Semen analysis and induction of acrosome reaction in spermatozoa of Tana mangabey (cercocebusgaleritus) and de brazza’s (cercopilhecus monkeys

Abstract

Semen from Tana Mangabeys (Cercocebus galeritus n=4) and De Brazza's monkeys (Cercopithecus neglects, n=3) was evaluated for routine parameters to establish fertility potential following electro-ejaculation. The correlations of semen parameters were analysed. Acrosomal status of sperm obtained from Mangabeys was monitored following challenge with dbcAMP and calcium ionophore A23187 in vitro by Fluorescein labeled Pissum sativum agglutinin (FITC-PSA) assay. The proportion of spermatozoa undergoing spontaneous and artificially induced acrosome reaction (AR) were compared. Twenty-six out of 33 (78.7%) attempts in Mangabeys and 17/26 (65.3%) in De Brazza’s monkeys produced ejaculates. Semen pH ranged from 8.0 to 9.0. Among Tana Mangabeys, the mean ± s.e.m percentage rapid progressive sperm motility was 65 ± 3, slow progressive motility was 13.5% ± 8.6%, non-progressive motility was 10.2% ± 1.2% while nonmotile sperm was 10.2% ± 0.6%. Respective grades of sperm motility were 50% ± 2%, 11.5% ± 1.7%, 14.2% ± 1.3% and 23.2% ±2.6% in De Brazza’s monkeys. The mean ± s.e.m ejaculate volume was 57.4 ± 6.8 pi in Mangabeys showing a correlation {r= 0.94 (P< 0.05)} with semen weight. The mean ± s.e.m ejaculate volume in De Brazza semen was 39.2 ± 3.6 pi. There was a correlation (r= 0.96) between weight of ejaculate and volume of its liquefied fraction among De Brazza’s monkeys. The weight of liquefied semen fraction showed a correlation (r= 0.87) to its volume and a correlation (r=0.92) to the weight of fresh ejaculate in De Brazza’s monkeys. The mean (Mean±SE) sperm concentration (1989 ± 200) xlO6 per ml in Mangabeys was significantly different (P <0.01) from (64.1± 12) xlO6 per ml recorded in De Brazza. There was no correlation {r= 0.067, (P=0.7)} between sperm concentration and volume in Mangabeys. Mean sperm abnormality was 29% in De Brazza’s monkeys compared to 16.2% in Mangabeys while abnormal sperm heads occured at rates of 10.1% compared to 4.5% respectively. Three fluorescence patterns were observed namely; Pattern IA (intact Acrosome), with fluorescence uniformly distributed over the anterior 2/3 of the sperm head. Pattern PA (patchy acrosome), with fluorescence as above, but in a patchy manner and Pattern AR (acrosome reacted), with a flourescence band across the sperm head along the cquitorial segment after staining with F1TC-PSA. The mean percentage of sperm with pattern IA at time, t = 0 minutes to time t = 150 minutes, decreased from 99% to 67.1% in control compared with 100% to 34% in experimental tubes while pattern PA increased from 1% to 19.4% in control compared with 0% to 29% in experimental. Mean percentage of pattern AR sperm increased from 0 % to 13.4% in control compared with 0% to 37% in experimental. Significant differences (P<0.05) between control and experimental tubes for the three sperm patterns where noticed throughout except at time, t = 120 minutes, where (P=0.0504). The highest inducible AR in sperm was 37%. This study showed that; i) Rectal probe electro-ejaculation can retrieve semen from the two species of monkeys although the volumes recovered were too low. Semen recovered from De Brazza’s monkeys showed poor parameters which may explain their low fertility. Very high sperm concentration from Mangabeys reveals high spermatogenetic potential. ii) The fluorescent isothiocynate labelled lectin, Pissum sativum agglutinin (FITC- PSA) which is specific for sperm head glyco-conjugates can be used to study time course acrosomal loss in Mangabey sperm. iii) Dibutyrly cAMP/CaIA23187 reagent mixture induces a higher proportion of acrosome reaction in sperm compared with the spontaneous reaction.