Effect of food supplementation on in vitro embryo production and growth performance in prepubertal Nelore heifers.

In vitro embryos production from prepubertal heifers can help contribute to breeding programs; however, strategies are necessary to increase their embryo production. The aim of this study was to investigate the effects of two nutritional plans on oocyte recovery, embryo production and growth performance of prepubertal Nelore heifers. Thirty-four Nelore heifers with age of 6.5 months were divided into two feeding treatments (NP1 and NP2). The NP1 diets served as the control and NP2 diets were formulated to contain an average of 1.22-fold more energy than NP1. After 3 months of supplementation, the animals underwent follicular aspiration (ovum pick-up, OPU) every 21 d for 3 months and embryos were produced in vitro. Wither height, chest depth, body weight and subcutaneous fat of animals were measured. The number of retrieved and viable oocytes per OPU were 1.49-fold and 1.42-fold greater in NP2 heifers (p = 0.018 and p = 0.049, respectively) than those in NP1 heifers. Heifers administered NP2 produced 29.7% blastocysts, a percentage higher than NP1 animals that produced 24.40% embryos (p < 0.05). Consequently, females in the NP2 treatment showed improved body development. These results indicate a positive effect of a higher energy diet on assisted reproduction and body development in prepubertal heifers.

Seasonality does not influence cortisol or testosterone production, or seminal quality of stallions located at low latitudes.

The effects of seasonality on the reproduction of stallions vary based on the latitude. Although previous studies have shown the influence of seasonality in raw semen quality in south-eastern Brazil, data regarding the influence of seasonality in cooled and frozen stored semen in Brazil is limited. Therefore, in this study, we have analysed if seasonality influences the hormone production (i.e., cortisol and testosterone), spermatogenesis, and quality of fresh, cooled, and frozen semen of stallions in central Brazil, and established the season most suitable for semen cryopreservation in a latitude of 15°S. Ten stallions were followed-up for one year, which was divided into two seasons, namely, drought, and rainy. Fresh, cooled, and frozen-thawed semen samples were assessed using CASA and flow cytometry. Additionally, the temperature and humidity index (THI) was calculated to determine the thermal stress. Although the THI varied between the two seasons, no thermal stress was observed throughout the year, nor were there differences in the physiological parameters of the stallions or plasma cortisol or testosterone levels. Furthermore, differences were not detected in total and progressive motility, sperm capacitation, and sperm membrane integrity, as well as in the number of live sperm with intact acrosomes and high mitochondrial membrane potential, between the two seasons in the fresh and frozen-thawed semen. Our data suggest that semen can be effectively collected and cryopreserved throughout the year within central regions of Brazil.

Freezing for the Future: Obtaining Fibroblast Samples from Deceased Wild Mammals for the Brazilian Cerrado Germplasm Bank.

We isolated and further characterized fibroblasts obtained from postmortem skin biopsies of three different Brazilian wild species (Chrysocyon brachyurus-maned wolf, Cerdocyon thous-crab-eating fox, Mazama gouazoubira-brown brocket deer). The effects of two cryoprotectants, 10% dimethyl sulfoxide (DMSO) and 5% dimethylformamide (DMF), were assessed to determine the most efficient cryopreservation protocol. Such an investigation promotes the creation of germplasm banks, using samples that would otherwise be rejected and permanently lost following the death of the animals. We utilized animal corpses that were involved in highway accidents, found dead in the natural environment, or referred to us from the veterinary hospital at the Brasília Zoo. Fibroblasts from C. brachyurus specimens presented a delay in cell growth in Dulbecco's modified Eagle's medium in relation to other species. This observation is a limiting factor for the future storage of cells from this species. Differences in cellular morphology were observed between C. brachyurus, C. thous, and M. gouazoubira, presenting branched, fusiform, and spherical forms, respectively. The cryoprotective solution containing 10% DMSO was more efficient than 5% DMF medium in preserving the viability of fibroblasts of the three species (p < 0.05). After defining the best cryopreservation solution, a germplasm bank was successfully formed. This biological reservoir is configured as the first germplasm bank containing somatic cells and gametes of wild mammals of the Cerrado biome of Brazil. This material will be used for future characterization of the species and multiplication by means of nuclear transfer cloning.

Low levels of sulfur and cobalt during the pre- and periconceptional periods affect the oocyte yield of donors and the DNA methylome of preimplantation bovine embryos.

Maternal nutrition is critical in mammalian development, influencing the epigenetic reprogramming of gametes, embryos, and fetal programming. We evaluated the effects of different levels of sulfur (S) and cobalt (Co) in the maternal diet throughout the pre- and periconceptional periods on the biochemical and reproductive parameters of the donors and the DNA methylome of the progeny in Bos indicus cattle. The low-S/Co group differed from the control with respect to homocysteine, folic acid, B12, insulin growth factor 1, and glucose. The oocyte yield was lower in heifers from the low S/Co group than that in the control heifers. Embryos from the low-S/Co group exhibited 2320 differentially methylated regions (DMRs) across the genome compared with the control embryos. We also characterized candidate DMRs linked to the DNMT1 and DNMT3B genes in the blood and sperm cells of the adult progeny. A DMR located in DNMT1 that was identified in embryos remained differentially methylated in the sperm of the progeny from the low-S/Co group. Therefore, we associated changes in specific compounds in the maternal diet with DNA methylation modifications in the progeny. Our results help to elucidate the impact of maternal nutrition on epigenetic reprogramming in livestock, opening new avenues of research to study the effect of disturbed epigenetic patterns in early life on health and fertility in adulthood. Considering that cattle are physiologically similar to humans with respect to gestational length, our study may serve as a model for studies related to the developmental origin of health and disease in humans.

Intrafollicular oocyte transfer (IFOT): Potential feasibility in the ovine species.

Intra-follicular oocyte transfer (IFOT) is a promising and innovative technique for in vivo embryo production previously described for equines and bovines. The aim of this study was to assess the feasibility of IFOT in the ovine species. Two preliminary in vivo and in vitro trials were performed to test the optimal procedures and timing for IFOT. In the in vivo trial, follicular growth was monitored with transrectal ultrasonography in ten adult ewes to preliminarily determine the ovulation and ideal timing for IFOT. The in vitro trial assessed i) the optimal inner diameter of the injection needle and ii) the recovery rate and integrity of injected cumulus-oocyte complexes (COCs) after follicle aspiration. For IFOT and embryo collection, five ewes were synchronized by CIDR insertion. Forty hours after CIDR removal, in ewes under sedation and general anesthesia, the ovaries were exposed by laparotomy, and the preovulatory follicle was injected with COCs previously collected from ovaries obtained from an abattoir. At 4 h after surgery, fully recovered ewes were housed in a paddock with a ram of proven fertility. Crayon marking on ram's chest was used to detect mating. Ovulation was assessed 40 h after the transfer of oocytes by transrectal ultrasonography. On day 6 after IFOT, embryo collection was performed by uterine flushing. In the in vitro testing, injection of >5 mm follicles with a 28 G needle loaded with 30 COCs in a 5 µL volume resulted in higher recovery rates and better preservation of COCs integrity. In the in vivo trial, ultrasound scanning revealed that ovulation occurred between 60 and 72 h after CIDR removal in all animals. In one ewe subjected to IFOT, 22/24 oocytes were effectively injected into the preovulatory follicle, but no embryos were collected after flushing. In the remaining four animals, 85/102 oocytes were injected, and six cleaved embryos, 12 morulae and 1 blastocyst were collected, including native embryos. This preliminary investigation indicated that IFOT in ovine species resulted in ovulation, fimbrial capture, tubal transport of heterologous oocytes and in vivo embryo production. Further studies are needed to optimize the embryo recovery rate and develop less invasive techniques for oocyte injection and uterine flushing, such as through a laparoscopic or transcervical approach.

Embryonic loss, abortion, and malformations in ewes caused by the ingestion of hay leaves of Cenostigma pyramidale / Perda embrionária, aborto e malformações em ovinos por ingestão de Cenostigma pyramidale na forma fenada

Determining if reproductive failures in ewes at the semiarid region in the state of Bahia are related to the consumption of the species Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis, and this study was developed using pregnant ewes divided into six groups: G1, G2, G3, G4 with six animals each, G5 and G6 with ten animals. Each group received fence leaves in the proportion of 1%, 2%, 0.5%, and 0.25% of live weight (LW) respectively; G5 and G6, with ten animals each, receiving 0.25% and 0.5% of the LW, respectively, and the Control Group, comprising 16 ewes, were grass feeding (Cynodon dactylon). Ewes from G1 to G4 were the same, except for two, and started ingestion of the plant four days after ending of natural mating on the 80th day of gestation, while those regarding from G5 to G6 groups started ingestion on the 26th day of gestation ending on the 98 day. The ultrasonographic test was performed weekly. In G1 ewes (1%), there was an embryonic loss on the 32nd and 39th days of gestation and abortion on the 46th day. In G2 (2%), the embryo loss was earlier (on the 26th day of gestation), and abortion on the 46th day of gestation. In G3 group (0.5%), there was an embryonic loss around the 40th day of gestation. In G4 group (0.25%), it was observed the occurrence of one death lamb with bone malformations. In G6 (0.5%), abortion occurred later (108 days), followed by retained placenta. This was also verified in G5 group (0.25%). The presence of fetal malformation was found in death lambs born in G4 group, born alive from G5 and G6 groups, and one aborted from G6. In G5 and G6 groups, there were also genetic alterations on surviving lambs. In addition to these results, recurrent estrus was observed without gestation in G1, G2, G3, and G4 ewes. From the Control Group, 13 normal lambs were born without genetic alterations; furthermore, concerning a quadruple birth, three lambs were born dead. The results infer that species of C. pyramidale in low doses causes reproductive losses in pregnant ewes, therefore it is not recommended for sheep diet over the first 60 days of gestation.(AU)

Para determinar se falhas reprodutivas em ovelhas na região semiárida da Bahia estão relacionadas ao consumo de Cenostigma pyramidale (Tul.) Gagnon & G.P. Lewis, foi realizado um estudo utilizando-se ovelhas prenhes divididas em seis grupos e dois Grupos Controle. Os grupos G1, G2, G3 e G4 com seis animais cada. Cada grupo recebeu folhas fenadas na proporção de 1%, 2%, 0,5% e 0,25% do peso vivo (PV) respectivamente; G5 e G6, com 10 animais cada, que receberam 0,25% e 0,5% do PV respectivamente. Os Grupos Controle foram alimentados com ração e capim (Cynodon dactylon). Ovelhas dos grupos 1 a 4 iniciaram ingestão da planta quatro dias após monta natural com término aos 80 dias de gestação, enquanto as dos grupos 5 a 6 iniciaram ingestão no 26º dia de gestação com término aos 98 dias. Avaliação ultrassonográfica foi realizada semanalmente. Nos animais do G1 (1%), verificou-se perda embrionária aos 32 e 39 dias de gestação, e aborto aos 46 dias. Nos do G2 (2%) a perda embrionária foi mais precoce (26 dias), e aborto aos 46 dias. No G3 (0,5%), houve perda embrionária em torno dos 40 dias. No G4 (0,25%), verificou-se ocorrência de natimorto com malformações aos 150 dias de gestação. No G6 (0,5%) o aborto ocorreu mais tardiamente (108 dias), seguido de retenção de placenta. Essa ocorrência também foi verificada no G5 (0,25%). A presença de malformação fetal foi encontrada em fetos natimorto do G4, nascidos vivos do G5 e G6, e um abortado do G6. No G5 e G6 também foram observadas alterações de aprumos em cordeiros sobreviventes. Do Grupo Controle nasceram 13 borregos normais, porém uma ovelha apresentou gestação quádrupla com três natimortos. Os resultados inferem que C. pyramidale fenada em baixas doses causa perdas reprodutivas em ovelhas gestantes, não sendo por isso recomendada para a dieta de ovelhas durante os primeiros 60 dias de gestação.(AU)

Resveratrol supplementation and cryopreservation of buck semen.

Resveratrol (Resv) was tested to assess its effects on buck semen freezability. Ejaculates of 4 bucks were collected, washed and diluted in a commercial extender at 30 °C. Extended semen was divided into 4 aliquots supplemented with increasing concentrations of Resv: 0 µM (control); 10 µM; 25 µM and 50 µM. Aliquots were cooled to 4 °C in 5h and frozen in LN2. Thawing was performed at 37 °C for 30 s. At the 3 stages of the experiment (30 °C, 4 °C, thawing), motility (CASA), osmotic resistance (Hos test) and integrity of cytoplasm and acrosome membranes (PI/PSA staining) were assessed. Moreover, in thawed samples, the oxidative status (MDA assay) and early apoptosis (DNA fragmentation by TUNEL assay) were evaluated. Resveratrol supplementation did not affect most of the motility parameters analysed, except for total motility, ALH (lateral head displacement) and velocity distribution (P < 0.05). Functional and morphological integrity of membranes was not affected at any stage of the experiment (P > 0.05). In thawed spermatozoa, the oxidative status was not preserved by Resv (P > 0.05) while early apoptosis, was significantly decreased in the 50 µM Resv group (P < 0.05). Resveratrol did not improve buck semen freezability; the observed effects on motility and DNA were not dose dependent and not mediated by a potential anti-oxidant activity.

The Replacement of Fetal Bovine Serum with Bovine Serum Albumin During Oocyte Maturation and Embryo Culture Does Not Improve Blastocyst Quality After Slow Freezing Cryopreservation.

In the present study, four experimental groups were used: fresh embryos, cultured during in vitro maturation and in vitro culture in media supplemented with bovine serum albumin (BSA) (fresh BSA) or fetal bovine serum (FBS) (fresh FBS); and two groups of cryopreserved and thawed embryos, produced under the same conditions (frozen BSA and frozen FBS). Experiment 1 evaluated the protein source effect on embryo development and response to cryopreservation. At day 7, half of the expanded blastocysts (Bx) from each group were cryopreserved and warmed and the other half were used as controls. After warming, embryos were incubated under the same conditions for 48 hours, and the hatching rate was measured at 24 and 48 hours. The total and the apoptotic cell numbers were measured in a subset of Bx after 24 hours. Experiment 2 used the Bx of experiment 1 to compare the expression of KRT8, PLAC8, FOSL1, HSP1A1, and HSPA5 genes in hatched blastocysts at 24 and 48 hours for all groups. The FBS group showed a higher percentage (p < 0.05) of embryos (42.8% vs. 27.9%) and higher rates of Bx (75.0% vs. 63.8%) on day 7, compared with the BSA group. At 24 hours postwarming, the fresh FBS group showed the highest hatching rate (p < 0.05) in comparison with other treatments. However, at 48 hours, the hatching rate was similar (p > 0.05) among groups: fresh FBS (68.1% ± 23.3%), fresh BSA (70.0% ± 31.0%), frozen FBS (39.2 ± 27.1), and frozen BSA (38.2 ± 23.9). After 24 hours, frozen BSA showed a higher number of cells compared with frozen FBS (p < 0.05). The expression of the PLAC8 gene was higher (p < 0.05) in fresh BSA embryos compared with frozen FBS embryos at 24 hours. In the present study, BSA replacement reduced embryo development, but did not affect the response to cryopreservation. However, upregulation of the PLAC8 gene suggests that embryos cultured in BSA might have better quality to support further development.

Reproductive Performance Following Transcervical Insemination with Frozen Thawed Semen in Ewes Submitted to Surgical Incision of Cervical Folds (SICF): Comparison with Laparoscopic Artificial Insemination.

Transcervical artificial insemination (AI) after the surgical incision of cervical folds (SICF) could represent a valid alternative to laparoscopic AI when frozen thawed semen is used. The aim of this experiment was to compare pregnancy (PR) and lambing rates (LR) of ewes submitted either to transcervical AI after SICF or to laparoscopic AI using frozen thawed semen. Pregnant at term ewes (n = 80) were allocated in two experimental groups. After lambing, one group (n = 39) was submitted to SICF. The remaining ewes that were regularly lambed were allocated to the group of laparoscopic AI (n = 40). Six months later, oestrous cycle of both experimental groups was synchronised and all ewes were artificially inseminated with frozen thawed semen. Ewes submitted to SICF underwent transcervical insemination and intrauterine deposition of semen was recorded. The remaining animals were submitted to laparoscopic AI. Pregnancy and LR were recorded. Intrauterine deposition of semen was possible in 89.7% pf ewes submitted to SICF. This group showed similar PR and LR compared to the laparoscopic group (respectively: PR, 71.8% vs. 70% and LR, 64.1% vs. 65%; p > 0.05). Transcervical AI after SICF may represent a valid alternative to laparoscopy in AI protocols requiring the use of frozen thawed semen.

Effect of delipidant agents during in vitro culture on the development, lipid content, gene expression and cryotolerance of bovine embryos.

In vitro produced embryos are still sensitive to the freezing process which can be explained, in part, by the high-lipid accumulation that characterizes these embryos. Therefore, we aimed to evaluate the effect of delipidating agents, L-carnitine and the trans-10 cis-12 conjugated linoleic acid (CLA) isomer, on blastocyst development, lipid content, gene expression and cryotolerance when added to embryo culture media. Embryos were cultured in four different media: T1: control (n = 616), synthetic oviduct fluid (SOF) media with 5% foetal bovine serum (FBS); T2: L-carnitine (n = 648), SOF medium with 5% FBS and 0.6 mg/ml of L-carnitine; T3: CLA (n = 627), SOF medium with 5% FBS and 100 µM trans-10 cis-12 CLA; and T4: L-carnitine + CLA: (n = 597), SOF medium with 5% FBS plus 0.6 mg/ml L-carnitine and 100 µM trans-10 cis-12 CLA. Supplementation of culture medium with either or both delipidating agents reduced (p < .05) blastocyst rate on D7 (T1 = 49 ± 3.5; T2 = 39 ± 3.0; T3 = 42 ± 3.9 and T4 = 39 ± 3.9), but did not affected gene expression (p > .05). Although embryos cultured in the presence of L-carnitine contained fewer (p < .05) lipid droplets than the control embryos, they showed a lower re-expansion rate 24 hr post-thaw than those (p < .05). In conclusion, although L-carnitine reduced the amount of lipids in cultured embryos, the use of L-carnitine and CLA during in vitro culture was not able to improve the embryo production and the response to cryopreservation.

Fetal development and blood hematological-biochemical parameters in Campeiro and Pantaneiro foals.

For a long time, Pantaneiro and Campeiro breeds were raised only within their places of origin. Consequently, there are few of these horses; therefore, establishing reproductive and clinical standards for these animals is necessary to implant new biotechnologies for reproduction to preserve their genetics. This study aimed to perform a descriptive evaluation of fetal age determination by fetus ocular orbit measurement in mares of the Campeiro and Pantaneiro breeds. We also evaluated sequential changes in hematology and biochemistry for foals from birth to six months of life by counting red blood cells, hemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin concentration, leukocytes, neutrophils, lymphocytes, eosinophils, monocytes, basophils, platelet count, fibrinogen, albumin, plasma protein, creatinine, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and globulins. There was no significant difference in relation to fetal gestational age and ocular orbit between the two breeds (P = 0.578). There was no significant difference in the hematological parameters between the Campeiro and Pantaneiro foals, but there were differences in the means and changes in the blood variables when compared to the literature. These hematological and biochemical variations provide useful information for clinical evaluations from Campeiro and Pantaneiro foals up to six months of age.

Transuterine embryo migration, distribution of sexes within uterine horns, and fetometry in Nellore (Bos indicus) cattle.

There is no consensus about the occurrence of transuterine embryo migration under natural breeding circumstances, neither data related to this phenomenon for zebu cattle. In this study, 5431 reproductive tracts of Nellore cows and heifers were evaluated in an abattoir in the state of Mato Grosso do Sul. A total of 1030 animals (19.0%) were pregnant at the time of slaughter (including 2 twin pregnancies). Regarding singleton pregnancies (n = 1028), 39.5% of them, the fetus was located in the left uterine horn and the remaining 60.5% in the right. These frequencies differed statistically from parity. In all 1028 (100.0%) cases, the presence of a single CL was perceived in the ovary ipsilateral (whether right or left) to the pregnant uterine horn, indicating the absence of transuterine embryo migration of the conceptus. The overall sex ratio found was 51.5%, considering only pregnancies with sex identified, not differing significantly between the number of males and the number of females. The sex frequencies obtained from the total number of singleton pregnancies were 46.5% males, 43.9% females, and the remaining 9.6% corresponding to unknown sex fetuses. The supposed sex predilection for uterine horns was not observed because the difference between the numbers of males and females for the same uterine horn was not statistically significant. The crown-rump (CR) and crown-nose (CN) measures, for the conceptus with CR length 2.00 cm to 15.00 cm, showed a high linear correlation coefficient (r = 0.990865), being CN = (0.3027 × CR) + 0.4491, r2 = 0.9818, the equation that describes the behavior between the variables for this length interval. In conclusion, in Nellore cattle, the transuterine migration of conceptus may not exist, or consists of a rare event. In addition, the sex ratio and predilection are not distinguished from the symmetrical distribution, and regarding fetometry, an equation that involves CR and CN, could be useful for the veterinary field routine, especially in reproductive evaluation.

Semen characteristics of the amazonian jundiá (Leiarius marmoratus Gill, 1870) / Característica seminal de jundiá amazônico (Leiarius marmoratus Gill, 1870)

The study evaluated qualitative and quantitative characteristics of Amazonian jundiá semen. The experiment was carried out in February 2015 at Cia do Peixe, a company located in Goiás state, Brazil, that specialises in fish fry production. Three male L. marmoratus farmed in dugout ponds, weighing 1.34 ± 0.29 kg and measuring 39.33 ± 1.15 cm in length, were tested. The specimens were captured and transferred to a 1000-L tank at the Reproduction Laboratory of the abovementioned company. Water temperature was measured at 7:00 a.m. and 5:00 p.m., and the fish were fed twice daily. For semen collection, the fish were captured from the tank using a dip net and constrained with a wet cotton towel. Their eyes were covered and their urogenital papilla was cleaned and dried with paper towel. Semen was collected in microcentrifuge tubes that were immersed in ice and analysed immediately. On average, the sperm motility rate was 83.33%, motility duration was 5.33 min, sperm concentration was 1,795,833 cells/ mm3, and vigour was 4. The morphological analysis of the sperm revealed tail anomalies in 17.66%, midpiece anomalies in 20%, and head anomalies in 5.33%. Based on qualitative and quantitative characteristics, L. marmoratus semen was shown to be suitable for use in artificial reproduction procedures.

Objetivou-se avaliar qualitativamente e quantitativamente as características seminais do Jundiá Amazônico. O experimento foi realizado em fevereiro de 2015, a Cia do Peixe, uma empresa localizada no Estado de Goiás, Brasil, especializada em produção de alevino. Três masculino L. marmoratus cultivados em tanques de esconderijo subterrâneo, pesando 1,34 ± 0,29 kg e medindo 39.33 ± 1,15 centímetros de comprimento, foram testados. Os espécimes foram capturados e transportado para um tanque de 1000 L no Laboratório da empresa acima indicado reprodução. A temperatura da água foi medida a 07:00 e 17:00 e os peixes foram alimentados duas vezes ao dia. Para a coleta de sêmen, os peixes foram capturados a partir do tanque usando uma rede de mergulho e constrangidos com uma toalha de algodão molhado. Seus olhos estavam cobertos e sua papila urogenital foi limpo e seco com toalha de papel. O sémen foi recolhido em tubos de microcentrífuga que foram imersas em gelo e analisadas imediatamente. A taxa de motilidade média foi 83,33%, a duração de motilidade média foi 5,33 minutos, concentração espermática foi de 1.795.833 celulas/ mm3 e o vigor 4. A análise morfológica revelou 17,66% de defeitos de cauda, 20% de defeitos de peça intermediária e 5,33% de defeitos de cabeça. O Jundiá da Amazônia (Leiarius marmoratus Gill, 1870) apresenta característica seminais e espermáticas quantitativas e qualitativas que permitem sua utilização em técnicas de reprodução artificial.

Isolation and characterization of mesenchymal stem cells derived from bovine Wharton's jelly and their potential for use in cloning by nuclear transfer / Isolamento e caracterização de células tronco mesenquimais derivadas de geléia de Wharton bovina e seu potencial para uso na clonagem por transferência nuclear

ABSTRACT: Wharton's jelly is a source of mesenchymal stem cells (MSCs) that had not yet been tested for bovine embryo production by nuclear transfer (NT). Thus, the objective of this study was to isolate, characterize and test MSCs derived from Wharton's jelly for embryo and pregnancy production by NT in cattle. The umbilical cord was collected during calving and cells derived from Wharton's jelly (WJCs) were isolated by explant and cultured in Dulbecco's Modified Eagle Medium. Skin Fibroblasts (FB) were isolated after 6 months of life. Morphological analysis was performed by bright field and scanning electron microscopy (SEM) during cell culture. Phenotypic and genotypic characterization by flow cytometry, immunocytochemistry, RT-PCR and differentiation induction in cell lineages were performed for WJC. In the NT procedure, oocytes at the arrested metaphase II stage were enucleated using micromanipulators, fused with WJCs or FB and later activated artificially. SEM micrographs revealed that WJCs have variable shape under culture. Mesenchymal markers of MSCs (CD29+, CD73+, CD90+ and CD105+) were expressed in bovine-derived WJC cultures, as evidenced by flow cytometry, immunocytochemistry and RT-PCR. When induced, these cells differentiated into osteocytes, chondrocytes and adipocytes. After classification, the WJCs were used in NT. Blastocyst formation rate by NT with WJCs at day 7 was 25.80±0.03%, similar to blatocyst rate with NT using skin fibroblasts (19.00±0.07%). Pregnancies were obtained and showed that WJCs constitute a new cell type for use in animal cloning.

RESUMO: A geleia de Wharton é uma fonte de células tronco mesenquimais (CTMs) que ainda não havia sido testada para a produção de embriões bovinos por transferência nuclear (TN). O objetivo deste estudo foi isolar, caracterizar e testar as CTMs derivadas da geleia de Wharton para produção de embriões e gestações por transferência nuclear em bovinos. O cordão umbilical foi coletado durante o nascimento e as células derivadas da geleia de Wharton (CGWs) foram isoladas por explante e cultivadas em Dulbecco's Modified Eagle Medium. Fibroblastos (FB) da pele foram isolados após 6 meses de vida. As análises morfológicas foram realizadas pelas microscopias de campo claro e eletrônica de varredura durante o cultivo celular. Caracterização fenotípica e genotípica por citometria de fluxo, imunocitoquímica, RT-PCR e indução da diferenciação em linhagens celulares foi realizada com as CGWs. No procedimento de TN, ovócitos no estágio de metáfase II foram enucleados usando micromanipuladores, fusionados com CGWs ou FB e então ativados artificialmente. Micrografias de microscopia de varredura revelaram que CGWs tiveram forma variada sob cultivo. Os marcadores mesenquimais de CTMs (CD29+, CD73+, CD90+ and CD105+) foram expressos em cultura de CGWs bovina, como evidenciado por citometria de fluxo, imunocitoquímica e RT-PCR. Quando induzidas, estas células diferenciaram-se em osteócitos, condrócitos e adipócitos. Após classificação, as CGWs foram utilizadas na TN. A taxa de formação de blastocistos por TN com CGWs no sétimo dia de cultivo foi de 25,80±0,03%, similar a produção de blastócitos por TN com fibroblastos de pele (19,00±0,07). Gestações foram obtidas e mostraram que CGWs constituem um novo tipo celular para ser usado na clonagem animal.

Intrafollicular transfer of fresh and vitrified immature bovine oocytes.

Embryo production by intrafollicular oocyte transfer (IFOT) represents an alternative for production of a large number of embryos without requiring any hormones and only basic laboratory handling. We aimed to (1) evaluate the efficiency of IFOT using immature oocytes (IFIOT) and (2) compare embryo development after IFIOT using fresh or vitrified immature oocytes. First, six IFIOTs were performed using immature oocytes obtained by ovum pickup. After insemination and uterine flush for embryo recovery, 21.3% of total transferred structures were recovered excluding the recipient's own oocyte or embryo, and of those, 26% (5.5% of transferred cumulus-oocyte complexes [COCs]) were morula or blastocyst. In the second study, we compared fresh and vitrified-warmed immature COCs. Four groups were used: (1) fresh immature COCs (Fresh-Vitro); (2) vitrified immature COCs (Vit-Vitro), with both groups 1 and 2 being matured, fertilized, and cultured in vitro; (3) fresh immature COCs submitted to IFIOT (Fresh-IFIOT); and (4) vitrified immature COCs submitted to IFIOT (Vit-IFIOT). Cumulus-oocyte complexes (n = 25) from Fresh-IFIOT or Vit-IFIOT groups were injected into dominant follicles (>10 mm) of synchronized heifers. After excluding one structure or blastocyst, the recovery rates per transferred oocyte were higher (P < 0.05) for Fresh-IFIOT (47.6%) than for Vit-IFIOT (12.0%). Blastocyst yield per initial oocyte was higher (P < 0.05) for Fresh-Vitro (42.1%) than for Fresh-IFIOT (12.9%). Vit-Vitro presented higher (P < 0.05) embryo development (6.3%), compared to Vit-IFIOT, which did not result in any extra embryo. Although IFOT did not improve developmental competence of vitrified oocytes, we achieved viable blastocysts and pregnancies produced after IFIOT of fresh bovine immature oocytes. Further work on this technique is warranted as an option both for research studies and for clinical bovine embryo production in the absence of laboratory facilities for IVF.

Production of Bovine Embryos and Calves Cloned by Nuclear Transfer Using Mesenchymal Stem Cells from Amniotic Fluid and Adipose Tissue.

The less differentiated the donor cells are used in nuclear transfer (NT), the more easily are they reprogrammed by the recipient cytoplasm. In this context, mesenchymal stem cells (MSCs) appear as an alternative to donor nuclei for NT. The amniotic fluid and adipose tissue are sources of MSCs that have not been tested for the production of cloned embryos in cattle. The objective of this study was to isolate, characterize, and use MSCs derived from amniotic fluid (MSC-AF) and adipose tissue (MSC-AT) to produce cloned calves. Isolation of MSC-AF was performed using in vivo ultrasound-guided transvaginal amniocentesis, and MSC-AT were isolated by explant culture. Cellular phenotypic and genotypic characterization by flow cytometry, immunohistochemistry, and RT-PCR were performed, as well as induction in different cell lineages. The NT was performed using MSC-AF and MSC-AT as nuclear donors. The mesenchymal markers of MSC were expressed in bovine MSC-AF and MSC-AT cultures, as evidenced by flow cytometry, immunohistochemistry, and RT-PCR. When induced, these cells differentiated into osteocytes, chondrocytes, and adipocytes. Embryo production was similar between the cell types, and two calves were born. The calf from MSC-AT was born healthy, and this fact opens a new possibility of using this type of cell to produce cloned cattle by NT.

Effects of Different Maturation Systems on Bovine Oocyte Quality, Plasma Membrane Phospholipid Composition and Resistance to Vitrification and Warming.

The objective of this study was to evaluate the effects of different maturation systems on oocyte resistance after vitrification and on the phospholipid profile of the oocyte plasma membrane (PM). Four different maturation systems were tested: 1) in vitro maturation using immature oocytes aspirated from slaughterhouse ovaries (CONT; n = 136); 2) in vitro maturation using immature oocytes obtained by ovum pick-up (OPU) from unstimulated heifers (IMA; n = 433); 3) in vitro maturation using immature oocytes obtained by OPU from stimulated heifers (FSH; n = 444); and 4) in vivo maturation using oocytes obtained from heifers stimulated 24 hours prior by an injection of GnRH (MII; n = 658). A sample of matured oocytes from each fresh group was analyzed by matrix associated laser desorption-ionization (MALDI-TOF) to determine their PM composition. Then, half of the matured oocytes from each group were vitrified/warmed (CONT VIT, IMA VIT, FSH VIT and MII VIT), while the other half were used as fresh controls. Afterwards, the eight groups underwent IVF and IVC, and blastocyst development was assessed at D2, D7 and D8. A chi-square test was used to compare embryo development between the groups. Corresponding phospholipid ion intensity was expressed in arbitrary units, and following principal components analyses (PCA) the data were distributed on a 3D graph. Oocytes obtained from superstimulated animals showed a greater rate of developmental (P<0.05) at D7 (MII = 62.4±17.5% and FSH = 58.8±16.1%) compared to those obtained from unstimulated animals (CONT = 37.9±8.5% and IMA = 50.6±14.4%). However, the maturation system did not affect the resistance of oocytes to vitrification because the blastocyst rate at D7 was similar (P>0.05) for all groups (CONT VIT = 2.8±3.5%, IMA VIT = 2.9±4.0%, FSH VIT = 4.3±7.2% and MII VIT = 3.6±7.2%). MALDI-TOF revealed that oocytes from all maturation groups had similar phospholipid contents, except for 760.6 ([PC (34:1) + H]+), which was more highly expressed in MII compared to FSH (P<0.05). The results suggest that although maturation systems improve embryonic development, they do not change the PM composition nor the resistance of bovine oocytes to vitrification.

In vitro penetration of fresh and vitrified swine oocytes by homologous spermatozoa using different incubation systems.

The present study consisted of two experiments. In the first one, ejaculates from four boars were used to compare in vitro penetration (IVP) rates of fresh and vitrified swine oocytes by homologous spermatozoa in four treatments: fresh oocytes in conventional incubation (CO2 incubator) (FC), vitrified oocytes in conventional incubation (VC), fresh oocytes in submarine (bag) incubation (FS) and vitrified oocytes in submarine incubation (VS). The IVP rates for FC, VC, FS and VS were 46.5, 44.3, 36.9 and 33.1%, respectively. Analysis through Chi-square tests identified no differences in IVP rates between FC and VC and between FS and VS (P > 0.05), but IVP rate for FC was greater (P < 0.05) than those for both FS and VS. Besides IVP rate for VC did not differ (P > 0.05) from those for FC and FS, but it was greater than that for VS (P < 0.05). Logistic regression analysis identified differential effects of treatments dependant on individual boars. The second experiment evaluated the influence of semen storage period on the semen quality of the two boars associated with greater IVP rate in the first experiment. Semen quality was estimated by IVP rate using the VC treatment and by the following methods: sperm motility, sperm morphology, hypoosmotic swelling test (HOST) and thermal stress test (TST). According to analysis using Chi-square tests, IVP rate did not differ (P > 0.05), for the first boar, between 0 (100.0%) and 24 h of semen storage (98.1%) nor after 48 and 72 h (66.0 and 59.3%, respectively), but IVP rates were greater during the 0-24 h period compared with the 48-72 h period (P < 0.05). For the second boar, IVP rate at 0 h (50.6%) was greater (P < 0.05) than at 24, 48 and 72 h of semen storage (34.3, 28.3 and 24.0%, respectively), with no further differences observed after 24 h (P > 0.05). Logistic regression analysis identified that the effect of storage on IVP rate was influenced by the effect of individual boars. No differences in semen quality during the storage period were identified by conventional methods of semen evaluation, for either boar (P > 0.05) using analysis of variance with repeated measures. These results indicate that IVP test can be used to estimate boar fertility, even when vitrified oocytes are used (if using conventional CO2 incubators) or using an alternative submarine incubation system (if using fresh oocytes). The IVP test was the only method of semen evaluation that identified the reduction in semen quality up to 72 h of storage.

Development of bovine embryos reconstructed by nuclear transfer of transfected and non-transfected adult fibroblast cells.

An association of two techniques, nuclear transfer (NT), and transfection of somatic animal cells, has numerous potential applications and considerable impact, mainly in agriculture, medicine, pharmacy, and fundamental biology. In addition, somatic cell nuclear transfer is the most efficient alternative to produce large transgenic animals. We compared in vitro and in vivo developmental capacities of NT using fibroblast cells isolated from a 14-month-old cloned Simmental heifer (FCE) vs the same line transfected with a plasmid containing neomycin-resistant genes (TFCE). There were no significant differences (P > 0.5) in either fusion (116/149 = 78% vs 216/301 = 72%), cleavage (78/116 = 67% vs 141/216 = 65%) and blastocyst (35/116 = 30% vs 52/216 = 24%) rates or in pregnancy rate at 30 to 35 days after embryo transfer (2/17 vs 3/17) between NT using FCE and TFCE, respectively. Transfection and long-term in vitro culture of transfected cells did not affect developmental capacity of NT embryos up to 40 days of gestation.