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Background The wisent (Bison bonasus) is a species that has undergone a population bottleneck. Homozygosity is prevalent within the population and may have a negative impact on semen quality in wisent bulls. Semen samples containing a large amount of functionally and morphologically impaired or dead spermatozoa have lower tolerance for cryopreservation process. Such samples are prone to involve damage acrosomes, to produce and release reactive oxygen which negatively affects proper function of spermatozoas. It is a good practice to select intact and viable gametes before subjecting the sample to cryopreservation to improve the efficiency of this process. The aim of this study was to assess the ability of Percoll® density gradient centrifugation in order to improve the quality of wisent spermatozoa after cryopreservation. Spermatozoa samples were analysed with computer-assisted semen analysis system and flow cytometry. Results Percoll® density gradient centrifugation resulted in increased percentage of motile spermatozoa, higher proportion of spermatozoa with normal morphology and proper functionality but also in a significant reduction of the total number of gametes. Nevertheless, the concentration of frozen spermatoza was still sufficient for obtaining a few complete insemination doses suggested for cattle from each epididymis. Conclusions While creating a high-quality genetic reserve, for in vitro fertilisation purposes, eliminating detritus and improving the overall quality of samples is more important than total number of spermatozoa. For these reasons, the achievement of higher post thaw quality of spermatozoa justifies the purification of samples by centrifugation in a Percoll® density gradient prior to the cryopreservation process.

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among reproductive-aged women. It is characterized by chronic anovulation, hyperandrogenism, and the presence of polycystic ovary in ultrasound examination. PCOS is specified by an increased number of follicles at all growing stages, mainly seen in the preantral and small antral follicles and an increased serum level of Anti-Müllerian Hormone (AMH). Because of the strong correlation between circulating AMH levels and antral follicle count on ultrasound, Anti-Müllerian Hormone has been proposed as an alternative marker of ovulatory dysfunction in PCOS. However, the results from the current literature are not homogeneous, and the specific threshold of AMH in PCOS and PCOM is, therefore, very challenging. This review aims to update the current knowledge about AMH, the pathophysiology of AMH in the pathogenesis of PCOS, and the role of Anti-Müllerian Hormone in the treatment of this syndrome.

The transition to menopause, usually occurring between the ages of 40 and 55, is a time when women are particularly vulnerable. When preexisting mental illness is present, symptoms are often amplified during this period. Moreover, women with mental illnesses experience menopausal symptoms similarly to healthy women. In this narrative review we summarize the current data regarding menopause in women with schizophrenia, schizoaffective disorder, and bipolar disorder, as well as current standards of management and care. The management of chronic disease in women suffering from severe mental illness is also considered.

Polycystic ovary syndrome (PCOS) is a one of the most common endocrine disorders, with a prevalence rate of 5–10% in reproductive aged women. It’s characterized by (1) chronic anovulation, (2) biochemical and/or clinical hyperandrogenism, and (3) polycystic ovarian morphology. PCOS has significant clinical implications and can lead to health problems related to the accumulation of adipose tissue, such as obesity, insulin resistance, metabolic syndrome, and type 2 diabetes. There is also evidence that PCOS patients are at higher risk of cardiovascular diseases, atherosclerosis, and high blood pressure. Several studies have reported the association between polycystic ovary syndrome (PCOS) and low-grade chronic inflammation. According to known data, inflammatory markers or their gene markers are higher in PCOS patients. Correlations have been found between increased levels of C-reactive protein (CRP), interleukin 18 (IL-18), tumor necrosis factor (TNF-α), interleukin 6 (IL-6), white blood cell count (WBC), monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α) in the PCOS women compared with age- and BMI-matched controls. Women with PCOS present also elevated levels of AGEs and increased RAGE (receptor for advanced glycation end products) expression. This chronic inflammatory state is aggravating by obesity and hyperinsulinemia. There are studies describing mutual impact of hyperinsulinemia and obesity, hyperandrogenism, and inflammatory state. Endothelial cell dysfunction may be also triggered by inflammatory cytokines. Many factors involved in oxidative stress, inflammation, and thrombosis were proposed as cardiovascular risk markers showing the endothelial cell damage in PCOS. Those markers include asymmetric dimethylarginine (ADMA), C-reactive protein (CRP), homocysteine, plasminogen activator inhibitor-I (PAI-I), PAI-I activity, vascular endothelial growth factor (VEGF) etc. It was also proposed that the uterine hyperinflammatory state in polycystic ovary syndrome may be responsible for significant pregnancy complications ranging from miscarriage to placental insufficiency. In this review, we discuss the most importance evidence concerning the role of the process of chronic inflammation in pathogenesis of PCOS.

Wisent, or European bison (Bison bonasus), is listed as "vulnerable" on the IUCN Red List of Threatened Species and is therefore protected by international law. For the first time, a Wisent embryo has been obtained in vitro. This procedure creates a new opportunity to protect and increase Wisent reproductive potential and thereby opens new possibilities for the establishment of a controlled and broad reserve of the gene pool.

TSG-6 is an ~35 kDa glycoprotein belonging to the hyaluronan binding family. Its expression is induced as a result of an inflammatory condition and during ovulation. TSG-6 is a crucial protein engaged in extracellular matrix synthesis and organization of cumulus-oophorus-complexes (COCs) in preovulatory ovarian follicles. TSG-6 catalyzes cross-linking via heavy chains of trypsin α inhibitor and hyaluronan. This reaction is essential for proper cumulus cell expansion. This process is correlated with purchasing competence by the oocyte. Disorders of the synthesis of TSG-6 cause irregularities in expansion of cumulus cells during ovarian follicle maturation. Therefore, TSG-6 is a potential molecular marker of oocyte maturation.

This paper reviews the basic knowledge about obtaining farm animal embryos in vitro with special focus on differences among species and application of this procedure in the future. In vitro production of farm animal embryos consists of in vitro maturation (IVM) of oocytes, in vitro fertilization (IVF) of matured oocytes, and in vitro culture (IVC) of embryos. Oocytes can be collected from live animals (by laparotomy, laparoscopy, Ovum Pick Up) or from slaughtered ones (by puncture, sectioning). Usually immature oocytes are isolated, and during IVM they reach maturity. Matured oocytes are cultured with sperm (IVF), leading to the formation of zygotes. In the case of fertilization problems (horse, pig), intracytoplasmic sperm injection is used. The zygotes are usually cultured (IVC) to the morula and blastocyst stages. These embryos can be transferred to recipients or frozen/vitrified. Offspring have been obtained after transfer of cattle, sheep, goat, pig and horse embryos. This procedure can be used in animal breeding, biotechnology, medicine, and

The aim of this study was to evaluate the influence of elevated temperature on bovine oviduct epithelial cells (BOECs), based on the expression and localization of both heat shock protein 70 (HSP70), responsible for the cellular defence mechanism, and oviduct specific glycoprotein 1 (OVGP1) which is the most important embryotrophic protein. BOECs were cultured alone and co-cultured with cattle embryos at control (38.5°C) and elevated temperature (41°C) for 168 h. The elevated temperature had no effect on the viability of BOECs but exerted a negative effect on embryo development. The elevated temperature increased the expression of HSP70 and decreased the expression of OVGP1 at both mRNA and protein levels in BOECs cultured alone and those co-cultured with embryos. However, the presence of embryos limited the decrease in OVGP1 expression in BOECs at elevated temperature but did not alter the expression of HSP70. These results demonstrate for the first time the influence of elevated temperature on BOECs, consequently providing insights into the interactions between the embryo and the oviduct at elevated temperature.

Persistent organic chlorine compounds such as DDT and its metabolites, hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) play an important role in chronic poisoning and take part in a number of pathological processes. This study estimates the degree of accumulation of organic Chlorine compounds and polychlorinated biphynyls in the liver, ovaries, and mammary gland tissues of cows.12 refs., 1 fig., 1 tab.

Objective The mechanism of aglepristone action in the placentation time in the bitch remains unclear. The aim of this study was to describe the mechanism by which aglepristone influences ovaries and uterus and to measure the levels of steroid sex hormones in non-pregnant bitches. Materials and Methods Fourteen bitches assigned to a study (n=9) and control (n=5) group were given aglepristone and saline solution, respectively, on the 19th and 20th day after LH peak. On the 26th day after LH peak an ovariohysterectomy was performed. Blood samples were screened for estradiol and progesterone concentrations. Ovaries and uterine horns and bodies were isolated for histological and morphometrical diagnosis and immunohistochemistry analysis of α-estrogen and progesterone receptor expression. Results A decrease of progesterone (p

Elevated temperature during in vitro maturation negatively affects the oocyte's developmental competence, leading to disturbances in nuclear and cytoplasmic maturation. In previous studies, the role of cumulus granulosa cells (CGC) in cumulus-oocyte complexes' (COC) response to elevated temperature was underestimated. However, CGC play an essential role in folliculogenesis, supporting the oocyte's metabolism as well as meiotic progression. Thus, CGC may be engaged in COC response to heat shock. Heat shock protein 70 (HSP70) is the major protein engaged in cellular response to heat stress. The aim of this study was to determine the HSP70 expression in both CGC and oocytes in response to elevated temperature after COC in vitro maturation. COC were collected from bovine ovarian follicles (diameter 2–6 mm) from slaughtered cows and divided into two treatment groups: I (control) – COC were in vitro matured in control temperature (38.5°C); II (experimental) – COC were in vitro matured in elevated temperature (41°C). After in vitro maturation they were mechanically separated into CGC and oocyte. In vitro maturation was conducted in TCM199 25 mM HEPES medium supplemented with 10% FBS, 0.02 IU mL–1 NIH-pFSH, 1 μg mL–1 17β-oestradiol, 22 μg mL–1 Na-pyruvate and 10 μg mL–1 gentamicin, adjusted to pH 7.4 in 5% CO2. The HSP70 expression in CGC and oocytes was performed by real-time PCR and normalized to S18/H2A and S18 gene expression, respectively. In addition, the immunocytofluorescent analysis of HSP70 expression in CGC and oocyte's were performed. The HSP70 was stained using primary monoclonal mouse antibodies raised against bovine HSP70 and secondary antibody raised against mouse conjugated with Alexa 488. Nuclei were stained with Hoechst 33342. Slides were analysed under laser confocal microscope (FV-500, Olympus, Center Valley, PA, USA). The HSP70 expression in CGC was measured as total optical density of HSP70 and normalized to total optical density of nuclei. Statistical analyses were performed by Portable Statgraphics 5.0 Centurion. Mean values of HSP70 expression in CGC and oocytes in real-time PCR and immunofluorescent analysis in CGC were compared using Tukey's HSD test (α = 0.01). After in vitro maturation, the expression of HSP70 in CGC was higher (0.13 ± 0.052 a.u., n = 35) in experimental temperature compared to the control (0.058 ± 0.008 a.u., n = 35) (P

Elevated temperatures have a negative impact on bovine reproduction. One of its effects is an increased concentration of reactive oxygen species (ROS) which may lead to female infertility. Oxidative stress impairs oocyte maturation, fertilization, and embryo development, and it also influences the reproductive tract. One of the defence mechanisms against the increase of ROS is the synthesis of antioxidants. Thus, the aim of this study was to analyse the expression of antioxidant enzymes (superoxide dismutase 1, SOD1; catalase, CAT; and glutathione peroxidase 1, GPX1) in bovine oviduct epithelial cells (BOEC) cultured with or without embryos at elevated temperatures. Ovaries and oviducts were collected from a slaughterhouse. BOECs were mechanically isolated from the oviducts. The oocytes were isolated from ovaries and then maturated and fertilized in vitro. BOEC, after formation of aggregates, were cultured (variant I) in 40-µL droplets of cultured medium (TCM199 25 mM HEPES medium supplemented with 10% FBS, 10 µg mL–1 gentamicin, and 50 µg mL–1 streptomycin) overlaid with mineral oil. Twenty aggregates per droplet were cultured at control (38.5°C) and elevated (41°C) temperatures for 168 h in 5% CO2 in air. Analogously, in variant II, BOEC aggregates were co-cultured with 15 bovine embryos per droplet. Subsequently, the SOD1, CAT, and GPX1 mRNA levels were analysed in BOEC by real-time RT–PCR (Light Cycler, Roche Diagnostics, Warsaw, Poland) and normalized to S18/H2A gene expression. Relative quantification was determined with LightCycler software version 3.5 (Roche Diagnostics) by the second derivative maximum method. Statistical analyses were performed by Portable Statgraphics 5.0 Centurion (Statpoint Technologies Inc., Warrenton, VA). Mean values of SOD1, CAT, and GPX1 expression in BOEC in RT-qPCR analysis were compared using Tukey's HSD test (a = 0.01). Elevated temperature leads to an up-regulation of SOD1 in BOEC cultured (38°C: 0.76 ± 0.12 a.u., n = 44; 41°C: 1.07 ± 0.21 a.u., n = 48) and co-cultured with bovine embryos (38°C: 0.71 ± 0.11 a.u., n = 36; 41°C: 1.04 ± 0.2 a.u., n = 36) and the difference was statistically significant (P

Wisent (Bison bonasus), also called the European bison, is listed as vulnerable on the International Union for the Conservation of Nature Red List of Threatened Species. In Poland, a program for protection in situ and ex situ is being implemented. One new approach is the use of the in vitro embryo production (IVP) procedures to obtain wisent offspring. In contrast to previous successes with cattle IVP, use of IVP with wisent is limited by the small size of the population (only ~5000 individuals in more than 200 herds in Europe) and seasonal reproduction. The aim of this preliminary study was to obtain hybrid embryos (Bison bonasus × Bos taurus) in vitro. Ovaries were isolated from wisent females outside the reproductive season and eliminated from breeding for reasons other than infertility. Cumulus-oocytes complexes (COC) were isolated from all follicles above 2 mm in diameter. All COC were matured in TCM 199 supplemented with 10% fetal bovine serum, 0.02 IU mL–1 of porcine FSH, 17 β-oestradiol, 0.2 mM Na pyruvate, and antibiotics. The COC were cultured for 24 h at 38.5°C and 5% CO2 in humidified air. The matured COC (Bison bonasus) were fertilized in vitro with sperm from Jersey bulls (Bos taurus) in TALP supplemented with 6 mg mL–1 of fatty acid free BSA (BSA FAF), 0.2 mM Na pyruvate, 20 µM penicillamine,10 µM hypotaurine, 1 µM epinephrine, 2 µg mL–1 heparin, and antibiotics. Spermatozoa were used at a final concentration of 1 × 105 per oocyte and were co-cultured for 18 h at 38.5°C and 5% CO2 in humidified air. The hybrid zygotes were cultured in KSOM supplemented with 5 µg mL–1 of MEM Nonessential Amino Acid Solution (100×), 3 mg mL–1 of BSA FAF, and antibiotic for 192 h at 38.5°C and 5% CO2 in humidified air. The medium was partly replaced by fresh medium after 48 and 144 h of culture. Development was evaluated every day. From 25 COC isolated from wisent ovaries, only 18 COC were qualified for in vitro maturation (60%). Of these, 15 COC (83.3%) matured. The percentage of hybrid embryos that cleaved was 80% after 48 h of culture, and the percentage of embryos that developed up to the 8-cell stage was 33% after 96 h of culture. The morula/blastocyst rate was 26.6% after 192 h of culture, as represented by 1 early blastocyst, 2 compact morulae, and 1 morula. The use of the cattle IVP procedure allowed to receive hybrid embryos (Bison bonasus × Bos taurus), but they developed slower than cattle embryos under the same conditions, based on our previous studies. This research will be continued and may make a contribution to the protection of this threatened species.

Elevated temperature has an adverse impact on cattle fertility, causing disorders in ovarian functions and follicle development. Heat shock caused by elevated temperature leads to disruption in the cytoskeleton structure and the nuclear maturation of oocytes. Furthermore, it has an impact on mural granulosa cells (MGC), which are responsible for maintaining an appropriate microenvironment for oocyte development and signal transmission through the ovarian follicle. Heat-shock protein 70 is considered as a fundamental marker of cellular defence mechanisms related to heat shock. It protects other proteins from denaturation by forming complexes and stabilisation of their structure. HSP70 has also an ability to repair damaged proteins and allows them to return to their native structure. Furthermore, members of the HSP70 subfamily participate in the folding of newly synthesised proteins and their transport to different cell compartments. The aim of this study was to determine the impact of elevated temperature on HSP70 expression in mural granulosa cells. MGCs were obtained postmortem from mural layers of cattle ovarian follicles with diameters greater than 15 mm and randomly assigned to one of 5 variants: I (control) – MGCs after isolation; II – MGCs cultured in medium with LH at 38.5°C; III – MGCs cultured in medium with LH at elevated temperature, 41°C; IV – MGCs cultured in medium without LH at 38.5°C; and V – MGCs cultured in medium without LH at elevated temperature, 41°C. HSP70 expression was determined using real-time PCR method, and was normalised to s18/h2a expression. Statistical analysis was made in Statgraphics (Statpoint Technologies Inc., Warrenton, VA, USA; P = 0.01) using one-way ANOVA to compare expression of hsp70 between experimental variants and multifactor ANOVA to determine the influence of temperature and LH stimulation on hsp70 expression. Mean values of hsp70 expression in real-time PCR were compared using Tukey's test (a = 0.05). The significant increase of hsp70 expression was observed in MGCs cultured at 41°C (groups III and V) in comparison to MGCs cultured at 38.5°C (groups II and IV) and the control group. Simultaneously, there is no significant impact of LH stimulation on hsp70 expression. In conclusion, mural granulosa cells are susceptible to elevated temperature, which induces activation of cellular defence mechanisms performed by increased hsp70 expression. This may lead to disorders in the function of MGCs followed by changes in follicular fluid composition and signal transmission through the follicle. Research was supported by 505-10-023300-L00171-99.

The TSG-6 is a ~35-kDa protein belonging to hyaluronan binding superfamily proteins. The TSG-6 plays role in inflammation and in inflammation-like processes (i.e. ovulation). The tsg-6 expression is induced in cumulus–oocyte complex (COC) cells just before ovulation. It is involved in the migration of cumulus cells though the formation and stabilisation of the extracellular matrix. Disturbances in secretion of this protein lead to a reduction in the number of ovulated oocytes. Although studies of the prevalence and role of TSG-6 in COC were conducted in several animal models, little is known about TSG-6 in cattle. The aim of this study was to assess tsg-6 mRNA expression and protein localization in bovine cumulus cells from COC at different maturation status. Ovaries were collected from the slaughterhouse. Cumulus cells were isolated from COCs in different stages of maturity. In variant I, COC were isolated from small follicles of Φ 2 to 6 mm. In variant II, COC were also isolated from small follicles and matured in vitro in TCM199 HEPES with 10% FBS and 0.02 IU NIH-pFSH mL–1, 1 µg mL–1 β-oestradiol, 0.2 µM sodium pyruvate, 50 µg mL–1 gentamicin in 5% CO2, 38.5°C for 24 h. In variant III, COCs were isolated from large follicles of Φ >15 mm. Analysis of tsg-6 expression in cumulus cells was performed using real-time PCR. Expression of Tsg-6 was normalized to that of s18. Statistical analysis of tsg-6 mRNA level in all variants was carried out by 1-way ANOVA, and comparisons of mean values were made with the Tukey honestly significant difference test (Statgraphic 5.1 Centurion); P

The oviduct provides the environment necessary for the gamete transport, completion of spermatozoa capacitation, oocyte fertilization and the early development of embryos. In cattle, all of these processes take place between Day 0 to 4 of the ovarian cycle (Day 0 is the day of ovulation). In previous studies, temporal changes in the bovine oviduct morphology were evaluated by dividing the ovarian cycle into luteal and follicular phases. In order to understand the relation between the bovine oviduct morphology and processes occurring there, the ovarian cycle has been further divided into four phases: I (Day 0–4), II (Day 5–10), III (Day 11–17) and IV (Day 18–20), with the day of ovulation considered Day 0 (1980 J. Dairy Sci. 63, 155–160). The aim of the study was to evaluate the oviduct morphology of the infundibulum, ampulla and isthmus in 4 phases of the ovarian cycle. Research material comprised cattle oviducts (classified into 1 of the 4 phases of the cycle based on ovarian morphology), dissected into infundibulum, ampulla and isthmus and subsequently sectioned and processed for histological preparations (hematoxylin and eosin, H&E, staining). Diameters of transverse cross-sections of oviduct and its lumen and thickness of tunicas: mucosa, muscularis and serosa were evaluated in relation to the region of oviduct and the phase of ovarian cycle. Values are given in μm. Statistical analysis was carried out by 1-way analysis of variance and comparisons of mean values were made with the Tukey honestly significant difference test (Statgraphics Plus 5); P

The objective of this study was to compare the calving rate after transfer of IVM/IVF/IVC embryos co cultured on both Vero and Vero/BRL cells (Duszewska 2000 Theriogenology 54, 1239–1247). Cumulus–oocyte complexes (COCs) were matured in TCM-199 supplemented with 10% FBS, 0.02 IU mL−1 FSH, 1 µg mL−1 17β-estradiol, 0.2 mM Na pyruvate, and 50 µg mL−1 gentamicin for 24 h at 38.5°C in 5% CO2. Spermatozoa were prepared by the swim-up procedure. COCs were fertilized in Fert-TALP supplemented with 6 mg/mL−1 fatty acid-free BSA, 0.2 mM Na pyruvate, 50 µg mL−1 gentamicin sulfate, 20 µM penicillamine, 10 µM hypotaurine, 1 µM epinephrine, and 2 µg/mL−1 heparin for 20 h at 38.5°C in 5% CO2. The zygotes were randomly allocated to one of the co-culture systems: Vero (2 × 103 cells in a 40-µL drop; 20 zygotes per drop), and Vero/BRL (1 × 103 Vero cells and 1 × 103 BRL cells in a 40-µL drop; 20 zygotes per drop). The zygotes from Vero and Vero/BRL were cultured for 168 h post-insemination in drops of Menezo B2 supplemented with 10% FBS until 144 h and from 144 h to 168 h without FBS, at 38.5°C in 5% CO2. Next, the blastocysts (Grade 1, according to IETS Manual) from Vero and Vero/BRL were transferred to recipients. The recipients were monitored daily for heat behavior, examined by ultrasound after 35 days and 65 days, and then observed monthly to confirm pregnancy. The results are presented in Table 1. Statistical significance was tested using the chi-square test. In spite of better development of cattle embryos on Vero/BRL cells than on Vero cells (P < 0.05), a lower rate of calving was obtained after transfer of these embryos to recipients than for those on Vero cells (P < 0.001). Higher loss of pregnancy after transfer of Vero/BRL embryos was observed in Days 35–65, which may indicate early fetal resorption. All calves were born naturally, healthy, and with normal weight. Table 1.Calving rate after transfer of embryos co-cultured on Vero cells and on Vero/BRL cells This work was supported by KBN Grant 2P06D05228.

The role of persistent chlorinated hydrocarbons (PCH) in the reproductive disorders in ruminants is not well documented. In the present study we have examined the effect of these compounds and their metabolites on the secretion of estradiol (E2) and progesterone (P4) by bovine granulosa cells in vitro. Granulosa cells were isolated from large follicles (> or = 8 mm diameter) by gently washing the internal follicle wall. Aliquots of approximately 4 X 10(5) viable granulosa cells in 0.5 ml medium were cultured at 37 degrees C in an atmosphere of 5% CO2 and 95% air. Granulosa cells were cultured for 96h in a medium containing different concentrations (10(-1)-10(-4) ng/ml) of a PCH combination. Estradiol and progesterone were measured in unextracted granulosa cell culture medium by Enzyme Immunoassay (EIA). The exposure of granulosa cells to a combination of these organochlorine compounds in vitro results in a slight decrease of estradiol secretion only at the highest studied concentration of the PCH combination. However, the secretion of progesterone by these cells was seriously decreased, even by concentrations found in ovaries from animals kept under natural environmental conditions. The in vitro culture system of granulosa cells from preovulatory follicles may be useful in screening toxic effects of pesticides in animal reproduction.

Higher air temperature in summer causes a significant reduction in fertility in cattle. Increase in female body temperature during the period of reproduction by only 2EC, also known as hyperthermia, leads to disturbances in the functioning of the female reproductive system, oocytes maturation, fertilization and embryos development. Particularly sensitive to high temperatures are embryos in the first and second day after fertilization (thermosensitive), but just at third till fifth day after fertilization their resistance to thermal stress significantly increases. Morula-stage and blastocyst-stage bovine embryos are insensitive to elevated temperatures (thermoresistant). Most probably this is due to the increasing number of cells within the embryo and the capacity to activate defense mechanisms based on the synthesis of various factors providing resistance to high temperatures. These factors include heat shock protein 70 (HSP70), antioxidants such as glutathione, and IGF-1. One of the responses of the embryo to elevated temperature is the induction of apoptosis, which is associated with the activation of embryonic genome. Owing to the apoptosis, cells damaged by high temperature may be eliminated from the embryo, which increases their chance of survival. Precise examination of the mechanisms responsible for the development of thermotolerance of preimplantation bovine embryos will enable their protection from the consequences of elevated temperature. The aim of this review is to summarise experiments in which in vitro embryo production system was used to estimate the influence of elevated temperature on cattle fertility.