DNA Status on Thawed Semen from Fighting Bull: A Comparison Between the SCD and the SCSA Tests     

F Martínez-Pastor  M del Rocío Fernández-Santos  ÁE Domínguez-Rebolledo  MC Esteso  JJ Garde  ; Biology of Reproduction Group 《Reproduction in domestic animals》2009,44(3):424-431

The assessment of sperm chromatin status is compulsory in a complete spermiogram. Here we applied the sperm chromatin structure assay (SCSA) and the sperm chromatin dispersion (SCD) test to assess the chromatin status of three fighting bulls. Cryopreserved semen (two straws/bull) were analysed by duplicate after thawing and after 6 h at 37°C with and without oxidative stress (1 m m FE²⁺). Results (SCD: percentage of spermatozoa with halo; SCSA: SD-DFI, %DFI and HDS) were analysed for differences between bulls and treatments, sensitivity and specificity (receiver operating characteristic curves) and repeatability (repeatability coefficients as 2SD of duplicate differences).%DFI for the three bulls was below 2% at 0 h, indicating no risk for fertility according to previous reports. It increased slightly for two of the bulls after FE²⁺ treatment (%DFI < 5%) and more pronouncedly for the other bull (C, %DFI∼10%), which merits further investigation. SCD rendered higher percentage of halos for bull C, but could not discriminate between samples with and without oxidizing treatment (AUC: 0.52). SCSA (%DFI) showed a high discriminating ability between treatments (AUC: 0.96). The repeatability coefficient was also higher for SCD (5.9) than for %DFI (1.8), indicating lower repeatability for SCD. Overall, %DFI might be the most useful parameter for assessing sperm chromatin on fighting bull. SCD might yield different information than SCSA, hence further research is warranted.  相似文献   

Effects of a chitin-binding vicilin from Enterolobium contortisiliquum seeds on bean bruchid pests (Callosobruchus maculatus and Zabrotes subfasciatus) and phytopathogenic fungi (Fusarium solani and Colletrichum lindemuntianum)     

Moura FT  Oliveira AS  Macedo LL  Vianna AL  Andrade LB  Martins-Miranda AS  Oliveira JT  Santos EA  de Sales MP 《Journal of agricultural and food chemistry》2007,55(2):260-266

Chitin-binding vicilin from Enterolobium contortisiliquum seeds was purified by ammonium sulfate followed by gel filtration on Sephacryl 300-SH and on Sephacryl 200-SH. The vicilin, called EcV, is a dimeric glycoprotein composed of 1.03% carbohydrates and a Mr of 151 kDa, consisting of two subunits of Mr of 66.2 and 63.8 kDa. The EcV homogeneity was confirmed in a PAGE where it was observed to be a unique acid protein band with slow mobility in this native gel. E. contortisiliquum vicilin (EcV) was tested for anti-insect activity against C. maculatus and Zabrotes subfasciatus larvae and for phytopathogenic fungi, F. solani and C. lindemuntianum. EcV was very effective against both bruchids, producing 50% mortality for Z. subfasciatus at an LD50 of 0.43% and affected 50% of the larvae mass with an ED50 of 0.65%. In artificial diets given to C. maculatus, 50% of the larvae mass was affected with an ED50 of 1.03%, and larva mortality was 50% at LD50 of 1.11%. EcV was not digested by midgut homogenates of C. maculatus and Z. Subfasciatus until 12 h of incubation, and at 24 h EcV was more resistant to Z. subfasciatus larval proteases. The binding to chitin present in larvae gut associated to low EcV digestibility could explain its lethal effects. EcV also exerted an inhibitory effect on the germination of F. solani at concentrations of 10 and 20 microg mL-1. The effect of EcV on fungi is possibly due to binding to chitin-containing structures of the fungal cell wall.  相似文献   

Involvement of Protein cAMP‐dependent Kinase,Phospholipase A2 and Phospholipase C in Sperm Acrosome Reaction of Chinchilla lanigera          下载免费PDF全文

MC Gramajo‐Bühler  L Zelarayán  G Sánchez‐Toranzo 《Reproduction in domestic animals》2016,51(1):150-157

The mechanisms involved in fertilization are the centre of attention in order to determine the conditions required to reproduce in vitro the events that take place in vivo, with special interest in endangered species. Previous data from mouse sperm, where acrosome reaction (AR) occurs more often in the interstitium of the cumulus oophorus, contribute to strengthen the use of progesterone as a physiological inducer of this process. We studied the participation of protein kinase A (PKA), phospholipases A₂ and C (PLA₂, PLC) in the AR induced by progesterone from Chinchilla epididymal spermatozoa. The addition of db‐cAMP to the incubation medium caused an increase of 58% in the AR, while the use of H89 (30 μm ), a PKA inhibitor, reflected a decrease of 40% in the percentage of reacted gametes. The assays conducted with arachidonic acid showed a maximum increase of 23% in the AR. When gametes were pre‐incubated with PLA₂ inhibitors, a dose‐dependent inhibitory effect was observed. The addition of phorbol12‐myristate13‐acetate (10 μm ) revealed higher percentages of AR induction (60%). When PLC was inhibited with neomycin and U73122, a dose‐dependent decrease in AR percentages was observed. Combined inhibition of PKA, PLA₂ and PLC, AR values similar to control were obtained. This work shows evidence, for the first time in Chinchilla, that progesterone activates the AC/cAMP/PKA system as well as sperm phospholipases and that these signalling pathways participate jointly and cooperatively in AR. These results contribute to the understanding of the complex regulation that is triggered in sperm after the effect of progesterone.  相似文献