119 LEPTIN ENHANCED THE DEVELOPMENT OF BUFFALO (BUBALUS BUBALIS) EMBRYO CULTURED IN VITRO

2009 ◽  
Vol 21 (1) ◽  
pp. 159 ◽  
Author(s):  
Y. Q. Lu ◽  
D. N. Ye ◽  
M. Zhang ◽  
S. S. Lu ◽  
K. H. Lu

Buffalo is an important livestock resource in many Asian and Mediterranean countries. In vitro embryo production (IVEP) and transfer of the embryos to produce calves with high genetic merit would be of great interest in buffalo species. The efficiency of the IVEP in buffalo is low compared to that in bovine. It may be due to the reproductive physiology of buffalo or the technical factors in IVEP procedures. Recent research revealed that supplementation of leptin in the in vitro culture (IVC) medium could significantly increase embryo development (2005 Mol. Cell Endocrinol. 229, 141–147; 2006 Reproduction 132, 247–256). In this study, the effect of leptin on buffalo embryo development in vitro was assessed by supplementation of the leptin into the IVC medium. Methods: Buffalo oocytes were aspirated form 2 to 6 mm follicles from slaughterhouse ovaries and washed in TCM199 and once more with in vitro maturation (IVM) medium (TCM199, 5% ECS, 15 μg mL–1 FSH). Oocytes with compact cumulus cells were matured in IVM medium at 38.5°C, 5% CO2 for 22–22 h. The frozen–thawed buffalo sperm underwent a centrifugation in Percoll gradient to remove the dead sperm. Ten to 15 matured oocytes were added to a drop of 40 μL modified Tyrode’s medium supplemented with 0.6% BSA, 2.0 mm caffeine and 20 μg mL–1 Heparin. Concentration of sperm added into the fertilization medium was 1 to 2 million per mL. Eight to 10 h after insemination, the presumptive zygotes were transferred to IVC medium (TCM199, 10% newborn cow serum) supplemented with 0 ng mL–1 (control), 10 ng mL–1, 100 ng mL–1 or 500 ng mL–1 of leptin. Cleavage and blastocyst development rate was recorded on Day 2 and Day 6 to 8 after insemination. The experiment was repeated 10 times, and a total of 831 oocytes were used with the IVF procedures. The results revealed that the cleavage rates in the group of 0 ng mL–1, 10 ng mL–1, 100 ng mL–1 and 500 ng mL–1 of leptin were 50.1 ± 3.5%, 55.0 ± 1.3%, 50.0 ± 1.8% and 52.9 ± 2.2%, respectively. No statistical difference was observed regarding cleavage rates between treatments (P > 0.05). The percentage of oocytes developing to blastocysts in the group of 10 ng mL–1 and 100 ng mL–1 leptin were 26.1 ± 1.5% and 23.5 ± 1.2%, respectively, significantly higher than that of 17.5 ± 2.1% in the control (P < 0.05). The blastocyst development rate in the group of 500 ng mL–1 leptin was 20.9 ± 1.4%, less than that of 10 ng mL–1 (P < 0.05). In conclusion, the results of this study indicated that supplementation of leptin in the IVC medium could enhance the blastocyst development in buffalo species and the optimal concentration of leptin in the present procedures was 10 ng mL–1. This work was jointly supported by National Science and Technology Supporting Program (No. 2006BAD04A18), Guangxi Science Foundation (0832012) and Guangxi University Key Research Program (No. 2005ZD05).

Author(s):  
Vijay Singh ◽  
A. K. Misra ◽  
Suresh Kumar ◽  
Champak Barman

The objective of the present experiment was to investigate the effect of cysteamine and b-mercaptoethanol supplementation on in -vitro maturation, cleavage of oocytes and development of embryo in buffalo (Bubalus bubalis). Oocytes were aspirated from abattoir ovarian follicles of 3-10 mm diameter followed by maturation in the media in vitro containing cysteamine/b-mercaptoethanol (treatment) and without antioxidant (control). Matured oocytes were co-incubated with sperm (approx.1×106/ml) of Murrah bull in mSOF medium using heparin (10 μg/ml). After 22 h of oocyte-sperm incubation, fertilized oocytes were stripped of cumulus cells and cultured in mSOF medium for 8 days to study embryo development. The oocyte maturation rate improved significantly (P<0.05) following addition of 50 or 100 μM of cysteamine and 10, 50 and 100 μM of b- mercaptoethanol (ME), respectively as compared to control. The cleavage rate was found to be significantly (P<0.05) higher at 50 and 100 μM of cysteamine and at all concentrations of b-mercaptoethanol as compared to control and development of embryos to morula stage was significantly (P<0.05) improved with 50 μM cysteamine/ b-mercaptoethanol.


1997 ◽  
Vol 9 (7) ◽  
pp. 697 ◽  
Author(s):  
Rupasri Ain ◽  
P. B. Seshagiri

The inßuence of the sperm motility stimulant pentoxifylline (PF) on preimplantation embryo development in hamsters was evaluated. Eight-cell embryos were cultured in hamster embryo culture medium (HECM)-2, with or without PF (0· 0233·6 mM). There was 90%, 37% and 29% inhibition of blastocyst development by 3·6 (used for human sperm), 0·9 and 0 ·45 mM PF, respectively. However, 23 µM PF (exposed to hamster oocytes during IVF) signicantly (P < 0·05) improved blastocyst development (63· 6% v. 51· 8%); morulae development was, however, not curtailed by 0·45 mM or 0·9 mM PF (51·8%±6·0 or 50·5%±11·3, respectively). Post-implantation viability of PF-treated embryos was assessed by embryo transfer; 43% of 80 PF-treated embryos implanted compared with 40% of 79 control embryos. Of the 9 recipients, 6 females delivered pups (19, i.e. 16% of transferred embryos or 53% of implanted embryos). These data show that in hamsters, continuous presence of PF at 0·45-3·6 mM is detrimental to 8-cell embryo development whereas 23 µM PF improves the development of embryos to viable blastocysts which produce live offspring.


2009 ◽  
Vol 21 (1) ◽  
pp. 131 ◽  
Author(s):  
M. De Blasi ◽  
E. Mariotti ◽  
M. Rubessa ◽  
S. Di Francesco ◽  
G. Campanile ◽  
...  

Despite the increasing interest, buffalo oocyte cryopreservation is still inefficient, especially in terms of blastocyst development after IVF. The aim of this work was to evaluate chromatin and spindle organization of buffalo in vitro-matured oocytes after vitrification/warming by cryotop and after their simple exposure to cryoprotectants (CP). An overall amount of 251 COC was selected and matured in vitro. In the vitrification group, COC were first exposed to 10% ethylene glycol (EG) + 10% DMSO for 3 min, and then to 20% EG + 20% of DMSO and 0.5 m sucrose, loaded on cryotops, and plunged into liquid nitrogen within 25 s. Oocytes were warmed into a 1.25 m sucrose solution for 1 min and then to decreasing concentrations of sucrose (0.625 m, 0.42 m, and 0.31 m) for 30s each. In order to test CP toxicity, COC were simply exposed to the vitrification and warming solutions. Two hours after warming, oocytes were fixed and immunostained for microtubules using a method previously described (Messinger SM and Albertini DF 1991 J. Cell Sci. 100, 289–298), stained for nuclei with Hoechst, and examined by fluorescence microscopy. Fresh in vitro-matured oocytes were fixed and stained as controls. Data were analyzed by chi-square test; results are shown in Table 1. The percentages of MII oocytes in the control and vitrification groups were greater than in the toxicity group, in which a greater percentage of telophase II stage oocytes were found compared with both the control and vitrification groups, indicating occurrence of activation. Of the MII oocytes, both exposure to CP and vitrification procedures gave greater percentages of oocytes with abnormal spindle and abnormal chromatin configuration compared with the control. An unexpected datum was the evidence of a significant percentage of spontaneously activated oocytes in the toxicity group. We speculate that the lack of activation in the vitrification group may be related to the slowing down of metabolic activity subsequent to thermal shock, and hence, that activation after vitrification may occur later than 2 h post-warming. In conclusion, the simple exposure to CP causes activation of the COC and damage to the cytoskeleton similar to that induced by the whole vitrification protocol. The damages to the meiotic spindle and DNA fragmentation may lead to aneuploidy incompatible with subsequent embryo development and account for the poor embryo development currently recorded in buffalo. Table 1.Chromatin and spindle organization in oocytes vitrified and exposed to cryoprotectants


2011 ◽  
Vol 23 (1) ◽  
pp. 211
Author(s):  
K. R. Babu ◽  
R. Sharma ◽  
K. P. Singh ◽  
A. George ◽  
M. S. Chauhan ◽  
...  

Ovarian nitric oxide (NO) and that produced within the oocytes and embryos have been reported to play important roles in oocyte meiotic maturation and embryo development. Production of NO is catalyzed by NO synthase (NOS), which exists in 3 isoforms, the constitutive endothelial (eNOS) and neuronal (nNOS) isoforms and the inducible (iNOS) isoform. We have previously shown that low concentrations of NO stimulate and high concentrations inhibit embryo development, and that endogenous NO produced by iNOS is necessary for optimal embryo development in the buffalo. The present study was aimed at localizing different isoforms of NOS and examining their relative mRNA abundance in buffalo oocytes and embryos. Oocytes from slaughterhouse ovaries were subjected to in vitro maturation in 100-μL droplets (10 to 15 oocytes/droplet) of in vitro maturation medium (TCM-199 + 10% FBS + 5 μg mL–1 of pFSH + 1 μg mL–1 of oestradiol-17β + 0.81 mM sodium pyruvate + 10% buffalo follicular fluid + 50 μg mL–1 of gentamicin) for 24 h in a CO2 incubator (5% CO2 in air) at 38.5°C. In vitro fertilization was carried out by incubating in vitro-matured oocytes with 2 to 4 million spermatozoa mL–1 for 18 h. The presumed zygotes were cultured on original beds of cumulus cells in in vitro culture medium (mCR2aa + 0.6% BSA + 10% FBS) for up to 8 days post-insemination. Immature and in vitro-matured oocytes and embryos at the 2-cell, 4-cell, 8- to 16-cell, morula, and blastocyst stages were examined for the presence of NOS isoforms by indirect immunofluorescence staining using epifluorescence microscopy and RT-PCR. Each experiment was repeated in triplicate, and data were analysed using one-way ANOVA, after arcsine transformation of percentage values. Expression of all 3 NOS isoforms was detected inside the cytoplasm, in all the stages of oocytes and embryos examined, by both immunofluorescence and RT-PCR. Abundance of the iNOS transcript was significantly higher (P ≤ 0.01) in the morula and blastocyst stages compared with that in immature and in vitro-matured oocytes and in embryos at the 2-cell, 4-cell, and 8- to 16-cell stages, indicating that its expression was up-regulated at the 8- to 16-cell stage. The expression of eNOS was significantly higher (P ≤ 0.05) in the immature and mature oocytes and in 8- to 16-cell stage embryos, morulae, and blastocysts than in the early-cleavage embryos at the 2- and 4-cell stages, indicating that it was down-regulated after fertilization and was up-regulated again at the 8- to 16-cell stage. Abundance of the nNOS transcript was not significantly different among all the stages of oocytes and embryos examined. These results demonstrate that different NOS isoforms are expressed in a dynamic manner during embryonic development in the buffalo. The role of an increase in expression of iNOS and eNOS at the 8- to 16-cell stage, at which a developmental block occurs in this species, needs to be examined.


2010 ◽  
Vol 22 (1) ◽  
pp. 184
Author(s):  
A. Gambini ◽  
J. Jarazo ◽  
R. Olivera ◽  
D. Salamone

The availability of viable equine oocytes is a limiting factor on in vitro embryo production; therefore, it is necessary to assess some of the variables that affect oocyte viability. The aim of our study was to evaluate one of those variables: the effect of time between the collection of the ovary and oocyte in vitro maturation. Ovaries of slaughtered mares were collected during the breeding season (Argentine, Southern hemisphere). They were separated in bags every half hour and treated separately after arriving at the laboratory. COCs were recovered by a combination of scraping and washing of all visible follicles with a syringe filled with DMEM supplemented with 1 mM sodium pyruvate and 15 IU mL-1 heparin. COCs were matured for 24 to 26 h in 3 groups, according to time interval: 4 to 7 (group I), 7 to 10 (II), and 10 to 12 (III) hours. The medium for maturation was TCM-199 supplemented with 10% fetal bovine serum (FBS), 1 μL mL-1 insulin-transferrin-selenium, 1 mM sodium pyruvate, 100 mM cysteamine, and 0.1 mg mL-1 of FSH at 39°C in a humidified atmosphere of 5% CO2 in air. The cumulus was removed by a trypsin treatment and vortexing in hyaluronidase (1 mg mL-1). Cloning and fusion procedures were performed following the zona-free technique described by Lagutina et al. (2007 Theriogenology 67, 90-98). Two experiments were carried out by using different activation protocols. In experiment 1, the activation process was 22 mM ionomycin in H-TALP for 4 min followed by 3h culture in 1.9 mM 6-DMAP in SOF, whereas in experiment 2, we used 8.7 mM ionomycin in H-TALP for 4 min followed by 4 h culture in 1 mM 6-DMAP and 10 mg mL-1 cycloheximide in SOF. Embryos were cultured in wells of well (WOW) system. Half of the medium was renewed on Day 3 with fresh SOF and on Day 5 with DMEM/F12 with 10% FBS. Cleavage was assessed 48 h after activation; the rate of blastocyst formation was recorded at Days 8 and 9. Results were compared using chi-square test (P < 0.05). In experiment 1, maturation rates were significantly different between group I (n = 135, 54.1%) and III (n = 94, 40.4%), group II did not differ from them (n = 138, 53%). Cleavage rates differed statistically between II (n = 44, 75%) and III (n = 27, 40.7%), but not with group I (n = 53, 98%). No significant differences were found in blastocyst development; however, we observed a certain tendency towards an increase in the blastocyst rate as the time interval was lower (I: 3/53, 5.7%; II: 1/44, 2.3%; III: 0/27, 0%). In experiment 2, there were no significant differences between group I and II in rates of maturation (n = 56, 59% v. n = 111, 44.5%), cleavage (n = 22, 91% v. n = 34, 82%) or blastocyst rates (1/22, 4.5% v. 7/34, 20.6%). We conclude that cloned equine embryo development, using the two activation protocols tested, is not affected when the time interval between ovary collection and oocyte IVM is within 4 to 10 h.


2015 ◽  
Vol 27 (1) ◽  
pp. 194
Author(s):  
S. Saugandhika ◽  
H. N. Malik ◽  
S. Saini ◽  
V. Sharma ◽  
S. Bag ◽  
...  

Interferon tau (IFN-tau) is known as maternal pregnancy recognition factor in ruminants. IFN-tau not only acts as a signalling molecule of pregnancy recognition but also performs various functions for successful implantation and pregnancy establishment. The aim of the present study was to produce recombinant buffalo interferon-tau (BuIFN-Tau) and observe if it has any effect on in vitro embryo development. The BuIFN-Tau gene was obtained through polymerase chain reaction (PCR) from hatched buffalo blastocysts and was cloned into pJET cloning vector. Screening of the recombinant colonies gave 8 distinct buffalo IFN-tau isoforms, out of which the predominant buffalo IFN-t tau1 isoform (gene bank accession number JX481984), was subcloned into expression vector pET22b without signal sequence. The recombinant plasmid was induced to express the recombinant protein by isopropyl b-D-1-thiogalactopyranoside. Analysis of the products of recombinant BuIFN-tau without signal sequence by SDS–PAGE revealed a new 20-kDa protein coinciding with the molecular weight of IFN-tau as reported earlier in literature. The purified recombinant BuIFN-tau was confirmed by Western blot using anti-HIS antibody and was subjected to three steps of large-scale purification using HIS affinity chromatography, anion exchange chromatography, and gel filtration chromatography. Finally, a relatively pure histidine-tagged recombinant protein, which had a purity of at least 90%, was generated as confirmed through SDS. The concentration of recombinant BuIFN-tau was 1 mg mL–1 by Bradford assay. The purified recombinant BuIFN-tau was used as supplement of the culture medium for IVF early buffalo embryos at the following concentrations: control, 1, 2, and 4 µg mL–1. Sixty oocytes each in 4 groups (with 20 oocytes/drop in three replicates for each group) were used for in vitro maturation. After 24 h, the matured oocytes were incubated with in vitro capacitated sperm cells for 18 h; thereafter, the presumptive zygotes were cultured in IVC medium supplemented with 0, 1, 2, or 4 µg mL–1 of the purified recombinant BuIFN-tau. The experiment was repeated 3 times. The data were analysed using SYSTAT 7.0 (SPSS Inc., Chicago, IL, USA) after arcsin transformation of percentage values. The differences were analysed by one-way ANOVA followed by Fisher's least significant difference test. Out of 3 concentrations of recombinant BuIFN-tau, the 2 µg mL–1 concentration significantly promoted the rate of blastocyst development, 45.55% against 31.1% (control; P < 0.01). Blastocyst development rate for low and high concentrations was 29.97% and 10.18% respectively. It is concluded that the addition of 2 µg mL–1 of recombinant BuIFN-tau enhances the blastocyst development rate in buffalo, and hence there is some evidence that BuIFN-tau has not only a role in maternal recognition of pregnancy but also in embryonic development.


2008 ◽  
Vol 20 (1) ◽  
pp. 177
Author(s):  
P. Bermejo-Álvarez ◽  
A. Gutiérrez-Adán ◽  
P. Lonergan ◽  
D. Rizos

The faster-developing blastocysts in IVC systems are generally considered more viable and better able to survive following cryopreservation or embryo transfer than those that develop more slowly. However, evidence from several species indicates that embryos that reach the blastocyst stage earliest are more likely to be males than females. The aim of this study was to determine whether the duration of maturation could affect early embryo development and, furthermore, the sex ratio of early- or late-cleaved embryos and blastocysts. Cumulus–oocyte complexes were matured in vitro for 16 h (n = 2198) or 24 h (n = 2204). Following IVF, presumptive zygotes from each group were examined every 4 h between 24 and 48 h postinsemination (hpi) for cleavage, and all embryos were cultured to Day 8 in synthetic oviduct fluid to assess blastocyst development. Two-cell embryos at each time point and blastocysts on Days 6, 7, and 8 from both groups were snap-frozen individually for sexing. Sexing was performed with a single PCR using a specific primer BRY. There was a significantly lower number of cleaved embryos from the 16-h compared with the 24-h maturation group at 28 (10.0 � 1.51 v. 28.8 � 3.57%), 32 (35.3 � 1.48 v. 57.6 � 3.33%), 36 (54.8 � 1.76 v. 67.4 � 2.81%), 40 (63.3 � 1.82 v. 72.0 � 2.54%), and 48 (70.6 � 1.78 v. 77.1 � 2.18%) hpi, respectively (mean � SEM; P d 0.05). However, the blastocyst yields on Day 6 (17.1 � 3.11 v. 16.4 � 2.11%), 7 (30.6 � 4.10 v. 34.6 � 3.51%), or 8 (34.1 � 3.90 v. 39.4 � 4.26%) were similar for both groups (mean � SEM; 16 v. 24 h, respectively). Significantly more 2-cell early cleaved embryos (up to 32 hpi) were male compared with the expected 1:1 ratio from both groups (16 h: 1.24:0.76 v. 24 h: 1.17:0.83, P ≤ 0.05); however, the overall sex ratio among 2-cell embryos was significantly different from the expected 1:1 in favor of males only for the 16-h group (1.18:0.82, P ≤ 0.05). The sex ratio of blastocysts on Day 6, 7, or 8 from both groups was not different from the expected 1:1. However, the total number of male blastocysts obtained after 8 days of culture from the 24-h group was significantly different from the expected 1:1 (1.19:0.81, P ≤ 0.05) and approached significance in the 16-h group. These results show that the maturational stage of the oocyte at the time of fertilization has an effect on the kinetics of early cleavage divisions but not on blastocyst yield. Furthermore, irrespective of the duration of maturation, the sex ratio of early-cleaving 2-cell embryos was weighted in favor of males, and this observation was maintained at the blastocyst stage.


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