1,721,194 research outputs found
E' possibile la reimmissione in naura del Goodeide Messicano Zoogoneticus tequila? sstudio su soggetti allevati i ambiente bioopico ed arricchito
No full textThe endangered Mexican fish Zoogoneticus tequila represents a new challenge for scientists: its biology, still unknown, could perhaps explain the reason for its extremely low consistency in natural environments. An experimental setting was prepared where four pairs of young Z. tequila from the only Italian colony were breed in two different tanks, biotopic and enriched. Because the captivity could promote behavioral traits that can be maladaptive in the wild, we carried out a random schedule for food dispensing in both groups, then obliging the fishes to actively look for it. During the experimental protocol, the observations were carried out for ten min. three times a day. Preliminary results showed a similar agonistic behavior in both the case study (biotopic) and the enriched tank. Aggressive behavior was extremely low and, although inter-male interactions were more unstable, no injuries were observed among the animals, apart from an episode of cannibalism in the biotopic tank realized by a female towards a young. The analysis of reproductive performance did not show differences between the two groups. The behaviour of animals in stressful situation were also recorded, namely the encounter with a male displaying enhanced sexual characters, such as the yellow-orange tail border, or with a predator. The behavioral response toward the male were more noticed in the enriched tank, where flicks of the tail and display of the fins were recorded compared to the biotope. On the other hand, the predator snake Thamnophis sp elicited an innate flight response in both the experimental conditions and in both sexes. All together those results seem to encourage the breeding of Z. tequila in captive condition, although more studies on the cognitive skills of the species should be carefully evaluated before its reintroduction in the natural environment.[...
Is Resveratrol Effective in Protecting Stallion Cooled Semen?
No full textThe aim of this work was to evaluate the effect of resveratrol (RSV) during liquid storage of
stallion sperm for 24 hours at either 10C or 4C. The antioxidant RSV was added to reduce
the oxidative damage that occurs during cold storage. Aliquots of 2 mL of diluted semen
were stored either at 4C or 10C under anaerobic conditions, in the absence (control
group) or presence of RSV at different concentrations (10, 20, 40, and 80 mM). Sperm
quality parameters were assessed at 0 hours and after 24 hours of storage. Resveratrol
treatment did not affect sperm quality parameters at 0 hours. At 24-hour storage, a significant
(P < .01) decrease of sperm quality was observed independently from RSV supplementation
and storage temperature. A significant decrease of viable spermatozoa with
high mitochondrial membrane potential (SYBRþ/PI/JC-1þ) was evident at 24-hour
storage in 40- and 80-mM RSV groups compared with control group. Moreover, a decline
of total motility in 80-mM RSV group compared with the control group and a decrease of
progressive motility and average path velocity in 80-mM RSV group compared with control
and 20-mM RSV groups were observed. In conclusion, our findings demonstrate that RSV
supplementation does not enhance sperm quality of stallion semen after 24 hours of
storage. Moreover, 40- and 80-mM RSV concentrations could damage sperm functional
status, probably acting as pro-oxidant. Finally, although 24-hour storage significantly
affected most of the sperm quality parameters, no significant differences were found in
groups maintained at 4C or 10C, suggesting that stallion semen could be equally preserved
at these different temperatures
EFFECT OF STAINING AND SORTING ON BOAR SPERM MEMBRANE INTEGRITY, MITOCHONDRIAL ACTIVITY AND IN VITRO BLASTOCYST DEVELOPMENT
No full textThe objective of this study was to determine the effects of staining with Hoechst 33342 and of the entire sorting procedure on boar sperm membrane integrity (using Annexin-V/PI), mitochondrial activity (using JC-1/SYBR/PI) and blastocyst development in vitro; the effect of storage at 17 degrees C for 24h prior to Hoechst staining and sorting was also investigated. The Hoechst staining and the whole sorting procedure reduced the percent of live spermatozoa in both fresh (day 0) and stored (day 1) semen, as determined by both assays; nevertheless, there was no increase in live sperm cells showing signs of early damage (Annexin-V positive, propidium negative), whose percentages remained nearly zero. The majority of Annexin-V positive cells were propidium positive, therefore dead. JC-1 staining evidenced a correlation between mitochondrial activity and viability. However, a significant difference between viable sperm cells and sperm cells with active mitochondria was detected in control and stained sperm, whereas almost all viable sorted spermatozoa had active mitochondria. No significant differences in the in vitro produced blastocysts both on day 0 and 1 were observed. In conclusion, despite the damages induced by sorting procedures, semen sorted as fresh or after storage at 17 degrees C can be successfully used for in vitro production of pig embryos
Porcine circovirus type 2 detection in in vitro produced porcine blastocysts after virus sperm exposure
Full text linkThis study was aimed at assessing the capability of semen experimentally infected with porcine circovirus type 2 (PCV2) to produce porcine blastocysts PCR positive for PCV2. Embryos were obtained from in vitro maturation (IVM) and in vitro fertilization (IVF) of porcine oocytes or by parthenogenesis. Sperm suspension was exposed to PCV2b and utilized for IVF. PCV2 spiked semen did not reveal any reduction in sperm viability or motility but its ability to produce infected blastocysts was irrelevant as only one out of 15 blastocysts obtained by IVF were PCV2b; however two blastocysts were PCV2a positive. Furthermore, the presence of PCV2 was demonstrated also in embryos obtained by parthenogenesis (one out of 17 was PCV2b and one PCV2a positive). Even if PCV2 firmly attaches to the surface of spermatozoa, experimentally spiked sperm were not effective in infecting oocytes during IVF and in producing PCR positive embryos. The infected blastocysts we obtained derived most probably from infected oocytes recovered at the abattoir
Improvement of in vitro fertilization by a tannin rich vegetal extract addition to frozen thawed boar sperm
Full text linkBoar spermatozoa are very susceptible to cryopreservation injuries and, for this reason, pig remains one of the few species in which fresh semen is still preferred to thawed one for routine artificial insemination (AI). The present work evaluated the effect of supplementing boar sperm thawing medium with Silvafeed SP (SSP), a mixture of Chestnut and Quebracho wood extracts (60/40 w/w) rich in polyphenols (92.4% tannin content) on in vitro fertilization (IVF) and on the following sperm parameters: sperm motility (assessed by CASA), viability, acrosome integrity, mitochondrial function and lipid peroxidation (assessed by flow cytometry) and capacitation status (immunolocalization of tyrosine phosphorylated proteins). Thawed spermatozoa were incubated 1 h at 37°C in BTS without (CTR) or with (5, 10, 20 g/mL) SSP. After incubation sperm suspension was divided in three aliquots: one was used for IVF trials, one for sperm analysis, and the last one was capacitated for 1 h at 39°C 5% CO2 in IVF medium. Sperm motility parameters, viability, acrosome integrity, mitochondrial functionality, lipid peroxidation and tyrosine phosphorylated protein immunolocalization, used as capacitation parameter, were not influenced by SSP. However, oocytes inseminated with thawed spermatozoa pretreated with all the different SSP concentrations presented a significant (P < 0.01) increase in penetration rate compared to CTR. In addition, 5 g/mL SSP exerted a positive effect (P<0.05) on the total efficiency of fertilization. These results encourage the use of SSP in the thawing medium since post-thawing fertility is a limit for the large-scale use of boar frozen semen
Sperm function and mitochondrial activity: An insight on boar sperm metabolism
Full text linkIn this study boar sperm mitochondrial activity was studied and deepened in order to delineate the main
metabolic strategies used by boar sperm to obtain energy and to link them to sperm function.
Boar spermatozoa were collected, diluted at 30 106 spz/mL and incubated for 1 h with: Rotenone
(ROT), complex I inhibitor, Dimethyl-malonate (DMM), complex II inhibitor, antimycin A (ANTI), complex
III inhibitor, oligomycin (OLIGO), ATP synthase inhibitor, Carbonyl cyanide m-chlorophenyl hydrazone
(CCCP), uncoupling agent, 2-deoxy-glucose (2DG), glucose agonist, and Dimethyl sulphoxide (DMSO) as
control vehicle. Viability and mitochondrial membrane potential (Sybr14/PI/JC1 staining) and sperm
motility (using CASA system) were assayed after incubation.
ROT, ANTI, OLIGO and CCCP significantly reduced total and progressive motility as well as cell velocities;
ANTI and CCCP depressed mitochondrial membrane potential but did not affect cell viability.
Cluster analysis of kinematic parameters showed some interesting features of sperm subpopulations:
ANTI and CCCP caused a shift in sperm subpopulation towards “slow non progressive” cells, OLIGO and
ROT caused a shift towards “average” and “slow non progressive” cells, while DMM and 2DG increased
the “fast progressive” cells subpopulation.
Sperm mitochondrial respiration and substrate oxidation, assayed polographically and spectrofluorimetrically,
respectively pointed out a high ATP turnover and a low spare respiratory capacity, mainly
linked to the NADH-O2 oxidase activity. Therefore, boar spermatozoa heavily rely on mitochondrial
oxidative phosphorylation, and especially on Complex I activity, to produce ATP and fuel motility
Implementing an open-access CASA software for the assessment of stallion sperm motility: Relationship with other sperm quality parameters
Full text linkSetting an open-access computer assisted sperm analysis (CASA) may benefit the evaluation of motility in mammalian sperm, especially when economic constraints do not allow the use of a commercial system. There have been successful attempts to develop such a device in Zebra fish sperm and the system has been used in very few studies on mammalian spermatozoa. Against this background, the present study aimed at developing an open-access CASA system for mammalian sperm using the horse as a model and based upon the Image J software previously established for Zebra fish sperm. Along with determining the sperm progressive motility and other kinetic parameters (such as amplitude of lateral head displacement), the “results” window was adjusted to simplify subsequent statistical analyses. The path window was enriched with colored sperm trajectories on the basis of the subpopulation they belong to and a number that allowed the sperm track to be associated to the sperm motility data shown in the “results” window. Data obtained from the novel plugin (named as CASA_bgm) were compared with those of the commercial CASA Hamilton-Thorn IVOS Vers.12, through Bland Altman's plots. While the percentage of total and progressive motile sperm, VCL, VAP, VSL, LIN and STR and ALH were in agreement with those obtained with the commercial system, BCF significantly differed between the two systems probably due to their settings. Interestingly, a positive and significant correlation between the percentages of total motile sperm evaluated through CASA_bgm and those showing high mitochondrial membrane potential evaluated by JC-1 staining was found. In conclusion, CASA_bgm ImageJ plugin could be useful and reliable for stallion sperm motility analysis and it is our aim to apply this system to other mammalian species
Allestimento di sistemi di coltura tridimensionale in matrice biocompatibile di cellule follicolari ovariche e di follicoli ovarici di mammifero
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Preparation of three-dimensional mammalian ovarian follicular cells and ovarian follicle culture systems in a biocompatible matrix
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