13 Generation of SLICK beef cattle by embryo microinjection: A case report

2021 ◽  
Vol 33 (2) ◽  
pp. 114
Author(s):  
P. Rodriguez-Villamil ◽  
F. L. Ongaratto ◽  
J. R. Bostrom ◽  
S. Larson ◽  
T. Sonstegard

Due to climate change, cattle can experience heat stress more frequently in traditionally temperate, non-tropical environments. Because of this and the fact that most of the world’s inefficient cattle reside in tropical zones, we set out to demonstrate our ability to adapt Angus animals to heat stress through a single gene edit in the prolactin receptor (PRLR). We selected PRLR, because it is known that the SLICK phenotype results from 1 of 3 different mutations in PRLR and therefore is related to heat stress regulation. The overall project was initiated through a partnership between Acceligen and BluePrint Genetics (BPG). BPG harvested 1415 oocytes from a total of 9 ovum pickup rounds from 7 different Angus donors. These oocytes were graded, selected, and put in maturation medium for shipping to Acceligen. Matured oocytes were fertilized in Fert-TALP medium and co-incubated with frozen/thawed semen from 3 different reproductive certified Angus bulls. Consequently, targeted editing was done on a single cell in the zygotes 12h after fertilization by introduction of guide (g)RNA/Cas9 (250ng μL−1 of each) through intracytoplasmic microinjection. Then, treated zygotes (n=1341) were cultured in synthetic oviductal fluid with amino acids (SOFaa) culture medium under a controlled atmosphere until on Day 6, when 277 (20%) grade 1 embryos were selected and 39 returned to Blueprint Genetics for transfer. Because the number of available recipients was limited, only 4 rounds of fresh embryo transfer were completed, and the remaining embryos (n=190) were vitrified for future transfers. Pregnancy checks by ultrasound on Day 30 revealed a 23% (9/39) rate of pregnancy, which decreased to 13% (5/39) by Day 60. In total, 4 animals reached term and delivered healthy calves. Genetic testing of the PRLR target site was done by amplicon sequencing, which showed 3 edited SLICK animals (75%) and one wild-type. Thus, the SLICK zygote editing by microinjection was demonstrated to be an efficient method to produce bovine beef animals and is currently being prepared for regulatory review in multiple countries and commercialization.

2017 ◽  
Author(s):  
Xi Lan ◽  
John C. F. Hsieh ◽  
Carl J. Schmidt ◽  
Qing Zhu ◽  
Susan J. Lamont

2001 ◽  
Vol 21 (24) ◽  
pp. 8575-8591 ◽  
Author(s):  
Lei Huang ◽  
Nahid F. Mivechi ◽  
Demetrius Moskophidis

ABSTRACT The murine hsp70 gene family includes the evolutionarily conserved hsp70.1 andhsp70.3 genes, which are the major proteins induced by heat and other stress stimuli.hsp70.1 andhsp70.3 encode identical proteins which protect cells and facilitate their recovery from stress-induced damage. While the hsp70 gene family has been widely studied and the roles of the proteins it encodes as molecular chaperones in a range of human pathologies are appreciated, little is known about the developmental regulation of hsp70.1 andhsp70.3 expression and the in vivo biological function of their products. To directly study the physiological role of these proteins in vivo, we have generated mice deficient in heat shock protein 70 (hsp70) by replacing thehsp70.1 orhsp70.3 gene with an in-frame β-galactosidase sequence. We report here that the expression ofhsp70.1 andhsp70.3 is developmentally regulated at the transcriptional level, and an overlapping expression pattern for both genes is observed during embryo development and in the tissues of adult mice. hsp70.1 −/− orhsp70.3 −/− mice are viable and fertile, with no obvious morphological abnormalities. In late embryonic stage and adult mice, both genes are expressed constitutively in tissues exposed directly to the environment (the epidermis and cornea) and in certain internal organs (the epithelium of the tongue, esophagus, and forestomach, and the kidney, bladder, and hippocampus). Exposure of mice to thermal stress results in the rapid induction and expression of hsp70, especially in organs not constitutively expressing hsp70 (the liver, pancreas, heart, lung, adrenal cortex, and intestine). Despite functional compensation in the single-gene-deficient mice by the intact homologous gene (i.e.,hsp70.3 inhsp70.1 −/− mice and vice versa), a marked reduction in hsp70 protein expression was observed in tissues under both normal and heat stress conditions. At the cellular level, inactivation of hsp70.1 orhsp70.3 resulted in deficient maintenance of acquired thermotolerance and increased sensitivity to heat stress-induced apoptosis. The additive or synergistic effects exhibited by coexpression of both hsp70 genes, and the evolutionary significance of the presence of both hsp70genes, is hence underlined.


Zygote ◽  
2018 ◽  
Vol 26 (2) ◽  
pp. 162-167 ◽  
Author(s):  
Mohamed Fathi ◽  
A. Salama ◽  
Magdy R. Badr

SummaryThe aim of the current study was to investigate the effect of caffeine supplementation during in vitro maturation (IVM) for different maturation times on the developmental potential of canine oocytes recovered from ovariohysterectomized bitches. The recovered cumulus–oocytes complexes were in vitro matured for 72 h. Here, 10 mM caffeine was added to the maturation medium for different incubation times (caffeine from 0–72 h maturation, caffeine for the first 24 h of maturation only, caffeine addition from 24 to 48 h maturation time, caffeine addition from 48 to 72 h maturation or in caffeine-free medium, control group). The matured oocytes were in vitro fertilized using frozen–thawed spermatozoa. The presumptive zygotes were in vitro cultured in synthetic oviductal fluid medium for 5 days. The results showed that both maturation and fertilization rates were significantly higher (P ˂ 0.05) using caffeine-treated medium for the first 24 h of maturation compared with the control and other two groups of caffeine treatment (from 24 to 48 h and from 48 to 72 h), whereas use of caffeine-treated medium for a 0–72 h incubation time did not affect these rates (P > 0.05). Interestingly, the matured oocytes in caffeine-supplemented medium for the first 24 h or from 0–72 h showed a significant (P ˂ 0.05) increase in the total number of cleaved embryos compared with the control group. In conclusion, supplementation of the maturation medium with 10 mM caffeine for the first 24 h of maturation or during the whole maturation time (0–72 h) improved nuclear maturation and subsequent embryo development preimplantation following in vitro fertilization.


2011 ◽  
Vol 23 (1) ◽  
pp. 218
Author(s):  
M. Nichi ◽  
R. P. Bertolla ◽  
T. B. Soler ◽  
C. N. M. Cortada ◽  
R. M. Zuge ◽  
...  

Previous studies have indicated that semen of heat-stressed bulls shows impaired mitochondrial activity and high levels of oxidative stress, which may cause structural damage to biomolecules, DNA, lipids, carbohydrates and proteins, as well as other cellular components (Nichi et al. 2006 Theriogenology 66, 822–828). Disruption of the sperm mitochondria could have a potential damaging effect not only on an individual sperm cell but also on the surrounding cells, especially regarding the sperm membrane, possibly due to the release of a high amount of reactive oxygen species (ROS) produced in this environment (rich in electrons) that would then lead to oxidative stress. To test this hypothesis, semen samples of 11 Simmental bulls kept in tropical environments were collected during the summer months. Semen was evaluated as follows: the 3-3′ diaminobenzidine stain (DAB) as an index of mitochondrial activity, the hypo-osmotic swelling test (HOST) as an index of membrane integrity, measurement of thiobarbituric acid reactive substances (TBARS) as an index of lipid peroxidation, and measurement of the enzymatic antioxidants superoxide dismutase, catalase and glutathione peroxidase activities. For correlation analysis, the Pearson test was used (variables were transformed when necessary), and for nonparametric variables, the Spearman rank test was used. A high positive correlation was found between sperm cells with highly active mitochondria (DAB class I) and the percentage of cells with intact membrane by HOST (r = 0.93; P < 0.05), and a negative correlation between the latter and the percentage of inactive mitochondria (r = –0.91; P < 0.05), indicating that the higher the percentage of cells showing impaired mitochondrial activity, the higher the percentage of cells with damaged membrane. There was also a positive correlation between TBARS and the percentage of cells with disrupted mitochondria (r = 0.86; P < 0.05), indicating that the higher the percentage of sperm with impaired mitochondrial activity, the higher the oxidative stress. No correlation existed between the enzymatic antioxidants and any of the variables studied. The results indicate that heat stress may lead to an increase in testicular ROS levels, overcoming the seminal antioxidant protection. This, in turn, may cause damage of the mitochondria and a subsequent release of more pro-oxidative substances, and an exponential increase of oxidative stress. Understanding these mechanisms may lead to more tailored antioxidant therapies in the future. The authors thank FAPESP for the scholarship and financial support.


2010 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
M. K. Jena ◽  
D. Malakar ◽  
A. K. De ◽  
S. Garg ◽  
Y. S. Akshey

The present study was carried out to see the developmental efficiency of zona-free and with zona parthenogenetic goat embryos cultured in Research Vitro Cleave from Cook Australia (RVCL), Embryo Development Media (EDM), modified synthetic oviductal fluid (mSOF), and modified Charles Rosenkrans media (mCR2a). Zona-free embryos were cultured in 4 media, whereas with zona embryos were cultured in 3 media except mCR2a. Ovaries were collected from slaughterhouse and oocytes were isolated by puncturing the follicles in medium containing Dulbecco’s phosphate-buffered saline, 3% BSA, and 50 μg mL-1 gentamicin. Oocytes were matured in maturation medium containing TCM-199 (HEPES modified), 0.05 mg mL-1 Na pyruvate, 0.003 mg mL-1 L-glutamine, 5.5 mg mL-1 glucose, 3 mg mL-1 BSA, 5 μg mL-1 FSH, 10 μg mL-1 LH, 1 μg mL-1 estradiol-17β, 50 μg mL-1 gentamicin, and 10% FBS in 5% CO2 in air at 38.5°C. The COC (15 to 20 oocytes) were placed in 100-μL droplets of maturation medium and incubated in a CO2 incubator (5% CO2 in air) with maximum humidity at 38.5°C for 27 h. Matured oocytes were made cumulus free by treatment with hyaluronidase (0.5 mg mL-1) and zona-free by pronase (2 mg mL-1) in zona-free parthenogenesis. Then the oocytes were activated by 5 μM Ca ionophore for 5 min in a CO2 incubator and then treated with 2 mM 6-DMAP for 4 h. Activation was also done by electrical activation with DC 1.78 kV cm-1, 20 μs, and 2 pulses. Then the zona-free oocytes were kept for in vitro culture in 4 types of media such as RVCL, EDM, mSOF, andm CR2a for 7 days in 5% CO2 in air at 38.5°C. The cleavage rate andmorulae formation were observed in RVCL 40.95%, 13.95%, in EDM 46.92%, 14.75%, in mCR2a 56.66%, 5.88%, and in mSOF 48.23%, 14.63%, respectively. The cleavage rate and morulae formation were also found 55.9%, 14.63% during chemical activation and 32%, 12.5% in electrical activation. Hence, better result was found in chemical activation than electrical activation. For with zona parthenogenesis, the matured oocytes were chemically activated by 5 μM Ca ionophore for 5 min and 2 mM 6-DMAP for 4 h. Then the oocytes were cultured in RVCL, EDM, and mSOF in 100-μL micro-drops media for 7 days. The cleavage, morulae, and early blastocyst production rate were as follows: cleavage rate 75.68%, 72.03%, and 57.11%; morulae 44.61%, 30.29%, and 40.22%; and early blastocyst 17.49%, 11.88%, and 25.01% in RVCL, EDM, and mSOF, respectively. Hatched blastocyst formation rate was 6.75%, 5.48%, and 1.15% in RVCL, EDM, and mSOF, respectively. It could be concluded that zona-free parthenogenetic embryos were produced better in EDM medium and with chemical activation. With zona parthenogenetic embryo development was significantly (P < 0.05) higher in RVCL and EDM media.


2017 ◽  
Vol 13 (Especial 2) ◽  
pp. 364-371
Author(s):  
Larissa Christyna de Paula ◽  
João Paulo Barros ◽  
João Victor Firmino Garcia ◽  
Aline Sousa Camargos ◽  
Paulo Eduardo Nogueira ◽  
...  

The embedded systems are present in the daily life of humans, from a simple microwave to a car of the years 2000. In recent years these systems have spread in Brazilian agriculture, such as irrigation control and animal feed control. Heat tolerance and adaptability to tropical environments are important factors to be considered in dairy cattle. The increase in the ambient temperature and, consequently, the heat stress causes a series of effects on the animal's metabolism that alter its behavior and well-being, directly affecting milk production. Surface temperature and respiratory rate are variables that can be used to identify heat stress by animals. Thus, a device, using the Arduino platform, it will be developed to measure the surface temperature and the respiratory rate of the animal, allowing a greater reliability in the information generated.


Reproduction ◽  
2004 ◽  
Vol 127 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Hisataka Iwata ◽  
Shu Hashimoto ◽  
Mayuko Ohota ◽  
Koji Kimura ◽  
Kenichi Shibano ◽  
...  

The concentrations of electrolytes (Na, K, Cl, Mg and Ca) and glucose in small follicle (SF) follicular fluid (SFF) and large follicle (LF) follicular fluid (LFF) from slaughterhouse-derived ovaries were studied. Oocytes were matured in medium based on synthetic oviductal fluid. The effects of various concentrations of electrolytes (Na, K, Ca and Mg) and glucose in the maturation medium on the progression of nuclear maturation and subsequent development were also studied. K in SFF was significantly greater than that in LFF. The Mg concentration in follicular fluid (FF) is 2.0–2.3 mM, which is greater than the concentration present in medium generally used for culture. The glucose concentration in FF is about 3.5–3.9 mM and rapidly decreases during the preservation of ovaries. LF oocytes resumed nuclear maturation and progressed to the M2 stage significantly faster than those collected from SF oocytes. In addition, more LF oocytes developed to blastocysts than did SF oocytes. Changing the Na/K ratio in the maturation medium from 16 to 24 did not affect either the progression of nuclear maturation or the rate of development. A low concentration of Mg (0.5 mM) combined with a low Ca concentration (0.5 mM) inhibited the rate of development, but did not affect the progression of nuclear maturation. On the other hand, increasing the Mg concentration to 2.0 mM from 0.5 mM hastened the progression of nuclear maturation and improved the rate of blastulation, irrespective of the Ca concentration. The progression of nuclear maturation was faster and the rate of development was greater with 5.56 mM glucose than with 1.5 mM glucose. The difference in time needed to progress to M2 among the experiment was about 2–3 h. Therefore, prolonging the maturation periods from 21 to 24 h did not change the rate of development. Our results show that the concentrations of Mg and glucose in the maturation medium and the follicle size enveloping the oocyte affect the progression of nuclear maturation and subsequent development. The time requirement for oocytes to reach M2 is strongly related to the developmental competence of the oocytes.


Zygote ◽  
2011 ◽  
Vol 20 (3) ◽  
pp. 249-259 ◽  
Author(s):  
Hisashi Nabenishi ◽  
Hiroshi Ohta ◽  
Toshihumi Nishimoto ◽  
Tetsuo Morita ◽  
Koji Ashizawa ◽  
...  

SummaryIn the present study, we investigated the effects of various concentrations of cysteine (0.0, 0.6, 1.2 and 1.8 mM) added to the maturation medium on nuclear maturation and subsequent embryonic development of bovine oocytes exposed to heat stress (HS: set at 39.5 °C for 5 h, 40.0 °C for 5 h, 40.5 °C for 6 h, and 40.0 °C for 4 h versus 38.5 °C for 20 h as the control group). This regime mimicked the circadian rhythm of the vaginal temperature of lactating dairy cows during the summer season in southwestern Japan. Moreover, we also evaluated the oocyte's reactive oxygen species (ROS) and glutathione (GSH) levels and the apoptosis levels of the oocytes and cumulus cells in the presence or absence of 1.2 mM cysteine. As a result, HS in the without-cysteine group significantly suppressed (p < 0.05) both the nuclear maturation rate up to the metaphase (M)II stage and the blastocyst formation rate compared with that of the control group. In addition, this group showed significantly higher (p < 0.05) ROS levels and significantly lower (p < 0.05) GSH levels than those of the control group. Moreover, the level of TdT-mediated dUTP nick end labelling (TUNEL)-positive cumulus cells in the HS without-cysteine group was significantly higher (p < 0.05) than that of the control group. However, the addition of 1.2 mM cysteine to the maturation medium restored not only the nuclear maturation, blastocyst formation rates and GSH contents, but also increased the ROS and TUNEL-positive levels of the cumulus cells, but not oocytes, to that of the control group. These results indicate that the addition of 1.2 mM cysteine during in vitro maturation (IVM) may alleviate the influence of heat stress for oocyte developmental competence by increasing GSH content and inhibiting the production of oocyte ROS followed by apoptosis of cumulus cells.


2014 ◽  
Vol 26 (1) ◽  
pp. 193 ◽  
Author(s):  
L. T. K. Do ◽  
V. V. Luu ◽  
Y. Sato ◽  
M. Taniguchi ◽  
T. Otoi

Heat stress can engender various disorders in reproductive functions such as impairment of oocyte maturation, fertilization, and embryonic development. Astaxanthin, an extremely common carotenoid, is a typical fat-soluble antioxidant that scavenges ROS and blocks lipid peroxidation. Moreover, astaxanthin has been shown to improve the development of embryos exposed to heat stress by a reduction in stress-inducible genes. This study was conducted to investigate the effects of astaxanthin supplementation on the meiotic competence, fertilization, and development of porcine oocytes exposed to high temperature (41°C) during maturation culture. Cumulus–oocyte complexes (COC) collected from ovaries were transferred into maturation medium supplemented with astaxanthin (0, 0.25, 0.5, or 1.0 ppm) and were then cultured for 46 h at 41°C or 38.5°C. After maturation culture, the COC were subjected to IVF and embryo culture to evaluate the fertility and development of oocytes. The total cell number and DNA fragmentation in the blastocysts were assessed using terminal deoxynucleotidyl transferase dUTP nick end labelling and Hoechst 33342 staining. The total numbers of oocytes matured at 41°C and 38.5°C in each treatment group were 432 to 470 and 426 to 444, respectively. Data were analysed using ANOVA, followed by Fisher's protected least significant difference test. Exposure to elevated temperatures during maturation culture significantly reduced the proportions of oocytes that reached metaphase II. When the COC were cultured in the maturation medium supplemented with 0.5 and 1.0 ppm of astaxanthin under heat stress conditions (41°C), the supplementation of astaxanthin significantly improved the proportions of maturation, fertilization, and blastocyst formation compared with the control group (0 ppm) (50–52%, 45–55%, and 11–12% v. 17, 25, and 6%, respectively). The supplementation of the maturation medium with 0.25 ppm of astaxanthin improved only blastocyst formation (9.6%). Similarly, the supplementation of astaxanthin at 1.0 ppm improved the proportions of maturation, fertilization, and blastocyst formation of oocytes matured at 38.5°C s compared with the control group (67, 57, and 18% v. 48, 33, and 12%, respectively). However, no beneficial effect of astaxanthin supplementation was found in the total cell number or DNA fragmentation in the blastocysts, irrespective of culture temperature. Our findings show that the supplementation of astaxanthin to maturation medium improves maturation, fertilization, and embryo development of porcine oocytes exposed to heat stress during maturation culture.


Zygote ◽  
2017 ◽  
Vol 25 (5) ◽  
pp. 612-630 ◽  
Author(s):  
Cécile Douet ◽  
Olivia Parodi ◽  
Nicola Antonio Martino ◽  
Giovanni Michele Lacalandra ◽  
Michele Nicassio ◽  
...  

SummaryMost wild equids and many domestic horse breeds are at risk of extinction, so there is an urgent need for genome resource banking. Embryos cryopreservation allows the preservation of genetics from male and female and is the fastest method to restore a breed. In the equine, embryo production in vitro would allow the production of several embryos per cycle. Intracytoplasmic sperm injection (ICSI) is used to generate horse embryos, but it requires expensive equipment and expertise in micromanipulation, and blastocyst development rates remain low. No conventional in vitro fertilization (IVF) technique for equine embryo production is available. The development of culture conditions able to mimic the maturation of the oocyte in preovulatory follicular fluid (pFF) and the post-maturation in oviductal fluid (OF) may improve embryo production in vitro. Our aim was to analyse the effect of in vitro maturation in pFF and incubation in OF on in vitro maturation of equine oocytes, fertilization using conventional IVF or ICSI, and embryo development after culture in synthetic oviductal fluid (SOF) or DMEM-F12. Oocytes collected from slaughtered mares or by ovum pick up were matured in vitro in pFF or semi-synthetic maturation medium (MM). The in vitro maturation, fertilization and development rates were not statistically different between pFF and MM. After in vitro maturation, oocytes were incubated with or without OF. Post-maturation in OF did not significantly improve the fertilization and development rates. Thus, in our study, exposure to physiological fluids for oocyte maturation and post-maturation does not improve in vitro embryo production in the horse.


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