14 research outputs found
Ecophysiological responses of the seminal vesicle of Libyan jird (Meriones libycus) to the Saharan conditions: histological, morphometric and immunohistochemical analysis
The Libyan jird (Meriones libycus) is a
nocturnal Saharan Rodent submitted to a seasonal cycle
of reproduction characterized by a short active period
during spring and beginning of summer, and a long
phase of sexual quiescence from the end of summer until
the end of winter. During this cycle, the male
reproductive organs, and more particularly seminal
vesicles, experience some important weight and
histological variations.
During the breeding period, the wall of each seminal
vesicle describes several folds radiating inside a broad
lumen filled with a very abundant secretion. The wall is
limited with high columnar epithelial cells surrounded
with extracellular matrix restricted to some connnective
fibres located in the narrow axis of the folds and in the
chorion. The fibro-muscular wall is narrow.
During sexual quiescence, the seminal vesicles
regress. No secretion has been observed inside the
lumen. The wall of lumen is now surrounded with a
single cubic epithelium. The persistent epithelial folds
possess a wide axis. The hypertrophied extracellular
matrix is constituted with a very tight and abundant
connective tissue. The fibro-muscular wall is thick.
A quantitative morphometric study was performed
with automatic image analysis that allowed to quantify The numerical values obtained agree with the
histological images observed, the epithelial surface area
(ÎĽm2) is high in spring and significantly weak during
sexual quiescence. The stroma and the fibro-muscular
wall occupy an important surface area on sections during
the resting period compared with the value collected
during the active phase. The study of the apoptosis by
TUNEL method revealed the presence of a considerable
number of apoptotic nuclei in the epithelial fraction
during the resting phase. The indirect immunohistochemical
method allowed us to visualize the
presence of types I and III collagen in the extracellular
matrix, weak during the period of breeding, intense and
diffuse during the resting season like in castrated
Meriones libycus
p21WAF-1 reorganizes the nucleus in tumor suppression
International audienceInterphasic nuclear organization has a key function in genome biology. We demonstrate that p21WAF-1, by influencing gene expression and inducing chromosomal repositioning in tumor suppression, plays a major role as a nuclear organizer. Transfection of U937 tumor cells with p21WAF-1 resulted in expression of the HUMSIAH (human seven in absentia homologue), Rb, and Rbr-2 genes and strong suppression of the malignant phenotype. p21(WAF-1) drastically modified the compartmentalization of the nuclear genome. DNase I genome exposure and fluorescence in situ hybridization show, respectively, a displacement of the sensitive sites to the periphery of the nucleus and repositioning of chromosomes 13, 16, 17, and 21. These findings, addressing nuclear architecture modulations, provide potentially significant perspectives for the understanding of tumor suppression