Release of phospholipase C ζand [Ca2+]i oscillation-inducing activity during mammalian fertilization

Yoon, Sook‐Young; Fissore, Rafael A.

doi:10.1530/rep-07-0259

Cited by 77 publications

(65 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has previously been that PLCζ is localized in the perinuclear theca in the post-acrosomal region [27,28]. Our present study confirmed, for the first time, that rat PLCζ is also localized in the acrosomal region in sperm (Fig.…”

Section: Discussionsupporting

confidence: 90%

Removal of Acrosomal Membrane from Sperm Head Improves Development of Rat Zygotes Derived from Intracytoplasmic Sperm Injection

2009

View full text Add to dashboard Cite

Abstract. When intracytoplasmic sperm injection (ICSI) is applied in the rat, sperm chromatin is introduced into the oocyte together with the acrosome, which does not enter the cytoplasm of the oocyte during normal fertilization, resulting in the rat giving birth to pups. Since successful ICSI was reported in rats, but with low efficiency, it has been observed that the acrosome of the sperm head seems to have detrimental effects on the embryonic development of ICSI oocytes. To improve ICSI in rats, the effects of removal of the acrosomal membrane from rat sperm on the development of ICSI oocytes were examined. While most control (non-treated) sperm had an intact acrosomal membrane, the Triton X-100 (TX)-and lysolecithin (LL)-treated groups showed high percentages of sperm with a removed acrosomal membrane. The timing of pronuclear formation in ICSI-oocytes using TX-or LL-treated sperm was significantly accelerated compared with that of the control sperm (P<0.05). However, neither TX nor LL treatment affected amounts of PLCζ in rat sperm. The rates of offspring derived from TX-(20.3 ± 4.4%) and LL-treated sperm (19.0 ± 2.8%) were also significantly higher than that of the control group (7.6 ± 2.3%; P<0.05). Our data clearly indicate that removal of acrosomal membranes from sperm by reagents is effective for generation of offspring via ICSI in rats. Key words: Acrosomal membranes, Intracytoplasmic sperm injection, Rat (J. Reprod. Dev. 55: [475][476][477][478][479] 2009) n rats, intracytoplasmic sperm injection (ICSI) is the only way to routinely obtain offspring routinely derived from oocytes fertilized 'in vitro' using fresh and cryopreserved sperm [1], although we have previously succeeded in generation of rat offspring using cryopreserved sperm via artificial insemination ('in vivo' fertilization) [2]. Because a reliable and reproducible protocol of in vitro fertilization (IVF) using cryopreserved sperm has not been widely applied for rats, although we have established an IVF protocol very recently [3]. Successful ICSI was first reported in mice [4] and has subsequently been applied to many mammalian species [5][6][7][8][9][10]. Moreover, ICSI has been used for efficient production of not only wild-type animals but also transgenic animals [11]. In the case of rats, the protocol of ICSI has been improved by using an injection pipette with a very small outer diameter (2-4 μm), resulting in successful generation of offspring derived from the ICSI oocytes [12][13][14]. However, the efficiency is still low even though improvements such as using a small injection pipette have been applied to rat ICSI. These results imply that further improvement is required.Recently, Morozumi and Yanagimachi [15] reported that removal of both the plasma and acrosomal membranes from mouse spermatozoa before ICSI accelerates the onset of oocyte activation. They also suggested that removal of acrosomal membranes prior to ICSI is recommended for animals with large sperm acrosomes in view of the potential harmful effects of acrosomal ...

show abstract

Section: Discussionsupporting

confidence: 90%

Removal of Acrosomal Membrane from Sperm Head Improves Development of Rat Zygotes Derived from Intracytoplasmic Sperm Injection

2009

View full text Add to dashboard Cite

show abstract

“…It has been reported that PLCz is detectable in the post-acrosomal region (Yoon & Fissore 2007) and in the acrosomal and post-acrosomal regions ) of mouse sperm, in the acrosomal region of rat sperm (Seita et al 2009), in the equatorial , or equatorial and post-acrosomal regions (Heytens et al 2009) of human sperm, and in the equatorial region of bull sperm (Yoon & Fissore 2007). In mice, it is known that the components of the tail are not required for induction of oocyte activation (Kuretake et al 1996).…”

Section: Discussionmentioning

confidence: 99%

Pre-treatment of sperm reduces success of ICSI in the pig

Nakai¹,

Ito²,

Sato³

et al. 2011

Reproduction

View full text Add to dashboard Cite

In pigs, although ICSI is a feasible fertilization technique, its efficiency is low. In general, injected pig sperm are insufficient to induce oocyte activation and embryonic development. Pretreatments for disrupting sperm membranes have been applied to improve the fertility of ICSI oocytes; however, we hypothesize that such pretreatment(s) may reduce the ability of the sperm to induce oocyte activation. We first evaluated the effects of sperm pretreatments (sonication (SO) to isolate the sperm heads from the tails, Triton X-100 (TX), and three cycles of repeated freezing/thawing (3!-FT) for disrupting sperm membranes) on the rate of pronucleus (PN) formation after ICSI. We found that oocytes injected with control (whole) sperm had higher rates of PN formation than those obtained after subjecting the sperm to SO, TX, and 3!-FT. The amounts of phospholipase Cz (PLCz), which is thought to be the oocyte-activating factor in mammalian sperm, in sperm treated by each method was significantly lower than that in whole untreated sperm. Furthermore, using immunofluorescence, it was found that in pig sperm, PLCz was localized to both the post-acrosomal region and the tail area. Thus we demonstrated for the first time that sperm pretreatment leads to a reduction of oocyte-activating capacity. Our data also show that in addition to its expected localization to the sperm head, PLCz is also localized in the tail of pig sperm, thus raising the possibility that injection of whole sperm may be required to attain successful activation in pigs.

show abstract

“…In vitro PLC assays, using recombinant PLCz confirmed the enzyme's high sensitivity to Ca 2þ , which render it nearly fully active at basal [Ca 2þ ] i concentrations ). Immunolocalization studies localized PLCz to the postacrosomal region of mouse sperm (Fujimoto et al 2004) and to the equatorial area of bull and human sperm (Yoon and Fissore 2007;Grasa et al 2008;Yoon et al 2008), regions that first come in contact with the ooplasm following gamete fusion, respectively (Sutovsky et al 2003).…”

Section: Identification Of Plczmentioning

confidence: 99%

Ca2+ Signaling During Mammalian Fertilization: Requirements, Players, and Adaptations

Wakai¹,

Vanderheyden²,

Fissore³

2011

Cold Spring Harbor Perspectives in Biology

View full text Add to dashboard Cite

Changes in the intracellular concentration of calcium ([Ca 2þ ] i ) represent a vital signaling mechanism enabling communication among cells and between cells and the environment. The initiation of embryo development depends on a [Ca 2þ ] i increase(s) in the egg, which is generally induced during fertilization. The [Ca 2þ ] i increase signals egg activation, which is the first stage in embryo development, and that consist of biochemical and structural changes that transform eggs into zygotes. The spatiotemporal patterns of [Ca 2þ ] i at fertilization show variability, most likely reflecting adaptations to fertilizing conditions and to the duration of embryonic cell cycles. In mammals, the focus of this review, the fertilization [Ca 2þ ] i signal displays unique properties in that it is initiated after gamete fusion by release of a sperm-derived factor and by periodic and extended [Ca 2þ ] i responses. Here, we will discuss the events of egg activation regulated by increases in [Ca 2þ ] i , the possible downstream targets that effect these egg activation events, and the property and identity of molecules both in sperm and eggs that underpin the initiation and persistence of the [Ca 2þ ] i responses in these species.A n increase in the intracellular concentration of calcium ([Ca 2þ ] i ) underlies the initiation, progression and/or completion of a wide variety of cellular processes, including fertilization, muscle contraction, secretion, cell division, and apoptosis (Berridge et al. 2000). To survive and proliferate, cells and organisms must communicate, and changes in [Ca 2þ ] i allow them to quickly respond to environmental, nutritional, or ligand challenges with responses that regulate cell fate and function. Cells devote significant amounts of their energy reserves to create and maintain ionic gradients between extracellular and intracellular milieus and also within the latter, thereby allowing brief alterations in these gradients to have profound signaling effects. In the case of Ca 2þ , myriad proteins have acquired the ability to bind Ca 2þ , which allows them to interpret and transform these elevations into cellular functions. This review will examine the cellular modifications induced by [Ca 2þ ] i changes during fertilization in mature mammalian oocytes, henceforth referred to as eggs.Oocytes during maturation ready themselves for fertilization and the initiation of embryogenesis. During this transition, oocytes undergo changes that include the resumption and progression of meiosis, the development of polyspermy-preventing mechanisms, the reorganization of the cytoskeleton with spindle formation and displacement to the cortex, and the translation, accumulation, and degradation of specific mRNAs and proteins involved in development (Horner and Wolfner 2008b (Stricker 1999;Miyazaki and Ito 2006). Elucidation of the signaling cascades and identification of the molecules/receptor(s) that initiate the Ca 2þ signal at fertilization has proven elusive, and this review will not dwell on th...

show abstract

Release of phospholipase C ζand [Ca2+]i oscillation-inducing activity during mammalian fertilization

Cited by 77 publications

References 68 publications

Removal of Acrosomal Membrane from Sperm Head Improves Development of Rat Zygotes Derived from Intracytoplasmic Sperm Injection

Removal of Acrosomal Membrane from Sperm Head Improves Development of Rat Zygotes Derived from Intracytoplasmic Sperm Injection

Pre-treatment of sperm reduces success of ICSI in the pig

Ca2+ Signaling During Mammalian Fertilization: Requirements, Players, and Adaptations

Contact Info

Product

Resources

About