture study to investigate demographic performance and habitat use of salt marsh harvest mice (Reithrodontomys raviventris halicoetes) in the Suisun Marsh. We examined the effects of different wetland types and microhabitats on 3 demographic variables: density, reproductive potential, and persistence. Our results indicate that microhabitats dominated by mixed vegetation or pickleweed (Salicornia spp.) supported similar salt marsh harvest mouse densities, reproductive potential, and persistence throughout much of the year, whereas few salt marsh harvest mice inhabited upland grass-dominated microhabitats. We found that densities were higher in diked wetlands, whereas post-winter persistence was higher in tidal wetlands, and reproductive potential did not differ statistically between wetland types. Our results emphasize the importance of mixed vegetation for providing adequate salt marsh harvest mouse habitat and suggest that, despite their physiognomic and hydrological differences, both diked and tidal wetlands support salt marsh harvest mouse populations by promoting different demographic attributes. We recommend that habitat management, restoration, and enhancement efforts include areas containing mixed vegetation in addition to pickleweed in both diked and tidal wetlands. © 2011 The Wildlife Society.     

Animal models for respiratory chain disease

Elucidation of the pathogenesis in respiratory chain diseases is of great importance for developing specific treatments. The limitations inherent to the use of patient material make studies of human tissues often difficult and the mouse has therefore emerged as a suitable model organism for studies of respiratory chain diseases. In this review, we present an overview of the field and discuss in depth a few examples of animal models reproducing pathology of human disease with primary and secondary respiratory chain involvement.     

Rapid atraumatic sex identification of developmental day 14–16 mice

Abstract

Embryonic mice have been used widely to study organ development. Days 14–16 are critical for sex organ development and differentiation in mice. Current methods for sex identification are limited. Even the simplest polymerase chain reaction method may injure the embryo. We determined that morphologic analysis of embryonic mammary anlagen could be used for rapid atraumatic sex identification of day 14–16 mice. The accuracy of our method was verified by molecular and anatomical approaches.     

Deanol Affects Choline Metabolism in Peripheral Tissues of Mice

Abstract: The enzymatic hydrolysis of UDP-galactose in rat and calf brain was studied. The hydrolysis occurs in two steps: The first is the conversion of UDP-galactose to galactose-1-phosphate catalyzed by nucleotide pyrophosphatase (EC 3.6.1.9), and the second is the conversion of the latter to free galactose by alkaline phosphatase (EC 3.1.3.1). The overall conversion has a pH optimum of 9.0, but there is considerable activity at pH 7.4, which is the optimum for UDP-galactose:ceramide galactosyltransferase in the synthesis of cerebrosides. Preparations from cytosol from calf brain cerebellum or stem that were enriched in UDP-galactose hydrolytic activity inhibit cerebroside synthesis under conditions optimal for the synthesis. Microsome-rich and nuclear debris fractions contain the highest apparent specific activity among the subcellular fractions studied. Hydrolysis of UDP-galactose occurs in all areas of brain, brainstem having the highest activity. The apparent specific activity in jimpy mouse brain homogenate is nearly twice as high as in the control brain homogenate.     

Behavioural discrimination among chromosomal races of the house mouse (Mus musculus domesticus)

This work is concerned with the extent of behavioural discrimination between three chromosomal races of the house mouse (the standard 40-chromosome race and a 32- and 36-chromosome races) found in the vicinity of a hybrid zone in northern Scotland. Mice were investigated for several elements of their social behaviour. Within-population dyadic encounters did not show consistent behavioural differences attributable to karyotype among five populations (two standard race, two 36-chromosome race, one 32-chromosome race). Between-population dyadic encounters revealed significant differences between three populations. The standard population examined appeared to be the most “open” to foreigners, the 32-chromosome population the most “closed” while the 36-chromosome mice displayed an intermediate response. Differences in behaviour displayed during between-population as compared to within-population dyadic encounters revealed the occurrence of behavioural discrimination between populations. The implication of these results on the dynamics of the hybrid zone are discussed.     

A gene (Bmn) controllingβ-mannosidase activity in the mouse is located in the distal part of chromosome 3

A gene (Bmn) with a major effect on -mannosidase activity in kidney and liver of the house mouse was revealed by assay with the synthetic substratep-nitrophenyl--d-mannoside. Activity is low in DBA/2J and CSB mice and high in C57BL/6J mice. By the use of the BXD series of recombinant inbred strains and by crosses between C57BL and CSB, it was possible to map the gene to the distal part of chromosome 3 by demonstration of linkage to a gene for cadmium resistance,cdm, as well as to theAdh-3 locus.This work was supported by Swedish Natural Science Research Council Project B-BU 2992-108.     

Purification and characterization of the Danish (skive) variant of mouse liver alcohol dehydrogenase

The partially inbred Danish (Skive) strain of mice exhibits a form of liver alcohol dehydrogenase (ADH) which differs in electrophoretic mobility from that of all other inbred mouse strains thus far examined, e.g., C57BL/10, DBA/2J, and BALB/c. In order to compare the catalytic and molecular properties of the variant and normal enzyme forms, they were purified to homogeneity by ion-exchange and affinity chromatography. Tryptic peptides of reduced and carboxymethylated subunits of the normal and variant ADH forms were mapped by thin-layer two-dimensional electrophoresis and chromatography and by reversed-phase high-performance liquid chromatography. A unique nonapeptide in the Danish mouse liver ADH which did not appear in enzymes from C57BL/10, DBA/2J, or BALB/c mice was identified by both methods. Amino acid sequencing of this peptide revealed that the Arg residue at position 124, as predicted from the cDNA sequence of ADH in DBA/2J mice, has been replaced by Leu in the Danish variant. The Leu for Arg substitution in the variant form appears to account for its decreased cathodic mobility with electrophoresis in starch gels at pH 7.2. The K _m and V _max of ADH from the Danish strain for three primary alcohols and three aldehydes were similar in value to those of ADH from the C57BL/10, DBA/2J, and BALB/c strains. Based on the X-ray structure of horse liver ADH, position 124 is on the solvent-exposed surface of the catalytic domain. The finding that the kinetic constants are similar for the normal and variant forms is consistent with the observation that this residue is not in the active site and that there is no known role for it in the ADH catalytic mechanism.This work was supported by NIAAA Grant AA-04307.