Ultrastructural localization of calcium deposits during in vitro culture of pig oocytes

Petr, Jaroslav; Rozinek, J.; Hruban, V.; Jílek, F.; Sedmı́ková, Markéta; Vaňourková, Zdeňka; Němeček, Zbyněk

doi:10.1002/1098-2795(200102)58:2<196::aid-mrd9>3.0.co;2-j

Cited by 12 publications

(6 citation statements)

References 39 publications

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“…Calcium has been proposed to play a major role in the regulation of key intracellular events. Cells strongly regulate the calcium signaling process based on its function during each developmental stage (Darszon, Nishigaki, Beltran, & Treviño, ; Petr et al, and Sedmiakova et al, ). Calcium contributes to growth, proliferation and cell death in the spermatogonium and spermatocyte cells in several mammalian species (Ravindranath, Papadopoulos, Vornberger, Zitzmann, & Dym, ; Treviño et al, ).…”

Section: Introductionmentioning

confidence: 99%

Subcellular distribution of calcium during spermatogenesis of zebrafish, Danio rerio

Golpour

Pšenička

Niksirat

2017

Journal of Morphology

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Calcium plays a variety of vital regulatory functions in many physiological and biochemical events in the cell. The aim of this study was to describe the ultrastructural distribution of calcium during different developmental stages of spermatogenesis in a model organism, the zebrafish (Danio rerio), using a combined oxalate-pyroantimonate technique. Samples were treated by potassium oxalate and potassium pyroantimonate during two fixation stages and examined using transmission electron microscopy to detect electron dense intracellular calcium. The subcellular distribution of intracellular calcium was characterized in spermatogonium, spermatocyte, spermatid, and spermatozoon stages. The area which is covered by intracellular calcium in different stages was quantified and compared using software. Isolated calcium deposits were mainly detectable in the cytoplasm and the nucleus of the spermatogonium and spermatocyte. In the spermatid, calcium was partially localized in the cytoplasm as isolated deposits. However, most calcium was transformed from isolated deposits into an unbound pool (free calcium) within the nucleus of the spermatid and the spermatozoon. Interestingly, in the spermatozoon, calcium was mainly localized in a form of an unbound pool which was detectable as an electron-dense mass within the nucleus. Also, sporadic calcium deposits were scattered in the midpiece and flagellum. The proportional area which was covered by intracellular calcium increased significantly from early to late stages of spermatogenesis. The extent of the area which was covered by intracellular calcium in the spermatozoon was the highest compared to earlier stages. Calcium deposits were also observed in the somatic cells (Sertoli, myoid, Leydig) of zebrafish testis. The notable changes in the distribution of intracellular calcium of germ cells during different developmental stages of zebrafish spermatogenesis suggest its different homeostasis and physiological functions during the process of male gamete development.

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Section: Introductionmentioning

confidence: 99%

Subcellular distribution of calcium during spermatogenesis of zebrafish, Danio rerio

Golpour

Pšenička

Niksirat

2017

Journal of Morphology

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“…Subcellular localization of calcium during different developmental stages of gametogenesis in rat (Ravindranath et al, 1994), pig (Petr et al, 2001; Rozinek et al, 2006), mouse (Sedmiâkovâ et al, 2003), and zebrafish (Golpour et al, 2016) using a combined oxalate–pyroantimonate technique have provided useful information regarding involvement of calcium in the basic processes of reproduction. Despite the importance of calcium in cellular events, and considering that fishes make up more than half of all vertebrates, there is no data available on the distribution of intracellular calcium during spermatogenesis in fish.…”

Section: Introductionmentioning

confidence: 99%

Ultrastructural Localization of Intracellular Calcium During Spermatogenesis of Sterlet (Acipenser ruthenus)

2016

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Calcium regulates many intracellular events such as growth and differentiation during different stages of gamete development. The aim of this study was to localize and quantify the intracellular distribution of calcium during different developmental stages of spermatogenesis in sterlet, Acipenser ruthenus, using a combined oxalate-pyroantimonate technique. The distribution of calcium was described in spermatogonium, spermatocyte, spermatid, and spermatozoon stages. In the spermatogonium and spermatocyte, calcium deposits were mainly localized in the nucleus and cytoplasm. The spermatid had calcium in the nucleus, developing acrosomal vesicle, and cytoplasm. Intracellular calcium transformed from scattered deposits in spermatogonia and spermatocyte stages into an unbound form in spermatid and the spermatozoon. The proportion of area covered by calcium increased significantly (p<0.05) from early to late stages of spermatogenesis. The largest proportion of area covered by calcium was observed in the nucleus of the spermatozoon. In conclusion, although most of the intracellular calcium is deposited in limited areas of the spermatogonium and spermatocyte, it is present an unbound form in the larger area of spermatids and spermatozoa which probably reflects changes in its physiological function and homeostasis during the process of male gamete production in spermatogenesis.

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“…In our previous study (Petr et al, 2001) we demonstrated that pig oocytes enclosed in ovarian follicles contain numerous calcium deposits in the nucleus, vacuoles, mitochondria, and on the surface of lipid droplets, but calcium deposits are absent from the endoplasmic reticulum. After oocyte isolation from the follicle, calcium deposits are quickly depleted, and their replenishment occurs gradually during in vitro culture of the oocytes.…”

Section: Introductionmentioning

confidence: 88%

“…The blockage of calcium influx from extracellular sources had a significant effect on the distribution of intracellular calcium deposits. For the detection of these deposits we used the combined oxalate-pyroantimonate method, which has been used effectively for the detection of intracellular calcium stores in various tissues (Borgers et al, 1981;Van Reempts et al, 1982;Menon et al, 1985;Ravindranath et al, 1994), human pre-implantation embryos (Sousa et al, 1997) and pig oocytes (Petr et al, 1997(Petr et al, , 1999(Petr et al, , 2000(Petr et al, , 2001.…”

mentioning

confidence: 99%

“…A significant amount of calcium ions bound to calcium-binding proteins and detectable using the combined oxalate-pyroantimonate method was present in the follicle-enclosed oocytes (Petr et al, 2001). After isolation from the follicle, there was a very rapid depletion of intracellular calcium deposits in the oocytes, and these intracellular stores were gradually replenished during their subsequent in vitro culture (Petr et al, 2001).…”

mentioning

confidence: 99%

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Ultrastructural localisation of calcium deposits in pig oocytes maturing in vitro: effects of verapamil

Rozinek

Vaňourková

Sedmı́ková

et al. 2003

Zygote

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The culture of pig oocytes in the presence of the calcium channel blocker verapamil (0.02 mM) resulted in the blocking of meiosis at the metaphase I stage, and only a small fraction (about 28%) of the oocytes were able to continue their maturation to the stage of metaphase II. Hence, meiotic maturation in pig oocytes is a calcium-dependent process. After isolation of the pig oocytes from their follicles, the intracellular calcium deposits in the oocyte and granulosa cells, detectable using the combined oxalate-pyroantimonate method, are depleted. The amount of calcium deposits in the oocyte and granulosa cells increased during oocyte meiotic maturation in vitro, especially in the nucleus, mitochondria, vacuoles and cytoplasm. The replenishment of calcium deposits is significantly changed under the effect of verapamil. The increase in calcium deposits in the oocyte nucleus was delayed, a much larger amount of deposits was formed in the mitochondria, and the amount of deposits in the vacuoles was demonstrably smaller. A significant peak in the accumulation of calcium deposits was observed in the cytoplasm of verapamil-treated oocytes after 16 h of in vitro culture. We propose that an altered pattern in the replenishment of calcium deposits can disturb intracellular signalling and prevent the exit of oocytes from the metaphase I stage.

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Ultrastructural localization of calcium deposits during in vitro culture of pig oocytes

Cited by 12 publications

References 39 publications

Subcellular distribution of calcium during spermatogenesis of zebrafish, Danio rerio

Subcellular distribution of calcium during spermatogenesis of zebrafish, Danio rerio

Ultrastructural Localization of Intracellular Calcium During Spermatogenesis of Sterlet (Acipenser ruthenus)

Ultrastructural localisation of calcium deposits in pig oocytes maturing in vitro: effects of verapamil

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