l‐Cysteine improves antioxidant enzyme activity,post‐thaw quality and fertility of Nili‐Ravi buffalo (Bubalus bubalis) bull spermatozoa

The effects of l ‐cysteine in extender on antioxidant enzymes profile during cryopreservation, post‐thaw quality parameters and in vivo fertility of Nili‐Ravi buffalo bull spermatozoa were studied. Semen samples from 4 buffalo bulls were diluted in Tris–citric acid‐based extender having different concentrations of l ‐cysteine (0.0, 0.5, 1.0, 2.0 and 3.0 mm ) and frozen in 0.5‐ml French straws. The antioxidative enzymes [catalase, super oxide dismutase and total glutathione (peroxidase and reductase)] were significantly higher (P < 0.05) at pre‐freezing and post‐thawing in extender containing 2.0 mm l ‐cysteine as compared to other groups. Post‐thaw total motility (%), progressive motility (%), rapid velocity (%), average path velocity (μm s^?1), straight line velocity (μm s^?1), curvilinear velocity (μm s^?1), beat cross frequency (Hz), viable spermatozoa with intact plasmalemma (%), acrosome and DNA integrity (%) were higher with the addition of 2.0 mm l ‐cysteine as compared to other groups (P < 0.05). The fertility rates (59 versus 43%) were higher (P < 0.05) in buffaloes inseminated with doses containing 2.0 mm of l ‐cysteine than in the control. In conclusion, the addition of 2.0 mm l ‐cysteine in extender improved the antioxidant enzymes profile, post‐thaw quality and in vivo fertility of Nili‐Ravi buffalo bull spermatozoa.     

Programmable fast‐freezing method improves the post‐thaw motion dynamics,integrities of plasmalemma,mitochondrial transmembrane,DNA and,acrosome, and in vivo fertility of water buffalo (Bubalus bubalis) spermatozoa

The effects of freezing methods (FR1, nonprogrammable/static, 5 cm above liquid nitrogen [LN₂] for 10 min, plunging in LN₂; FR2, programmable medium, +4°C to ?15°C at 3°C min^?1, from ?15 to ?80°C at 10°C min^?1 and final holding for 1 min at ?80°C, plunging in LN₂; FR3, programmable fast, from initial holding at +4°C for 2 min, from +4°C to ?20°C at 10°C min^?1, from ?20°C to ?100°C at 30°C min^?1, final holding for 1 min at ?100°C and plunging in LN₂) were assessed on post‐thaw in vitro quality and in vivo fertility of water buffalo spermatozoa. Mean sperm progressive motility (%), rapid velocity (%), average path velocity (μm s^?1), straight line velocity (μm s^?1), curved line velocity (μm s^?1), integrities (%) of plasmalemma, mitochondrial transmembrane, DNA and acrosome were higher (p < .05) in samples cryopreserved with FR3 compared to FR1 and FR2. Similarly, in vivo fertility (%) of buffalo spermatozoa was higher (p < .05) with FR3 than FR1 (%; 68.0 versus 50.0). We concluded that programmable fast‐freezing method (FR3) improves the post‐thaw in vitro quality and in vivo fertility of water buffalo spermatozoa.     

Effect of l‐arginine addition on long‐term storability of ram semen

This study was conducted to investigate the effect of l ‐arginine addition on long‐term storability of ram semen. Six Akkaraman rams were used as material. Semen samples were collected. Pooled samples were diluted and were divided into six equal aliquots. While aliquot 1 was kept as control, the stock solutions including 0.1, 0.5, 1, 5 and 10 mm l ‐arginine were added to other aliquots. All aliquots were routinely frozen in 0.25‐ml straws at ?130°C liquid nitrogen vapour and stored in liquid nitrogen ?196°C until being analysed. The equilibrated and thawed sperm motility, membrane integrity and arginase activity were evaluated. While the 10 mm l ‐arginine supplementation significantly (p < .001) decreased equilibrated sperm motility, the 5 mm significantly (p < .05) increased the membrane integrity and arginase activity in comparison with the control group. The motility (p < .001) and membrane integrity (p < .01) were determined to be highest in 0.5 mm group, while significant reductions were observed in motility (p < .001) of 10 mm group and arginase activity (p < .05) of 1, 10 mm groups as compared to the control group. It was concluded that in vitro addition of 0.5 mm l ‐arginine to ram semen may be useful, but 10 mm may be harmful to spermatozoa quality during long‐term storage.     

Cryoprotectant effect of trehalose in extender on post‐thaw quality and in vivo fertility of water buffalo (Bubalus bubalis) bull spermatozoa

This study was designed to ascertain the cryoprotectant effects of different concentrations of trehalose [0 (T0), 25 (T25), 35 (T35), 45 (T45) mm ], egg yolk [20% (E20), 15% (E15) v/v] and glycerol [7% (G7), 5% (G5) v/v] in Tris‐citric acid‐based extender on post‐thaw quality and in vivo fertility of buffalo bull spermatozoa. Twenty‐five ejaculates were collected from five bulls and split into four parts. After that, the split ejaculates from each of the bull were diluted either in T0E20G7 (control) or T25E20G5 or T35E15G5 or T45E15G5 extender. Finally, the sperm suspension was frozen in 0.54‐ml French straws. Post‐thaw sperm total motility (%), progressive motility (%), rapid velocity (%), average path velocity (μm/s), straightline velocity (μm/s), curvilinear velocity (μm/s), linearity (%), plasma membrane and acrosome integrities (%) were higher (p < .05) in T45E15G5 extender as compared to other treatment groups and control. The fertility rate (56.8% versus 41.3%) was higher (p < .05) in buffaloes inseminated with semen doses cryopreserved in extender containing T45E15G5 combination of cryoprotectants than the control. In conclusion, addition of 45 mm trehalose along with 15% egg yolk and 5% glycerol in extender improves the post‐thaw quality and in vivo fertility of buffalo bull spermatozoa.     

Isolation of bacteria in semen and evaluation of antibiotics in extender for cryopreservation of buffalo (Bubalus bubalis) bull spermatozoa

This study was designed to investigate the occurrence of bacterial species in water buffalo semen at the time of collection/processing and to assess the efficacy of some selected antibiotics (GTLS; gentamycin, tylosin and linco‐spectin or SP; streptomycin and penicillin) in cryodiluent on bacterial control and quality including in vivo fertility of buffalo spermatozoa. For this purpose, four experiments were conducted. In experiment 1, a total of 11 bacterial species were isolated from buffalo ejaculates. In experiment 2, total aerobic bacterial counts at post dilution and thawing were lower (P < 0.05) in GTLS than in SP or control. The majority of the bacterial isolates from ejaculates were more susceptible to GTLS than SP. In experiment 3, sperm acrosome integrity was higher (P < 0.05) in GTLS and SP compared to control. In experiment 4, the in vivo fertility results for GTLS were higher (P < 0.05) than that for SP. In conclusion, a number of bacterial species were isolated from the bubaline semen, which requires an efficient control before its use in artificial insemination program. The GTLS combination of antibiotics may be incorporated into a freezing extender/protocol without compromising the post‐thaw quality and in vivo fertility of buffalo bull spermatozoa.     

A new approach for cryoprotectant‐free freezing of goat epididymal spermatozoa

A cryoprotectant‐free method was successfully used for rapid freezing of goat epididymal spermatozoa. Lowering sperm volume may increase the temperature exchange rate and improve the freezing output of spermatozoa. The aim of this study was to compare two different packaging types [0.25 ml French straws (FS) and 96‐well immune plate (WIP)] for rapid freezing of goat epididymal spermatozoa. Eleven pairs of the goat testes were transferred to the laboratory; cauda epididymidides were dissected and sliced in TRIS‐BSA solution for 15 min and temperature 33–35 °C. Sperm concentration was adjusted to 20 × 10⁶ ml^?1, and the suspension was subjected to rapid freezing within FS or WIP. The volume of spermatozoa in WIP method was set at 25 μl. Sperm motility, viability and abnormalities, and sperm DNA integrity were compared between two devices. The results showed similar effectiveness of WIP and FS on post‐thaw sperm parameters. In conclusion, for cryoprotectant‐free rapid freezing of goat epididymal spermatozoa, it is recommended to use WIP instead of French 0.25 ml straws.     

Addition of pomegranate juice (Punica granatum) in tris‐based extender improves post‐thaw quality,motion dynamics and in vivo fertility of Nili Ravi buffalo (Bubalus bubalis) bull spermatozoa

The aim of the present study was to determine the protective effects of pomegranate juice in tris‐based extender on semen parameters, computer‐assisted sperm analysis (CASA) motion characteristics and field fertility of post‐thawed Nili Ravi buffalo (Bubalus bubalis) bull spermatozoa. Two consecutive ejaculates/collection from each of the five adult Nili Ravi buffalo bulls were collected with artificial vagina at 42°C for a period of 7 weeks, diluted in extender containing different concentrations of pomegranate juice (0.0%, 2.5%, 5%, 7.5% and 10%). Diluted samples were packed and frozen in 0.54 ml French straws. The addition of 10% pomegranate juice in extender significantly improved post‐thaw sperm morphology (%), motilities (CASA total motility, progressive motility (%) as well as VAP, VSL, VCL, STR, DAP, DSL) compared to the control group (p < 0.05). Plasma membrane, acrosome membrane and DNA integrity were significantly higher in extender with 10% pomegranate juice than the control group (p < 0.05). Field fertility rate (60.39% vs. 46.53%) was higher (p < 0.05) in extender with 10% pomegranate juice as compared to the control. It is therefore concluded that the addition of 10% pomegranate juice in tris‐based extender improves post‐thaw semen parameters, CASA motion dynamics and field fertility in Nili Ravi buffaloes.     

Antioxidant activity of Nigella sativa Seeds Aqueous Extract and its use for cryopreservation of buffalo spermatozoa

The free radical scavenging activity (RSA) of Nigella sativa extract and its efficiency for cryopreservation of buffalo spermatozoa was investigated. In experiment 1, Nigella sativa extract was prepared and evaluated for RSA using 2,2‐diphenyl‐1‐picrylhydrazyl assay. The results showed increased pattern of RSA at 1%–5% of Nigella sativa extract. In experiment 2, buffalo semen from three bulls (24 ejaculates) was incubated at 0%, 0.1%, 0.3%, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5% and 6% extract to assess in vitro tolerability to Nigella sativa in terms of progressive motility (PM). Buffalo spermatozoa showed tolerance to all levels; rather, sperm PM was increased at 1%–4% extract. In experiment 3, semen from three bulls (24 ejaculates) was cryopreserved with 0%, 1%, 2%, 3%, 4% and 5% of Nigella sativa extract. Sperm PM and plasma membrane integrity (PMI) were evaluated after dilution and cooling, while PM, PMI, viability and DNA integrity were evaluated after thawing. Nigella sativa extract at 4% in extender improved (p < .05) post‐dilution, post‐cooling and post‐thaw sperm quality. In conclusion, Nigella sativa extract at all concentrations (1%–6%) showed antioxidant activity and its supplementation at 4% in extender improved buffalo sperm quality at all stages of cryopreservation.     

Supplementing oregano essential oil to boar diet with strengthened fish oil: Effects on semen antioxidant status and semen quality parameters

Previous research has shown benefits of dietary fish oil supplementation on semen quality of boars. However, little is known about how antioxidant protects lipid peroxidation on spermatozoa from n‐3 polyunsaturated fatty acid (PUFA) addition. This study evaluated the effect of oregano essential oil (OEO) supplementation on semen antioxidant status and semen quality in boars fed a diet enriched with fish oil. Thirty‐four mature boars of proven fertility, received daily 2.5 kg basal diet top‐dressed with 45 g soybean oil and 15 g fish oil to meet the n‐3 PUFA requirement of spermatozoa, randomly allocated to one of four groups supplemented with 100 mg α‐tocopheryl acetate kg^?1 (control), or 250 or 500 or 750 mg OEO kg^?1 for 16 weeks. Semen was collected at weeks 0, 8, 12 and 16 for measurements of sperm production, motion characteristics, sperm α‐tocopherol content, antioxidant enzyme activities, reactive oxygen species (ROS), DNA damage (8‐hydroxydeoxyguanosine, 8‐OHdG), lipoperoxidation (malondialdehyde, MDA) and seminal total antioxidant capacity (TAC). Sperm production and motion characteristics were similar (p > .05) among groups throughout the experimental week 16, but increased (p < .01) with experimental week. Although higher α‐tocopherol content and superoxide dismutase (SOD) activities were in OEO group spermatozoa, feeding diet with 500 mg/kg OEO resulted in elevation in seminal TAC, decrease in sperm ROS, MDA and 8‐OHdG than control group (p < .05). Overall, these results support the view that oregano essential oil has a positive effect on antioxidant capacity in boar when used fish oil.     

Cryoprotective effect of l‐carnitine on motility,vitality and DNA oxidation of human spermatozoa

Successful cryopreservation for human spermatozoa markedly influences the reproductive outcomes of assisted reproductive technologies. But in spite of its usefulness, cryopreservation significantly decreases sperm quality. l ‐carnitine has been found to improve the quality of spermatozoa in selected cases with male infertility. Here, we examined the efficacy of l ‐carnitine in improving sperm motility and vitality and reducing sperm DNA oxidation during cryopreservation. Semen samples from infertile patients (n = 22) were collected and analysed. Cryopreservation medium supplemented with l ‐carnitine was mixed with the semen at a ratio of 1 : 1 (v/v). The final l ‐carnitine concentration in each cryovial was 0.5 mg ml^?1 per 5 × 10⁶ cell ml^?1. Controls were cryopreserved without addition of l ‐carnitine. After 24 h of cryopreservation, thawed sperm samples were analysed for motility, vitality and DNA oxidation. Sperm vitality was assessed by the eosin–nigrosin test, while sperm DNA oxidation was measured by flow cytometry. Addition of l ‐carnitine significantly improved sperm motility and vitality (P < 0.05) compared with the control. The flow cytometry experiment showed no statistical difference (P > 0.05) in the levels of DNA oxidation between samples and controls. In conclusion, l ‐carnitine improves human sperm motility and vitality, but has no effect on sperm DNA oxidation after cryopreservation.     

Lycopene and resveratrol improve post‐thaw bull sperm parameters: sperm motility,mitochondrial activity and DNA integrity

We focussed on evaluating the protective effect of lycopene and resveratrol on post‐thaw bull sperm and oxidative stress parameters. Nine ejaculates for each bull were used in the study. Each ejaculate, splitted into three equal aliquots and diluted at 37 °C with base extenders containing lycopene (1 × 10^?3 g ml^?1) and resveratrol (1 mm ), and no antioxidant (control), was cooled to 5 °C and then frozen. Frozen straws were thawed in a water bath for evaluation. The supplementation of the semen extender with lycopene and resveratrol increased the percentages of post‐thawed computer‐assisted sperm analysis (CASA) motility (55.8 ± 3.8 and 61.9 ± 4.0%) and progressive motility (38 ± 2.4 and 37 ± 8.8), compared with the controls (50.7 ± 2.65 and 33.3 ± 3.74%, respectively, P < 0.05). Resveratrol provided a higher ALH (4.3 ± 0.1), in comparison with the control (3.9 ± 0.3, P < 0.05). The supplementation of the semen extender with lycopene and resveratrol produced a higher mitochondrial activity (24.6 ± 2.9 and 30.1 ± 6.5% respectively), compared with that of the control (11.8 ± 9.5%, P < 0.05). It was determined that both antioxidants resulted in a lower percentage of sperm with damaged DNA than that of the control (P < 0.05). Sperm motion characteristics except for ALH, acrosome integrity, sperm viability and oxidative stress parameters were not affected by the adding of lycopene and resveratrol.     

Cumene hydroperoxide induced changes in oxidation–reduction potential in fresh and frozen seminal ejaculates

Oxidation–reduction potential (ORP) is a newer integrated measure of the balance between total oxidants (reactive oxygen species—ROS) and reductants (antioxidants) that reflects oxidative stress in a biological system. This study measures ORP and evaluates the effect of exogenous induction of oxidative stress by cumene hydroperoxide (CH) on ORP in fresh and frozen semen using the MiOXSYS Analyzer. Semen samples from healthy donors (n = 20) were collected and evaluated for sperm parameters. All samples were then flash‐frozen at ?80°C. Oxidative stress was induced by CH (5 and 50 μmoles/ml). Static ORP (sORP—(mV/10⁶ sperm/ml) and capacity ORP (cORP—μC/10⁶ sperm/ml) were measured in all samples before and after freezing. All values are reported as mean ± SEM. Both 5 and 50 μmoles/ml of CH resulted in a significant decline in per cent motility compared to control in pre‐freeze semen samples. The increase in both pre‐freeze and post‐thaw semen samples for sORP was higher in the controls than with 50 μmoles/ml of CH. The change from pre‐freeze to post‐thaw cORP was comparable. The system is a simple, sensitive and portable tool to measure the seminal ORP and its dynamic impact on sperm parameters in both fresh and frozen semen specimens.     

Improvement in sperm functional competence through modified low‐dose packaging in French mini straws of bull semen

To achieve the targeted artificial insemination coverage with the current rate of semen production, without affecting the conception rate, it needs to reduce the number of spermatozoa per insemination dose in India as per international practice. Therefore, this study was planned to perform different levels of semen dilution, compare in vitro post‐thaw semen quality and develop a modified low‐dose semen packaging method in French mini straw to minimise semen dilution effect. Sixteen ejaculates were collected from Karan Fries bulls (n = 4). The mean percentage post‐thaw motility, viability, membrane integrity, acrosome integrity, lipid peroxidation and capacitation status were estimated as post‐thaw sperm function assays in semen sample diluted to 20, 15, 10 and 5 million spermatozoa per 0.25 ml and filled in the French mini straw by conventional packaging. No significant (p > .05) difference in post‐thaw sperm quality was observed between 15 and 20 million doses; however, below 15 million sperm quality get reduced. There was no significant difference in post‐thaw semen quality traits between 20 million conventional packaging and 5 million spermatozoa/dose in modified packaging. In conclusions, the modified packaging is a very effective method for low‐dose cryopreservation with acceptable post‐thaw semen quality.     

Proper ubiquitination effect on the fertilisation outcome post‐ICSI

Ubiquitin is an 8.5‐kDa protein that tags outlived proteins for degradation by the proteasome. It also marks defective spermatozoa during epididymal passage and has been proposed as a biomarker of sperm quality. This study evaluates the relationship between sperm ubiquitination, protamine deficiency, semen parameters and fertilisation rate in infertile individuals undergoing the intracytoplasmic sperm insemination (ICSI) procedure. Semen samples from 73 ICSI candidates were collected and analysed according to World Health Organization criteria. A portion of each sample was evaluated for sperm ubiquitination using the sperm ubiquitin tag immunoassay (SUTI) with flow cytometry, and protamine deficiency by chromomycin A3 (CMA3) staining. In addition, the relationship between the fertilisation rate and sperm ubiquitination was calculated in ICSI candidates. The intensity of ubiquitination showed a significant negative correlation with sperm concentration (r = ?0.255, P = 0.032) and a positive correlation with fertilisation rate (r = 0.384, P = 0.013) post‐ICSI. No correlation was observed between protamine deficiency and the percentage of ubiquitination or ubiquitination intensity. The results of this study suggest that sperm ubiquitination prior to capacitation may be considered as a marker of defective spermatozoon. Spermatozoa that undergo proper ubiquitination may have a higher chance for fertilisation, because they are made redundant by the ubiquitin–proteasome pathway in the epididymis compared to hypo‐ubiquitinated spermatozoa.     

Utilisation of sperm‐binding assay combined with computer‐assisted sperm analysis to evaluate frozen‐thawed bull semen

Due to homologies between the chicken egg perivitelline membrane with mammalian zona pellucida proteins, spermatozoa of several species are able to bind to this membrane. However, adequate standardisation is required to attest possible applications of this technique for semen evaluation of a given species. Therefore, we thawed and divided cryopreserved semen samples into two aliquotes, one kept in water bath at 37 °C (thawed) and the other submitted to snap‐freezing to damage sperm cells (dead spermatozoa). Aliquotes were mixed into different ratios of thawed:dead cells and analysed for motility, membrane and acrosomal integrity, and mitochondrial activity. In parallel, chicken egg perivitelline membranes were inseminated with these ratios, and the number of spermatozoa bound per mm² of membrane was assessed by conventional microscopy (CM) and computer‐assisted sperm analysis (CASA). Linear regression showed high correlation between thawed:dead sperm ratio and number of spermatozoa bound to the membrane (CM: r² = 0.91 and CASA: r² = 0.92 respectively). Additionally, positive correlations were found between the number of spermatozoa bound to the membrane and acrosomal integrity, membrane integrity, mitochondrial activity and motility. These findings indicate that sperm‐egg‐binding assay associated with CASA is a reliable, practical and inexpensive method for examining the fertilising capacity of cryopreserved bull semen.     

Comparison of Tris egg yolk‐based,Triladyl® and Optixell® extender on post‐thaw quality,Kinematics and in vivo fertility of Nili Ravi Buffalo (Bubalus bubalis) bull spermatozoa

Our objectives were to ascertain the comparison of Tris egg yolk‐based, Triladyl ^® and Optixell ^® extender on postthaw quality, CASA parameters and in vivo fertility of Nili Ravi buffalo (Bubalus bubalis) bull spermatozoa. Semen samples (n = 35) from five bulls were diluted in Tris egg yolk‐based, Triladyl ^® , Optixell ^® extender and frozen in 0.50 ml French straws. Postthaw sperm CASA motility (%) was higher (p < 0.05) in Optixell extender as compared to Triladyl and Tris egg yolk‐based extender. Although sperm progressive motility (%), morphology (%), average path velocity (μm/s), straight line velocity (μm/s), curvilinear velocity (μm/s), amplitude of lateral head displacement (μm), beat cross‐frequency (Hz), straightness (%), length of curvilinear path (μm), length of average path (μm), intact plasma and acrosome membrane (%), and DNA integrity (%) were higher (p < 0.05) in spermatozoa cryopreserved in Optixell ^® extender as compared to Tris egg yolk‐based and Triladyl ^® extender. The fertility rates (68.18%, 45.45%, 55.4%) were higher (p < 0.05) in buffaloes inseminated with semen doses frozen in Optixell extender than the Tris egg yolk‐based and Triladyl ^® extender respectively. It is concluded that Optixell ^® extender improves postthaw semen quality and fertility in Nili Ravi buffaloes.     

Study on correlation of sperm quality parameters with antioxidant and oxidant status of buffalo bull semen during various stages of cryopreservation

This investigation was carried out to study the correlation of sperm quality parameters with antioxidant and oxidant status of buffalo bull semen during various stages of cryopreservation. Semen samples were evaluated for sperm parameters (mass motility [MM], concentration [CON], progressive motility [PM], viability [VIB], acrosomal integrity [AI] and hypo‐osmotic swelling [HOS] response), antioxidants (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx] and total antioxidant capacity [TAC]) and oxidants (Lipid peroxidation [LPO] and reactive oxygen species [ROS]) at fresh, pre‐freeze and post‐thaw stages. Sperm parameters (PM, VIB, AI and HOS response) and antioxidants (SOD, CAT and TAC) were significantly (p < .05) reduced at fresh stage, and oxidants (LPO and ROS) were significantly (p < .05) increased at pre‐freeze and post‐thaw stages. At fresh stage, MM was negatively correlated with LPO (p < .05), and CON was positively correlated with SOD, TAC and CAT, negatively correlated with LPO and CAT was positively (p < .01) correlated with VIB and HOS response. At pre‐freeze stage, CAT was positively correlated with PM and AI (p < .05), and AI was negatively (p < .05) correlated with ROS. At post‐thaw stage, CAT was positively correlated with PM, VIB, HOS response and AI,, and LPO was negatively correlated with HOS, AI and VIB. The study of correlations of these parameters at different preservation stages with bull fertility may play an important role in developing models for predicting future fertility of bulls in the absence of conception rate data.     

DNA hydroxymethylation rate in the AChE and HoxC4 promoter associated with human sperm quality

The relationship of altered DNA 5′‐hydroxymethylation in human spermatozoa with seminal parameters remains unclear. The aim of the study was to investigate the association between the 5′‐hydroxymethylcytosine (5hmC) rate in the promoters of acetylcholinesterase (AChE) and homeobox C4 (HoxC4) genes and human sperm concentration/motility. The study population consisted of three groups: asthenozoospermia (AZ), oligoasthenozoospermia (OAZ) and normozoospermia (NZ). The 5hmC rate in the promoter was measured by CCGG loci‐dependent MspI/HpaII restriction mapping of glycosylation‐modified sperm DNA combined with a hydroxymethylation‐specific real‐time polymerase chain reaction assay. The 5hmC rate in the AChE promoter in group AZ and OAZ was higher than that in group NZ (p < .05). A weak inverse correlation between 5hmC rate of AChE and sperm motility was observed in all subjects (r = ?.172, p < .05). The 5hmC rate in the HoxC4 promoter in group OAZ was lower than that in group NZ (p < .05). These results indicated that altered 5hmC rates of AChE and HoxC4 promoters are associated with low sperm motility and sperm concentration respectively.     

Saturated,omega‐6 and omega‐3 dietary fatty acid effects on the characteristics of fresh,frozen–thawed semen and blood parameters in rams

The aim of this study was to investigate the effects of several dietary fatty acids (FAs) on semen quality and blood parameters in rams. We gave diet‐supplemented treatments (35 g day^?1 ram^?1) by C16:0 (palm oil), C18:2 [sunflower oil (SO)] and an n‐3 source [fish oil (FO)] to 12 rams, who were fed for 15 weeks during their breeding season. Semen was collected once per week. Semen samples were extended with Tris‐based cryoprotective diluents, then cooled to 5 °C and stored in liquid nitrogen. Positive responses were seen with FO after 4 weeks. The mean prefreezing semen characteristics improved with the intake of FO (P < 0.05). Interestingly, maximum sperm output in FO was achieved 7.5 × 10⁹ when compared to palm oil 5.3 × 10⁹. Rams that received FO had the highest total testosterone concentrations (11.3 ng ml^?1 for FO, 10.8 ng ml^?1 for SO and 10.2 ng ml^?1 for palm oil) during the experiment (P < 0.05). FO also improved the rams' sperm characteristics after thawing (P < 0.05). Although C16:0 is a major saturated FA in ram sperm and all rams have been fed isoenergetic rations, the unique FAs of FO improved fresh semen quality and freezing ability compared to other oils.     

Dynamics of anti‐human leukocyte antigen antibodies after renal transplantation and their impact on graft outcome

The purpose of this study was to sequentially monitor anti‐HLA antibodies and correlate the results with antibody‐mediated rejection (AMR), graft survival (GS), and graft function (GF). We collected sera from 111 kidney transplant recipients on transplant days 0, 7, 14, 30, 60, 90, 180, and 360 and analyzed PRA levels by ELISA. DSAs were analyzed by single‐antigen beads in rejecting kidneys. At pre‐transplant, 79.3% of the patients were non‐sensitized (PRA = 0%) and 20.7% were sensitized (PRA > 1%). After transplant, patients were grouped by PRA profile: no anti‐HLA antibodies pre‐ or post‐transplant (group HLApre?/post?; n = 80); de novo anti‐HLA antibodies post‐transplant (group HLApre?/post+; n = 8); sensitized pre‐transplant/increased PRA post‐transplant (group HLApre+/post↑; n = 9); and sensitized pre‐transplant/decreased PRA post‐transplant (group HLApre+/post↓; n = 14). De novo anti‐HLA antibodies were detected at 7–180 d. In sensitized patients, PRA levels changed within the first 30 d post‐transplant. Incidence of AMR was higher in HLApre?/post+ and HLApre+/post↑ than in HLApre?/post?, and HLApre+/post↓ (p < 0.001) groups. One‐yr death‐censored GS was 36% in group HLApre+/post↑, compared with 98%, 88% and 100% in groups HLApre?/post?, HLApre?/post+, and HLApre+/post↓, respectively (p < 0.001). Excluding first‐year graft losses, GF and GS were similar among the groups. In conclusion, post‐transplant antibody monitoring can identify recipients at higher risk of AMR.