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Lipid metabolism is essential for ensuring oocyte maturation and embryo development. ß-Oxidized fatty acids (FA) are a potent source of energy for cells, particularly for bovine somatic follicular cells. Superstimulatory protocols using follicle stimulating hormone (FSH) or FSH combined with equine chorionic gonadotropin (eCG) are capable of stimulating the follicular microenvironment and drive the expression of biomarker genes associated with lipid metabolism in the cumulus-oocyte complex (COC) for better embryo development. In this study, we assesed the effects of FSH and FSH/eCG protocols on the expression of genes related to lipid metabolism in bovine granulosa cells (GCs). Further, we measured triglyceride levels in follicular fluid (FF) obtained from both superstimulatd and non-superstimulated cows (synchronized cows). In summary, superstimulation with gonadotropins maintained the TG levels in bovine FF and ensured GCs mRNA abundance of ACSL1, ACSL3, ACSL6, SCD, ELOVL5, ELOVL6, FASN, FADS2, and SREBP1. We, however, found the abundance of CPTIB mRNA to be lower in GCs obtained from cows subjected to FSH/eCG protocols than synchronized cows. In conclusion, the findings of this study showed that ovarian superstimulation around the preovulatory phase has a mild impact on the lipid metabolism in GCs.

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Steroids and gonadotrophins are essential for the regulation of late stages of preantral development and antral follicular development. Although the luteinizing hormone receptor (LHCGR) has been detected in the preantral follicles of rats, rabbits, and pigs, its expression, in bovine fetal ovary, has not been demonstrated. Based on this, we aimed to investigate the expression of the LHCGR and LHCGR mRNA binding protein (LRBP), as well as, to quantify bta-miR-222 (a regulatory microRNA of the LHCGR gene) during the development of bovine fetal ovary. In summary, LHCGR expression was observed in the preantral follicle in bovine fetal ovary, from oogonias to primordial, primary and secondary stages, and the mRNA abundance was lower on day 150 than day 60. However, the mRNA abundance of LRBP followed the opposite pattern. Similar to LRBP, the abundance of bta-miR-222 was higher on day 150 than day 60 or 90 of gestation. The LHCGR protein was detected in oogonia, primordial, primary, and secondary follicles. Moreover, both oocytes and granulosa cells showed positive immunostaining for LHCGR. In conclusion, we suggest the involvement of LHCGR/LRBP/bta-mir222 with mechanisms related to the development of preantral follicles in cattle.

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The polyspermy occurrence is considerably lower under in vivo compared to in vitro embryo culture conditions, suggesting that the presence of some factors in the maternal environment is responsible for this. The α-L-fucosidase (FUCA) is a natural glycosidase present in the oviductal fluid, therefore, this study aimed at investigating the effect of adding FUCA to the hardening of the zona pellucida (ZP), polyspermy control, and embryonic yield and quality of bovine blastocysts produced in vitro. In the first experiment, the effect of FUCA (0.125 U/mL) was evaluated during the entire in vitro fertilization (IVF). However, it was demonstrated to be embryotoxic by completely inhibiting the blastocyst formation. In the second experiment, the FUCA (0.125 U/mL) was tested as short-term incubation before IVF (pre-fertilization step) for 30 min or 2 h, which demonstrated that FUCA treatment for 30 min resulted in ZP hardening. In the third experiment, a pre-fertilization FUCA treatment (1 h) at different concentrations (0, 0.0625, and 0.125 U/mL) showed that FUCA (0.0625 U/mL) improved pre-fertilization ZP hardening and tended to increase monospermic fertilization rates but did not improve embryo yield and quality. Together, it has been demonstrated that FUCA can induce oocyte pre-fertilization ZP hardening and might improve monospermic fertilization performance, and this effect is dependent on both variables (protein concentration and incubation time).

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Traditionally, in vitro oocyte and embryo culture progresses through a series of varying culture medium. To investigate simplifying the in vitro production of bovine cumulus-oocyte complexes (COCs), this study used synthetic oviductal fluid (SOF) supplemented with conjugated linoleic acid (CLA). Special interest was placed on gene expression linked to lipid metabolism and oocyte maturation. COCs were matured in different media: Medium 199 (M199 group), M199 with 100 µM CLA (M199 + CLA group), SOF (SOF group), and SOF with 100 µM CLA (SOF + CLA group). COCs matured with SOF showed a higher relative abundance of mRNA of quality indicators gremlin 1 (GREM1) and prostaglandin-endoperoxide synthase 2 (PTGS2) in oocytes, and GREM1 in cumulus cells compared with in the M199 group. SOF medium COCs had a higher relative abundance of fatty acid desaturase 2 (FADS2) compared with the M199 group, which is essential for lipid metabolism in oocytes. Furthermore, the abundance of stearoyl-coenzyme A desaturase 1 (SCD1) in oocytes matured with SOF was not influenced by the addition of CLA, whereas the relative abundance of SCD1 was reduced in M199 medium with CLA. We concluded that maturation in SOF medium results in a greater abundance of genes linked to quality and lipidic metabolism in oocytes, regardless of the addition of CLA.

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Alcohol has been widely consumed for centuries and is linked to the aggravation of diseases. Several studies have shown that excessive consumption of ethanol results in morphophysiological changes in the male reproductive system. One of the effects of ethanol is the decrease in testosterone concentration and hormonal therapies are an alternative to minimize the changes resulting from chronic alcoholism. Qualitative studies were commonly carried out to evaluate the male histopathological alterations resulting from ethanol consumption, being necessary quantitative and non-subjective techniques. This study analyzes the importance of fractal analysis as a useful tool to identify and quantify tissue remodeling in rats submitted to ethanol consumption and hormone therapy with testosterone. Prostate of animals submitted to chronic ethanol consumption showed tissue disorganization, which was confirmed by an increasing of fractal dimension. Regarding the prostatic stroma, collagen fractal dimension and quantification revealed lower values in animals that were only submitted to androgen therapy. Thus, we can conclude that the fractal analysis was a useful tool to quantify tissue changes caused by ethanol consumption and androgen therapy.

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Abstract Alcohol has been widely consumed for centuries and is linked to the aggravation of diseases. Several studies have shown that excessive consumption of ethanol results in morphophysiological changes in the male reproductive system. One of the effects of ethanol is the decrease in testosterone concentration and hormonal therapies are an alternative to minimize the changes resulting from chronic alcoholism. Qualitative studies were commonly carried out to evaluate the male histopathological alterations resulting from ethanol consumption, being necessary quantitative and non-subjective techniques. This study analyzes the importance of fractal analysis as a useful tool to identify and quantify tissue remodeling in rats submitted to ethanol consumption and hormone therapy with testosterone. Prostate of animals submitted to chronic ethanol consumption showed tissue disorganization, which was confirmed by an increasing of fractal dimension. Regarding the prostatic stroma, collagen fractal dimension and quantification revealed lower values in animals that were only submitted to androgen therapy. Thus, we can conclude that the fractal analysis was a useful tool to quantify tissue changes caused by ethanol consumption and androgen therapy.

RESUMEN

We aimed to evaluate the morphological ovarian response to equine chorionic gonadotropin (eCG) prior to ovum pick-up (OPU) and its effects on the molecular phenotype of immature cumulus-oocyte complexes (COCs) from Nelore cow (Bos indicus) donors. To this end, 20 Nelore cows were distributed randomly into the synchronized-OPU (Sync-OPU) and synchronized plus stimulated-OPU (Sync + eCG-OPU) groups using a cross-over experimental design, as each cow was used in both treatments. On a random day of the estrus cycle (Day 0), all cows received an intravaginal implant with 1.0 g of progesterone and 2 mg IM of estradiol benzoate. On the morning of Day 3, only the Sync + eCG-OPU group received 400 IU of eCG IM. On the morning of Day 5, the P4 device was removed and OPU was conducted in both groups. Before OPU management, ultrasonography was used to identify and measure the follicles. The aspirated COCs were morphologically classified based on their cumulus cells (CC) layers and the texture of the ooplasm. The COCs classified as Grade 1, Grade 2, and Grade 3 were considered viable and used for the assessment of quality markers. Oocytes and CC were mechanically separated from pools of 25 immature COCs of the Sync-OPU and Sync + eCG-OPU groups immediately after the follicular aspiration and stored at -80 °C until RNA extraction. Relative quantification of several markers for oocyte quality was assessed by RT-qPCR. The eCG treatment increased the number of follicles sized 3.0-5.0 mm and >5.0 mm compared to that in Sync-OPU group. Moreover, the protocol with eCG improved the total number of oocytes and the number of viable oocytes, which is related to a high number of oocytes in Grade 3. Regarding the impact on transcriptional regulation in immature oocytes, the mRNA encoding BMP15, SMAD1, SMAD2, SMAD3, ACACA, and CPT1A was upregulated in Sync + eCG-OPU compared with the Sync-OPU group. Moreover, the relative mRNA abundance of CTSZ, a member of the cathepsins family functionally related to reduced oocyte competence, was lower in the Sync + eCG-OPU group than in the Sync-OPU group. In addition, CC CTSB, CTSS, and CTSK mRNA abundances were lower in the Sync + eCG-OPU group than in the Sync-OPU group. However, the relative abundance of AREG and EREG mRNA was higher in CC recovered from cows stimulated with eCG. In conclusion, the eCG approach addressing follicular stimulation in Nelore cows had a positive impact on early antral follicle development, followed by a positive morphological and molecular phenotype in bovine COCs.

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The number of visible ovarian antral follicles (antral follicle count-AFC) is repeatable in bovine individuals, but highly variable between animals, and with differences between Bos taurus and Bos indicus breeds. Several studies have tried to determine the correlation between AFC and increased fertility in cattle. While the impacts of AFC on embryo production, hormonal levels, and pregnancy rates have been described, the molecular effects of AFC on bovine oviducts have not yet been investigated. Here, the aim was to investigate the impact of breeds, such as Aberdeen Angus and Nelore heifer with high or low AFC, on abundance of transcripts and protein related to oviductal transport, sperm reservoir formation, monospermy control, and gamete interaction in the oviducts. In summary, the ovulation side was the major factor that affected transcript abundance on bovine oviducts. However, a discreet effect among AFC and cattle breeds was also observed. Based on this, we concluded and reinforced here that differential microenvironments between ipsilateral and contralateral oviducts have a major effect on modulating the transcripts related to oviductal transport, sperm reservoir formation, monospermy control, and gamete interaction. However, we cannot exclude that there is minimal effect of AFC or breed on regulation of some genes (such as AGTR1, ACE1, FUCA1, and VEGFA) in bovine oviducts.

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La producción de leche en el ganado taurina presenta una serie de obstáculos en las regiones tropicales como Brasil. Una de estas barreras es la tensión térmica (ET), lo que implica una pérdida económica importante para los productores. La pérdida de capital debe caer en gran medida en la producción de leche y fallas reproductivas asociadas con ET. Ya se ha demostrado varios cambios reproductivos derivados de la ET. A nivel celular se observó entre las células foliculares de comunicación a través de vesículas extracelulares (EVs). Se observó la comunicación entre las células del cúmulo y células de la granulosa de los vehículos eléctricos. Lo que esta revisión se pretende correlacionar los vehículos eléctricos producidos en el interior de los folículos con los efectos de ET en ovocitos bovinos.

The production of taurine cattle milk presents a number of obstacles in tropical regions like Brazil. One of these barriers is the thermal stress (ET), which entails a major economic loss for producers. The loss of capital should largely fall in milk production and reproductive failures associated with ET. Already it has been demonstrated several reproductive changes arising from the ET. At the cellular level, it was noted between the communication follicular cells through extracellular vesicles (EVs). Communication was observed between cumulus cells and granulosa cells by EVs. Therefore, this review intends to correlate the EVs produced inside the follicles with the effects of ET on bovine oocytes.

A produção de leite de bovinos taurinos apresenta uma série de entraves em regiões tropicais como o Brasil. Um desses entraves é o estresse térmico (ET), que acarreta uma perda econômica importante para os produtores. A perda de capital se deve em grande parte à queda na produção de leite e nas falhas reprodutivas associadas ao ET. Já foram demonstradas várias alterações reprodutivas oriundas do ET. A nível celular, foi notada a comunicação entre células foliculares, por meio de vesículas extracelulares (EVs). Foi observada a comunicação entre células do cummuluse células da granulosa por meio de EVs. Sendo assim, esta revisão tem por finalidade correlacionar as EVs produzidas no interior dos folículos com os efeitos do ET sobre os oócitos bovinos.

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RESUMEN

La producción de leche en el ganado taurina presenta una serie de obstáculos en las regiones tropicales como Brasil. Una de estas barreras es la tensión térmica (ET), lo que implica una pérdida económica importante para los productores. La pérdida de capital debe caer en gran medida en la producción de leche y fallas reproductivas asociadas con ET. Ya se ha demostrado varios cambios reproductivos derivados de la ET. A nivel celular se observó entre las células foliculares de comunicación a través de vesículas extracelulares (EVs). Se observó la comunicación entre las células del cúmulo y células de la granulosa de los vehículos eléctricos. Lo que esta revisión se pretende correlacionar los vehículos eléctricos producidos en el interior de los folículos con los efectos de ET en ovocitos bovinos.(AU)

The production of taurine cattle milk presents a number of obstacles in tropical regions like Brazil. One of these barriers is the thermal stress (ET), which entails a major economic loss for producers. The loss of capital should largely fall in milk production and reproductive failures associated with ET. Already it has been demonstrated several reproductive changes arising from the ET. At the cellular level, it was noted between the communication follicular cells through extracellular vesicles (EVs). Communication was observed between cumulus cells and granulosa cells by EVs. Therefore, this review intends to correlate the EVs produced inside the follicles with the effects of ET on bovine oocytes.(AU)

A produção de leite de bovinos taurinos apresenta uma série de entraves em regiões tropicais como o Brasil. Um desses entraves é o estresse térmico (ET), que acarreta uma perda econômica importante para os produtores. A perda de capital se deve em grande parte à queda na produção de leite e nas falhas reprodutivas associadas ao ET. Já foram demonstradas várias alterações reprodutivas oriundas do ET. A nível celular, foi notada a comunicação entre células foliculares, por meio de vesículas extracelulares (EVs). Foi observada a comunicação entre células do cummuluse células da granulosa por meio de EVs. Sendo assim, esta revisão tem por finalidade correlacionar as EVs produzidas no interior dos folículos com os efeitos do ET sobre os oócitos bovinos.(AU)

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O corpo lúteo é uma glândula endócrina, ovariana e transitória, formada a partir do folículo ovulado, cujo principal produto secretado é a progesterona, essencial para o estabelecimento e a manutenção da prenhez e para a ciclicidade ovariana. Dessa forma, o conhecimento aprofundado da fisiologia luteínica, além de seu valor intrínseco como conhecimento básico, pode também contribuir para a reprodução animal em seu aspecto aplicado. Este artigo revisa os principais mecanismos reguladores do desenvolvimento e da regressão do corpo lúteo, incluindo agentes endócrinos e reguladores locais como fatores de crescimento, peptídeos vasoativos, esteróides e prostaglandinas.

The corpus luteum is a transitory, endocrine ovarian gland, formed following ovulation, which secrets progesterone, an essential hormone for pregnancy establishment and maintenance as well as ovarian cyclicity. Therefore, a more complete understanding of the luteal physiology, apart from its intrinsic value as basic knowledge, may also contribute within the applied aspect of animal reproduction. This article reviews the principal mechanisms that regulate luteal development and regression, including endocrine agents and local regulators such as growth factors, vasoative peptides, steroids and prostaglandins.

Asunto(s)

RESUMEN

O corpo lúteo é uma glândula endócrina, ovariana e transitória, formada a partir do folículo ovulado, cujo principal produto secretado é a progesterona, essencial para o estabelecimento e a manutenção da prenhez e para a ciclicidade ovariana. Dessa forma, o conhecimento aprofundado da fisiologia luteínica, além de seu valor intrínseco como conhecimento básico, pode também contribuir para a reprodução animal em seu aspecto aplicado. Este artigo revisa os principais mecanismos reguladores do desenvolvimento e da regressão do corpo lúteo, incluindo agentes endócrinos e reguladores locais como fatores de crescimento, peptídeos vasoativos, esteróides e prostaglandinas.(AU)

The corpus luteum is a transitory, endocrine ovarian gland, formed following ovulation, which secrets progesterone, an essential hormone for pregnancy establishment and maintenance as well as ovarian cyclicity. Therefore, a more complete understanding of the luteal physiology, apart from its intrinsic value as basic knowledge, may also contribute within the applied aspect of animal reproduction. This article reviews the principal mechanisms that regulate luteal development and regression, including endocrine agents and local regulators such as growth factors, vasoative peptides, steroids and prostaglandins.(AU)

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