Predicting the mating system from phenotypic correlations between life-history and sperm quality traits in the Alpine whitefish Coregonus zugensis

The mating behavior and reproductive strategies of Alpine whitefish like Coregonus zugensis (Nusslin) are poorly understood, probably because they spawn in deep water where direct observations are difficult. In this study, we interpret life-history and sperm quality traits of fish that we caught from their spawning place. We found that males invest heavily into gonadal tissue (up to 5.6% of their body weight), which is, in comparison to other fish, consistent with external fertilization, distinct pairing and moderate to high communal spawning, or no pairing and low to moderate communal spawning. Sperm competition theory and recent experimental studies on other salmonids predict that males optimize ejaculate characteristics in relation to the costs of sperm and the level of competition they have to expect: dominant males are predicted to invest less into ejaculate quality and to have slower spermatozoa than subdominant males. We found that spermatozoa of older males are slower than those of younger males. Moreover, older males have larger breeding tubercles, a secondary sexual trait that has, in some previous studies, been found to be linked to good condition and to good genetic quality. Our results suggest that C. zugensis has age-linked reproductive strategies, that multimale spawning is common, i.e., that sperm competition plays a significant role, and that older males are on average dominant over younger males at the spawning place.

The relationships between scrotal surface temperature, age and sperm quality in stallions

In horses, spermatogenesis normally occurs at an average intratesticular temperature of 35. °C; therefore, mechanisms for testicular thermoregulation are essential. Measuring the scrotal surface temperature by thermography is one of the methodologies used to evaluate the effectiveness of testicular thermoregulation. The objective of this study was to determine the relationship between the control of scrotal surface temperature and sperm quality in horses of different ages. In total, 24 Quarter Horse stallions were divided into three groups: YS (young stallions), AS (adult stallions) and OS (old stallions). Initially, we calculated the testicular volume (TV) and evaluated various aspects of the semen (sperm kinetics, plasma membrane integrity and sperm morphology) for all the animals. We also evaluated rectal temperature (RT), body surface temperature (BST,) and average scrotal surface temperature in the testicular region (SST) before (M0) and after sun exposure (M1). Differences were observed (p<0.05) between the RT and BST before and after sun exposure in all three groups. However, there were no differences (p>0.05) in the SST values at these two time points, thus demonstrating the efficiency of the mechanisms for testicular thermoregulation. The SST was similar (p>0.05) among all three groups. Based on these results, we conclude that fertile stallions of different age groups are able to maintain SST and measuring the heat radiating from the scrotum using a digital infrared thermographer. We can also conclude that measuring the heat radiating from the scrotum using a digital infrared thermographer is a practical and efficient tool for monitoring SST in horses. © 2013 Elsevier B.V.

Inappropriate management conditions, especially for the regressed class, are related to sperm quality in Prochilodus lineatus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Absence of effects on the rat sperm quality after subacute exposure to low doses of fungicide prochloraz

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Modulatory activity of antioxidants against the toxicity of Rifampicin in vivo

The World Health Organization (WHO) has shown concern about the burden of tuberculosis in the developing countries. Even though rifampicin is an effective drug in the management of tuberculosis, it has been documented to have some toxic effects in humans. Therefore, this study intends to investigate the modulatory effect of vitamins C and E on the hepatotoxicity, sperm quality and brain toxicity of Rifampicin. Forty Wistar albino rats were used, 10 animals per group. Group 1 animals received 0.3 mL of distilled water, the Group 2 animals received the therapeutic dose of rifampicin, Group 3 animals received therapeutic doses of rifampicin plus vitamin E, while Group 4 received therapeutic doses of rifampicin and vitamin C. The administration was performed orally during three months; the animals were sacrificed by cervical dislocation at the end of that period. Blood samples were collected and liver function and lipid profile was analyzed using fully automated clinical chemistry device. The liver, brain and reproductive organs underwent histopathological examination. Sperm samples were collected from the epididymis to achieve count and motility and morphological analysis. Results showed rifampicin alone to raise (p < 0.05) liver function enzymes (Aspartate amino transferase [AST], Serum alanine amino transferase [ALT] and Total Bilirubin) when compared with controls. While the vitamin E treated group showed remarkable protection, the vitamin C treated group showed questionable protection against the rifampicin induced liver damage. Sperm count results showed an important (p < 0.05) increase in the sperm quality in vitamin E and C treated groups. However, the vitamin E plus Rifampicin treated group showed increased lipid peroxidation. The histopathological findings revealed structural damages by rifampicin in liver, brain and epididymis while some remarkable architectural integrity was observed in the antioxidant-treated groups. It can be concluded that vitamin E or C improved sperm quality and protected against the brain damage caused by rifampicin. Moreover, vitamin E demonstrated remarkable hepatoprotection against rifampicin induced damage while vitamin C shows a questionable hepatoprotection.

Relationship between first polar body morphology before intracytoplasmic sperm injection and fertilization rate, cleavage rate, and embryo quality

Objectives: To evaluate the influence of the morphology of the first polar body (PB) on intracytoplasmic sperm injection (ICSI) outcomes. Methods: The morphology of the first PB was assessed in 3177 metaphase 11 oocytes and classified as: intact and normal size, fragmented, or enlarged size. The rates of fertilization, cleavage, and embryo quality were evaluated on day 2. Results: The rates of fertilization, cleavage, and formation of good quality embryos resulting from the insemination of oocytes with an enlarged first PB (20.7%, 18.7%, and 5.0%, respectively) were significantly lower than those for oocytes with an intact first PB of normal size (70.8%, 62.5%, and 19%, respectively) or a fragmented first PB (69.7%, 60.5%, and 17.1%, respectively). Rates did not differ significantly between oocytes with an intact first PB of normal size and oocytes with a fragmented first PB (P>0.05). Conclusions: The presence of an enlarged PB is related to poorer rates of fertilization, cleavage, and top quality embryos. However, identification of first PB fragmentation does not seem to interfere with ICSI outcomes. (C) 2008 International Federation ofGynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Testicular thermoregulation in Bos indicus, crossbred and Bos taurus bulls: relationship with scrotal, testicular vascular cone and testicular morphology, and effects on semen quality and sperm production

Mechanisms of testicular thermoregulation, the relationship of scrotal, testicular vascular cone (TVC), and testicular morphology with thermoregulatory capability, and their effects on semen quality and sperm production were studied in 20 Bos indicus, 28 crossbred, and 26 Bos taurus bulls. The ratio of testicular artery length and volume to testicular volume were larger (P < 0.05) in B. indicus and crossbred bulls than in B. taurus bulls (1.03 and 0.94 cm/cm(2). versus 0.48 cm/cm(3); 0.034 and 0.047 ml/cm(3) versus 0.017 ml/cm(3), respectively). Testicular artery wall thickness (average 192.5, 229.0, and 290.0 mum, respectively) and arterial-venous blood distance in the TVC (average 330.5, 373.7, and 609.4 pm, respectively) were smallest in B. indicus, intermediary in crossbred, and greatest in B. taurus bulls (P < 0.05); the proximity between arterial and venous blood was consistent with the estimated decrease in arterial blood temperature after passage through the TVC (5.9, 5.0, and 2.9 degreesC, in B. indicus, crossbred, and B. taurus bulls, respectively). In crossbred and B. taurus bulls, there was a positive top-to-bottom scrotal temperature gradient and a negative testicular subtunic temperature gradient. However, in B. indicus bulls, both scrotal and testicular subtunic temperatures gradients were positive. Differences in the vascular arrangement, characteristics of the artery (e.g. wall thickness) or thickness of the tunica albuginea may have affected the testicular arterial blood and subtunic temperatures in B. indicus bulls. Better testicular thermoregulatory capability was associated with increased scrotal shape (pendulosity), testicular artery length and volume, and top-to-bottom gradient of the distance between the artery wall and the veins in the TVC. Increased semen quality was associated with increased testicular volume and scrotal subcutaneous (SQT) temperature gradient, and with decreased scrotal surface and testicular temperatures. Increased sperm production was associated with increased testicular artery volume, testicular volume, and SQT temperature gradient, and with decreased testicular artery wall thickness, scrotal circumference (SC), and scrotal surface, testicular subtunic, and epididymal temperatures. In conclusion, morphology of the TVC may contribute to the greater resistance of B. indicus bulls to high ambient temperatures by conferring a better testicular blood supply and by facilitating heat transfer between the testicular artery and veins. Testicular thermoregulation was associated with opposing scrotal and testicular subtunic temperatures gradients only in crossbred and B. taurus bulls. Scrotal, TVC, and testicular morphology influence testicular thermoregulatory capability and were associated with differences in semen quality and sperm production. (C) 2003 Elsevier B.V. All rights reserved.

Effect of age and genetic group on characteristics of the scrotum, testes and testicular vascular cones, and on sperm production and semen quality in AI bulls in Brazil

The objectives were to determine the effects of age and genetic group on characteristics of the scrotum, testes and testicular vascular cones (TVC), and on sperm production and semen quality in 107 Bos indicus, B, taurus and cross-bred bulls at three artificial insemination (AI) centers in Brazil. In addition, predictors of sperm production and semen quality were identified. In general, scrotal circumference (SC), scrotal shape score, scrotal neck perimeter, and testicular size (length, width and volume) increased (P < 0.05) with age. Although there were no significant differences among genetic groups for SC or testicular size, B. indicus bulls had the least pendulous scrotal shape, the shortest scrotal neck length, and the greatest scrotal neck perimeter (P < 0.05). Fat covering the TVC was thinner (P < 0.05) in bulls <= 36 months of age and in B. taunts bulls than in older bulls and B. indicus bulls, respectively. Age and genetic group did not affect testicular ultrasonic echotexture. B. indicus bulls tended (P < 0.1) to have the lowest average scrotal surface temperature (SST). In general, ejaculate volume, total number of spermatozoa and number of viable spermatozoa increased (P < 0.05) with age. However, there was no significant effect of age on sperm concentration, motility, major and total defects. The proportion of spermatozoa with minor defects was highest (P < 0.05) in bulls 37-60 months of age. B. indicus bulls had higher (P < 0.01) sperm concentration, total number of spermatozoa and number of viable spermatozoa than B. taunts bulls, with intermediate values for cross-bred bulls. Increased sperm production was associated with increased testicular volume, SC, TVC fat cover, and SST top-to-bottom gradient. Decreased semen quality was associated with increased SC and bottom SST, and decreased scrotal shape, scrotal neck perimeter and vascular cone diameter. In summary, age and genetic group affected the characteristics of the scrotum, testes, and TVC, sperm production and semen quality. In addition, characteristics of the scrotum, testes and TVC were associated with sperm production and semen quality in bulls and could be assessed for breeding soundness evaluation. (c) 2002 Elsevier B.V. All rights reserved.

Effects of environmental factors, age and genotype on sperm production and semen quality in Bos indicus and Bos taurus AI bulls in Brazil

The effects of ambient temperature and humidity, month, age and genotype on sperm production and semen quality in AI bulls in Brazil were evaluated. Data from two consecutive years were analyzed separately. Seven Bos indicus and 11 Bos taurus bulls from one artificial insemination (AI) center were evaluated in Year 1 and 24 B. indicus and 16 B. taurus bulls from three AI centers were evaluated in Year 2. Ambient temperature and humidity did not significantly affect sperm production and semen quality, probably because there was little variation in these variables. Month accounted for less than 2% of the variation in sperm production and semen quality. Increased bull age was associated with decreased sperm motility (P < 0.10) and increased minor sperm defects (P < 0.001) in Year 1. B. indicus bulls had greater (P < 0.005) sperm concentration than B. taurus bulls in both years (1.7 x 10(9)/ml versus 1.2 x 10(9)/ml in Year 1 and 1.6 x 10(9)/ml versus 1.2 x 10(9)/ml in Year 2, respectively). Ejaculate volume was not significantly affected by genotype in Year 1 (6.6 ml versus 6.9 ml in B. indicus and B. taurus bulls, respectively), but B. indicus bulls had greater (P < 0.05) total (11.4 x 10(9) versus 8.2 x 10(9)) and viable (6.7 x 10(9) versus 4.9 x 10(9)) numbers of spermatozoa in the ejaculate than B. taurus bulls. In Year 2, B. taurus bulls had greater (P < 0.05) ejaculate volume than B. indicus bulls (8.2 ml versus 6.7 ml, respectively) and total and viable number of spermatozoa in the ejaculate were not significantly different between genotypes (10.3 x 10(9) versus 9.1 x 10(9) and 6.1 x 10(9) versus 5.4 x 10(9) in B. indicus and B. taurus bulls, respectively). Sperm motility was not significantly affected by genotype (mean, 59%). In Year 1, B. indicus bulls tended (P < 0.10) to have more major sperm defects and had more (P < 0.05) total sperm defects than B. taurus bulls (11.8% versus 8.7% and 13.6% versus 10.0%, respectively). In Year 2, B. indicus bulls tended (P < 0.10) to have more total sperm defects than B. taurus bulls (16.2% versus 13.3%, respectively). In conclusion, neither ambient temperature and humidity nor month (season) significantly affected sperm production and semen quality. B. indicus bulls had significantly greater sperm concentration and B. taurus bulls had significantly fewer morphologically defective spermatozoa. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Impairment on sperm quality and fertility of adult rats after antiandrogen exposure during prepuberty

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

SPERM QUALITY IN ADULT MALE RATS EXPOSED TO CADMIUM IN UTERO and LACTATION

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Slimmer or Fertile? Pharmacological Mechanisms Involved in Reduced Sperm Quality and Fertility in Rats Exposed to the Anorexigen Sibutramine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of sperm quality in successive regular collections from captive black-and-gold howler monkeys (Alouatta caraya)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)