scholarly journals Metabolomic Analysis Reveals Changes in Preimplantation Embryos Following Fresh or Vitrified Transfer

2020 ◽  
Vol 21 (19) ◽  
pp. 7116
Author(s):  
Ximo Garcia-Dominguez ◽  
Gianfranco Diretto ◽  
Sarah Frusciante ◽  
José Salvador Vicente ◽  
Francisco Marco-Jiménez
Keyword(s):  
Embryo Transfer ◽  
Unsaturated Fatty Acids ◽  
Ex Vivo ◽  
Krebs Cycle ◽  
Cumulative Effect ◽  
Developmental Trajectory ◽  
Preimplantation Embryos ◽  
Embryo Cryopreservation ◽  
Embryo Survival

Although assisted reproduction technologies (ARTs) are recognised as safe, and most of the offspring seem apparently healthy, there is clear evidence that ARTs are associated with changes in the embryo’s developmental trajectory, which incur physiological consequences during the prenatal and postnatal stages of life. The present study aimed to address the influence of early (day-3 embryos) embryo transfer and cryopreservation on embryo survival, size, and metabolome at the preimplantation stage (day-6 embryos). To this end, fresh-transferred (FT) and vitrified-transferred (VT) embryos were compared using naturally-conceived (NC) embryos as a control reference. The results show that as in vitro manipulation was increased (NC < FT < VT), both embryo survival rate (0.91 ± 0.02, 0.78 ± 0.05 and 0.63 ± 0.05, for NC, FT, and VT groups, respectively) and embryo size (3.21 ± 0.49 mm, 2.15 ± 0.51 mm, 1.76 ± 0.46 mm of diameter for NC, FT, and VT groups, respectively) were significantly decreased. Moreover, an unbiased metabolomics analysis showed overall down-accumulation in 40 metabolites among the three experimental groups, with embryo transfer and embryo cryopreservation procedures both exerting a cumulative effect. In this regard, targeted metabolomics findings revealed a significant reduction in some metabolites involved in metabolic pathways, such as the Krebs cycle, amino acids, unsaturated fatty acids, and arachidonic acid metabolisms. Altogether, these findings highlight a synergistic effect between the embryo transfer and vitrification procedures in preimplantation embryos. However, the ex vivo manipulation during embryo transfer seemed to be the major trigger of the embryonic changes, as the deviations added by the vitrification process were relatively smaller.

47 A New Device and Method for Successful Vitrification of In Vitro-Produced Ovine Embryos

2018 ◽  
Vol 30 (1) ◽  
pp. 163
Author(s):  
S. Ledda ◽  
J. M. Kelly ◽  
S. K. Walker ◽  
Y. Natan ◽  
A. Arav
Keyword(s):  
Survival Rate ◽  
Embryo Transfer ◽  
Blastocyst Stage ◽  
Embryo Cryopreservation ◽  
Control Group ◽  
Hatching Rate ◽  
High Survival ◽  
Embryo Survival ◽  
New Device

To advance the use of embryo vitrification technology in veterinary practice, we developed a system in which embryo vitrification, warming, and dilution can be performed within a straw. An in-straw embryo cryopreservation method reduces the need for equipment and technical skills and can facilitate direct embryo transfer to the uterus. This study proposes the use of a new device named “Sarah” that is designed to permit all in-straw embryo cryopreservation procedures. Ovine in vitro-produced (IVP) embryos were vitrified at either early blastocyst stage (EB, n = 65, 6 days post-IVF) or fully expanded blastocyst stage (FB, n = 168, 7 days post-IVF). The vitrification procedure using Sarah constituted a 0.25-mL straw with a capsule having 50-µm pores inserted at one end. Embryos at each stage (EB and FB) were divided into 2 subgroups and vitrified by 1 of 2 methods: (1) multi-step (MS) group-a straw containing 2 embryos was sequentially loaded vertically into 1.5-mL tubes containing 6 different vitrification solutions: 10, 20, 40, 60, 80, or 100% ES (with 100% ES being 7.5% DMSO +7.5% EG + 20% FCS in TCM-199; 90 s each step) followed by 30 s each in 75 and 100% VS (100% VS being 18% DMSO +18% EG + 0.5 M trehalose + BSA in TCM-199); and (2) two-step (TS) group-the straw (2 embryos/straw) was loaded with 100% of ES (5 min), followed by 100% VS solution for 30 s. For both methods, at the end of the preparation steps, the straws were plunged directly into liquid N2. Non-vitrified embryos were maintained in in vitro culture as a control group (n = 102). The warming procedure consisted of placing the straws directly into 5-mL tubes containing 100, 50, 25% WS (WS = 1 M sucrose in TCM-199+ 20% FCS) at 38.6°C (for first solution) and at room temperature for all the rest (5 min each), before being placed into the holding medium. Embryos were recovered from the straws, incubated at 38.6 C in 5% CO2 in air in TCM 199 + 5% FCS, and evaluated for blastocoel re-expansion, embryo survival, and hatching rate at 2, 14, 48 h post-warming. Blastocyst re-expansion (2 h) after warming increased as the developmental stage progressed and was not affected by the vitrification method. In fact, it was significantly (P < 0.05) higher for FB vitrified in the MS and TS methods (77.90% and 71.25%, respectively) compared with the EB method (62.5% and 48.50%, respectively). At 24 h, survival rate of vitrified FB was significantly higher (P < 0.05) in the MS system (95.35%) compared with those in TS (86.25%). Survival rates of FB embryos for both methods (MS and TS) were significantly higher (P < 0.001) than EB embryos vitrified in MS (56.25%) and TS (56.55) methods. After 48 h of culture, the hatching rate for FB vitrified in the MS system (87.21%) was comparable with TS (77.5%) and control (85.3%) groups but significantly higher (P < 0.001) than vitrified EB in MS (43.75%) and TS (36.36%). In conclusion, we showed that a high survival rate of IVP embryos can be achieved by this new in-straw vitrification and warming device (“Sarah”), with hatching rates in vitro comparable with that of control fresh embryos. This method has the potential for use in direct embryo transfer in field conditions.

scholarly journals Birth of a Live Cria After Transfer of a Vitrified-Warmed Alpaca (Vicugna pacos) Preimplantation Embryo

2020 ◽  
Vol 7 ◽  
Author(s):  
Jennifer C. Lutz ◽  
Susan L. Johnson ◽  
Kimberly J. Duprey ◽  
Paul J. Taylor ◽  
Henry William Vivanco-Mackie ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Preimplantation Embryos ◽  
Embryo Survival ◽  
Important Species ◽  
Vicugna Pacos ◽  
Improvement Programs ◽  
The One ◽  
Humidified Air

The alpaca (Vicugna pacos) is an important species for the production of fiber and food. Genetic improvement programs for alpacas have been hindered, however, by the lack of field-practical techniques for artificial insemination and embryo transfer. In particular, successful techniques for the cryopreservation of alpaca preimplantation embryos have not been reported previously. The objective of this study was to develop a field-practical and efficacious technique for cryopreservation of alpaca preimplantation embryos using a modification of a vitrification protocol originally devised for horses and adapted for dromedary camels. Four naturally cycling non-superovulated Huacaya females serving as embryo donors were mated to males of proven fertility. Donors received 30 μg of gonadorelin at the time of breeding, and embryos were non-surgically recovered 7 days after mating. Recovered embryos (n = 4) were placed individually through a series of three vitrification solutions at 20°C (VS1: 1.4 M glycerol; VS2: 1.4 M glycerol + 3.6 M ethylene glycol; VS3: 3.4 M glycerol + 4.6 M ethylene glycol) before loading into an open-pulled straw (OPS) and plunging directly into liquid nitrogen for storage. At warming, each individual embryo was sequentially placed through warming solutions (WS1: 0.5 M galactose at 37°C; WS2: 0.25 M galactose at 20°C), and warmed embryos were incubated at 37°C in 5% CO2 in humidified air for 20–22 h in 1 ml Syngro® holding medium supplemented with 10% (v/v) alpaca serum to perform an initial in vitro assessment of post-warming viability. Embryos whose diameter increased during culture (n = 2) were transferred individually into synchronous recipients, whereas embryos that did not grow (n = 2) were transferred together into a single recipient to perform an in vivo assessment of post-warming viability. Initial pregnancy detection was performed ultrasonographically 29 days post-transfer when fetal heartbeat could be detected, and one of three recipients was pregnant (25% embryo survival rate). On November 13, 2019, the one pregnant recipient delivered what is believed to be the world's first cria produced from a vitrified-warmed alpaca embryo.

scholarly journals Fertility Preservation Success Subsequent to Concurrent Aromatase Inhibitor Treatment and Ovarian Stimulation in Women With Breast Cancer

2015 ◽  
Vol 33 (22) ◽  
pp. 2424-2429 ◽  
Author(s):  
Kutluk Oktay ◽  
Volkan Turan ◽  
Giuliano Bedoschi ◽  
Fernanda S. Pacheco ◽  
Fred Moy
Keyword(s):  
Breast Cancer ◽  
In Vitro Fertilization ◽  
Fertility Preservation ◽  
Embryo Transfer ◽  
Ovarian Stimulation ◽  
Live Birth Rate ◽  
Embryo Cryopreservation ◽  
Vitro Fertilization ◽  
Embryo Freezing

Purpose We have previously reported an approach to ovarian stimulation for the purpose of fertility preservation (FP) in women with breast cancer via embryo freezing with the concurrent use of letrozole. The aim of this study was to provide the pregnancy and FP outcomes when embryos generated with the same protocol are used. Patients and Methods In all, 131 women with stage ≤ 3 breast cancer underwent ovarian stimulation and received concurrent letrozole 5 mg per day before receiving adjuvant chemotherapy and cryopreserving embryos. Results Thirty-three of the 131 women underwent 40 attempts to transfer embryos to their own uterus (n = 18) or via the use of a gestational carrier (n = 22) at a mean age of 41.5 ± 4.3 years with a median 5.25 years after embryo cryopreservation. The overall live birth rate per embryo transfer was similar to the US national mean among infertile women of a similar age undergoing in vitro fertilization–embryo transfer (45.0 v 38.2; P = .2). Seven (38.8%) of the 18 pregnancies were twins with no higher-order pregnancies being encountered. No fetal anomalies or malformations were reported in 25 children after a mean follow-up of 40.4 ± 26.4 months. Seventeen of the 33 women attempting pregnancy had at least one child, translating into an FP rate of 51.5% per attempting woman. Conclusion Embryo cryopreservation after ovarian stimulation with the letrozole and follicle-stimulating hormone protocol preserves fertility in women with breast cancer and results in pregnancy rates comparable to those expected in a noncancer population undergoing in vitro fertilization.

100 EMBRYO SURVIVAL AND CONCEPTUS ELONGATION FOLLOWING ASYNCHRONOUS EMBRYO TRANSFER IN CATTLE

2015 ◽  
Vol 27 (1) ◽  
pp. 143
Author(s):  
F. Randi ◽  
B. Fernandez ◽  
M. McDonald ◽  
C. Johnson ◽  
N. Forde ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Prostaglandin F2α ◽  
Early Embryo ◽  
Embryo Survival ◽  
Treatment Groups ◽  
Length Data ◽  
Uterine Environment ◽  
To Receive ◽  
Intravaginal Device

Maternal progesterone (P4) regulates early conceptus growth and development in ruminants. Early embryo transfer studies in sheep and cattle demonstrated a need for close synchrony between the embryo and the uterine environment of the recipient. However, manipulating P4 may be one way of strategically regulating the temporal changes that normally occur in the uterine environment in order to allow flexibility in the timing of embryo transfer. For example, previous studies have demonstrated that P4 administration during the first few days of the oestrous cycle facilitates pregnancy establishment with older embryos. The aim of this study was to examine the effect of embryo-uterine synchrony on conceptus elongation in cattle. Oestrous cycles of crossbred beef heifers were synchronised using an 8-day P4-Releasing Intravaginal Device (PRID Delta®, CEVA, Mountain View, CA, USA) with administration of a prostaglandin F2α analogue (Enzaprost®, CEVA; 5 mL equivalent to 25 mg of dinoprost) given on the day before PRID removal. Heifers were checked for signs of oestrus 4 times per day commencing 30 h after PRID withdrawal. Only those seen in standing oestrus (n = 50) were randomly assigned to 1 of 5 treatment groups to receive Day 7 in vitro-produced blastocysts (n = 10 per recipient) (1) on Day 5 post-oestrus; (2) on Day 5, with P4 supplementation via PRID from Day 3 to 5 + 750 IU of eCG at PRID insertion; (3) on Day 5, PRID Delta from Day 3 to 5 plus 3000 IU of hCG at PRID insertion; (4) on Day 7, or (5) on Day 9. At embryo age Day 14, all heifers were slaughtered and the uterus was flushed to recover and measure conceptuses. Data are summarised in Table 1. Fewer recipients yielded conceptuses (P < 0.05) and fewer conceptuses overall were recovered (P < 0.05) following transfer on Day 5 compared with Day 7 or Day 9. Supplementation with P4 resulted in short cycles (evidenced by corpus luteum regression and/or a recent ovulation at slaughter) in 33.3 to 54.5% of recipients receiving embryos on Day 5. Mean conceptus length was greater (P < 0.05) following transfer to an advanced uterus. In conclusion, transfer of embryos to a retarded (Day 5) uterine environment results in poor embryo survival. Supplementation with P4 shortened the interoestrous period in a significant number of heifers. Transfer to an advanced uterine environment promotes conceptus elongation, presumably driven by P4. Table 1.Embryo survival and conceptus length data

Embryo cryopreservation and in vitro culture of preimplantation embryos in Campbell's hamster (Phodopus campbelli)

2015 ◽  
Vol 83 (6) ◽  
pp. 1056-1063 ◽  
Author(s):  
Sergei Amstislavsky ◽  
Eugeny Brusentsev ◽  
Elena Kizilova ◽  
Tatyana Igonina ◽  
Tatyana Abramova ◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Preimplantation Embryos ◽  
Embryo Cryopreservation ◽  
Phodopus Campbelli

scholarly journals Single-cell Transcriptomic Analysis Reveals the Cellular Heterogeneity of Mesenchymal Stem Cells

2021 ◽  
Author(s):  
Chen Zhang ◽  
Xueshuai Han ◽  
Jingkun Liu ◽  
Lei Chen ◽  
Ying Lei ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Single Cell ◽  
Ex Vivo ◽  
Developmental Trajectory ◽  
Cellular Heterogeneity ◽  
Multipotent Progenitor Cells ◽  
Definition Of

Ex vivo-expanded mesenchymal stem cells (MSCs) have been demonstrated to be a heterogeneous mixture of cells exhibiting varying proliferative, multipotential, and immunomodulatory capacities. However, the exact characteristics of MSCs remain largely unknown. By single-cell RNA sequencing of 61,296 MSCs derived from bone marrow and Wharton's jelly, we revealed five distinct subpopulations. The developmental trajectory of these five MSC subpopulations were mapped, revealing a differentiation path from stem-like active proliferative cells (APCs) to multipotent progenitor cells, followed by the branching into two paths - adipogenesis or osteochondrogenesis - and subsequent differentiation into unipotent prechondrocytes. The stem-like APCs, expressing the perivascular mesodermal progenitor markers CSPG4/MCAM/NES, uniquely exhibited strong proliferation and stemness signatures. Remarkably, the prechondrocyte subpopulation specifically expressed immunomodulatory genes and was able to suppress activated CD3+ T cell proliferation in vitro, supporting the role of this population in immunoregulation. In summary, our analysis mapped the heterogeneous subpopulations of MSCs and identified two subpopulations with potential functions in self-renewal and immunoregulation. Our findings advance the definition of MSCs by identifying the specific functions of its heterogeneous cellular composition, allowing for more specific and effective MSC application through the purification of its functional subpopulations.

91 PRELIMINARY RESULTS OF SURGICAL EQUINE EMBRYO TRANSFER AFTER OPEN PULLED STRAW VITRIFICATION

2006 ◽  
Vol 18 (2) ◽  
pp. 154 ◽  
Author(s):  
G. Duchamp ◽  
F. Guignot ◽  
J. Grizelj ◽  
M. Vidament ◽  
P. Mermillod
Keyword(s):  
Calf Serum ◽  
Embryo Cryopreservation ◽  
Success Rates ◽  
Ringer Lactate ◽  
Embryo Survival ◽  
Preliminary Study ◽  
Higher Sensitivity ◽  
Conventional Freezing

In equine species, embryo cryopreservation is not as widely developed as in some other species. Slow freezing has been applied to equine embryos but with relatively low success rates. This higher sensitivity to conventional freezing procedures may be explained by the presence of a capsule surrounding the equine embryo that may impair cryoprotectant penetration. Recently, good in vitro embryo survival rate was obtained after open pulled straw (OPS) vitrification (Moussa et al. 2005 Theriogenology 64, 1619–1632). The aim of the present study was to evaluate in vivo survival of vitrified embryos five days after surgical transfer into Welsh pony mares. Morulae (M), early blastocysts (EB), and blastocysts (B) ranging from 140 to 320 μm in diameter were collected (n = 20) in a Ringer lactate solution on Day 6.75 after ovulation. Before vitrification, embryos were assessed morphologically and their size was measured (McKinnon and Squires 1988 J. Am. Vet. Med. Assoc. 192, 401–406). Then, embryos were vitrified using the OPS method described by Berthelot et al. (2001 Reprod. Nutr. Dev. 41, 267–272). Briefly, embryos were washed twice in HEMES-TCM-199 + 20% newborn calf serum (NBCS) for 1 min, equilibrated in HEPES-TCM-199 + 20% NBCS with 7.5% dimethyl sulfoxide (DMSO) + 7.5% ethylene glycol (EG) for 3 min, and then with 18% DMSO + 18% EG + 0.4 M sucrose for 45 s. One embryo was then loaded per straw. For transfer, four straws were quickly thawed (5 s in air) and the narrow end of the straw containing the embryo was immersed in HEPES-TCM-199 + 20% NBCS + PBS + 0.2 M sucrose. Five to 8 min after thawing, four embryos were surgically transferred into the cranial portion of the uterine horn in each of five pony mare recipients. Five days after transfer, embryos recovered by transcervical flushing of the uterus were classified as viable if morphology was normal, no dark inner cells were present, the capsule was intact, and the diameter was at least 1000 μm. The results are shown in the table. One recipient of vitrified embryos had an endometritis and no embryo was recovered. From the four other recipients, nine embryos were recovered out of 16 (56%) transferred, seven of which were viable (44%). The results of the present preliminary study demonstrating survival of equine embryos transferred after OPS vitrification is very encouraging. However, the results should be confirmed by birth of foals after transfer of OPS-vitrified embryos to recipients. Table

96 THE EFFECT OF CHEMICAL DELIPIDATION ON CRYOPRESERVABILITY OF CAT EMBRYOS

2011 ◽  
Vol 23 (1) ◽  
pp. 153 ◽  
Author(s):  
T. Tharasanit ◽  
M. Techakumphu
Keyword(s):  
Embryo Cryopreservation ◽  
Blastocyst Formation ◽  
Freezing And Thawing ◽  
Intracellular Lipid ◽  
Embryo Survival ◽  
Senior Research ◽  
In Utero Development ◽  
Long Term Preservation

Embryo cryopreservation is a desired technique for long-term preservation of embryos. However, the success rate of cryopreserved in vitro produced cat embryos is currently poor. Until recently, the mechanism underlying the cause of cryoinjury that occurs during cooling and cryopreservation is not well understood. This study aimed to examine the effect of chemical delipidation (forskolin) before cryopreservation of 4- to 8-cell cat embryos on post-thaw embryo survival and in vitro developmental capability. A total of 333 cumulus oocyte complexes (COCs) were matured and fertilized in vitro. At 24 h post-IVF, the presumptive embryos were randomly assigned into one of the following groups: 1) non-frozen control (n = 63); 2) forskolin treatment without freezing (n = 52); 3) freezing without forskolin (n = 77); and 4) freezing after forskolin treatment (n = 89). The embryos were cryopreserved using a programmable controlled-rate freezer. After freezing and thawing, the embryos were subsequently cultured in vitro for a further 6 days. The development competence was assessed by morula and blastocyst rates on Days 5 and 8 of their development, respectively. Percentages of cleaved embryos on Day 2 (IVF = Day 0) did not significantly differ among groups, indicating that there was no adverse effect of forskolin on cleavage rates. Furthermore, blastocyst formation rates of cat embryos treated with forskolin (53.5 ± 3.1) did not significantly differ when compared with non-treated controls (54 ± 9.3). Forskolin-treated embryos survived after cryopreservation at a higher rate than non-forskolin treatment, in terms of survival (93.1 ± 2.6 v. 88.2 ± 1.4), morula (56.9 ± 7.6 v. 40.8 ± 5.7), and blastocyst formation (47.6 ± 6.4 v. 35.6 ± 3.6) rates. It is concluded that partial delipidation of cat embryos before cryopreservation improves the cryopreservability of cat embryos. This study demonstrates that intracellular lipid has an impact on cryopreservability of cat embryos. Further study is required to examine in utero development of these delipidated embryos after embryo transfer. This study was financially supported by the Zoo organisation of Thailand and CHE-TRF Senior Research Scholars RTA-5080010.

66 DEVELOPMENT OF IN VITRO-PRODUCED CAT EMBRYOS AFTER VITRIFICATION AND NONSURGICAL EMBRYO TRANSFER: PRELIMINARY RESULTS

2009 ◽  
Vol 21 (1) ◽  
pp. 133
Author(s):  
E. Iacono ◽  
B. Merlo ◽  
M. Regazzini ◽  
D. Zambelli
Keyword(s):  
Ethylene Glycol ◽  
Embryo Transfer ◽  
Domestic Cat ◽  
Embryo Survival ◽  
Abdominal Ultrasonography ◽  
Preliminary Results ◽  
Pregnancy Status ◽  
Viable Embryo

There are no refereed reports on vitrification of domestic cat embryos derived from in vitro-matured oocytes and transferred using a nonsurgical embryo transfer technique. The aim of this study was to verify the effects of vitrification on the in vitro and in vivo developmental ability of in vitro-produced (IVP) cat blastocysts. Oocytes recovered from minced ovaries were matured, fertilized, and cultured in vitro as previously reported (Merlo B et al. 2005 Theriogenology 63, 2032–2039). On Day 7 of in vitro culture (IVC), blastocysts were selected and vitrified in straws (Cristal ET 0.25 mL, 133 mm, IMV-Technologies, Paillette Crista, France). For vitrification (modified from Campos-Chillòn LF et al. 2006 Theriogenology 65, 1200–1214), the embryos were transferred in 1 mL of V1 [ethylene glycol 3.5 m in HEPES synthetic oviductal fluid (HSOF)] for 3 min, and then in 10 μL of V2 (ethylene glycol 7 m, galactose 0.5 m, Ficoll 70 18% in HSOF) for 20 s. Finally, the embryos were loaded in straws preloaded with 190 μL of dilution solution (galactose 0.5 m in HSOF). Straws were heat sealed and immediately plunged into liquid nitrogen. Vitrified embryos were warmed in air for 10 s, and then in a waterbath at 37°C for 30 s. For developmental ability and in vitro evaluation, 27 embryos were warmed and immediately examined: 25 re-expanded, 2 did not re-expand, and 1 had damaged zona pellucida. Re-expanded embryos were cultured in SOF plus amino acids, 16 mg mL–1 BSA, and 5% fetal bovine serum at 38.5°C in 5% O2, 5% CO2, 90% N2. After 24 h of IVC, only 4 blastocysts were expanded, and after 48 h, embryos were clearly degenerated or shrunk. in vivo developmental ability was tested by nonsurgical embryo transfer of 8 vitrified-warmed embryos and 6 IVP fresh embryos into 2 natural estrus queens, injected with 200 IU of hCG i.m. (Day 0) for induction of ovulation. Ovulation was confirmed by plasmatic progesterone assay on Day 5. Nonsurgical embryo transfer was made on Day 8 using the catheter proposed by Zambelli et al. 2001 for transcervical insemination in the cat. The catheter was connected to a 1-mL syringe and loaded with the embryos. Then, it was inserted in the vagina and transrectally guided into the uterus, where the embryos were deposited. To assess pregnancy status, abdominal ultrasonography was done on recipients on Day 13, 25, and 40. On Day 13, an embryonic vesicle was observed in both queens, although a smaller diameter than expected was detected in the recipient of the vitrified embryos. On Day 25, a viable embryo was detected only in the recipient of fresh IVP embryos. On Day 40, the gestational chamber was still present but no sign of a viable embryo was detected. Further studies are in progress to improve the nominal incidence of pregnancy and frequency of embryo survival after vitrification. Nevertheless, the preliminary results obtained using an AI catheter for nonsurgical embryo transfer are encouraging, and the improvement of the technique could make it reliable in the cat. Supported by Animal Stem Cells Laboratory, Regione Emilia Romagna, PRRIITT Project Number M-404AIWTSV.

363 FACTORS INFLUENCING PREGNANCY RATES FOLLOWING TRANSFER OF BOVINE IN VIVO EMBRYOS BIOPSIED FOR SEX DETERMINATION

2007 ◽  
Vol 19 (1) ◽  
pp. 297
Author(s):  
S. Li ◽  
W. Yu ◽  
J. Fu ◽  
Y. Bai ◽  
F. Jin ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Embryo Transfer ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Embryo Survival ◽  
Chi Square Test ◽  
First Time ◽  
Fresh Embryos

Data collected from commercial embryo transfer programs in 63 farms in China during June 2002 to December 2005 was analyzed to examine the effects of various factors (biopsy, freezing, sample size, embryo development and quality, in vitro culture, and recipient quality) on pregnancy rates of in vivo-biopsied embryos. Embryos were flushed from superovulated dairy cattle and subjected to a biopsy for sexing determination using protocols and sexing kits supplied by AB Technology Ltd. Fresh embryos were implanted on the same day or frozen with AG freeze medium (AB Technology Ltd., Pullman, WA, USA) for later transfer. Recipients were synchronized with CIDA + PG protocols. Embryos were cultured in 6-well dishes containing 1.3 mL of holding medium (AB Technology Ltd.) in each well at room temperature (20–25�C) for examination of embryo survival in vitro. The chi-square test was used in statistic analysis. The implantation of fresh embryos after biopsy did not affect pregnancy rates (49.6%, 257/518) compared to that of non-biopsied fresh and frozen–thawed embryo groups (52.9%, 47/140 and 46.6%, 177/380, respectively). However, for biopsied embryos subjected to frozen and thawed procedures before implantation, particularly for those subjected to the removal of a larger biopsy, a reduced pregnancy rate was observed (41.8%, 297/710; P &lt; 0.01). Pregnancy rates among biopsied embryos at 3 different development stages (morula-early blastocyst, blastocyst, and expanded blastocyst) were not different. Similar results were found between embryo groups of grade 1 and 2. A significant decrease in pregnancy rate (0/10) was observed with embryos held in vitro for a longer period of time (&gt;5 h), suggesting detrimental effects of in vitro conditions on embryo survival. The highest pregnancy rate (68.0%) was observed in recipients synchronized for the first time before being implanted with biopsied embryos. Significant decreases in such rates were found in recipients synchronized for the second or third times or those with an abortion history at the first or second synchronization-implantation treatment (P &lt; 0.01). Better pregnancy rates (45.6%, 41/90; 46.1%, 76/165; and 45.5%, 5/11) were obtained for recipients implanted with biopsied embryos at Days 7.5, 8.0, and 8.5 post-heat detection, respectively, compared to 16% at Day 7 (3/18, P &lt; 0.05). It is concluded that mechanical treatment (cutting) does not reduce the survival of biopsied embryos; however, cryopreservation reduces their ability to survive in vivo. The analyses also suggest that holding embryos in vitro should not be longer than 5 h unless more favorable in vitro conditions can be provided. To achieve better results of implantation of biopsied embryos, embryo transfer should be performed during 7.5–8.5 days post-estrus, and the healthy recipients synchronized for the first time should be used.

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