Reduced influence of penile disability on the mating capacity of male staggerer mice]

Most staggerer mutant mice do not mate spontaneously. This deficiency may be attributed to a penile disability (during erection, the penis in extension is directed backward). The main characteristics of this phenomenon and its involvement in the reproduction of the staggerer mutant have been considered in our study. Seventy-four percent (n = 66) of staggerer males presented this temporary abnormality at least once. It appeared when the males were 84 +/- 37-d old (M +/- SD). In most animals the penile abnormality was labile and did not exceed 1 wk duration in 48% (n = 32) of the males. Three males mated in spite of presenting this abnormal erection. Moreover, 25% of males (n = 23) did not present this disability; nevertheless, most of them (91%) still did not reproduce. Other mechanisms are certainly responsible for the inefficient mating. In any case, the influence of penile disability on this deficiency appears to be weak.     

Divalent cation changes in cerebellar Purkinje cells after climbing fiber deafferentation.

A secondary ion mass spectrometry (SIMS) microscope was used to detect intracellular stores of calcium, magnesium, sodium and potassium. Measurements were made in semithin sections of fixed tissues of normal and climbing fiber deafferented cerebellar cortex. Quantitative data were collected from 150 microns diameter image fields in the molecular and granule layers. The results indicate smaller quantities of both calcium and magnesium in the deafferented cerebellar cortex compared to the normals, the molecular as well as the granule layer being affected. The results are discussed in terms of the usefulness and limitations of the SIMS microscope for histological preparations.     

Genomic organization and nucleotide sequence of a long mosaic repetitive DNA in the mouse genome

A long mosaic repetitive sequence (LMRS) was isolated from a mouse liver genome library using a mouse repetitive DNA as a probe. LMRS exhibits the following features: (1) it is almost 15 kb in length; (2) it is partly organized in tandem array and frequently interrupted by other repeated sequences; and (3) it is located predominantly on the A3 band of the mouse X Chromosome (Chr). One fragment of LMRS (B6) shows restriction fragment length polymorphism (RFLP) between different mouse strains, and is thus potentially useful for mapping studies. The nucleotide sequence confirms a mosaic organization of LMRS which includes three repeats in the 5 part, showing similarity with the 5 end of L1Md-A2, and seven long A+T rich segments in the central part of the element. Our findings suggest that this sequence may have arisen from the duplication of an ancestral motif and has expanded by successive waves of amplification and invasion by foreign sequences.The nucleotide sequence data reported in this paper have been submitted to EMBL and have been assigned the accession number X55036.     

Microvascular transposition of the arterial supply to the testis of the boar.

The origin of the arterial supply to a testis was changed in 7 boars with a microsurgical technique. A. testicularis was connected, end to side, to a branch of the femoral artery. The capillary blood flow was unchanged, indicating viable transplants. The temperature difference between testis and body disappeared after the surgery, indicating an interruption of the heat transfer in the pampiniform plexus. The lower values of the histological score and the possibly lower peripheral plasma concentration of testosterone after the arterial by-pass may indicate a physiological importance of the counter current exchange.     

The influence of fish oil supplementation on plasma lipoproteins and arterial lipids in vervet monkeys with established atherosclerosis.

There is controversy about whether supplementing diets with marine fish oil can regress, promote or prevent atherosclerosis. Therefore the effects of an Atlantic pilchard oil (FO) supplement and dietary change were measured in a proven atherosclerosis model. Vervet or African Green monkeys were fed an atherogenic diet (AD) for long enough to ensure progression before treatments started. Matched groups were then treated for 20 months, either by adding FO to the AD (AD/FO), or by changing to a therapeutic diet with FO (TD/FO). Control treatments consisted of supplementing with sunflower oil (SO) instead of FO, so that treatments were AD/SO and TD/SO. The same total polyunsaturates were supplied by the FO and SO and the dose of FO was realistic (2.5% of total energy). A reference group (R) received the TD with no oil supplements. Supplementing with FO did not change the concentrations of total, low or high density lipoprotein cholesterol in plasma. After The AD/FO the intimas of aortas contained more total (p < or = 0.001), free (p < or = 0.05) and esterified (p < or = 0.05) cholesterol, total phospholipid (p < or = 0.01) and sphingomyelin (p < or = 0.05) than after the AD/SO. After FO supplementation eicosapentaenoic acid was significantly higher and arachidonic acid significantly lower in the plasma and aorta intima phosphatidylcholine. None of these changes was anti-atherogenic in terms of atherosclerosis measured in the same individuals (1). Nor did FO increase the efficacy of the TD.