While artificial insemination (AI) with frozen-thawed sperm results in low fertility rates in don... more While artificial insemination (AI) with frozen-thawed sperm results in low fertility rates in donkeys, the addition of seminal plasma, removed during cryopreservation, partially counteracts that reduction. Related to this, an apparent inflammatory reaction in jennies is induced following AI with frozen-thawed sperm, as a high amount of polymorphonuclear neutrophils (PMN) are observed within the donkey uterus six hours after AI. While PMN appear to select the sperm that ultimately reach the oviduct, two mechanisms, phagocytosis and NETosis, have been purported to be involved in that clearance. Remarkably, sperm interacts with PMN, but the presence of seminal plasma reduces that binding. As seminal plasma is a complex fluid made up of different molecules, including proteins, this study aimed to evaluate how different seminal plasma fractions, separated by molecular weight (<3, 3–10, 10–30, 30–50, 50–100, and >100 kDa), affect sperm–PMN binding. Sperm motility, viability, and spe...
When artificial reproduction technologies designed for use with horses are used with donkeys, suc... more When artificial reproduction technologies designed for use with horses are used with donkeys, success is dependent on awareness of the physiological differences between these species, yet little information is available on many aspects of donkey reproduction. The present work examines the activity of the CL in Catalonian jennies after induced luteolysis. Plasma progesterone concentration, luteal blood flow (determined by color Doppler), and CL cross-sectional area (CL-CSA; determined by B-mode ultrasound examination) were assessed after a single dose (5 mg intramuscular) of dinoprost thromethamine (DT, a PGF2α analog) on Day 10 after ovulation in two experiments. In experiment 1, a preliminary experiment, data were collected daily for 4 days after DT administration. Values for all the measured variables decreased over this period. In experiment 2, data were collected during the first 24 hours after DT administration because in experiment 1, most luteolytic activity occurred during t...
Although cryopreservation of stallion spermatozoa allows long-term preservation of spermatozoa fr... more Although cryopreservation of stallion spermatozoa allows long-term preservation of spermatozoa from particular stallions and facilitates international trade, it is understood to inflict damages on sperm cells that may finally reduce their fertilizing ability. In addition, individual differences are known to exist in the sperm ability to withstand freeze-thawing protocols. To date, these differences have mainly been reported on the basis of sperm motility and membrane integrity. For this reason, the present work sought to determine differences between good (good freezability ejaculates: GFE) and poor (poor freezability ejaculates: PFE) freezability stallion ejaculates in other sperm parameters, including peroxide and superoxide levels, potential of mitochondrial membrane and nuclear integrity. With this purpose, a total of 24 stallion ejaculates were cryopreserved and classified into two groups (GFE vs. PFE), depending on their sperm membrane integrity and motility after freeze-thawing. From the total of 24 ejaculates, 13 were classified as GFE and the other 11 were classified as PFE. Apart from differences in sperm membrane permeability and lipid disorder after freezethawing, GFE presented significantly (p < 0.05) higher percentages of viable spermatozoa with high content of peroxides and of superoxides than PFE. In contrast, and despite cryopreservation of stallion spermatozoa increasing DNA fragmentation and disrupting disulphide bonds in sperm head proteins, no significant differences between GFE and PFE were seen. We can thus conclude that good and poor freezability stallion ejaculates differ in their reactive oxygen species levels after cryopreservation, but not in the damage extent on sperm nucleus.
In the donkey, artificial insemination (AI) with frozen-thawed semen is associated with low ferti... more In the donkey, artificial insemination (AI) with frozen-thawed semen is associated with low fertility rates, which could be partially augmented through adding seminal plasma (SP) and increasing sperm concentration. On the other hand, post-AI endometrial inflammation in the jenny is significantly higher than in the mare. While previous studies analyzed this response through recovering Polymorphonuclear Neutrophils (PMN) from uterine washings, successive lavages can detrimentally impact the endometrium, leading to fertility issues. For this reason, the first set of experiments in this work intended to set an in vitro model through harvesting PMN from the peripheral blood of jennies. Thereafter, how PMN, which require a triggering agent like formyl-methionyl-leucyl-phenylalanine (FMLP) to be activated, are affected by donkey semen was interrogated. Finally, we tested how four concentrations of spermatozoa (100 × 106, 200 × 106, 500 × 106 and 1000 × 106 spermatozoa/mL) affected their in...
Resumen: El estudio de revisión aquí presentado tiene como propósitos: (1) aportar una panorámica... more Resumen: El estudio de revisión aquí presentado tiene como propósitos: (1) aportar una panorámica del desarrollo de la línea de investigación que se ocupa del estudio de las salidas de campo como recurso didáctico en Didáctica de las Ciencias Experimentales; y, (2) sintetizar las principales implicaciones educativas referidas a la misma. Así, se revisaron los artículos publicados entre el año 2000 y 2017 y alojados en las bases de datos de Web of Science y Scopus. Los resultados obtenidos giran en torno a los campos: (1) autor/es y año; (2) país; (3) disciplina científica; (4) etapa educativa; (5) contexto; (6) metodología; y (7) implicaciones educativas. Los resultados principales apuntan a la irrupción de la producción científica sobre esta línea de investigación, a pesar de no abundar autores muy prolíficos en ella. Además, se ha comprobado que Estados Unidos es el país donde se realizan mayor número de trabajos, mientras que la etapa educativa preferente para ejecutar las salidas de campo es la Educación Primaria. Los espacios naturales se colocan como el contexto más visitado y el Medio Ambiente, la Biología y la Geología como las disciplinas predilectas para realizar salidas de campo. Finalmente, las principales implicaciones educativas señalan la promoción de actitudes y emociones positivas, así como la adquisición de los contenidos como puntos fuertes de las salidas de campo.
While artificial insemination (AI) with frozen-thawed sperm results in low fertility rates in don... more While artificial insemination (AI) with frozen-thawed sperm results in low fertility rates in donkeys, the addition of seminal plasma, removed during cryopreservation, partially counteracts that reduction. Related to this, an apparent inflammatory reaction in jennies is induced following AI with frozen-thawed sperm, as a high amount of polymorphonuclear neutrophils (PMN) are observed within the donkey uterus six hours after AI. While PMN appear to select the sperm that ultimately reach the oviduct, two mechanisms, phagocytosis and NETosis, have been purported to be involved in that clearance. Remarkably, sperm interacts with PMN, but the presence of seminal plasma reduces that binding. As seminal plasma is a complex fluid made up of different molecules, including proteins, this study aimed to evaluate how different seminal plasma fractions, separated by molecular weight (<3, 3–10, 10–30, 30–50, 50–100, and >100 kDa), affect sperm–PMN binding. Sperm motility, viability, and spe...
When artificial reproduction technologies designed for use with horses are used with donkeys, suc... more When artificial reproduction technologies designed for use with horses are used with donkeys, success is dependent on awareness of the physiological differences between these species, yet little information is available on many aspects of donkey reproduction. The present work examines the activity of the CL in Catalonian jennies after induced luteolysis. Plasma progesterone concentration, luteal blood flow (determined by color Doppler), and CL cross-sectional area (CL-CSA; determined by B-mode ultrasound examination) were assessed after a single dose (5 mg intramuscular) of dinoprost thromethamine (DT, a PGF2α analog) on Day 10 after ovulation in two experiments. In experiment 1, a preliminary experiment, data were collected daily for 4 days after DT administration. Values for all the measured variables decreased over this period. In experiment 2, data were collected during the first 24 hours after DT administration because in experiment 1, most luteolytic activity occurred during t...
Although cryopreservation of stallion spermatozoa allows long-term preservation of spermatozoa fr... more Although cryopreservation of stallion spermatozoa allows long-term preservation of spermatozoa from particular stallions and facilitates international trade, it is understood to inflict damages on sperm cells that may finally reduce their fertilizing ability. In addition, individual differences are known to exist in the sperm ability to withstand freeze-thawing protocols. To date, these differences have mainly been reported on the basis of sperm motility and membrane integrity. For this reason, the present work sought to determine differences between good (good freezability ejaculates: GFE) and poor (poor freezability ejaculates: PFE) freezability stallion ejaculates in other sperm parameters, including peroxide and superoxide levels, potential of mitochondrial membrane and nuclear integrity. With this purpose, a total of 24 stallion ejaculates were cryopreserved and classified into two groups (GFE vs. PFE), depending on their sperm membrane integrity and motility after freeze-thawing. From the total of 24 ejaculates, 13 were classified as GFE and the other 11 were classified as PFE. Apart from differences in sperm membrane permeability and lipid disorder after freezethawing, GFE presented significantly (p < 0.05) higher percentages of viable spermatozoa with high content of peroxides and of superoxides than PFE. In contrast, and despite cryopreservation of stallion spermatozoa increasing DNA fragmentation and disrupting disulphide bonds in sperm head proteins, no significant differences between GFE and PFE were seen. We can thus conclude that good and poor freezability stallion ejaculates differ in their reactive oxygen species levels after cryopreservation, but not in the damage extent on sperm nucleus.
In the donkey, artificial insemination (AI) with frozen-thawed semen is associated with low ferti... more In the donkey, artificial insemination (AI) with frozen-thawed semen is associated with low fertility rates, which could be partially augmented through adding seminal plasma (SP) and increasing sperm concentration. On the other hand, post-AI endometrial inflammation in the jenny is significantly higher than in the mare. While previous studies analyzed this response through recovering Polymorphonuclear Neutrophils (PMN) from uterine washings, successive lavages can detrimentally impact the endometrium, leading to fertility issues. For this reason, the first set of experiments in this work intended to set an in vitro model through harvesting PMN from the peripheral blood of jennies. Thereafter, how PMN, which require a triggering agent like formyl-methionyl-leucyl-phenylalanine (FMLP) to be activated, are affected by donkey semen was interrogated. Finally, we tested how four concentrations of spermatozoa (100 × 106, 200 × 106, 500 × 106 and 1000 × 106 spermatozoa/mL) affected their in...
Resumen: El estudio de revisión aquí presentado tiene como propósitos: (1) aportar una panorámica... more Resumen: El estudio de revisión aquí presentado tiene como propósitos: (1) aportar una panorámica del desarrollo de la línea de investigación que se ocupa del estudio de las salidas de campo como recurso didáctico en Didáctica de las Ciencias Experimentales; y, (2) sintetizar las principales implicaciones educativas referidas a la misma. Así, se revisaron los artículos publicados entre el año 2000 y 2017 y alojados en las bases de datos de Web of Science y Scopus. Los resultados obtenidos giran en torno a los campos: (1) autor/es y año; (2) país; (3) disciplina científica; (4) etapa educativa; (5) contexto; (6) metodología; y (7) implicaciones educativas. Los resultados principales apuntan a la irrupción de la producción científica sobre esta línea de investigación, a pesar de no abundar autores muy prolíficos en ella. Además, se ha comprobado que Estados Unidos es el país donde se realizan mayor número de trabajos, mientras que la etapa educativa preferente para ejecutar las salidas de campo es la Educación Primaria. Los espacios naturales se colocan como el contexto más visitado y el Medio Ambiente, la Biología y la Geología como las disciplinas predilectas para realizar salidas de campo. Finalmente, las principales implicaciones educativas señalan la promoción de actitudes y emociones positivas, así como la adquisición de los contenidos como puntos fuertes de las salidas de campo.
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