scholarly journals Ribosomal RNA gene expression and chromosome aberrations in bovine oocytes and preimplantation embryos

Reproduction ◽  
2001 ◽  
pp. 21-30 ◽  
Author(s):  
P Hyttel ◽  
D Viuff ◽  
T Fair ◽  
J Laurincik ◽  
PD Thomsen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Chromosome Aberrations ◽  
Rrna Genes ◽  
Preimplantation Embryos ◽  
Fertilization In Vitro ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Oocyte Growth

This review focuses on the key features of development of the bovine oocyte and embryo, with comparisons of the developmental characteristics of embryos produced in vivo and in vitro. The oocyte is transcriptionally quiescent in the primordial and primary follicle. In the secondary follicle transcription is initiated in the oocyte and a ribosome-synthesizing nucleolus is established in this cell. Transcription and nucleolar activity are enhanced in the tertiary follicle during oocyte growth. When the oocyte reaches approximately 110 microm in diameter, corresponding to a follicle of about 3 mm in diameter, transcription ceases and the nucleolus is inactivated, forming a dense spherical remnant. During the final phase of follicular dominance this remnant becomes vacuolated and, in conjunction with resumption of meiosis, it disperses. The rRNA genes are apparently re-activated during the four-cell stage, that is, the third cell cycle after fertilization, but a nucleolus is not formed. During the subsequent cell cycle, that is, during the eight-cell stage, ribosome-synthesizing nucleoli are again established. Bovine embryos produced in vitro apparently display the same pattern of nucleolus development as that in embryos developed in vivo. Examination of the ploidy of embryonic cells using fluorescence in situ hybridization has revealed that the production of bovine embryos in vitro is associated with increased chromosome aberrations in the embryos. Blastocysts produced in vitro display a significantly higher rate of mixoploidy, that is, when the embryo consists of both normal diploid and abnormal polyploid cells, than that in embryos developed in vivo. The rate of mixoploidy among embryos produced in vitro increases with increasing developmental stage. Moreover, after fertilization in vitro, initially there is a high rate of 'true' polyploidy, that is, when all cells of the embryos are polyploid. However, the polyploid embryos are eliminated before they cleave beyond the eight-cell stage, the stage at which major activation of the embryonic genome occurs in cattle.

180 IDENTIFICATION AND QUANTIFICATION OF DIFFERENTIALLY REPRESENTED TRANSCRIPTS IN PREIMPLANTATION BOVINE EMBRYOS

2008 ◽  
Vol 20 (1) ◽  
pp. 169 ◽  
Author(s):  
C. E. McHughes ◽  
G. K. Springer ◽  
L. D. Spate ◽  
R. Li ◽  
R. J. Woods ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Nuclear Transfer ◽  
Developmental Stages ◽  
Reproductive Technologies ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Production Techniques

Identification of transcripts that are present at key development stages of preimplantation embryos is critical for a better understanding of early embryogenesis. To that end, this project had two goals. The first was to characterize the relative abundance of multiple transcripts during several developmental stages, including metaphase II-stage oocytes (MPII), and 2-cell-stage (2-cell), precompact morula (PCM), and in vitro-produced blastocyst-stage (IVTBL) embryos. The second was to characterize differences in the relative abundance of transcripts present in in vivo- (IVVBL), in vitro-, and nuclear transfer-produced (NTBL) blastocysts. It was our hypothesis that the identification of differentially represented transcripts from these stages would reveal not only developmentally important genes, but also genes that might be aberrantly expressed due to embryo production techniques. Individual clusters from a large bovine EST project (http://genome.rnet.missouri.edu/Bovine/), which focused on female reproductive tissues and embryos, were compared using Fisher's exact test weighted by number of transcripts per tissue by gene (SAS PROC FREQ; SAS Institute, Inc., Cary, NC, USA). Of the 3144 transcripts that were present during embryogenesis, 125 were found to be differentially represented (P < 0.01) in at least one pairwise comparison (Table 1). Some transcripts found to increase in representation from the MPII to the 2-cell stage include protein kinases, PRKACA and CKS1, as well as the metabolism-related gene, PTTG1. These same transcripts were also found to decrease in representation from the 2-cell to the PCM stage. RPL15 (translation) and FTH1 (immune function) were both more highly represented in the PCM than in the 2-cell stage. From PCM to IVTBL, we saw an increase in RPS11, another translation-related transcript. When comparing blastocyst-stage embryos from different production techniques, several transcripts involved in energy production (e.g., COX7B and COX8A) were found to be more highly represented in the NTBL than in the IVTBL. COX8A was also more highly represented in the IVVBL than in the IVTBL. By investigating these differentially represented transcripts, we will be able to better understand the developmental implications of embryo manipulation. We may also be able to better develop reproductive technologies that lead to in vitro- and nuclear transfer-derived embryos which more closely follow a normal program of development. Table 1. Differentially represented transcripts between developmental stages

159 USE OF PHYTOHEMAGGLUTININ-L, AS AN AGGLUTINATOR AGENT, TO PRODUCE CHIMERAS OF IVF BOVINE EMBRYOS

2010 ◽  
Vol 22 (1) ◽  
pp. 238
Author(s):  
I. P. Emanuelli ◽  
B. F. Agostinho ◽  
M. P. M. Mancini ◽  
C. M. Barros ◽  
M. F. G. Nogueira
Keyword(s):  
Embryonic Stem ◽  
Blastocyst Stage ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Exact Test ◽  
Fisher's Exact Test ◽  
Stage Of Development ◽  
Fisher’S Exact Test

Embryonic chimeras have been used as a tool to understand embryogenesis and organogenesis, as well as to prove, in vivo, the pluripotency of the embryonic stem cells. One of the techniques used to obtain embryonic chimeras is aggregation, which can be performed with intact or half-embryos and in different stages of the development, produced by in vivo or in vitro systems and in different wells. However, its efficiency tends to reduce when advanced stages, such as morulae and blastocysts, are used. The aim of this work was to evaluate the effect of the treatment with an agglutinating agent (phytohemagglutinin-L; PHA) in the percentage of chimeras produced with IVF bovine embryos. Bovine ovaries (from abattoir) were used to obtain 270 COC that were matured in drops (90 μL) of TCM-199 bicarbonate medium, supplemented with 10% of FCS, and incubated in vitro for 22 to 24 h. The fertilization occurred in TALP-IVF medium, and the COC were maintained in the incubator for 18 h. After fertilization, the presumptive zygotes were transferred to SOF culture medium to in vitro culture. In vitro maturation, fertilization, and culture were performed under 38.5°C, 5% CO2 in air and saturated humidity. The chimerism by aggregation was tested between 2 intact (zona-free) 8- to 16-cell stage embryos in the presence (G1, n = 16) or absence of PHA (G2, n = 14) and between one half-morula and one half-blastocyst with (G3, n = 15) or without PHA (G4, n = 12). The embryos in groups G1 and G3 were treated with PHA in a concentration of 500 μLg mL-1 for 3 min. After PHA treatment, the pairs of embryos were allocated in wells, under previously described culture conditions, until expanded blastocyst stage could be observed (Day 7 of culture). At 24 h of culture, embryonic aggregation pairs were first evaluated to detect only cohesive masses of cells. The results (chimerism rate) were 62.5%, 42.9%, 40.0%, and 25.0%, respectively, for groups G1, G2, G3, and G4. There were no significant differences neither among groups (chi-square, P = 0.252) nor between G1 and G2 (P = 0.464), G3, and G4 (P = 0.683; Fisher’s exact test). Main effects as use of PHA (G1 + G3 v. G2 + G4, P = 0.284) and stage of embryos (G1 + G2 v. G3 + G4, P = 0.183; Fisher’s exact test) were not statistically significant. However, when all groups were compared, the power of the performed test (0.354) was below the desired power of 0.800 (i.e. one must be cautious in over-interpreting the lack of difference among them). In the conditions of this study, it was concluded that the treatment with PHA did not increase the rate of aggregation in the embryonic chimera production, even for half-embryos in advanced stage of development (morulae and blastocysts). Granted by FAPESP, Brazil: 06/06491-2 and 07/07705-9 (MFGN) and 07/04291-9 (MPMM).

scholarly journals Effect of Increased Urea Levels on Mouse Preimplantation Embryos Developed in Vivo and in Vitro

2012 ◽  
Vol 56 (2) ◽  
pp. 211-216 ◽  
Author(s):  
Ján Bystriansky ◽  
Ján Burkuš ◽  
Štefan Juhás ◽  
Dušan Fabian ◽  
Juraj Koppel
Keyword(s):  
Apoptotic Cell ◽  
Nitrogen Concentration ◽  
High Plasma ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Plasma Urea ◽  
High Concentrations

Abstract High plasma urea nitrogen concentration has been proposed as an important factor contributing to the decline in reproductive parameters of domestic animals. The aim of this study was to evaluate the effect of urea on the development of preimplantation embryos in a mouse model. During in vivo tests, acute renal failure (ARF) accompanied by hyper-uraemia was induced by intramuscular administration of glycerol (50%) into hind limbs of fertilised dams. During in vitro tests, embryos collected from healthy dams were cultured in a medium with the addition of various concentrations of urea from the 4-cell stage to the blastocyst stage. Stereomicroscopic evaluation and fluorescence staining of embryos obtained from dams with ARF showed that high blood urea is connected with an increase in the number blastocysts containing at least one apoptotic cell and in the incidences of dead cells per blastocyst, but it did not affect their ability to reach the blastocyst stage. In vitro tests showed that culture of embryos with urea at concentration of 10 mM negatively affected the quality of obtained blastocysts. Blastocysts showed significantly lower numbers of cells and increased incidence of dead cells. An increase in apoptosis incidence was observed even in blastocysts obtained from cultures with 5 mM urea. Urea at concentrations 50 mM and higher negatively affected the ability of embryos to reach the blastocyst stage and the highest used concentrations (from 500 mM) caused overall developmental arrest of embryos at the 4- or 5- cell stage. These results show that elevated levels of urea may cause changes in the microenvironment of developing preimplantation embryos, which can negatively affect their quality. Embryo growth remains un-affected up to very high concentrations of urea.

Spent culture medium analysis from individually cultured bovine embryos demonstrates metabolomic differences

Zygote ◽  
2017 ◽  
Vol 25 (6) ◽  
pp. 662-674 ◽  
Author(s):  
Kayla J. Perkel ◽  
Pavneesh Madan
Keyword(s):  
Culture Medium ◽  
Physiological State ◽  
Proton Nuclear Magnetic Resonance ◽  
Preimplantation Embryos ◽  
Bovine Embryos ◽  
Cleavage Rate ◽  
Cell Stage ◽  
Isoleucine Leucine ◽  
H Nmr

SummarySpent culture medium can provide valuable information regarding the physiological state of a bovine preimplantation embryos through non-invasive analysis of the sum/depleted metabolite constituents. Metabolomics has become of great interest as an adjunct technique to morphological and cleavage-rate assessment, but more importantly, in improving our understanding of metabolism. In this study, in vitro produced bovine embryos developing at different rates were evaluated using proton nuclear magnetic resonance (1H NMR). Spent culture medium from individually cultured embryos (2-cell to blastocyst stage) were divided into two groups based on their cleavage rate fast growing (FG) and slow growing (SG; developmentally delayed by 12–24 h), then analyzed by a 600 MHz NMR spectrometer. Sixteen metabolites were detected and investigated for sum/depletion throughout development. Data indicate distinct differences between the 4-cell SG and FG embryos for pyruvate (P < 0.05, n = 9) and at the 16-cell stage for acetate, tryptophan, leucine/isoleucine, valine and histidine. Overall sum/depletion levels of metabolites demonstrated that embryos produced glutamate, but consumed histidine, tyrosine, glycine, methionine, tryptophan, phenylalanine, lysine, arginine, acetate, threonine, alanine, pyruvate, valine, isoleucine/leucine, and lactate with an overall trend of higher consumption of these metabolites by FG groups. Principal component analysis revealed distinct clustering of the plain medium, SG, and FG group, signifying the uniqueness of the metabolomic signatures of each of these groups. This study is the first of its kind to characterize the metabolomic profiles of SG and FG bovine embryos produced in vitro using 1H NMR. Elucidating differences between embryos of varying developmental rates could contribute to a better understanding of embryonic health and physiology.

scholarly journals Coordinated Formation of IMPDH2 Cytoophidium in Mouse Oocytes and Granulosa Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Shiwen Ni ◽  
Teng Zhang ◽  
Chenmin Zhou ◽  
Min Long ◽  
Xuan Hou ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Granulosa Cells ◽  
De Novo ◽  
Biological Significance ◽  
Preimplantation Embryos ◽  
Inosine Monophosphate Dehydrogenase ◽  
Cell Stage ◽  
Simultaneous Formation

Inosine monophosphate dehydrogenase (IMPDH), the rate-limiting enzyme catalyzing de novo biosynthesis of guanine nucleotides, aggregates under certain circumstances into a type of non-membranous filamentous macrostructure termed “cytoophidium” or “rod and ring” in several types of cells. However, the biological significance and underlying mechanism of IMPDH assembling into cytoophidium remain elusive. In mouse ovaries, IMPDH is reported to be crucial for the maintenance of oocyte–follicle developmental synchrony by providing GTP substrate for granulosa cell natriuretic peptide C/natriuretic peptide receptor 2 (NPPC/NPR2) system to produce cGMP for sustaining oocyte meiotic arrest. Oocytes and the associated somatic cells in the ovary hence render an exciting model system for exploring the functional significance of formation of IMPDH cytoophidium within the cell. We report here that IMPDH2 cytoophidium forms in vivo in the growing oocytes naturally and in vitro in the cumulus-enclosed oocytes treated with IMPDH inhibitor mycophenolic acid (MPA). Inhibition of IMPDH activity in oocytes and preimplantation embryos compromises oocyte meiotic and developmental competences and the development of embryos beyond the 4-cell stage, respectively. IMPDH cytoopidium also forms in vivo in the granulosa cells of the preovulatory follicles after the surge of luteinizing hormone (LH), which coincides with the resumption of oocyte meiosis and the reduction of IMPDH2 protein expression. In cultured COCs, MPA-treatment causes the simultaneous formation of IMPDH cytoopidium in cumulus cells and the resumption of meiosis in oocytes, which is mediated by the MTOR pathway and is prevented by guanosine supplementation. Therefore, our results indicate that cytoophidia do form in the oocytes and granulosa cells at particular stages of development, which may contribute to the oocyte acquisition of meiotic and developmental competences and the induction of meiosis re-initiation by the LH surge, respectively.

scholarly journals 160 IN VIVO-CULTURE OF BOVINE EMBRYOS: TRANSFER OF SEMEN PRE-INCUBATED OOCYTES, ZYGOTES AND 4 TO 8 CELL STAGE EMBRYOS INTO THE BOVINE OVIDUCT

2005 ◽  
Vol 17 (2) ◽  
pp. 231
Author(s):  
V. Havlicek ◽  
F. Wetscher ◽  
T. Huber ◽  
M. Gilles ◽  
D. Tesfaye ◽  
...  
Keyword(s):  
Embryo Development ◽  
Calf Serum ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Group Iii ◽  
Group I ◽  
In Vivo Culture ◽  
Group Ii

Oviduct as well as oocyte and embryo development are subject to developmental changes which have crucial effects on the application of in vivo culture. The present study aimed at optimizing in vivo culture of IVP bovine embryos at different developmental stages in the bovine oviduct. Cumulus oocyte complexes (COC) were collected from slaughterhouse ovaries, matured in vitro for 22 h and assigned to four groups. In groups I and II, oocytes were pre-incubated for 3 to 4 h with 5 × 106 sperm/mL, and then immediately transferred to recipients, which had just completed ovulation (group I), or kept in vitro for a further 12 to 18 h and transferred to Day 1 synchronized recipients (group II). In groups III and IV, COC were subjected to standard IVF/IVC; then embryos were either transferred at the 4- to 8-cell stage on Day 3 into the oviducts of Day 3-synchronized recipients (group III) or kept in vitro for a further 4 to 5 days (group IV). Thirty-four 18- to 30-month-old temporary recipients were synchronized using a standard Ovsynch protocol. COC and embryos were transferred and re-collected by transvaginal endoscopy. COC or embryos were loaded into a 180° curved glass capillary, which was inserted via the infundibulum 5 to 8 cm deep into the ampulla ipsilateral to the CL. On recipient Day 7, a 90° curved metal canula served for tubal flushing prior to conventional uterine embryo flushing. Sixty mL of PBS containing 1% fetal calf serum were rinsed through the oviduct into the uterus and a further 400 mL of medium were finally used for flushing of the uterine horn and collected via an embryo filter. Embryo development was evaluated directly after flushing (Day 7) and on Day 8. For statistical analysis (ANOVA), the blastocyst rates (Days 7 and 8) in group III were related to COC corrected by the collection rate. In group I, 575 COC were transferred to 11 recipients and 420 (73%) were re-collected as oocytes or embryos. The blastocyst yields on Day 7 and Day 8 were 23% (97) and 25% (104), respectively. In group II, the transfer of 489 presumptive zygotes into 13 heifers resulted in only 175 re-collected (36%), of which 15% developed into blastocysts (Day 7: 26; Day 8: 27). Ten heifers (group III) served for in vivo culture of 643 embryos at the 4- to 8-cell stage. On Day 7, 568 (88%) embryos were flushed and 171 (30%) reached the blastocyst stage. A further 24 h culture in vitro finally resulted in 244 (42%) blastocysts. The complete in vitro production system delivered 13% (63/477) blastocysts on Day 7 and 34% (161/477) blastocysts on Day 8. The collection rates (P < 0.001) and the blastocyst rates on Day 7 (P < 0.05) and Day 8 (P < 0.001) differed significantly in all groups. The present data demonstrate that the developmental stage of transferred complexes has an influence on embryo recovery as well as an embryo development. This work was supported by Austrian BMBWK and BMLFUW (#1227).

scholarly journals 243TEMPORAL DIVERGENCE IN THE PATTERN OF MRNA EXPRESSION IN BOVINE EMBRYOS CULTURED FROM THE ZYGOTE TO BLASTOCYST STAGE IN VITRO OR IN VIVO

2004 ◽  
Vol 16 (2) ◽  
pp. 242
Author(s):  
P. Lonergan ◽  
D. Rizos ◽  
A. Gutierrez-Adan ◽  
P.M. Moreira ◽  
B. Pintado ◽  
...  
Keyword(s):  
Growth Factor ◽  
Relative Abundance ◽  
Transcript Abundance ◽  
Blastocyst Stage ◽  
Insulin Like Growth Factor ◽  
Bovine Embryos ◽  
Interferon Tau ◽  
Cell Stage

The objective of this study was to examine the time during the post-fertilization culture period that gene expression patterns of in vitro cultured bovine embryos diverge from those of their in vivo cultured counterparts. Presumptive bovine zygotes were produced by IVM/IVF of immature oocytes collected from the ovaries of slaughtered animals. At approximately 20h post-insemination (hpi), presumptive zygotes were randomly divided into two culture groups, either in vitro in synthetic oviduct fluid or in vivo, and transferred into the ewe oviduct. Embryos were recovered from both systems at approximately 30hpi (2-cell), two (4-cell), three (8-cell), four (16-cell), five (early morula), six (compact morula) or seven (blastocyst) days pi and snap-frozen for the analysis of transcript abundance using real-time PCR. The transcripts studied were interferon-tau, apoptosis regulator box-a (Bax), connexin 43, sarcosine oxidase, glucose transporter 5, mitochondrial Mn-superoxide dismutase, insulin-like growth factor II, and insulin-like growth factor-I receptor, most of which are known from our previous work to be differentially transcribed in blastocysts derived from culture in vitro or in vivo. Analysis was done on pools of 10 embryos. Data were analyzed using one-way repeated measures ANOVA. The relative abundance of the transcripts studied varied throughout the preimplantation period and was strongly influenced by the culture environment. For example, transcripts for interferon-tau were detected from the 8-cell stage onwards in in vitro-cultured embryos but not until the early morula stage in those cultured in vivo. Levels of this transcript increased significantly at the compact morula and blastocyst stages in both groups but were significantly higher (P&lt;0.05) in in vitro-cultured embryos at both stages. mRNA for Bax was not detected before the 8-cell stage in in vitro cultured embryos and not until the 16-cell stage in in vivo cultured embryos. The abundance of this transcript increased significantly thereafter up to the blastocyst stage in both groups. The level of expression was significantly higher (P&lt;0.05) at all stages of development in in vitro-cultured embryos than those cultured in vivo. The relative abundance of Cx43 transcripts decreased in both in vitro- and in vivo-cultured embryos at the 8- to 16-cell stage. Levels remained low thereafter in the in vitro-cultured embryos but significantly increased in those cultured in vivo. Transcript abundance was significantly higher in in vivo cultured embryos from Day 4 onwards with a ten-fold difference presence at the blastocyst stage. Differences also existed for the other transcripts studied. These data demonstrate that changes in transcript abundance in blastocyst stage embryos are in many cases a consequence of perturbed transcription earlier in development. Depending on the transcript, these differences may be evident in as short as 10h of culture.

Differential expression of activin subunits, activin receptors and follistatin genes in bovine oocytes and preimplantation embryos

1998 ◽  
Vol 10 (3) ◽  
pp. 293 ◽  
Author(s):  
K. Yoshioka ◽  
M. Takata ◽  
T. Taniguchi ◽  
H. Yamanaka ◽  
K. Sekikawa
Keyword(s):  
In Vitro Maturation ◽  
Preimplantation Embryos ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Α Subunit ◽  
Polymerase Chain ◽  
Bovine Oocytes ◽  
Activin Receptors ◽  
Inhibin Subunits

The presence of inhibin subunits (α, βA and βB), activin binding protein follistatin and activin receptors (ActR-I, ActR-IB, ActR-II and ActR-IIB) mRNA transcripts in bovine oocytes and preimplantation embryos was examined by reverse transcription-polymerase chain reaction. Immature and matured oocytes, zygotes, 2-cell, 3–4-cell, 5–8-cell, 9–16-cell embryos, morulae, blastocysts and hatched blastocysts were produced by in vitro maturation, fertilization and culture for this study. Activin βA subunit and follistatin transcripts were detected in all of the stages tested. However, α subunit transcripts were detected only in oocytes (immature and matured), blastocysts and hatched blastocysts, and no βB subunit transcripts were found in any of the stages. Whereas ActR-I transcripts were detectable in all stages, ActR-IB transcripts were not detectable in oocytes or embryos except in matured oocytes. Activin type II receptors (ActR-II and ActR-IIB) transcripts were detectable in oocytes and embryos except for ActR-IIB, which was not found in the 5–8-cell stage embryos. The results suggest that bovine embryos may produce activin A (homodimer of the βA subunits) at least from zygotes to morulae. Furthermore, bovine oocytes and embryos express the activin receptors mainly by the combination of ActR-I and either ActR-II or ActR-IIB.

scholarly journals Involvement of Nlrp9a/b/c in mouse preimplantation development

Reproduction ◽  
2020 ◽  
Vol 160 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Satoko Kanzaki ◽  
Shiori Tamura ◽  
Toshiaki Ito ◽  
Mizuki Wakabayashi ◽  
Koji Saito ◽  
...  
Keyword(s):  
Asymmetric Cell Division ◽  
Culture Conditions ◽  
Preimplantation Development ◽  
Preimplantation Embryos ◽  
Dependent Manner ◽  
Blastocyst Development ◽  
Triple Mutant ◽  
Cell Stage

Nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing proteins (NRLPs) are central components of the inflammasome. Accumulating evidence has shown that a reproductive clade of NRLPs is predominantly expressed in oocyte to cleavage stage embryos and participates in mammalian preimplantation development as a component of a multiprotein complex known as the subcortical maternal complex (SCMC). Nlrp9s belong to the reproductive class of NLRPs; Nlrp9b is unique in acting as an inflammasome against rotavirus in intestines. Here we generated mice carrying mutations in all three members of the Nlrp9a/b/c gene (Nlrp9 triple mutant (TMut) mice). When crossed with WT males, the Nlrp9 TMut females were fertile, but deliveries with fewer pups were increased in the mutants. Consistent with this, blastocyst development was retarded and lethality to the preimplantation embryos increased in the Nlrp9 TMut females in vivo. Under in vitro culture conditions, the fertilized eggs from the Nlrp9 TMut females exhibited developmental arrest at the two-cell stage, accompanied by asymmetric cell division. By contrast, double-mutant (DMut) oocytes (any genetic combination) did not exhibit the two-cell block in vitro, showing the functional redundancy of Nlrp9a/b/c. Finally, Nlrp9 could bind to components of the SCMC. These results show that Nlrp9 functions as an immune or reproductive NLRP in a cell-type-dependent manner.

145 CHANGES IN OXYGEN COMSUMPTION RATES OF EMBRYOS IN KOREAN CATTLE

2010 ◽  
Vol 22 (1) ◽  
pp. 231
Author(s):  
C. Y. Choe ◽  
S. R. Cho ◽  
J. K. Son ◽  
S. H. Choi ◽  
C. Y. Cho ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Embryo Quality ◽  
Blastocyst Stage ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Significant Difference ◽  
Morula Stage

Oxygen consumption has been regarded as a useful indicator for assessment of mammalian embryo quality. This study was carried out to identify whether oxygen consumption rates measured in bovine embryos using SECM can be used as a standard criteria to evaluate bovine embryo quality. Oxygen consumption of bovine embryos at various developmental stages was measured and analyzed using SECM and ANOVA analysis, respectively. We found that the oxygen consumption significantly increased in blastocyst-stage embryos compared to other stage embryos (from 2-cell stage to morula stage), indicating that oxygen consumption reflects the cell number (5.2-7.6 × 1014 mol-1 s-1 v. 1.2-2.4 × 1014 mol-1 s-1, P < 0.05). There was no significant difference between 2-cell-stage embryos and 8-cell-stage embryos. In the morula-stage embryos, the oxygen consumption of in vivo derived embryos was significantly higher than that of in vitro produced embryos (4.0 × 1014 mol-1 s-1 v. 2.4 × 1014 mol-1 s-1, P < 0.05). However, there was no significant difference in consumption of oxygen by in vivo and in vitro derived bovine blastocyst-stage embryos (P > 0.05). Good-quality embryos with grade 1 or 2 showed significantly higher oxygen consumption than grade 3 or 4 embryos. These results showed that SECM could measure oxygen consumption in bovine embryos and the oxygen consumption could reflect embryonic development stage and embryo quality.

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