Clearance of desialylated mouse alpha-macroglobulin and murinoglobulin in the mouse.

Mouse alpha-macroglobulin and murinoglobulin were labeled with 125I and utilized for plasma clearance studies performed with mice. Desialylated murinoglobulin was rapidly cleared from the circulation with a half-life of about 5 min. On the other hand, desialylated alpha-macroglobulin showed a biphasic curve: about half was cleared at a rate similar to that of the intact molecule while the remaining half had a shorter half-life of about 20 min which was prolonged by a simultaneous injection of a 200-fold excess of unlabeled asialoorosomucoid. Virtually no cross competition was observed between these asialoglobulins and formaldehyde-treated bovine serum albumin or trypsin-bound alpha-macroglobulin. These results suggest that the intravascular elimination of desialylated alpha-macroglobulin and murinoglobulin is independent of the clearance systems responsible for formaldehyde-modified proteins or proteinase-bound alpha-macroglobulins, and that the structure or spatial arrangement, or both, of oligosaccharide units of alpha-macroglobulin is somewhat different from that of murinoglobulin, resulting in a difference of avidity of interaction with the asialoglycoprotein receptor. The desialylated alpha-macroglobulin and murinoglobulin accumulated principally in the liver.     

Microdissection of the mouse egg

A rapid and efficient method for microdissection of the mouse egg is described. The dissection is carried out in hanging drops of medium surrounded by heavy liquid paraffin oil at room temperature. Eggs are first deformed into a cylindrical shape and then dissected at a predetermined site with a glass needle on a Leitz micromanipulator. The survival rate of the dissected fragments is 75–90% and between 20 and 30 eggs can be dissected in an hour. Development of the dissected eggs is at least as good as that described after other types of manipulation. Cytoplasts and karyoplasts of various sizes can be prepared, as well as gynogenetic and androgenetic eggs with different amounts of cytoplasm. This procedure may help to examine nuclear-cytoplasmic interactions in eggs reconstituted from a variety of fragments.     

Biopsy of the mouse prostate

Many transgenic and knockout mouse models of prostate cancer have become available over the past decade. In this paper we describe a simple biopsy technique of the murine prostate. This technique allows sequential follow-up of the prostate in an individual mouse. Its use could also reduce the number of mice used in studies of the prostate gland.     

Growth of the laboratory mouse

Summary Body weights and tail lengths were observed every 3 days from birth to 60 days of age and every 6 days from 60 to 96 days in four lines of mice: C57BL/6J, an inbred; J, a synthetic outbred; GR, Goodale large body size line; and FR, Falconer large body size line. Mean 96-day body weights for lines C57BL, J, GR and FR were 25.4, 29.7, 48.8 and 49.1 gm for males, and 19.9, 23.8, 38.5 and 38.2 gm for females, respectively. Lines GR and FR gave identical body weights at all ages studied. Both of these lines had previously plateaued in response to selection for large body size. The variability in body weight was smallest for lines C57BL and J, intermediate for FR and highest for GR. The pattern of variance over time was very similar in all lines and both sexes, showing a minimum at birth and a maximum at age of inflection. Growth in tail length of the four lines showed similar between line differences except that length in GR was greater than in FR. Age at vaginal opening in females coincided closely with age of inflection in body weight growth. Age at point of inflection did not differ between lines but appeared to occur somewhat earlier in females than in males.

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Zusammenfassung Vier Linien von Laboratoriumsmäusen: der Inzuchtstamm C57BL/6J, der Kreuzungsstamm J, eine vonGoodale auf Körpergröße selektierte Linie GR und die vonFalconer auf Körpergröße ausgelesene Linie FR, wurden auf Körpergewicht und Schwanzlänge untersucht, und zwar von der Geburt bis zum 60. Lebenstage in 3 tägigem Abstand, von 60. bis 96. Lebenstage in 6tägigem Abstand. Am 96. Lebenstag betrugen die Durchschnittsgewichte für die 4 Linien 25,4; 29,7; 48,8 und 49,1 g für Männchen und 19,9; 23,8; 38,5 und 38,2 g für Weibchen. Die Linien GR und FR zeigten in allen untersuchten Altersstadien gleiche Gewichte. Beide waren durch vorangegangene Selektion auf Körpergröße weitgehend angeglichen. Die Variabilität des Gewichtes erwies sich bei den Linien C57BL und J als am geringsten, als intermediär bei FR und als am höchsten bei GR. Das Varianzmuster war bei allen Linien und für beide Geschlechter innerhalb des Untersuchungszeitraumes sehr ähnlich, mit einem Minimum bei der Geburt und einem Maximum am Ende der Wachstumsperiode (Inflexion). Das Schwanzwachstum zeigte die Linienunterschiede in gleicher Weise, lediglich der Stamm GR hatte eine größere Länge als FR. Das Öffnen der Vagina fällt zeitlich mit der Inflexion der weiblichen Tiere zusammen. Der Zeitpunkt der Inflexion differiert nicht zwischen den untersuchten Linien, scheint jedoch bei den weiblichen Tieren etwas früher als bei den männlichen zu liegen.

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Department of Animal Science.     

Immunological mutants of the mouse

Mutations at more than 30 loci in mice have been shown to cause deleterious effects on the immune system. Immunologic defects caused by certain of these mutations are determined at the level of hematopoietic progenitor cells or at the level of hematopoietic cell-stromal cell interactions. The immunological mutants described in this paper serve as experimental tools with which to increase our understanding of the development and regulation of the mammalian immune system.     

The karyotype of the mouse

A denaturating and renaturating technique, applied to mouse chromosomes, makes visible characteristic banding patterns by which all elements of the karyotype can be individually distinguished. The Y chromosome as a whole appears darkly stained. The X chromosome comprises 6.33% of the homogametic haploid set. The banding pattern of the chromosomes is compared with that obtained by aid of the quinacrine dihydrochloride fluorescence technique. After its use a banding pattern results which is similar to, but less distinct than, that found after the renaturation procedure.     

Baculovirus expression of mouse lactoferrin receptor and tissue distribution in the mouse

Lactoferrin (Lf) has been shown to have a role in the immune system and in early development of the mouse embryo. A specific receptor for Lf has been suggested to mediate the functions of Lf. We have recently identified a Lf receptor (LfR) in human fetal small intestine. We therefore hypothesized that the mouse homologue of this protein functions as a LfR. We expressed mouse Lf (MLf) and the mouse homologue (MLfR) in a baculovirus-insect cell system. The recombinant MLfR (rMLfR) was purified by immobilized recombinant MLf (rMLf) affinity chromatography, demonstrating an interaction between rMLf and the rMLfR. RT-PCR revealed that MLfR was expressed in various tissues and during embryonic development. Immunohistochemical analysis revealed that the MLfR was localized in various tissues including small intestinal epithelium, stomach, kidney, ovary, and various regions of brain. In summary, the MLfR functions as a receptor for MLf, is expressed and localized in various tissues, and may be involved in the indispensable function of MLf during early embryonic development.     

Harvesting the mouse genome

The sequencing of the black 6 mouse (strain C57Bl/6) has reached an important juncture. The BAC fingerprint map is almost complete, the BACs have been endsequenced and a seven-fold coverage whole-genome shotgun has been assembled. Now the BAC-by-BAC sequencing phase is under way and in-depth comparative analysis can be carried out on regions that have been the subject of targeted sequencing. This paper reviews the progress so far and looks forward to the promises of finished sequence.     

Immunization of the nude mouse against mouse hepatitis virus through the transfer of sensitized lymphocytes]

Nude (nu/nu) mice failed to resist to virulent mouse hepatitis virus (MHV) infection after vaccination with inactivated virus. Resistance was induced in nu/nu mice by the transfer of spleen cells from heterozygous haired (nu/ +) mice concomitantly with the vaccination, and the effect was more remarkable with spleen cells from immunized nu/ + mice. Antibody was demonstrable in nu/nu mice having received nu/ + cells and survived challenge infection.     

Binding of mouse choriomammotropin to prolactin receptors in the mouse mammary gland.

The interaction between mouse choriomammotropin and mouse mammary glands was examined by radioreceptor assays using ovine prolactin (NIH-P-S9) iodinated by lactoperoxidase as a tracer. Mouse pituitary extracts and placental extracts were subjected to 10% acrylamide gel electrophoresis. Gels were cut into 2-mm segments after electrophoresis, and stored in 1 ml 0.05 M phosphate buffer (pH 7.4) containing 0.05 M NaCl overnight for elution. Lactating mammary tissues from D strain mice were incubated for 120 min in 1 ml Medium 199 containing 6 ng of 125I-prolactin and 0.1 ml of each eluate. Pituitary extracts displaced 125I-prolactin only at the position which coincides with the prolactin band. Displacement was observed at two positions of the gel when placental extracts were used. Relative mobilities (Rm) were 0.21 and 0.71, respectively. The slowly migrating component of choriomammotropin inhibited the binding of 125-I-prolactin more strongly that the rapidly migrating one. Neither of them was identified as a distinct band in stained gels. The molecular weight of ovine prolactin, mouse pituitary prolactin and the slowly migrating component of mouse choriomammotropin was estimated to be 23000 using disc electrophoresis but the ion charges of these hormones were considerably different.     

Metaphase distribution of the mouse chromosomes

The reports in the literature agree that non-random distribution patterns do occur for the acrocentric human chromosomes in metaphase cell preparations, and it has been suggested that it is a property of acrocentric chromosomes that promotes these non-random patterns. Under this hypothesis, the telocentric chromosomes of the mouse should not show deviation from a random distribution within a cell. This possibility is examined using our data for several types of mouse cells and there is no indication of any significant clustering. However, certain translocations do appear to lead to significant non-random patterns. Alternate hypotheses are presented as possible explanations for this occurrence.This project was supported by: California State Department of Mental Hygiene; Mental Retardation Program, NPI, UCLA; MCH-927, Interdisciplinary Training in Mental Retardation; HD-04612, Mental Retardation Research Center, UCLA; HD-00345, Research Training in Mental Retardation; HD-05615, Developmental Biology in Mental Retardation, and Cancer Research Funds of the University of California.