CERSYRA

Valdepeñas, Spain
Valdepeñas, Spain
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Ramon M.,CERSYRA | Perez-Guzman M.D.,CERSYRA | Jimenez-Rabadan P.,CERSYRA | Garcia-Alvarez O.,Campus Universitario Sn | And 5 more authors.
PLoS ONE | Year: 2013

Background: Sperm cryopreservation has become an indispensable tool in biology. Initially, studies were aimed towards the development of efficient freezing protocols in different species that would allow for an efficient storage of semen samples for long periods of time, ensuring its viability. Nowadays, it is widely known that an important individual component exists in the cryoresistance of semen, and efforts are aimed at identifying those sperm characteristics that may allow us to predict this cryoresistance. This knowledge would lead, ultimately, to the design of optimized freezing protocols for the sperm characteristics of each male. Methodology/Principal Findings: We have evaluated the changes that occur in the sperm head dimensions throughout the cryopreservation process. We have found three different patterns of response, each of one related to a different sperm quality at thawing. We have been able to characterize males based on these patterns. For each male, its pattern remained constant among different ejaculates. This latter would imply that males always respond in the same way to freezing, giving even more importance to this sperm feature. Conclusions/Significance: Changes in the sperm head during cryopreservation process have resulted useful to identify the ability of semen of males for freezing. We suggest that analyses of these response patterns would represent an important tool to characterize the cryoresistance of males when implemented within breeding programs. We also propose follow-up experiments to examine the outcomes of the use of different freezing protocols depending on the pattern of response of males. © 2013 Ramón et al.


Marcos-Carcavilla A.,INIA | Mutikainen M.,Mtt Agrifood Research Finland | Gonzalez C.,INIA | Kantanen J.,Mtt Agrifood Research Finland | And 3 more authors.
Cell Stress and Chaperones | Year: 2010

Molecular chaperones have long been understood to be preferentially transcribed in response to multiple perturbations of the cellular homeostasis. In this study, several polymorphisms in the gene encoding the inducible form of the cytoplasmic Hsp90 (HSP90AA1) were addressed in 24 sheep breeds reared in different climatic regions of Europe, Africa, and Asia. Significant differences in the genotype frequencies for a C/G single nucleotide polymorphism (SNP) located at position-660 in the HSP90AA1 5'flanking region were found between the different breeds. Regression analyses reflected significant correlations (from 0.41 to 0.62) between the alternative genotypes of this polymorphism and several climatic and geographic variables characteristic of the regions where these breeds are reared. Real-time analysis revealed that animals bearing the CC -660 genotype presented higher expression levels than those presenting the CG-660 or GG-660 in summer, but not in spring. Mutation at -660 site seems to affect HSP90AA1 transcription rates which could have important effects on the adaptation to different environmental conditions in sheep. Thus, the variability found in the genotype frequencies for the SNP at -660 in the ovine HSP90AA1 locus could be the result of the different environmental pressures occurring in the regions where these breed are maintained. © Cell Stress Society International 2009.


Ramon M.,National Wildlife Research Institute IREC UCLM CSIC JCCM | Legarra A.,French National Institute for Agricultural Research | Ugarte E.,Basque Institute of Agricultural Research and Development | Garde J.J.,National Wildlife Research Institute IREC UCLM CSIC JCCM | Perez-Guzman M.D.,CERSYRA
Journal of Dairy Science | Year: 2010

The objective of this study was to estimate economic weights of major components of milk (fat and protein) for the Manchega dairy sheep breed. An economic study was carried out and the profit associated with fat and protein yields of milk was calculated as the difference between incomes and costs. Incomes were obtained from milk sales to cheese industry and a reference marked price was used. Costs were calculated considering the energy necessary to produce each of the components of milk, and the price per milk forage unit was calculated as the total expense in feedstuff divided by the total (theoretical) needs of the flock. Economic values were defined as partial derivatives of the profit function with respect to each trait. Economic weights for fat and protein yields were similar, being slightly greater for protein in all cases. For carrier, economic weights were close to zero and negative because an increase in carrier production without changes in fat and protein composition leads to an increase in energy demands, holding the sale price of milk constant. When genetic standard deviations were taken into account and standardized economic values were calculated, an increase in economic value of protein and a decrease in economic value of fat yields were observed. The consequences that different changes in production system conditions have on the estimated economic weights were also studied. In general, economic weights were relatively insensitive to changes in production levels and market prices except for changes on milk price. Given the economic importance shown for fat and protein, milk components should be taken into consideration when breeding objectives for dairy sheep are established. © 2010 American Dairy Science Association.


Ramon M.,CERSYRA | Ramon M.,Campus Universitario Sn | Soler A.J.,Campus Universitario Sn | Ortiz J.A.,Medianilla SL Finca Las Lomas | And 4 more authors.
Biology of Reproduction | Year: 2013

Sperm design and velocity play key roles in influencing sperm performance and, therefore, can determine fertilization success. Several interspecific studies have demonstrated how these features correlate, and it has been hypothesized that selection may drive changes in these sperm traits. Here, we examine the association between sperm design and swimming velocity in a study conducted at an intraspecific level in Iberian red deer (Cervus elaphus hispanicus). We addressed how the structure of different sperm subpopulations, based on sperm morphometry and velocity, are interrelated and, in turn, how they associate with fertility. Our results show that males with high fertility rates have ejaculates with high percentages of spermatozoa exhibiting fast and linear movements and that these are highly correlated with a large proportion of spermatozoa having small and elongated heads. On the other hand, males with low fertility are characterized by a subpopulation structure in which slow and nonlinear as well as small and wide spermatozoa are predominant. These findings provide insight regarding how sperm size and velocity are interrelated and how they both are associated with fertility. © 2013 by the Society for the Study of Reproduction, Inc.


Ramon M.,CERSYRA | Salces-Ortiz J.,INIA | Gonzalez C.,INIA | Perez-Guzman M.D.,CERSYRA | And 4 more authors.
PLoS ONE | Year: 2014

The present study addresses the effect of heat stress on males' reproduction ability. For that, we have evaluated the sperm DNA fragmentation (DFI) by SCSA of ejaculates incubated at 37°C during 0, 24 and 48 hours after its collection, as a way to mimic the temperature circumstances to which spermatozoa will be subject to in the ewe uterus. The effects of temperature and temperature-humidity index (THI) from day 60 prior collection to the date of semen collection on DFI were examined. To better understand the causes determining the sensitivity of spermatozoa to heat, this study was conducted in 60 males with alternative genotypes for the SNP G/C-660 of the HSP90AA1 promoter, which encode for the Hsp90α protein. The Hsp90α protein predominates in the brain and testis, and its role in spermatogenesis has been described in several species. Ridge regression analyses showed that days 29 to 35 and 7 to 14 before sperm collection (bsc) were the most critical regarding the effect of heat stress over DFI values. Mixed model analyses revealed that DFI increases over a threshold of 30°C for maximum temperature and 22 for THI at days 29 to 35 and 7 to 14 bsc only in animals carrying the GG-660 genotype. The period 29-35 bsc coincide with the meiosis I process for which the effect of the Hsp90α has been described in mice. The period 7-14 bsc may correspond with later stages of the meiosis II and early stages of epididymal maturation in which the replacement of histones by protamines occurs. Because of GG-660 genotype has been associated to lower levels of HSP90AA1 expression, suboptimal amounts of HSP90AA1 mRNA in GG-660 animals under heat stress conditions make spermatozoa DNA more susceptible to be fragmented. Thus, selecting against the GG-660 genotype could decrease the DNA fragmentation and spermatozoa thermal susceptibility in the heat season, and its putative subsequent fertility gains. © 2014 Ramón et al.


PubMed | CERSYRA and Campus Universitario Sn
Type: | Journal: Animal reproduction science | Year: 2015

The potential protective effect of reduced glutathione (GSH) and trolox (TRX), an analogue of vitamin E, supplementation during in vitro culture (2h, 39C) of electroejaculated frozen/thawed red deer sperm was investigated. Cryopreserved sperm were thawed and incubated with no additive (Control) and 1mM or 5mM of each antioxidant to find out whether these supplementations can maintain the sperm quality, considering the use of thawed samples for in vitro techniques such as in vitro fertilisation (IVF), sperm sex sorting or refreezing. The effect of GSH on sperm motility was positive compared to TRX which was negative (P<0.001). After 2h of incubation at 39C, use of GSH improved motility while TRX supplementation reduced sperm motility compared with Control samples without antioxidant. Use of TRX at both concentrations (1 and 5mM; TRX1 and TRX5) resulted in lesser percentages of apoptotic sperm (12.41.1% and 11.70.9%) than GSH1, GSH5 (15.21% and 14.61.1%) and Control samples (16.91.2%) (P<0.001). Use of GSH at both concentrations (1 and 5mM) resulted in greater mitochondrial activity as compared with findings for the Control, TRX1 and TRX5 groups. Results of this study indicate that GSH is a suitable supplement for electroejaculated red deer sperm. It would be necessary to conduct fertility trials (in vivo and in vitro), to assess whether GSH supplementation of thawed red deer sperm could improve fertility rates.


PubMed | CERSYRA, Sabio Irec Csic Uclm Jccm Campus Universitario Sn and INIA
Type: Journal Article | Journal: PloS one | Year: 2015

Heat shock (HS) is one of the best-studied exogenous cellular stresses. Almost all tissues, cell types, metabolic pathways and biochemical reactions are affected in greater or lesser extent by HS. However, there are some especially thermo sensible cellular types such as the mammalian male germ cells. The present study examined the role of three INDELs in conjunction with the -660G/C polymorphism located at the HSP90AA1 promoter region over the gene expression rate under HS. Specially, the -668insC INDEL, which is very close to the -660G/C transversion, is a good candidate to be implied in the transcriptional regulation of the gene by itself or in a cooperative way with this SNP. Animals carrying the genotype II-668 showed higher transcription rates than those with ID-668 (FC = 3.07) and DD-668 (FC = 3.40) genotypes for samples collected under HS. A linkage between gene expression and sperm DNA fragmentation was also found. When HS conditions were present along or in some stages of the spermatogenesis, alternative genotypes of the -668insC and -660G/C mutations are involved in the effect of HS over sperm DNA fragmentation. Thus, unfavorable genotypes in terms of gene expression induction (ID-668GC-660 and DD-668GG-660) do not produce enough mRNA (stored as messenger ribonucleoprotein particles) and Hsp90 protein to cope with future thermal stress which might occur in posterior stages when transcriptional activity is reduced and cell types and molecular processes are more sensible to heat (spermatocytes in pachytene and spermatids protamination). This would result in the impairment of DNA packaging and the consequent commitment of the events occurring shortly after fertilization and during embryonic development. In the short-term, the assessment of the relationship between sperm DNA fragmentation sensitivity and rams fertility will be of interest to a better understanding of the mechanisms of response to HS and its consequences on animal production and reproduction performance.


Salces-Ortiz J.,Institute Nac Invest Agrarias Y Alimentarias | Gonzalez C.,Institute Nac Invest Agrarias Y Alimentarias | Moreno-Sanchez N.,Institute Nac Invest Agrarias Y Alimentarias | Calvo J.H.,ARAID | And 2 more authors.
PLoS ONE | Year: 2013

The aim of this work was to investigate the association between polymorphisms located at the HSP90AA1 ovine gene promoter and gene expression rate under different environmental conditions, using a mixed model approach. Blood samples from 120 unrelated rams of the Manchega sheep breed were collected at three time points differing in environmental conditions. Rams were selected on the basis of their genotype for the transversion G/C located 660 base pairs upstream the gene transcription initiation site. Animals were also genotyped for another set of 6 SNPs located at the gene promoter. Two SNPs, G/C-660 and A/G-444, were associated with gene overexpression resulting from heat stress. The composed genotype CC-660-AG-444 was the genotype having the highest expression rates with fold changes ranging from 2.2 to 3.0. The genotype AG-522 showed the highest expression levels under control conditions with a fold change of 1.4. Under these conditions, the composed genotype CC-601-TT-524-AG-522-TT-468 is expected to be correlated with higher basal expression of the gene according to genotype frequencies and linkage disequilibrium values. Some putative transcription factors were predicted for binding sites where the SNPs considered are located. Since the expression rate of the gene under alternative environmental conditions seems to depend on the composed genotype of several SNPs located at its promoter, a cooperative regulation of the transcription of the HSP90AA1 gene could be hypothesized. Nevertheless epigenetic regulation mechanisms cannot be discarded. © 2013 Salces-Ortiz et al.


PubMed | CERSYRA
Type: | Journal: Reproduction in domestic animals = Zuchthygiene | Year: 2014

Sperm are the most diverse cell type known. This diversity is thought to reflect adaptation to conditions under which sperm function as a way to ensure the survival of sperm in fertilization environments and to maximize fertilizing capacity thereof. The existence of morphological diversity among species is widely assumed, although this diversity seems less clear as we go deeper (between males, between ejaculates from the same male and even within the same ejaculate), with different theories addressing this heterogeneity. Moreover, the development of assisted reproductive techniques (ART) has led to changes in the physiological conditions in which sperm fertilize, which could lead, ultimately, to a selection towards more favourable sperm design. Regardless of the origin of this diversity, when studying the relationship between shape and function of sperm, it is advisable to assess the degree of heterogeneity of sperm and takes into account to be more likely to identify those morphological characteristics determining the fertile ability of sperm. Otherwise, these relationships could be hidden as a result of considering an average shape not representative of morphological characteristics of sperm. In addition, the knowledge of this morphological diversity in terms of changes arising from modifications in the sperm environment and mechanisms that generate these changes could be useful for understanding the reproductive capacity of males but also in enhancing their fertile ability.


PubMed | CERSYRA
Type: Journal Article | Journal: Biology of reproduction | Year: 2013

Sperm design and velocity play key roles in influencing sperm performance and, therefore, can determine fertilization success. Several interspecific studies have demonstrated how these features correlate, and it has been hypothesized that selection may drive changes in these sperm traits. Here, we examine the association between sperm design and swimming velocity in a study conducted at an intraspecific level in Iberian red deer (Cervus elaphus hispanicus). We addressed how the structure of different sperm subpopulations, based on sperm morphometry and velocity, are interrelated and, in turn, how they associate with fertility. Our results show that males with high fertility rates have ejaculates with high percentages of spermatozoa exhibiting fast and linear movements and that these are highly correlated with a large proportion of spermatozoa having small and elongated heads. On the other hand, males with low fertility are characterized by a subpopulation structure in which slow and nonlinear as well as small and wide spermatozoa are predominant. These findings provide insight regarding how sperm size and velocity are interrelated and how they both are associated with fertility.

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