Natural, but not lyophilized, low density lypoproteins were an acceptable alternative to egg yolk for cryopreservation of ram semen

The objective was to evaluate the suitability of using natural or lyophilized low density lipoproteins (LDL), in lieu of whole egg yolk, in extenders for cryopreserving ram semen. Once extragonadal sperm reserves were depleted in 10 fertile Santa Inês cross rams, two ejaculates per ram were collected for cryopreservation. Nine extenders were used: Tris-16% egg yolk extender with 5% glycerol as a control (T1), and substitution of whole egg yolk with 8, 12, 16 or 20% natural LDL (T2-T5, respectively), or with 8, 12, 16, or 20% lyophilized LDL (T6-T9). Semen was diluted to 100 × 10⁶ sperm/mL, packaged into 0.25 mL straws, cooled, held at 5 °C for 3 h, and then frozen in liquid nitrogen vapor. Immediately after thawing (37 °C for 30 s), sperm total and progressive motility, and kinetic parameters were analyzed with computer assisted semen analysis (CASA). Percentage of sperm with plasma membrane functional integrity was assessed by the hypoosmotic swelling test (HOST), sperm membrane physical integrity with propidium iodide (PI), and acrosome integrity with FITC-PSA using an epifluorescent microscope. For all sperm end points, there was no difference between the control and natural LDL treatments (P > 0.05): total motility (T1: 20.9 ± 11.9 and average of T2-T5: 25.9 ± 13.6%; mean ± SD), progressive motility (T1: 6.6 ± 4.2 and average of T2-T5: 11.7 ± 7.5%), HOST⁺ (T1: 23.7 ± 6.9 and average of T2-T5: 23.2 ± 8.7 %) and PI⁻/PSA⁻ (T1: 13.8 ± 7.8 and average of T2-T5: 18.1 ± 7.8%). However, lyophilization was apparently unable to preserve the protective function of LDL; every sperm end point was significantly worse than in the control and natural LDL groups. We concluded that natural LDL was appropriate for cryopreserving ram semen, as it yielded results similar to those obtained with whole egg yolk.     

Effect of single layer centrifugation using Androcoll-E-Large on the sperm quality parameters of cooled-stored donkey semen doses

The aim of this study was to determine the effect of single layer centrifugation (SLC) using Androcoll-E-Large on donkey sperm quality parameters after 24 h of cool-storage. Ejaculates were collected from Andalusian donkeys and then cooled at 5°C. SLC was carried out after 24 h of cool-storage using Androcoll-E-Large. In the first experiment, all sperm parameters assessed (total and progressive sperm motility, viability, sperm morphology and sperm kinematics VCL, VSL, VAP, LIN, STR, WOB, ALH and BCF) were statistically compared between semen samples processed or not with Androcoll-E-Large. Significant differences (P<0.05) were found between SLC-selected and unselected semen samples for all parameters assessed, obtaining better results after SLC. In the second experiment, semen samples were classified in two groups according to their sperm progressive motility (PM) before SLC. Then, the increments obtained in semen quality parameters after SLC were compared between groups. No significant differences were found between groups, indicating that SLC improved the sperm quality parameters of entire set of semen samples processed with independence to their original PM. In conclusion, SLC with Androcoll-E-Large can be used in donkeys, increasing the sperm quality of cooled-stored donkey semen doses after 24 h of cool storage.     

应用生殖免疫方法制作性别化冷冻精液对奶牛性别控制的研究

本实验在种公牛站精液生产过程中应用生殖免疫技术方法 ,制作性别化冷冻精液 ,结合人工授精技术进行奶牛性别控制的研究实验。根据精子DNA含量存在的差异 ,利用荧光染料与精子DNA结合 ,通过蔗糖溶液密度梯度离心法 ,分离出和鉴别出牛精液中的X与Y精子作为抗原。经与小鼠免疫后 ,制成H Y抗血清IgG ,再经酶联免疫吸附法 (ELISA)析测表明 ,获得了具有一定纯度和工作效价的阳性抗Y精子的H Y抗血清IgG ,H Y抗血清对性别化精液冷冻前 ,解冻后活力的影响与对照组无显著差异。配种受胎试验结果表明 ,性别化冷冻精液在获得与正常冷冻精液相似的情期受胎率的同时 ,对后代性别比率有显著影响 ,奶牛产母犊率可达 60 7% ,比自然产母犊性比率理论值提高 1 0 7个百分点 (P <0 0 5 )。     

Biological data from a data‐deficient shark: the Arabian smoothhound Mustelus mosis (Carcharhiniformes: Triakidae)

The present study provides information on length distribution, reproductive biology and diet of Mustelus mosis based on individuals caught in waters off the eastern Arabian Peninsula. Although ageing of vertebral centra was attempted, band pairs were of low clarity and counts could not be confidently assigned.     

Isolation of microsatellite loci from the endemic and endangered Adriatic sturgeon (<Emphasis Type="Italic">Acipenser naccarii</Emphasis>)

With the aim of elaborating a breeding plan on a captive stock of the highly endangered Adriatic sturgeon (Acipenser naccarii), a total of 10 polymorphic microsatellite loci were isolated from an enriched library. The results of cross amplification of additional 8 loci previously isolated from A. oxyrinchus, A. fulvescens and Scaphyrinchus platorhynchus are also reported. Given the tetraploid condition of the species the genetic variability was estimated basing on the number of alleles per individuals and the average band sharing.     

Genetic monitoring of progeny derived from natural spawning of Acipenser ruthenus Linnaeus, 1758 and Acipenser stellatus Pallas, 1771 as well as their hybrids in the Lower Volga river during the period 2017 to 2019

The state of natural spawning of sturgeons in the Lower Volga River was investigated through genetic monitoring of juveniles (larvae, fingerlings, subadults) captured at seven traditionally used monitoring locations. Sampling was performed during the period 2017–2019. In total, 460 individuals were caught and genotyped using a set of six microsatellite loci (Afug41, Afug51, Afug135, An20, AoxD161, AoxD165) and mtDNA control region sequencing. The observed species-specific microsatellite alleles revealed the presence of juvenile sturgeons originating from natural spawning also included some hybrids between Acipenser stellatus and A. ruthenus. Thus, the majority of sterlet breeding takes place in natural spawning grounds but also sterlet hybridizes with a small number of stellate sturgeons. Juveniles of other sturgeon species were not identified, and it is concluded that natural spawning activities of Russian sturgeon, beluga and ship sturgeon were insignificant or even absent in the Lower Volga during the observation period.     

Ejaculate characteristics over seasons in five species of lancehead pitvipers (Bothrops spp) kept in captivity

Due to their major medical importance in Latin America, lancehead pitvipers are frequently kept and bred in captivity for venom extraction to the production of antivenom serums. Nevertheless, despite the great contribution given to captive breeding, much of the knowledge of Bothrops' reproductive biology derived from sporadic and insufficient data provided by zoological collections. Thus, we aimed to investigate seasonal changes in gonadosomatic index (GSI) and seminal parameters (e.g., volume, concentration, motility, viability, and acrosome integrity) of five species of lancehead pitvipers from different biomes and phylogenetic groups, maintained in the indoors serpentarium at Butantan Institute (Brazil). Patterns of variation in GSI and semen parameters differed from one species to another, suggesting that captive populations should perhaps be managed distinctly to maximize reproductive success. Furthermore, in none of the studied species did changes in GSI occur concomitantly with seminal variations. GSI remained unaltered year-round for Jararaca (Bothrops jararaca) and Brazilian lancehead (Bothrops moojeni), whereas it peaked in the autumn for Common lancehead (Bothrops atrox), Jararacussu (Bothrops jararacussu), and Whitetail lancehead (Bothrops leucurus). But surprisingly, the scenario was inverted when we estimated the total number of motile spermatozoa per season, as Jararaca and Brazilian lancehead displayed seasonal differences and the other species did not vary throughout the year. Potential ecological and evolutionary factors underlying these differences were also discussed in the present article. Together, these findings can help to better define breeding management strategies for each species in captivity, in addition to optimizing the future use of artificial insemination and semen cryopreservation.     

The 1999 and 2010 WHO reference values for human semen analysis to predict sperm DNA damage: A comparative study

Standard semen parameters are often used to predict male fertility, but whether the 2010 World Health Organization (WHO 2010) thresholds are better predictors than the 1999 thresholds has not been investigated. In this study, we addressed this issue using sperm DNA fragmentation (SDF) as a marker of male fertility in 134 subfertile male individuals. To compare the predictive value of the 1999 thresholds with the 2010 cutoffs, the Youden indices (YIs) of all possible thresholds were calculated using receiver operating characteristic (ROC) curves and compared to each other and to the respective YIs of optimal thresholds. We found that the area under the ROC curves of progressive motility and vitality was the highest among standard semen parameters, and that the YI of both parameters from the 2010 manual was comparable to the respective optimal YIs. In contrast, the threshold of sperm concentration and total sperm number from both WHO recommendations demonstrated low YIs, with substantial differences to the respective optimal YIs. The YIs of normal morphology cutoffs from both WHO manuals were slightly different from each other and from the respective optimal YIs. In conclusion, the 2010 thresholds for progressive motility and vitality are superior to the 1999 thresholds in predicting SDF, whereas the cutoff value of sperm concentration, total sperm number and normal morphology may need further revisions to increase their accuracy.