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

Reproduction ◽  
2011 ◽  
Vol 142 (2) ◽  
pp. 285-293 ◽  
Author(s):  
Michiko Nakai ◽  
Junya Ito ◽  
Ken-ichi Sato ◽  
Junko Noguchi ◽  
Hiroyuki Kaneko ◽  
...  

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 Cζ (PLCζ), 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, PLCζ 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, PLCζ 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.

Zygote ◽  
1999 ◽  
Vol 7 (3) ◽  
pp. 187-193 ◽  
Author(s):  
T. Kasai ◽  
K. Hoshi ◽  
R. Yanagimachi

To analyse the effect of the state of the sperm plasma membrane on oocyte activation rate following intracytoplasmic sperm injection (ICSI), three types of human and mouse spermatozoa (intact, immobilised and Triton X-100 treated) were individually injected into mouse oocytes. At 30, 60 and 120 min after injection, maternal chromosomes and sperm nuclei within oocytes were examined. Following human sperm injection, the fastest and the most efficient oocyte activation and sperm head decondensation occurred when the spermatozoa were treated with Triton X-100. Intact spermatozoa were the least effective in activating oocytes. Thus, the rate of mouse oocyte activation following human sperm injection is greatly influenced by the state of the sperm plasma membrane during injection. When mouse spermatozoa were injected into mouse oocytes, the rates of oocyte activation and sperm head decondensation within activated oocytes were the same irrespective of the type of sperm treatment prior to injection. We witnessed that live human spermatozoa injected into moue oocytes often kept moving very actively within the ooplasm for more than 60 min, whereas motile mouse spermatozoa usually became immotile within 20 min after injection into the ooplasm. In 0.002% Triton X-100 solution, mouse spermatozoa are immobilised faster than human spermatozoa. These facts seem to suggest that human sperm plasma membranes are physically and biochemically more stable than those of mouse spermatozoa. Perhaps the physical and chemical properties of the sperm plasma membrane vary from species to species. For those species whose spermatozoa have ‘stable’ plasma membranes, prior removal or ‘damage’ of sperm plasma membranes would increase the success rate of ICSI.


1995 ◽  
Vol 42 (2) ◽  
pp. 171-176
Author(s):  
R Rzepecki ◽  
E Markiewicz ◽  
J Szopa

The nuclear matrices from White bush (Cucurbita pepo var. patisonina) cell nuclei have been isolated using three methods: I, standard procedure involving extraction of cell nuclei with 2 M NaCl and 1% Triton X-100; II, the same with pre-treatment of cell nuclei with 0.5 mM CuSO4 (stabilisation step); and III, method with extraction by lithium diiodosalicylate (LIS), and compared the polypeptide pattern. The isolated matrices specifically bind SAR DNA derived from human beta-interferon gene in the exogenous SAR binding assay and in the gel mobility shift assay. Using IgG against the 32 kDa endonuclease we have found in the DNA-protein blot assay that this protein is one of the proteins binding SAR DNA. We have identified three proteins with molecular mass of 65 kDa, 60 kDa and 32 kDa which are responsible for SAR DNA binding in the gel mobility shift assay experiments.


2012 ◽  
Vol 15 (Supplement) ◽  
pp. 27-30 ◽  
Author(s):  
Jl Ballescá ◽  
Rafael Oliva

ABSTRACT The study of the sperm proteins is crucial for understanding its normal function and alterations in infertile patients. The sperm is a highly specialized cell with a very large flagella, with little cytoplasm and a highly condensed nucleus. The most abundant proteins in the nucleus of mammalian sperm are the protamines. The main functions of the protamines are the condensation of the DNA, possibly contributing to the generation of a more hydrodynamic sperm head and to the protection of the genetic message. However, in addition to protamines, about 5.0-15.0% of the paternal genome is also complexed with histones and histone variants. It has also demonstrated a differential distribution of genes in regions associated with histone and protamine-associated regions, suggesting a potential epigenetic relevance in embryonic development. More recently, detailed lists of proteins have been described corresponding to the different compartments of the sperm cell thanks to the application of recent proteomic techniques based on mass spectrometry (MS). Differential proteomics is also being applied to identify the presence of protein abnormalities found in infertile patients


2007 ◽  
Vol 19 (1) ◽  
pp. 303
Author(s):  
M. Nakai ◽  
N. Kashiwazaki ◽  
N. Maedomari ◽  
M. Ozawa ◽  
J. Noguchi ◽  
...  

During fertilization, sperm penetration (gamete membrane fusion and exposure of sperm cytoplasm) allows oocyte activation (resumption of oocyte meiosis, pronuclear formation, etc.) by inducing an elevation of the intracellular free Ca2+ concentration. So a spermatozoon ought to be able to fully activate an oocyte. However, in pig ICSI oocytes, although a spermatozoon is injected successfully into ooplasm, complete activation is deficient in some of the oocytes. A variety of sperm pre-treatments before ICSI have been reported; however, there is a possibility that the treatment affects the ability to activate oocytes after the injection. We examined the effect of sperm treatments (freezing, freeze-drying, and sonication) on the ability to activate oocytes. Ejaculated boar semen was centrifuged (10 min, 600g) and the supernatant was discarded. The sperm pellet was resuspended in Modena solution (Weitze 1991 Reprod. Domest. Anim. (Suppl. 1), 231–253). The sperm were then treated with or without sonication for 10 s (fresh whole and sonicated sperm, respectively). The freezing of sperm was carried out as was described (Kikuchi et al. 1998 Theriogenology 50, 615–623). Frozen–thawed spermatozoa were then treated with or without sonication (frozen–thawed sonicated and whole sperm, respectively). The fresh whole and sonicated sperm were subjected to a freeze-drying system and the sperm were then re-hydrated (freeze-dried whole and sonicated sperm, respectively). A whole sperm or 1 or 3 sonicated sperm heads were then injected into in vitro-matured oocytes, as described previously (Nakai et al. 2003 Biol. Reprod. 68, 1003–1008; 2006 Reproduction 131, 603–611). Sham injection was also performed. No artificial stimulation was added to the injected oocytes. The oocytes with more than one pronucleus(i) at 10 h after the injection were defined as being activated. As shown in Table 1, the rates of activated oocytes after injection of one sonicated head or sham injection were significantly lower than those of the oocytes injected with whole sperm or 3 sonicated sperm heads in each sperm source (P < 0.05 by ANOVA and Duncan's multiple range test). Furthermore, the rates of activated oocytes for each injection category were not different among the 3 sperm sources. These results suggest that sonication before ICSI may reduce the quantity of activation-inducing sperm factor. It is also suggested that sperm pre-treatment such as freezing or freeze-drying does not affect the ability for oocyte activation. Table 1. Effect of sperm treatment on oocyte activation after ICSI


2008 ◽  
Vol 78 (Suppl_1) ◽  
pp. 309-309
Author(s):  
Naomi Kashiwazaki ◽  
Daisuke Sano ◽  
Yuki Yamamoto ◽  
Tomo Samejima ◽  
Junya Ito

2008 ◽  
Vol 20 (8) ◽  
pp. 875 ◽  
Author(s):  
Sylvia J. Bedford-Guaus ◽  
Sook-Young Yoon ◽  
Rafael A. Fissore ◽  
Young-Ho Choi ◽  
Katrin Hinrichs

Methods presently used to activate mare oocytes for assisted reproduction technologies provide low rates of advanced embryonic development. Because phospholipase Cζ (PLCζ) is the postulated sperm-borne factor responsible for oocyte activation at fertilisation, the aim of the present study was to investigate the pattern of [Ca2+]i oscillations and developmental rates achieved by microinjection of three concentrations of mouse PLCζ complementary (c) RNA (1, 0.5 or 0.25 μg μL–1) into mare oocytes. The frequency of [Ca2+]i oscillations was no different (P > 0.05) after injection of 1, 0.5 or 0.25 μg μL–1 PLCζ cRNA (41.1 ± 5.3, 47 ± 4.0 and 55.4 ± 9.0, respectively). However, [Ca2+]i oscillations persisted longest (P < 0.05) for oocytes injected with 0.5 μg μL–1 PLCζ cRNA (570.7 ± 64.2 min). There was no significant difference in cleavage rates after injection of the three concentrations of PLCζ (P > 0.05; range 97–100%), but the proportion of oocytes reaching advanced stages of embryonic development (>64 nuclei) was significantly lower for oocytes injected with 0.25 μg μL–1 PLCζ cRNA (3%) than for those injected with 1 μg μL–1 PLCζ cRNA (15%). Based on these results, microinjection of PLCζ may prove an effective and consistent method for the parthenogenetic activation of mare oocytes for nuclear transfer and provides a physiologically relevant tool with which to study fertilisation-dependent [Ca2+]i signalling in this species.


Reproduction ◽  
2017 ◽  
Vol 154 (3) ◽  
pp. 307-318 ◽  
Author(s):  
Luis Águila ◽  
Ricardo Felmer ◽  
María Elena Arias ◽  
Felipe Navarrete ◽  
David Martin-Hidalgo ◽  
...  

The efficiency of intracytoplasmic sperm injection (ICSI) in the bovine is low compared to other species. It is unknown whether defective oocyte activation and/or sperm head decondensation limit the success of this technique in this species. To elucidate where the main obstacle lies, we used homologous and heterologous ICSI and parthenogenetic activation procedures. We also evaluated whetherin vitromaturation negatively impacted the early stages of activation after ICSI. Here we showed that injected bovine sperm are resistant to nuclear decondensation by bovine oocytes and this is only partly overcome by exogenous activation. Remarkably, when we used heterologous ICSI,in vivo-matured mouse eggs were capable of mounting calcium oscillations and displaying normal PN formation following injection of bovine sperm, althoughin vitro-matured mouse oocytes were unable to do so. Together, our data demonstrate that bovine sperm are especially resistant to nuclear decondensation byin vitro-matured oocytes and this deficiency cannot be simply overcome by exogenous activation protocols, even by inducing physiological calcium oscillations. Therefore, the inability of a suboptimal ooplasmic environment to induce sperm head decondensation limits the success of ICSI in the bovine. Studies aimed to improve the cytoplasmic milieu ofin vitro-matured oocytes and to replicate the molecular changes associated within vivocapacitation and acrosome reaction will deepen our understanding of the mechanism of fertilization and improve the success of ICSI in this species.


Sign in / Sign up

Export Citation Format

Share Document