Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 May 21;10(5):e0126848.
doi: 10.1371/journal.pone.0126848. eCollection 2015.

Development of apical blebbing in the boar epididymis

Jennifer Hughes  1 , Trish Berger  1
Affiliations

Development of apical blebbing in the boar epididymis

Jennifer Hughes et al. PLoS One. .

Abstract

Microvesicles are of increasing interest in biology as part of normal function of numerous systems; from the immune system (T cell activation) to implantation of the embryo (invasion of the trophoblasts) and sperm maturation (protein transfer in the epididymis). Yet, the mechanisms involved in the appearance of apical blebbing from healthy cells as part of their normal function remain understudied. Microvesicles are produced via one of two pathways: exocytosis or apical blebbing also termed ectocytosis. This work quantifies the histological appearance of apical blebbing in the porcine epididymis during development and examines the role of endogenous estrogens in regulating this blebbing. Apical blebbing appears at puberty and increases in a linear manner into sexual maturity suggesting that this blebbing is a mature phenotype. Endogenous estrogen levels were reduced with an aromatase inhibitor but such a reduction did not affect apical blebbing in treated animals compared with their vehicle-treated littermates. Epididymal production of apical blebs is a secretion mechanism of functionally mature principal cells regulated by factors other than estradiol.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Hormonal response to letrozole treatment.
Hormone levels in control animals were normalized to 100, indicated by the dotted line. Estradiol, estrogen conjugates and testosterone are testicular tissue levels. FSH and LH are plasma levels. * indicates significant difference from control levels (p < 0.05) [24].
Fig 2
Fig 2. Apical blebbing morphology.
A 11 week corpus tubule, B 16 week corpus tubule, C 20 week corpus, inset is lower magnification of same tubule, D 40 week corpus, inset is lower magnification of same tubule. Note apical blebbing is evident in both the 20 and 40 week samples (arrowheads); 16 week samples have fewer blebs and this 11 week corpus section has none. L = lumen, S = sperm, scale bars are 5 μm.
Fig 3
Fig 3. Development of apical blebbing in the caput epididymis (A) and the corpus epididymis (B).
Bars represent least squares means and SEM from 5 animals. Values with different superscripts are different in the analysis of transformed data (p ≤ 0.05). The dashed line represents the linear regression with non-transformed data (p < 0.001).
Fig 4
Fig 4. Apical blebbing in letrozole treated versus control littermates.
Bars represent least squares means with SEM from 4 and 5 animals in the caput and corpus epidiymis, respectively. Apical blebbing in caput and corpus epididymis were not altered when estrogens were reduced.
Fig 5
Fig 5. TUNEL labeling of corpus epididymis.
A Apoptotic cells are dark brown and visible near the basement membrane of the epithelium in 16 week corpus epididymis (arrows). B Hematoxylin and eosin stain of the same region as A; apical blebbing is evident in a large segment of the tubule (arrowheads). The apoptotic cells are not numerous enough to account for the apical blebbing seen in B. Scale bars indicate 5 μm.
Fig 6
Fig 6. Labeling of clear cells in the caput epididymis.
A Cross section of caput epididymis from 16 week boar showing V-ATPase positive cells (arrowheads), L = Lumen. Some background staining is evident. Inset: Positive control mouse caput epididymis with similar staining pattern for V-ATPase positive cells. B Hematoxylin and eosin staining of the same region as A; arrowheads indicate clear cells. Inset: Higher magnification of boxed area including a clear cell. Scale bars indicate 5 μm.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Antonyak MA, Li B, Boroughs LK, Johnson JL, Druso JE, Bryant KL, et al. (2011) Cancer cell-derived microvesicles induce transformation by transferring tissue transglutaminase and fibronectin to recipient cells. Proceedings of the National Academy of Sciences 108: 4852–4857. 10.1073/pnas.1017667108 - DOI - PMC - PubMed
    1. Gyorgy B, Szabo TG, Pasztoi M, Pal Z, Misjak P, Aradi B, et al. (2011) Membrane vesicles, current state-of-the-art: emerging role of extracellular vesicles. Cell Mol Life Sci 68: 2667–2688. 10.1007/s00018-011-0689-3 - DOI - PMC - PubMed
    1. Girouard J, Frenette G, Sullivan R (2009) Compartmentalization of proteins in epididymosomes coordinates the association of epididymal proteins with the different functional structures of bovine spermatozoa. Biol Reprod 80: 965–972. 10.1095/biolreprod.108.073551 - DOI - PMC - PubMed
    1. Cocucci E, Racchetti G, Meldolesi J (2009) Shedding microvesicles: artefacts no more. Trends in Cell Biology 19: 43–51. 10.1016/j.tcb.2008.11.003 - DOI - PubMed
    1. Valadi H, Ekstrom K, Bossios A, Sjostrand M, Lee JJ, Lotvall JO (2007) Exosome-mediated transfer of mRNAs and microRNAs is a novel mechanism of genetic exchange between cells. Nature Cell Biology 9: 654–U672. - PubMed

Publication types

Grants and funding

This research was supported in part by the National Research Initiative Competitive Grant 2008-35203-19082 from the USDA National Institute of Food and Agriculture to TB, W2171 multistate research project to TB, a W.K. Kellogg Endowment to TB, Humphries Fellowship to JRH, Austin Eugene Lyons Memorial Fellowship to JRH and the infrastructure support of the Department of Animal Science, College of Agricultural and Environmental Sciences, and The California Agricultural Experiment Station of the University of California-Davis. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.