The traditional point of view regarding dairy cattle selection has been challenged by recent geno... more The traditional point of view regarding dairy cattle selection has been challenged by recent genomic studies indicating that livestock productivity prediction can be redefined based on the evaluation of genomic and phenotypic data. Several studies that included different genomic-derived traits only indicated that interactions among them or even with conventional phenotypic evaluation criteria require further elucidation. Unfortunately, certain genomic and phenotypic-derived traits have been shown to be secondary factors influencing dairy production. Thus, these factors, as well as evaluation criteria, need to be defined. Owing to the variety of genomic and phenotypic udder-derived traits which may affect the modern dairy cow functionality and conformation, a definition of currently important traits in the broad sense is indicated. This is essential for cattle productivity and dairy sustainability. The main objective of the present review is to elucidate the possible relationships am...
Short title: Bovine spermatogonial stem cell propagation Summary sentence: Bovine spermatogonial ... more Short title: Bovine spermatogonial stem cell propagation Summary sentence: Bovine spermatogonial stem cells can be propagated through the use of a specialized medium including growth factors (EGF, FGF2, LIF and GDNF) and a serial long-term culture approach
RESULTADOS Y DISCUSION El porcentaje de espermatozoides vivos y con excelente integridad funciona... more RESULTADOS Y DISCUSION El porcentaje de espermatozoides vivos y con excelente integridad funcional de membrana (HOS+) fue estadisticamente similar entre el control (hora 0) y 8 horas (tanto a TA como a 4oC), con una tendencia a disminuir el porcentaje de espermatozoide vivos con el tiempo. Asi mismo, durante las 8 horas evaluadas, no hubo cambios significativos en los porcentajes de espermatozoides con acrosomas anormales. Aun con falta de irrigacion sanguinea, una vez separado del cuerpo, el organo del epididimo, especificamente la cola, provee un ambiente adecuado para mantener a los espermatozoides. Estos muestran una buena tasa de supervivencia, integridad funcional de la membrana celular (entre 70 y 80%) y bajo nivel de dano acrosomal (entre 2 y 6%) tras haber permanecido 8 horas dentro del organo ex vivo en solucion salina isotonica. Las temperaturas bajas no parecen mejorar la calidad espermatica bajo las condiciones de preservacion senaladas, al menos dentro del periodo de 8...
The brocket deer (Genus Mazama) is a highly diverse cervid group distributed from Mexico to Argen... more The brocket deer (Genus Mazama) is a highly diverse cervid group distributed from Mexico to Argentina, with a downward population trend. However, literature on the basic reproductive biology of the genus is scarce. This work aimed to study biometric, histological and stereological aspects of the testes of Dwarf Red Brocket (Mazama rufina). Testes from free‐ranging adult brockets (n = 3) were retrieved from necropsies. Testes were histologically processed. From histological images, several stereological parameters were estimated, and seminiferous epithelium cycle morphology was described. Testes volumes were between 8.2 and 18.4 ml and weights from 8.3 to 19.4 g. Gonadosomatic index (% paired‐testes weight to body weight) went from 0.17 to 0.64. The tubular cross‐sectional diameter was 179.8 ± 2.8 µm. Estimated volume densities for parenchyma and interstitium were 78.8% and 21.2% respectively. There were (in millions/ml) 96.0 ± 13.1 germ cells and 37.7 ± 6.0 somatic cells. Specific cell densities were (all expressed in millions/ml) as follows: spermatogonia 13.1 ± 4.2; primary spermatocytes 43.1 ± 5.0; round spermatids 36.8 ± 8.0 (lower density near the caudal pole, p < 0.01); sustentacular (Sertoli) cells 16.8 ± 4.1 and interstitial endocrine (Leydig) cells 17.4 ± 3.4. Sertoli cell index (germ cells per Sertoli cell) was 6.72. Eight stages of the cycle were described, and frequencies estimated, resembling those of goats. M. rufina adult testis anatomy is similar to that of other cervids and domestic ruminants, with an apparently lower spermatogenic efficiency. This work is a first approximation to the physiology of the testis of M. rufina. Basic knowledge of the reproductive physiology of vulnerable species may allow biotechnological approaches for the restitution of animal populations.
The main objective of this study was to analyze the effects of the inbreeding degree in high-prod... more The main objective of this study was to analyze the effects of the inbreeding degree in high-producing primiparous dairy cows genotypically and phenotypically evaluated and its impacts on production and reproductive parameters. Eighty Holstein–Friesian primiparous cows (age: ~26 months; ~450 kg body weight) were previously genomically analyzed to determine the Inbreeding Index (II) and were divided into two groups: low inbreeding group (LI: <2.5; n = 40) and high inbreeding group (HI: ≥2.5 and ≤5.0; n = 40). Genomic determinations of production and reproductive parameters (14 in total), together with analyses of production (12) and reproductive (11) phenotypic parameters (23 in total) were carried out. Statistically significant differences were obtained between groups concerning the genomic parameters of Milk Production at 305 d and Protein Production at 305 d and the reproductive parameter Daughter Calving Ease, the first two being higher in cows of the HI group and the third lo...
Provide an accurate summary of the background, research objectives, including details of the spec... more Provide an accurate summary of the background, research objectives, including details of the species or strain of animal used, key methods, principal findings and conclusions of the study.
Effective tools for male contraception are important in the control of reproduction in animal pop... more Effective tools for male contraception are important in the control of reproduction in animal populations. The aim of the present study was to evaluate the effects of active immunization against gonadotropin-releasing hormone (GnRH) on male reproductive function assessing testicular morphological changes and serum-gonadotropin levels in pre-pubertal rabbits, guinea pigs and ram lambs. An anti-GnRH vaccine was developed by linking a GnRH-homologous molecule to a tetanus clostridial toxoid (Al(OH)3 coadjuvant). After vaccination protocols testicular morphometry, histopathological alterations and endocrine responses (FSH, LH, testosterone and cortisol serum levels) were evaluated. Testicular volume was significantly reduced in vaccinated animals with respect to the control group in rabbits, guinea pigs and ram lambs (P<0.05 to P<0.001). The anti-GnRH vaccine generated a reduction in testicular volume of 15-, 27- and 11-fold, respectively. Tubule diameters decreased in the vaccina...
The objective of this review is to outline existing artificial mitochondria transfer techniques a... more The objective of this review is to outline existing artificial mitochondria transfer techniques and to describe the future steps necessary to develop new therapeutic applications in medicine. Inspired by the symbiotic origin of mitochondria and by the cell's capacity to transfer these organelles to damaged neighbors, many researchers have developed procedures to artificially transfer mitochondria from one cell to another. The techniques currently in use today range from simple coincubations of isolated mitochondria and recipient cells to the use of physical approaches to induce integration. These methods mimic natural mitochondria transfer. In order to use mitochondrial transfer in medicine, we must answer key questions about how to replicate aspects of natural transport processes to improve current artificial transfer methods. Another priority is to determine the optimum quantity and cell/tissue source of the mitochondria in order to induce cell reprogramming or tissue repair, ...
This article reviews the current body of knowledge on biotechnological applications of spermatogo... more This article reviews the current body of knowledge on biotechnological applications of spermatogonial stem cells (SSCs). SSCs are the founding adult germ stem cells of the sperm producing process spermatogenesis. SSCs belong to the male germline and can be expanded in vitro in several species. Through mechanisms not fully understood they can derive pluripotent stem cells in vitro. Thus, they can be genetically modified with some advantages over embryonic stem cell-based technologies. SSCs can be transplanted to homotopical or ectopical locations, offering great potentials in fertility related issues and regenerative clinical applications in domestic or wild animals and men.
Dairy cattle breeding has historically focused on relatively small numbers of elite bulls as sire... more Dairy cattle breeding has historically focused on relatively small numbers of elite bulls as sires of sons. In recent years, even if generation intervals were reduced and more diverse sires of sons could have been selected, genomic selection has not fundamentally changed the fact that a large number of individuals are being analyzed. However, a relatively small number of elite bulls are still siring those animals. Therefore inbreeding-derived negative consequences in the gene pool have brought concern. The detrimental effects of non-additive genetic changes such as inbreeding depression and dominance have been widely disseminated while seriously affecting bioeconomically important parameters because of an antagonistic relationship between dairy production and reproductive traits. Therefore, the estimation of benefits and limitations of inbreeding and variance of the selection response deserves to be evaluated and discussed to preserve genetic variability, a significant concern in th...
Spermatogonial stem cells (SSCs) are the germ cells at the basis of spermatogenesis in adult mamm... more Spermatogonial stem cells (SSCs) are the germ cells at the basis of spermatogenesis in adult mammals. SSCs offer many biotechnological possibilities and are fundamental cells in the study of spermatogenesis (Aponte, World J Stem Cells 7:669-680, 2015). This chapter describes detailed procedures for SSC isolation, culture, cryopreservation, and characterization in bovine, murine, and human models.
Data related to the effects of r-met-hu G-CSF (filgrastim) on male reproductive function and deve... more Data related to the effects of r-met-hu G-CSF (filgrastim) on male reproductive function and development in prepubertal domestic mammals (guinea pigs and ram lambs).Data relates to blood cell counts; hormone levels -FSH-LH-Testosterone; Testis weight and volume. Seminiferous tubules cross-section diameter; Stereology: unbiased cell counting, daily sperm production (DSP), DSP/gram of parenchyma)Data is subject to ANOVA, Bonferroni media test.<br><br>
This study aimed to test the effects of the drug r-met-hu-G-CSF (Filgrastim) on spermatogenic eff... more This study aimed to test the effects of the drug r-met-hu-G-CSF (Filgrastim) on spermatogenic efficiency in prepubertal Brahman bulls. Twelve intact, healthy prepubertal bulls were administered 0, 1 (LD=low dose) or 4 (HD=high dose) µg/Kg r-met-hu-G-CSF (daily-4-days, +hematological analysis). Bulls were castrated (D0 or D60). BW (body weight) and SC (scrotal circumference) were recorded. Testis weight and volume were taken at castration with samples for testis histology and stereology: germ cell types, spermatids count, and DSP (Daily sperm production per gram)/g of testicular parenchyma. Testicular weight, volume, BW, SC, and gonadosomatic index (GSI) were NS (LD-HD; P>0.05). At D0 (age-11-mo), the most advanced germ cell types (maGCt) ranged from intermediate-spermatogonia to pachytene-spermatocytes. After 2-mo, control animals had round spermatids as maGCt, LD-animals 75% of round spermatids and 25% elongated spermatids, and HD-animals round spermatids. Spermatids/testis were higher (LD=1.23±0.2 millions) than (controls=0.65±0.1 millions); (P<0.05). Spermatogenesis efficiency (DSP/g) was higher with LD (5.4±0.4 million) than controls (3.2±0.2 million; P<0.01). In conclusion, r-met-hu-G-CSF raises spermatogenic efficiency in prepubertal Brahman bulls.
RESUMEN DEL SEGUNDO SEMINARIO INTERNACIONAL DE SANIDAD AGROPECUARIA (SISA) Uso de la histología y... more RESUMEN DEL SEGUNDO SEMINARIO INTERNACIONAL DE SANIDAD AGROPECUARIA (SISA) Uso de la histología y microscopia confocal en la caracterización de esporas de hongos fitopatógenos: Caso Thecaphora solani Use of histology and confocal microscopy for spore characterization of phytopathogenic fungi: Case Thecaphora solani
Genomics comprises a set of current and valuable technologies implemented as selection tools in d... more Genomics comprises a set of current and valuable technologies implemented as selection tools in dairy cattle commercial breeding programs. The intensive progeny testing for production and reproductive traits based on genomic breeding values (GEBVs) has been crucial to increasing dairy cattle productivity. The knowledge of key genes and haplotypes, including their regulation mechanisms, as markers for productivity traits, may improve the strategies on the present and future for dairy cattle selection. Genome-wide association studies (GWAS) such as quantitative trait loci (QTL), single nucleotide polymorphisms (SNPs), or single-step genomic best linear unbiased prediction (ssGBLUP) methods have already been included in global dairy programs for the estimation of marker-assisted selection-derived effects. The increase in genetic progress based on genomic predicting accuracy has also contributed to the understanding of genetic effects in dairy cattle offspring. However, the crossing wit...
The main objective of this study was to analyse the effects of r-met-hu G-CSF application as an i... more The main objective of this study was to analyse the effects of r-met-hu G-CSF application as an inductor of early sexual development in prepubertal ram lambs. 20 Corriedale ram lambs (age= 2 months; ~18 kg l.w.) were divided in 4 groups: a control group (T1; n= 5) and 3 treated groups (T2, T3 and T4; n= 5 each) were administered a subcutaneous injection of r-met-hu G-CSF/Filgrastim daily for 4 consecutive days [(T2; 1 µg/kg l.w.; 18 µg/day; total= 72 µg), (T3; 10 µg/kg l.w.; 180 µg/day; total= 720 µg) y (T4; 20 µg/kg l.w.; 360 µg/day; total= 1.440 µg)]. A haematological analysis (white blood cells) was performed to determine the response of the spinal cord and confirm the hematopoietic effect of r-met-hu G-CSF. The testis weight, testicular morphometry and testicular volume were evaluated as well. To determine the effectiveness of the r-met-hu G-CSF treatment on sexual development, histological alterations (seminiferous tubules, Sertoli cells, gonocytes, spermatogonia, among others) were also evaluated as well as the endocrine response (FSH, LH, testosterone and cortisol) by ELISA. Significant differences were found in the number of leukocytes between the T4 vs. T1, T2 and T3 groups, from day 3 onwards (p<0.05). Lymphocyte percentage was significantly higher in T3 and T4 (p<0.05) compared to control (T1) and T2 from day 2 onwards. In addition, significant differences were observed in the testicular weight between the T1/T2 and the T3/T4 groups (p<0.05), as well as between the T1 and the T3/T4 regarding testicular volume (p<0.05). The hormone levels differed significantly in FSH concentration obtained in T3 compared to the other groups from day 3 onwards (p<0.05). Regarding LH and testosterone, significant differences were found between the T4 and the rest of the groups, which were evident from day 2 (LH) and day 3 (testosterone) (p<0.05). The cortisol did not differ among groups (p>0,05). With regard to histological alterations, T3 showed a more advanced cellular profile presenting primary spermatocytes, while T4 reached the generation of round spermatids. In conclusion, the application of r-met-hu G-CSF (Filgrastim) as a stimulating factor for early sexual development affected fast and positively the white blood cells´ haematopoiesis and the hormonal activity when applied at high concentrations, and accelerated the testicular development in prepubertal lambs, affecting not only endocrine hormone levels but also the testicular weight and volume, as well as the spermatogenic process.
The traditional point of view regarding dairy cattle selection has been challenged by recent geno... more The traditional point of view regarding dairy cattle selection has been challenged by recent genomic studies indicating that livestock productivity prediction can be redefined based on the evaluation of genomic and phenotypic data. Several studies that included different genomic-derived traits only indicated that interactions among them or even with conventional phenotypic evaluation criteria require further elucidation. Unfortunately, certain genomic and phenotypic-derived traits have been shown to be secondary factors influencing dairy production. Thus, these factors, as well as evaluation criteria, need to be defined. Owing to the variety of genomic and phenotypic udder-derived traits which may affect the modern dairy cow functionality and conformation, a definition of currently important traits in the broad sense is indicated. This is essential for cattle productivity and dairy sustainability. The main objective of the present review is to elucidate the possible relationships am...
Short title: Bovine spermatogonial stem cell propagation Summary sentence: Bovine spermatogonial ... more Short title: Bovine spermatogonial stem cell propagation Summary sentence: Bovine spermatogonial stem cells can be propagated through the use of a specialized medium including growth factors (EGF, FGF2, LIF and GDNF) and a serial long-term culture approach
RESULTADOS Y DISCUSION El porcentaje de espermatozoides vivos y con excelente integridad funciona... more RESULTADOS Y DISCUSION El porcentaje de espermatozoides vivos y con excelente integridad funcional de membrana (HOS+) fue estadisticamente similar entre el control (hora 0) y 8 horas (tanto a TA como a 4oC), con una tendencia a disminuir el porcentaje de espermatozoide vivos con el tiempo. Asi mismo, durante las 8 horas evaluadas, no hubo cambios significativos en los porcentajes de espermatozoides con acrosomas anormales. Aun con falta de irrigacion sanguinea, una vez separado del cuerpo, el organo del epididimo, especificamente la cola, provee un ambiente adecuado para mantener a los espermatozoides. Estos muestran una buena tasa de supervivencia, integridad funcional de la membrana celular (entre 70 y 80%) y bajo nivel de dano acrosomal (entre 2 y 6%) tras haber permanecido 8 horas dentro del organo ex vivo en solucion salina isotonica. Las temperaturas bajas no parecen mejorar la calidad espermatica bajo las condiciones de preservacion senaladas, al menos dentro del periodo de 8...
The brocket deer (Genus Mazama) is a highly diverse cervid group distributed from Mexico to Argen... more The brocket deer (Genus Mazama) is a highly diverse cervid group distributed from Mexico to Argentina, with a downward population trend. However, literature on the basic reproductive biology of the genus is scarce. This work aimed to study biometric, histological and stereological aspects of the testes of Dwarf Red Brocket (Mazama rufina). Testes from free‐ranging adult brockets (n = 3) were retrieved from necropsies. Testes were histologically processed. From histological images, several stereological parameters were estimated, and seminiferous epithelium cycle morphology was described. Testes volumes were between 8.2 and 18.4 ml and weights from 8.3 to 19.4 g. Gonadosomatic index (% paired‐testes weight to body weight) went from 0.17 to 0.64. The tubular cross‐sectional diameter was 179.8 ± 2.8 µm. Estimated volume densities for parenchyma and interstitium were 78.8% and 21.2% respectively. There were (in millions/ml) 96.0 ± 13.1 germ cells and 37.7 ± 6.0 somatic cells. Specific cell densities were (all expressed in millions/ml) as follows: spermatogonia 13.1 ± 4.2; primary spermatocytes 43.1 ± 5.0; round spermatids 36.8 ± 8.0 (lower density near the caudal pole, p < 0.01); sustentacular (Sertoli) cells 16.8 ± 4.1 and interstitial endocrine (Leydig) cells 17.4 ± 3.4. Sertoli cell index (germ cells per Sertoli cell) was 6.72. Eight stages of the cycle were described, and frequencies estimated, resembling those of goats. M. rufina adult testis anatomy is similar to that of other cervids and domestic ruminants, with an apparently lower spermatogenic efficiency. This work is a first approximation to the physiology of the testis of M. rufina. Basic knowledge of the reproductive physiology of vulnerable species may allow biotechnological approaches for the restitution of animal populations.
The main objective of this study was to analyze the effects of the inbreeding degree in high-prod... more The main objective of this study was to analyze the effects of the inbreeding degree in high-producing primiparous dairy cows genotypically and phenotypically evaluated and its impacts on production and reproductive parameters. Eighty Holstein–Friesian primiparous cows (age: ~26 months; ~450 kg body weight) were previously genomically analyzed to determine the Inbreeding Index (II) and were divided into two groups: low inbreeding group (LI: <2.5; n = 40) and high inbreeding group (HI: ≥2.5 and ≤5.0; n = 40). Genomic determinations of production and reproductive parameters (14 in total), together with analyses of production (12) and reproductive (11) phenotypic parameters (23 in total) were carried out. Statistically significant differences were obtained between groups concerning the genomic parameters of Milk Production at 305 d and Protein Production at 305 d and the reproductive parameter Daughter Calving Ease, the first two being higher in cows of the HI group and the third lo...
Provide an accurate summary of the background, research objectives, including details of the spec... more Provide an accurate summary of the background, research objectives, including details of the species or strain of animal used, key methods, principal findings and conclusions of the study.
Effective tools for male contraception are important in the control of reproduction in animal pop... more Effective tools for male contraception are important in the control of reproduction in animal populations. The aim of the present study was to evaluate the effects of active immunization against gonadotropin-releasing hormone (GnRH) on male reproductive function assessing testicular morphological changes and serum-gonadotropin levels in pre-pubertal rabbits, guinea pigs and ram lambs. An anti-GnRH vaccine was developed by linking a GnRH-homologous molecule to a tetanus clostridial toxoid (Al(OH)3 coadjuvant). After vaccination protocols testicular morphometry, histopathological alterations and endocrine responses (FSH, LH, testosterone and cortisol serum levels) were evaluated. Testicular volume was significantly reduced in vaccinated animals with respect to the control group in rabbits, guinea pigs and ram lambs (P<0.05 to P<0.001). The anti-GnRH vaccine generated a reduction in testicular volume of 15-, 27- and 11-fold, respectively. Tubule diameters decreased in the vaccina...
The objective of this review is to outline existing artificial mitochondria transfer techniques a... more The objective of this review is to outline existing artificial mitochondria transfer techniques and to describe the future steps necessary to develop new therapeutic applications in medicine. Inspired by the symbiotic origin of mitochondria and by the cell's capacity to transfer these organelles to damaged neighbors, many researchers have developed procedures to artificially transfer mitochondria from one cell to another. The techniques currently in use today range from simple coincubations of isolated mitochondria and recipient cells to the use of physical approaches to induce integration. These methods mimic natural mitochondria transfer. In order to use mitochondrial transfer in medicine, we must answer key questions about how to replicate aspects of natural transport processes to improve current artificial transfer methods. Another priority is to determine the optimum quantity and cell/tissue source of the mitochondria in order to induce cell reprogramming or tissue repair, ...
This article reviews the current body of knowledge on biotechnological applications of spermatogo... more This article reviews the current body of knowledge on biotechnological applications of spermatogonial stem cells (SSCs). SSCs are the founding adult germ stem cells of the sperm producing process spermatogenesis. SSCs belong to the male germline and can be expanded in vitro in several species. Through mechanisms not fully understood they can derive pluripotent stem cells in vitro. Thus, they can be genetically modified with some advantages over embryonic stem cell-based technologies. SSCs can be transplanted to homotopical or ectopical locations, offering great potentials in fertility related issues and regenerative clinical applications in domestic or wild animals and men.
Dairy cattle breeding has historically focused on relatively small numbers of elite bulls as sire... more Dairy cattle breeding has historically focused on relatively small numbers of elite bulls as sires of sons. In recent years, even if generation intervals were reduced and more diverse sires of sons could have been selected, genomic selection has not fundamentally changed the fact that a large number of individuals are being analyzed. However, a relatively small number of elite bulls are still siring those animals. Therefore inbreeding-derived negative consequences in the gene pool have brought concern. The detrimental effects of non-additive genetic changes such as inbreeding depression and dominance have been widely disseminated while seriously affecting bioeconomically important parameters because of an antagonistic relationship between dairy production and reproductive traits. Therefore, the estimation of benefits and limitations of inbreeding and variance of the selection response deserves to be evaluated and discussed to preserve genetic variability, a significant concern in th...
Spermatogonial stem cells (SSCs) are the germ cells at the basis of spermatogenesis in adult mamm... more Spermatogonial stem cells (SSCs) are the germ cells at the basis of spermatogenesis in adult mammals. SSCs offer many biotechnological possibilities and are fundamental cells in the study of spermatogenesis (Aponte, World J Stem Cells 7:669-680, 2015). This chapter describes detailed procedures for SSC isolation, culture, cryopreservation, and characterization in bovine, murine, and human models.
Data related to the effects of r-met-hu G-CSF (filgrastim) on male reproductive function and deve... more Data related to the effects of r-met-hu G-CSF (filgrastim) on male reproductive function and development in prepubertal domestic mammals (guinea pigs and ram lambs).Data relates to blood cell counts; hormone levels -FSH-LH-Testosterone; Testis weight and volume. Seminiferous tubules cross-section diameter; Stereology: unbiased cell counting, daily sperm production (DSP), DSP/gram of parenchyma)Data is subject to ANOVA, Bonferroni media test.<br><br>
This study aimed to test the effects of the drug r-met-hu-G-CSF (Filgrastim) on spermatogenic eff... more This study aimed to test the effects of the drug r-met-hu-G-CSF (Filgrastim) on spermatogenic efficiency in prepubertal Brahman bulls. Twelve intact, healthy prepubertal bulls were administered 0, 1 (LD=low dose) or 4 (HD=high dose) µg/Kg r-met-hu-G-CSF (daily-4-days, +hematological analysis). Bulls were castrated (D0 or D60). BW (body weight) and SC (scrotal circumference) were recorded. Testis weight and volume were taken at castration with samples for testis histology and stereology: germ cell types, spermatids count, and DSP (Daily sperm production per gram)/g of testicular parenchyma. Testicular weight, volume, BW, SC, and gonadosomatic index (GSI) were NS (LD-HD; P>0.05). At D0 (age-11-mo), the most advanced germ cell types (maGCt) ranged from intermediate-spermatogonia to pachytene-spermatocytes. After 2-mo, control animals had round spermatids as maGCt, LD-animals 75% of round spermatids and 25% elongated spermatids, and HD-animals round spermatids. Spermatids/testis were higher (LD=1.23±0.2 millions) than (controls=0.65±0.1 millions); (P<0.05). Spermatogenesis efficiency (DSP/g) was higher with LD (5.4±0.4 million) than controls (3.2±0.2 million; P<0.01). In conclusion, r-met-hu-G-CSF raises spermatogenic efficiency in prepubertal Brahman bulls.
RESUMEN DEL SEGUNDO SEMINARIO INTERNACIONAL DE SANIDAD AGROPECUARIA (SISA) Uso de la histología y... more RESUMEN DEL SEGUNDO SEMINARIO INTERNACIONAL DE SANIDAD AGROPECUARIA (SISA) Uso de la histología y microscopia confocal en la caracterización de esporas de hongos fitopatógenos: Caso Thecaphora solani Use of histology and confocal microscopy for spore characterization of phytopathogenic fungi: Case Thecaphora solani
Genomics comprises a set of current and valuable technologies implemented as selection tools in d... more Genomics comprises a set of current and valuable technologies implemented as selection tools in dairy cattle commercial breeding programs. The intensive progeny testing for production and reproductive traits based on genomic breeding values (GEBVs) has been crucial to increasing dairy cattle productivity. The knowledge of key genes and haplotypes, including their regulation mechanisms, as markers for productivity traits, may improve the strategies on the present and future for dairy cattle selection. Genome-wide association studies (GWAS) such as quantitative trait loci (QTL), single nucleotide polymorphisms (SNPs), or single-step genomic best linear unbiased prediction (ssGBLUP) methods have already been included in global dairy programs for the estimation of marker-assisted selection-derived effects. The increase in genetic progress based on genomic predicting accuracy has also contributed to the understanding of genetic effects in dairy cattle offspring. However, the crossing wit...
The main objective of this study was to analyse the effects of r-met-hu G-CSF application as an i... more The main objective of this study was to analyse the effects of r-met-hu G-CSF application as an inductor of early sexual development in prepubertal ram lambs. 20 Corriedale ram lambs (age= 2 months; ~18 kg l.w.) were divided in 4 groups: a control group (T1; n= 5) and 3 treated groups (T2, T3 and T4; n= 5 each) were administered a subcutaneous injection of r-met-hu G-CSF/Filgrastim daily for 4 consecutive days [(T2; 1 µg/kg l.w.; 18 µg/day; total= 72 µg), (T3; 10 µg/kg l.w.; 180 µg/day; total= 720 µg) y (T4; 20 µg/kg l.w.; 360 µg/day; total= 1.440 µg)]. A haematological analysis (white blood cells) was performed to determine the response of the spinal cord and confirm the hematopoietic effect of r-met-hu G-CSF. The testis weight, testicular morphometry and testicular volume were evaluated as well. To determine the effectiveness of the r-met-hu G-CSF treatment on sexual development, histological alterations (seminiferous tubules, Sertoli cells, gonocytes, spermatogonia, among others) were also evaluated as well as the endocrine response (FSH, LH, testosterone and cortisol) by ELISA. Significant differences were found in the number of leukocytes between the T4 vs. T1, T2 and T3 groups, from day 3 onwards (p<0.05). Lymphocyte percentage was significantly higher in T3 and T4 (p<0.05) compared to control (T1) and T2 from day 2 onwards. In addition, significant differences were observed in the testicular weight between the T1/T2 and the T3/T4 groups (p<0.05), as well as between the T1 and the T3/T4 regarding testicular volume (p<0.05). The hormone levels differed significantly in FSH concentration obtained in T3 compared to the other groups from day 3 onwards (p<0.05). Regarding LH and testosterone, significant differences were found between the T4 and the rest of the groups, which were evident from day 2 (LH) and day 3 (testosterone) (p<0.05). The cortisol did not differ among groups (p>0,05). With regard to histological alterations, T3 showed a more advanced cellular profile presenting primary spermatocytes, while T4 reached the generation of round spermatids. In conclusion, the application of r-met-hu G-CSF (Filgrastim) as a stimulating factor for early sexual development affected fast and positively the white blood cells´ haematopoiesis and the hormonal activity when applied at high concentrations, and accelerated the testicular development in prepubertal lambs, affecting not only endocrine hormone levels but also the testicular weight and volume, as well as the spermatogenic process.
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