Osmolality and composition of the extender during the cold storage of Prochilodus lineatus (Characiformes: Prochilodontidae) sperm

This study evaluates the effects of extender osmolality and composition on the cooling of Prochilodus lineatus sperm. Sperm was diluted in six extenders: two compositions (powdered coconut water(tm) = ACP; Beltsville Thawing Solution(tm) = BTS) x three osmolalities (285, 325, and 365 mOsm/kg) plus an undiluted control, and stored at 6-8°C. Motility rate and velocities (curvilinear, straight line, and average path) were determined every other day. Osmolality did not affect the quality of cooled sperm, thus data were pooled. Motility was higher on d 0 compared to the other days and diluted samples (85-90%) yielded higher motility than control (75%). On d 2, motility was higher in BTS-diluted samples and control, but on d 4 and 6, control yielded the highest motility. Velocities decreased from d 0 to 6 in diluted samples, but not in control. On d 0, velocities were higher in BTS-diluted sperm, but, on d 2, 4, and 6, control yielded higher velocities despite of the large variation among males. Thus P. lineatus sperm should be stored in BTS or without dilution, for a maximum of two days at 6-8°C. Extender osmolality between 285 and 365 mOsm/kg does not affect sperm quality during cold storage...

Neste trabalho avaliou-se os efeitos da osmolalidade e da composição do diluidor no sêmen de Prochilodus lineatus, após o resfriamento. O sêmen foi diluído em seis diluidores: duas composições (água de coco em pó(r) = ACP; Beltsville Thawing Solution(r) = BTS) x três osmolalidades (285, 325 e 365 mOsm/kg) mais uma alíquota sem diluição como controle e armazenadas a 6-8°C. A taxa de motilidade e velocidades (curvilinear, retilinear e média de percurso) foram determinadas a cada dois dias. A osmolalidade não afetou a qualidade do sêmen resfriado, dessa forma foi feito um 'pool' desses dados. A motilidade foi maior no d 0 comparado aos outros dias e as amostras diluídas (85-90%) apresentaram as maiores motilidades do que o controle (75%). No d 2, a motilidade foi maior nas amostras diluídas em BTS e controle, mas nos d 4 e 6, o sêmen controle apresentou as maiores motilidades. As velocidades diminuíram do d 0 para o d 6 nas amostras diluídas, mas não no controle. No d 0, as velocidades foram maiores nas amostras diluídas em BTS, mas, nos d 2, 4 e 6, o controle apresentou as maiores velocidades apesar da grande variação entre os machos. Assim, o sêmen de P. lineatus deve ser resfriado em BTS ou sem diluição (controle), por no máximo dois dias a 6-8°C. A osmolalidade do diluidor entre 285 e 365 mOsm/kg não afeta a qualidade do sêmen durante o resfriamento...

Initiation and s uppression of sperm motility is osmolality dependent in two South American fish species: streaked prochilod (Prochilodus lineatus) and piracanjuba(Brycon orbignyanus)

Solutions to induce or suppress the initiation of sperm motility in fish ha ve been used to improve reproductive success during artificial fertilization and preservation techniques . The aim of the present study was to evaluate the effects of three solutions (NaCl, glucose , and BTS™) - each prepared with 10 different osmolalities - on the initiation and suppression of fresh sperm motility in Prochilodus lineat us and Brycon orbignyanus . Sperm was diluted in each of the 30 solution s and immediately observed under a light microscope to determine which solution s trigger ed or suppress ed the initiation of sperm motility. When present, motility rate ( % motile sperm ) w as determined at 0, 30 , and 120 s post - activation and the motility quality score ranging from 0 ( no movement ) to 5 ( rapidly swimming sperm) was determined at 0 and 30 s post - activation . Osmolality , but not solution composition , significantly affected both motility rate and quality score . Solutions at osmolali ties up to 270 mOsm/kg in P. lineatus and up to 180 mOsm/kg in B. orbignyanus induced motility in at least 60% of sperm , with a minimum quality score of 3.0 , and were therefore classified as activating agents. The greatest motility at 0 , 30 , and 120 s post - activation was observed with solutions ranging from 135 to 225 mOsm/kg for P. lineatus and at 135 mOsm/kg for B. orbignyanus . On the other hand, solutions ranging from 360 to 450 mOsm/kg in P. lineatus and 270 to 450 mOsm/kg in B. orbignyanus suppressed motility in at least 95% of sperm and were classified as immobilizing media . The osmolality of the surrounding medium is the key factor in the initiation or suppression of sperm motility in P. lineatus a nd B. orbignyanu.

Mitochondrial DNA mutations and male infertility.

Infertility can be defined as difficulty in conceiving a child after 1 year of unprotected intercourse. Infertility can arise either because of the male factor or female factor or both. According to the current estimates, 15% of couples attempting their first pregnancy could not succeed. Infertility is either primary or secondary. Mitochondria have profound effect on all biochemical pathways, including the one that drivessperm motility. Sperm motility is heavily dependent on the ATP generated by oxidative phosphorylation in the mitochondrial sheath. In this review, the very positive role of mitochondrial genome's association with infertility is discussed