O-084 Computer vision can distinguish between euploid and aneuploid embryos. A novel artificial intelligence (AI) approach to measure cell division activity associated with chromosomal status

Abstract Study question Can we distinguish between top-grade euploid and aneuploid embryos by AI measurement of cell edges in time-lapse videos? Summary answer Aneuploid embryos can be distinguished from euploid embryos by AI determination of a longer time to blastulation and higher cell activity. What is known already Continuous monitoring of the embryo development has brought out morphokinetic parameters that are used to predict pre-implantation genetic testing (PGT) results. Previous publications showed that euploid embryos reach blastulation earlier than non-euploid embryos. However, time-lapse data are currently under-utilized in making predictions about embryo chromosomal content. AI and computer vision could take advantage of the massive amount of data embedded in the images of embryo development. This is the first attempt to distinguish between euploid and aneuploid embryos by computer vision in an objective and indirect way based on the measurement of cell edges as a proxy for cell activity. Study design, size, duration We performed a retrospective analysis of 1,314 time-lapse videos from embryos cultured to the blastocyst stage with PGT results. This single-center study involved two phases; a comparison of the start time of blastulation between euploid (n = 544) and aneuploid embryos (n = 797). In phase two, we designed a novel methodology to examine whether precise measurement of cell edges over time could reflect cell activity differences in blastulation. Participants/materials, setting, methods We assumed that the delay in blastulation is reflected by higher cell activity that could be determined accurately for the first time using computer vision and machine learning to measure the length of the edges (from t2 to t8). We compared computer vision based measurements of cell edges, reflecting cell number and size, in videos of 231 top-grade euploid (n = 111) and aneuploid (n = 120) embryos. Main results and the role of chance The mean and standard deviation of blastulation start time was 100.1±6.8 h for euploid embryos and 101.8±8.2 h for aneuploid embryos (p < 0.001). Regarding the measurement of cell activity, a computer vision algorithm identified the edges and provided a certainty score for each edge, higher when the algorithm is more certain that this is a cell edge (as opposed to noise in the images). A threshold was set to distinguish cell edges from noise using this score. The following results for top-grade embryos are shown as the sum of the edge lengths (µm) average of 160 pictures per embryo (frames between t2 and t8). The total length of the cell edges increased from two cells (420±85 µm) to eight cells (861±237 µm), in line with the mitosis events. Both the average total edge measured (450±162 µm for euploid embryos and 489±215 µm for aneuploid embryos, p < 0.01) and the average total of the difference between consecutive frames (135±47 µm for euploid embryos and 153±64 µm for aneuploid embryos, p < 0.01) were higher for aneuploid embryos than for euploid embryos. A regression model to differentiate between the two classes achieved 73% sensitivity and 73% specificity on this dataset. Limitations, reasons for caution The main limitation of this study is the difficulty to correlate our findings to other measure of cell activity. A more robust AI function (using not only cell edges lengths) would be required for future analysis to measure the cell activity in cell division up to the blastocyst stage. Wider implications of the findings Our results show for the first time that an AI based system can precisely measure microscopic cell edges in the dividing embryo. Using this novel method, we could distinguish between euploid and aneuploid embryos. This non-invasive method could further enhance our knowledge of the developing embryo. Trial registration number Not Applicable

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Analysis of Morphokinetic Parameters of Feline Embryos Using a Time-Lapse System

Animals ◽

10.3390/ani11030748 ◽

2021 ◽

Vol 11 (3) ◽

pp. 748

Author(s):

Joanna Kochan ◽

Agnieszka Nowak ◽

Barbara Kij ◽

Sylwia Prochowska ◽

Wojciech Niżański

Keyword(s):

Embryo Development ◽

Embryo Quality ◽

Time Lapse ◽

Blastocyst Stage ◽

Cavity Formation ◽

Non Invasive ◽

Morphokinetic Parameters ◽

Morphological Defects ◽

Development In Vitro

The aim of this study was to analyze the morphokinetic parameters of feline embryos using a time lapse system. Oocytes matured in vitro were fertilized (IVF) and in vitro cultured in a time lapse-system (Primo Vision®, Gothenburg, Sweden). The first cell division of embryos occurred between 17 h post insemination (hpi) and 38 hpi, with the highest proportion of embryos (46%) cleaving between 21 and 24 hpi. The timing of the first cleavage significantly affected further embryo development, with the highest development occurring in embryos that cleaved at 21–22 hpi. Embryos that cleaved very early (17–18 hpi) developed poorly to the blastocyst stage (2%) and none of the embryos that cleaved later than 27 hpi were able to reach the blastocyst stage. Morphological defects were observed in 48% of the embryos. There were no statistically significant differences between the timing intervals of the first cleavage division and the frequency of morphological defects in embryos. Multiple (MUL) morphological defects were detected in more than half (56%) of the abnormal embryos. The most frequent single morphological defects were cytoplasmic fragmentation (FR) (8%) and blastomere asymmetry (AS) (6%). Direct cleavage (DC) from 1–3 or 3–5 blastomeres, reverse cleavage (RC) and vacuoles were rarely observed (2–3%). The timing of blastocyst cavity formation is a very good indicator of embryo quality. In our study, blastocyst cavity formation occurred between 127–167 hpi, with the highest frequency of hatching observed in blastocysts that cavitated between 142–150 hpi. Blastocysts in which cavitation began after 161 h did not hatch. In conclusion, the timing of the first and second cleavage divisions, the timing of blastocyst cavity formation and morphological anomalies can all be used as early and non-invasive indicators of cat embryo development in vitro.

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P–187 Multinucleation and reverse cleavage, sings of early embryo self-repair mechanisms

Human Reproduction ◽

10.1093/humrep/deab130.186 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

A Munuer. Puigvert ◽

V. Montalv Pallès ◽

J Mass. Hernáez ◽

A García-Faura ◽

B Marquè. López-Teijón ◽

...

Keyword(s):

Embryo Development ◽

Culture Media ◽

Live Birth Rate ◽

Time Lapse ◽

Blastocyst Stage ◽

Early Embryo ◽

Control Group ◽

Complete Fusion ◽

Depth Analysis ◽

Self Repair

Abstract Study question Have multinucleation and reverse cleavage any effect on embryo development and clinical outcomes on IVF treatments? Summary answer Embryos capable of repairing dysmorphisms and developing up to blastocyst stage keep intact their ability to become healthy babies. What is known already Time-lapse systems allow IVF laboratories to perform in-depth analysis of embryo development using the continuous monitoring tool. Some events that are impossible to detect with conventional morphologic evaluation, such as reverse cleavage or multinucleation, can be detected using time-lapse. Even though the low scientific evidence, the presence of these events is considered a negative factor when the embryo quality assessment is performed. However, it has been described the possibility that embryos have self-repair intrinsic methods. Study design, size, duration Retrospective study including data from 3,577 cycles with 21,274 embryos cultured until blastocyst stage using one-step culture media in time-lapse incubators (Embryoscope, Vitrolife) up to day 5/6 between 2014 and 2019. Participants/materials, setting, methods Three embryo groups were considered: Control group, embryos without multinucleation or reverse cleavage (CG; n = 16,897); Multinucleation group, embryos with at least one blastomere multinucleated on D + 2/3 (MNC; n = 3,879) and Reverse Cleavage group, embryos undergoing complete fusion of two blastomeres on D + 2/3 (RC; n = 498). Single embryo transfer was performed on blastocyst stage. Clinical outcome rates were compared between groups and analyzed by Chi-square test. Main results and the role of chance As published by other groups, the 2.3% of our embryos showed at least one reverse cleavage event and we observed multinucleation in the 18.2% of the embryos. Blastocyst rate of dysmorphism groups was significantly lower (p < 0.05) than Control group (MNC=20.0%; RC = 27.7%; CG = 58.0%). Once transferred, MNC and RC evolutive embryos showed significantly lower pregnancy (MNC=47.9%; RC = 46.8%; CG = 60.8%; p < 0.05) and clinical pregnancy rates (MNC=39.4%; RC = 40.4% CG = 50.6%; p < 0.05) than the Control group (p < 0.05). However, during the post-implantational development the negative effect of dysmorphisms disappears, reaching values of live birth rate comparable to the Control group (MNC=28.3%; RC = 31.9% CG = 33.8%; p = 0.17). These results prove the importance of blastocyst culture and the inherent capability of the embryos to overcome some abnormal dynamics as multinucleation and reverse cleavage. Thus, these embryos showing the poor-prognosis events can be considered for transfer or vitrify. Limitations, reasons for caution There is a wide difference on sample size between groups despite the fact that the statistical analysis considers that into account. There are some ongoing pregnancies in all groups. Wider implications of the findings: When analyzing the development of embryos undergoing reverse cleavage and multinucleation, we hypothesize that these embryos could be showing a self-correction mechanism for some type of error detected. Embryos capable of repairing and developing up to blastocyst stage keep intact their ability to become healthy babies. Trial registration number Not applicable

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Use of time-lapse imaging to evaluate morphokinetics of in vitro equine blastocyst development after oocyte holding for two days at 15°C versus room temperature before intracytoplasmic sperm injection

Reproduction Fertility and Development ◽

10.1071/rd19223 ◽

2019 ◽

Vol 31 (12) ◽

pp. 1862 ◽

Cited By ~ 3

Author(s):

N. A. Martino ◽

G. Marzano ◽

A. Mastrorocco ◽

G. M. Lacalandra ◽

L. Vincenti ◽

...

Keyword(s):

Embryo Development ◽

Intracytoplasmic Sperm Injection ◽

Room Temperature ◽

Time Lapse ◽

Blastocyst Stage ◽

Blastocyst Development ◽

Cell Stage ◽

Group 13 ◽

Time Lapse Imaging

Time-lapse imaging was used to establish the morphokinetics of equine embryo development to the blastocyst stage after invitro oocyte maturation (IVM), intracytoplasmic sperm injection (ICSI) and embryo culture, in oocytes held overnight at room temperature (22–27°C; standard conditions) before IVM. Embryos that developed to the blastocyst stage underwent precleavage cytoplasmic extrusion and cleavage to the 2-, 3- and 4-cell stages significantly earlier than did embryos that arrested in development. We then determined the rate of blastocyst formation after ICSI in oocytes held for 2 days at either 15°C or room temperature before IVM (15-2d and RT-2d treatment groups respectively). The blastocyst development rate was significantly higher in the 15-2d than in the RT-2d group (13% vs 0% respectively). The failure of blastocyst development in the RT-2d group precluded comparison of morphokinetics of blastocyst development between treatments. In any condition examined, development to the blastocyst stage was characterised by earlier cytoplasmic extrusion before cleavage, earlier cleavage to 2- and 4-cell stages and reduced duration at the 2-cell stage compared with non-competent embryos. In conclusion, this study presents morphokinetic parameters predictive of embryo development invitro to the blastocyst stage after ICSI in the horse. We conclude that time-lapse imaging allows increased precision for evaluating effects of different treatments on equine embryo development.

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Fluctuation in radioresponse of HeLa cells during the cell cycle evaluated based on micronucleus frequency

Scientific Reports ◽

10.1038/s41598-020-77969-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Hiroaki Shimono ◽

Atsushi Kaida ◽

Hisao Homma ◽

Hitomi Nojima ◽

Yusuke Onozato ◽

...

Keyword(s):

Cell Cycle ◽

Hela Cells ◽

Time Lapse ◽

S Phase ◽

G1 Phase ◽

M Phase ◽

G2 Phase ◽

The Difference ◽

Time Lapse Imaging ◽

First Time

AbstractIn this study, we examined the fluctuation in radioresponse of HeLa cells during the cell cycle. For this purpose, we used HeLa cells expressing two types of fluorescent ubiquitination-based cell cycle indicators (Fucci), HeLa-Fucci (CA)2 and HeLa-Fucci (SA), and combined this approach with the micronucleus (MN) assay to assess radioresponse. The Fucci system distinguishes cell cycle phases based on the colour of fluorescence and cell morphology under live conditions. Time-lapse imaging allowed us to further identify sub-positions within the G1 and S phases at the time of irradiation by two independent means, and to quantitate the number of MNs by following each cell through M phase until the next G1 phase. Notably, we found that radioresponse was low in late G1 phase, but rapidly increased in early S phase. It then decreased until late S phase and increased in G2 phase. For the first time, we demonstrated the unique fluctuation of radioresponse by the MN assay during the cell cycle in HeLa cells. We discuss the difference between previous clonogenic experiments using M phase-synchronised cell populations and ours, as well as the clinical implications of the present findings.

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282 GENE EXPRESSION PATTERNS AND QUALITY OF BOVINE EMBRYOS PRODUCED UNDER DIFFERENT OXYGEN CONCENTRATIONS

Reproduction Fertility and Development ◽

10.1071/rdv19n1ab282 ◽

2007 ◽

Vol 19 (1) ◽

pp. 256

Author(s):

W. J. Son ◽

M. K. B. ◽

Y. J. Jeong ◽

S. Balasubramanian ◽

S. Y. Choe ◽

...

Keyword(s):

Gene Expression ◽

Embryo Development ◽

Expression Patterns ◽

Cell Number ◽

Blastocyst Stage ◽

Total Cell ◽

Blastocyst Development ◽

Glut 1

Various factors are known to influence the survival and development of in vitro-produced embryos, including co-culture with somatic cells, antioxidants, and O2 tension. Studies in several species report that embryo development and quality were enhanced at low O2 concentrations. This study compared the effects of 2 O2 concentrations on IVP embryo development, embryo quality, and gene expression to those of in vivo counterparts. Cumulus–oocyte complexes were matured in vitro in TCM-199 with hormones and 10% FCS, and inseminated in TALP medium. Presumptive zygotes were cultured in SOF medium under either 5% or 20% O2 in air. In triplicate, sets of 5 embryos at the 2-cell, 4-cell, 8-cell, 16-cell, morula, and Day 7 blastocyst stages were used for analyzing the expression patterns of apoptotic (Bax and Bcl2), metabolism (Glut-1 and Glut-5), stress (Sox, Hsp70, and G6PDH), compaction (Cx43), oxidation (PRDX5, NADH, and MnSOD), and implantation (VEGF and IFN-tau) genes using real-time quantitative PCR. The expression of each gene was normalized to that of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Statistical analysis was performed with Bonferroni and Duncan tests by ANOVA (P < 0.05). Cleavage rates did not differ among groups. Blastocyst and hatched blastocyst development in 5% O2 was significantly (P < 0.05) higher than in 20% O2. Total cell number of in vivo blastocysts was significantly (P < 0.05) higher than that of IVP blastocysts. ICM ratio and apoptosis of in vivo blastocysts were significantly (P < 0.05) lower than for IVP blastocysts. The relative abundances (RAs) of Glut-1, Glut-5, MnSOD, NADH, PRDX5, Cx43, Bcl2, and IFN-τ were significantly (P < 0.05) higher in in vivo embryos, whereas the RAs of Sox, G6PDH, Hsp70, Bax, and VEGF were significantly (P < 0.05) lower than for IVP counterparts. In conclusion, culture at 5% O2 concentration resulted in higher rates of development to the blastocyst stage, higher total cell numbers, and decreased apoptosis. Furthermore, differences in expression of genes including Glut-1, Glut-5, Sox, G6PDH, Hsp70, Bax, Bcl2, Cx43, PRDX5, NADH, MnSOD, VEGF, and IFN-τ may prove useful in determining optimal culture conditions. This work was supported by ARPC (204119-03-SB010), Republic of Korea.

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278 EFFECT OF FOLLICULAR WAVE SYNCHRONIZATION AND SUPERSTIMULATION ON THE NORMALITY OF BOVINE EMBRYOS PRODUCED IN VITRO

Reproduction Fertility and Development ◽

10.1071/rdv22n1ab278 ◽

2010 ◽

Vol 22 (1) ◽

pp. 296 ◽

Cited By ~ 1

Author(s):

K. Imai ◽

T. Somfai ◽

M. Ohtake ◽

Y. Inaba ◽

Y. Aikawa ◽

...

Keyword(s):

Cell Division ◽

Development Program ◽

Time Lapse ◽

Oocyte Quality ◽

Blastocyst Stage ◽

In Vitro Production ◽

Cell Stage ◽

Follicular Wave ◽

Significant Difference

We previously reported that follicular wave synchronization by dominant follicle removal on Day 5 and the start of a superstimulatory treatment on Day 7 after ovum pick-up (OPU) was effective to increase oocyte quality (Imai et al. 2008 Reprod. Fertil. Dev. 20, 182). The present study was designed to examine the effect of superstimulatory treatment-induced follicular wave synchronization on quality of embryos obtained by OPU and in vitro production. Japanese Black cows were reared under the same feeding and environmental conditions and 2 OPU sessions were conducted in each cow. The first OPU session was performed in 7 cows at arbitrary days of estrous cycle using a 7.5-MHz linear transducer with needle connected to an ultrasound scanner. Then, follicles larger than 8 mm in diameter were aspirated and CIDR was inserted on Day 5 (the day of first OPU session = Day 0). The cows then received 30 mg of FSH twice a day from Days 7 to 10 in decreasing doses (4, 4, 3, 3, 2, 2, 1, 1 mg per shot) by i.m. injections. Cloprostenol (PGF; 0.75 mg) was administered in the morning of Day 9. The second OPU session was performed 48 h after PGF administration (Day 11) and only follicles larger than 5 mm in diameter were aspirated. The CIDR was removed from the cows just before OPU. Grade 1 and 2 cumulus oocyte complexes were in vitro matured, fertilized (IVF), and cultured as described by Imai et al. (2006 J. Reprod. Dev. 52, Suppl. S19-29). Some zygotes were fixed and stained to check their sperm penetration. Embryo development was monitored by time-lapse cinematography for 168 h after IVF. Cleavage pattern of embryos was classified morphologically into normal and abnormal (including those with multiple fragments, protrusions, 3 to 4 blastomeres, and uneven cell division) groups at their first cleavage. Normal penetration rate of second OPU session was significantly (P < 0.05) higher than that of the first OPU session. There were no differences in the mean percentage of total blastocyst and grade 1 blastocyst rates between the first (45.2 and 46.9%, respectively) and second (47.5 and 41.8%, respectively) OPU sessions. However, the rates of blastocysts developing from embryos that were beyond the 4-cell stage at 48 h after IVF was significantly (P < 0.05) higher after the second OPU session (81.2%) than after the first OPU session (67.4%). Furthermore, a significant difference (P < 0.05) was found in the rates of normal cleavage at the first cell division in embryos that developed to the blastocyst stage between the first and second OPU sessions (53.3% and 73.9%, respectively). These results indicate that superstimulatory treatment-induced follicular wave synchronization improved the normality of fertilization and development of cattle oocytes obtained by OPU. This work was supported by the Research and Development Program for New Bio-industry Initiatives.

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Progesterone and conceptus elongation in cattle: a direct effect on the embryo or an indirect effect via the endometrium?

Reproduction ◽

10.1530/rep-09-0152 ◽

2009 ◽

Vol 138 (3) ◽

pp. 507-517 ◽

Cited By ~ 198

Author(s):

M Clemente ◽

J de La Fuente ◽

T Fair ◽

A Al Naib ◽

A Gutierrez-Adan ◽

...

Keyword(s):

Embryo Development ◽

Direct Effect ◽

Cell Number ◽

Blastocyst Stage ◽

Bovine Embryo ◽

Fourfold Increase ◽

Uterine Environment ◽

High Concentrations

The steroid hormone progesterone (P4) plays a key role in the reproductive events associated with pregnancy establishment and maintenance. High concentrations of circulating P4 in the immediate post-conception period have been associated with an advancement of conceptus elongation, an associated increase in interferon-τ production and higher pregnancy rates in cattle. Using in vitro and in vivo models and ∼8500 bovine oocytes across six experiments, the aim of this study was to establish the route through which P4 affects bovine embryo development in vitro and in vivo. mRNA for P4 receptors was present at all stages of embryo development raising the possibility of a direct effect of P4 on the embryo. Exposure to P4 in vitro in the absence or presence of oviduct epithelial cells did not affect the proportion of embryos developing to the blastocyst stage, blastocyst cell number or the relative abundance of selected transcripts in the blastocyst. Furthermore, exposure to P4 in vitro did not affect post-hatching elongation of the embryo following transfer to synchronized recipients and recovery on Day 14. By contrast, transfer of in vitro derived blastocysts to a uterine environment previously primed by elevated P4 resulted in a fourfold increase in conceptus length on Day 14. These data provide clear evidence to support the hypothesis that P4-induced changes in the uterine environment are responsible for the advancement in conceptus elongation reported previously in cattle and that, interestingly, the embryo does not need to be present during the period of high P4 in order to exhibit advanced elongation.

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A Multi-Well Thin-Si LAPS and All-in-One Readout System for Ion Activity Monitor of Epithelium Cells

Proceedings ◽

10.3390/proceedings2131020 ◽

2018 ◽

Vol 2 (13) ◽

pp. 1020

Author(s):

Yu-Jing Lin ◽

Po-Yen Lin ◽

Yu-Ping Chen ◽

Hui-Ling Liu ◽

Tsung-Ru Wu ◽

...

Keyword(s):

Cell Activity ◽

Cell Number ◽

Integrated System ◽

Easy Access ◽

Label Free ◽

Readout System ◽

Fully Integrated ◽

Sensor Structure ◽

Ion Activities ◽

The Difference

To measure the ion activities of cells, an easy-access and fully-integrated system is necessary in culture room with high cleanness and easy maintenance. A new sensor structure integrated with readout system based on light-addressable potentiometric sensor (LAPS) to quantitatively monitor real-time cell activity with the advantages of label free and 2D image ability is proposed. The difference of cell number and acidification could be easily observed by 2D images by means of this proposed methodology.

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141 BENEFICIAL EFFECT OF ETHYLENEDIAMINETETRAACETIC ACID COMBINED WITH HEMOGLOBIN ON PRE-IMPLANTATION DEVELOPMENT OF PORCINE IN VITRO PRODUCED EMBRYOS

Reproduction Fertility and Development ◽

10.1071/rdv17n2ab141 ◽

2005 ◽

Vol 17 (2) ◽

pp. 221

Author(s):

J.H. Kim ◽

G.S. Lee ◽

H.S. Kim ◽

S.H. Lee ◽

D.H. Nam ◽

...

Keyword(s):

Beneficial Effect ◽

Embryo Development ◽

Ethylenediaminetetraacetic Acid ◽

Cell Number ◽

Blastocyst Stage ◽

Total Cell ◽

Blastocyst Formation ◽

Total Cell Number ◽

Porcine Embryo

Developing a porcine embryo culture system is important for increasing the rates of implantation and pregnancy of somatic cell nuclear transfer (SCNT) embryos. Ethylenediaminetetraacetic acid (EDTA) was shown to inhibit glycolytic activity of cleavage stage embryos, thereby preventing the premature stimulation of glycolysis and enhancing development. However, EDTA should not be used for later-stage embryos as the inhibition of glycolysis reduces energy production at the blastocyst stage and significantly inhibits inner cell mass development. On the other hand, addition of a nitric oxide (NO) scavenger, hemoglobin (Hb), to the culture medium is known to promote embryo development to the blastocyst stage. This study was conducted to evaluate the beneficial effect of EDTA combined with Hb on pre-implantation development of porcine embryos in vitro. Porcine embryos produced by in vitro maturation and fertilization were cultured for 6 days in North Carolina State University (NCSU)-23 medium supplemented with EDTA or/and Hb. All data were subjected to one-way ANOVA and protected least significant difference (LSD) test using the general linear models (GLM) procedure of the statistical analysis system (SAS Institute, Inc., Cary, NC, USA) program to determine differences among experimental groups. Statistical significance was determined when the P value was less than 0.05. In Exp. 1, culturing porcine zygotes with 100 mM EDTA (n = 537) significantly increased cleavage rates (85.3%) at 48 h post-insemination compared to supplementing with 0, 1, or 10 mM EDTA (78.9, 79.7, or 78.2%, respectively). However, EDTA at these concentrations did not promote blastocyst formation compared to the control. In addition, no difference was observed in total cell numbers in blastocysts among the experimental groups (41.8, 42.6, 45.8, 44.5, respectively). In Exp. 2, in vitro-fertilized oocytes were cultured with 0, 1, or 10 mg/mL Hb. Culturing with Hb did not promote porcine embryo development, but significantly increased the total cell number of blastocysts obtained from 1 mg/mL Hb supplementation (n = 566) compared to that of the control (56.8 vs. 41.6). In Exp. 3, culturing embryos (n = 548) with 100 mM EDTA + 1 mg/mL Hb significantly improved rates of cleavage (84.0% vs. 75.2%) and blastocyst formation (19.2% vs. 12.7%), and the total number of cells in blastocysts compared to those of the control (58.4 vs. 42.3). In conclusion, our results demonstrated that EDTA or Hb have different roles in supporting in vitro pre-implantation development of porcine embryos; EDTA mainly stimulated early cleavage up to the 2- to 4-cell stage, and Hb promoted the total cell number of blastocysts. However, combined supplementation with these two chemicals improved cleavage, blastocyst formation, and total cell number in blastocysts. This study was supported by a grant from Korea Ministry of Science and Technology (Biodiscovery).

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Effects of Endogenous Hormones and Sugars on Fruit Size Driven by Cell Division between Korla Fragrant Pear and Its Bud Mutation

HortScience ◽

10.21273/hortsci15734-21 ◽

2021 ◽

pp. 1-8

Author(s):

Jia Tian ◽

Yue Wen ◽

Feng Zhang ◽

Jingyi Sai ◽

Yan Zhang ◽

...

Keyword(s):

Cell Division ◽

Cell Volume ◽

Chromosome Doubling ◽

Fruit Size ◽

Tree Breeding ◽

Cell Number ◽

Endogenous Hormones ◽

Glucose Content ◽

Bud Mutation ◽

The Difference

Large-fruit bud mutations are important factors in fruit tree breeding. However, little is known about the differences between varieties and bud mutations. The ploidy identification of Korla fragrant pear (Pyrus sinkiangensis Yu) and its large bud mutation Zaomeixiang pear showed that the large-fruit characteristic was not caused by chromosome doubling. By counting mesocarp cells at different stages, we found that the number of cells increased continuously after pollination, and the difference was the greatest at 28 days after full bloom (DAFB), and was about 9.4 × 106. After 28 days, the difference in cell volume became bigger and bigger, so both the cell volume and cell number caused the difference in fruit size between Korla fragrant pear and Zaomeixiang pear. To obtain more insights into the differences in fruit size driven by cell division, we analyzed the endogenous hormones [indole ascetic acid (IAA), zeatin riboside (ZR), gibberellic acid (GA), and abscisic acid (ABA)], and the main sugars (glucose, fructose, sucrose, and sorbitol). The ZR content of Zaomeixiang pear was always greater than that of Korla fragrant pear at all stages. The ABA content was the opposite except for at 7 DAFB during cell division; the greatest difference was 30.87 ng/g, which appeared at 28 DAFB. ABA and ZR correlated negatively with cell number. After 7 DAFB, the ratio of IAA/ABA, ZR/ABA, and GA/ABA in Zaomeixiang pear was always greater than that for Korla fragrant pear at 28 DAFB. The difference in glucose content at 21 DAFB was the greatest, at 4.80 ng/g. Large amounts of sorbitol accumulated during whole-cell division. Glucose and sorbitol correlated positively with cell numbers. In summary, the data suggest that the different contents of glucose, sorbitol, ZR, and ABA, and the ratio of endogenous hormones might be related to cell division in Korla fragrant pear and Zaomeixiang pear. The result provides a theoretical basis for the large-size fruit’s high-quality production and genetic breeding of Korla fragrant pear and its bud mutation.

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