Fases do desenvolvimento e diferenciação testicular em cutias (Dasyprocta aguti) criadas em cativeiros

A cutia (Dasyprocta aguti) é um roedor silvestre encontrado amplamente na região Nordeste do Brasil. É uma espécie muito utilizada pela população humana de baixa renda como fonte alternativa de proteína na alimentação. Foram utilizadas 31 cutias, machos, provenientes da Universidade Federal do Piauí (FUFPI), Estado do Piauí e da Escola Superior de Agricultura de Mossoró Estado do Rio Grande do Norte. Os animais foram divididos em grupos etários desde o nascimento até os 14 meses de idade. O diâmetro nuclear médio foi obtido pela medida de 10 núcleos do tipo celular estudado em cada testículo, no estágio 1 do ciclo do epitélio seminífero. Nos animais que não apresentaram o epitélio organizado em estágios bem definidos em virtude da idade, foram feitas medidas em secções transversais escolhidas somente pelo contorno circular. O início da assincronia do processo espermatogênico foi observado a partir dos seis meses de idade. A puberdade, na cutia Dasyprocta aguti, foi definitivamente estabelecida a partir dos nove meses de idade, pois estavam presentes todos os tipos celulares e espermatozóides liberados no lume tubular em grande parte do parênquima testicular.

Análise histométrica do desenvolvimento testicular de cutias (Dasyprocta aguti) criadas em cativeiros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Testicular arteries systematization based on different levels of scrotal configuration in caprines

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of the bipartite scrotum on the testicular and scrotal temperatures in goats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alterações do padrão ultrassonográfico do parênquima testicular em bovinos jovens da raça Nelore

The ultrasononographic examination of testicles is a noninvasive and rapid method that, allied to clinical examination, can lead to an early diagnostic of testicles disorders. The aim of the present study is to enhance andrologic evaluation and to make public altered ultrasonographic testicular parenchyma pattern in young Nelore bulls. Testes of 114 Nelore bulls from 9 to 15 months old were submitted to ultrasonographic evaluation (Frontal and transverse planes of testes). In this group, 111 animals presented testicular parenchyma with uniform pattern at low echogenicity, and the testicular echogenicity increased in proportion to the animal's age. Three animals, from 9 to 15 months old, presented heterogeneous testicular parenchyma with multiple hyperechoics

Testicular structure and spermatogenesis of Amazonian freshwater cururu stingray Potamotrygon cf. histrix

The cururu stingray Potamotrygon cf. histrix, a new and endemic Amazonian freshwater species, presents appropriate characteristics for fish keeping and is exploited from its natural environment. The present study identified the testicular structure and spermatogenesis of this species. Gonads from adult male specimens were dissected, fixed and processed for histological analysis. The testes were of testicular/epigonial type. The presence of germinal papillae was observed in the upper portion of organ with primordial germ cells and Sertoli cell precursors. The testis was lobular with zonal organization and cystic gametogenesis, with the occurrence of spermatoblasts. The Sertoli cells underwent morphological modifications over the course of gamete formation. The spermatozoids had long heads and were spiraled on their own axis. Information on the reproductive biology will serve as basis for studies on the reproduction and phylogeny of this peculiar group of cartilaginous fish.

Testicular traits as selection criteria for young Nellore bulls

The objective of this study was to evaluate the possible use of biometric testicular traits as selection criteria for young Nellore bulls using Bayesian inference to estimate heritability coefficients and genetic correlations. Multitrait analysis was performed including 17,211 records of scrotal circumference obtained during andrological assessment (SCAND) and 15,313 records of testicular volume and shape. In addition, 50,809 records of scrotal circumference at 18 mo (SC18), used as an anchor trait, were analyzed. The (co) variance components and breeding values were estimated by Gibbs sampling using the Gibbs2F90 program under an animal model that included contemporary groups as fixed effects, age of the animal as a linear covariate, and direct additive genetic effects as random effects. Heritabilities of 0.42, 0.43, 0.31, 0.20, 0.04, 0.16, 0.15, and 0.10 were obtained for SC18, SCAND, testicular volume, testicular shape, minor defects, major defects, total defects, and satisfactory andrological evaluation, respectively. The genetic correlations between SC18 and the other traits were 0.84 (SCAND), 0.75 (testicular shape), 0.44 (testicular volume), -0.23 (minor defects), -0.16 (major defects), -0.24 (total defects), and 0.56 (satisfactory andrological evaluation). Genetic correlations of 0.94 and 0.52 were obtained between SCAND and testicular volume and shape, respectively, and of 0.52 between testicular volume and testicular shape. In addition to favorable genetic parameter estimates, SC18 was found to be the most advantageous testicular trait due to its easy measurement before andrological assessment of the animals, even though the utilization of biometric testicular traits as selection criteria was also found to be possible. In conclusion, SC18 and biometric testicular traits can be adopted as a selection criterion to improve the fertility of young Nellore bulls.

Estimation of genetic parameters for body weights, scrotal circumference, and testicular volume measured at different ages in Nellore cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Testicular structure and description of the seminal pathway in Leporinus macrocephalus (Anostomidae, Teleostei)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genetic parameter estimates and response to selection for weight and testicular traits in Nelore cattle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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.

Testicular fine needle aspiration cytology from a stallion with testicular degeneration after external genitalia trauma.

A seven-year-old Quarter Horse had a serious external genitalia trauma with severe swelling of ventrum, penis, prepuce and scrotum after falling over a fence. Appropriated treatment was rapidly started after clinical examination. During recovery period, the spermatogenesis assess by semen evaluation was not possible due to stallion's inability to ejaculate. Therefore, for testicular evaluation fine needle aspiration cytology (FNAC) was performed. The first FNAC showed a deviation of germ cell line towards immature cells, mainly by primary spermatocytes (59.5%) with very few late spermatids and spermatozoa (2.5% each), and an increased Sertoli cells/germ cells ratio (478/100), which characterized testicular degeneration. One month after the first FNAC, the second exam presented a drastic decrease of Sertoli cells/germ cells ratio (7/100) and marked increase of mature cell number, specially by early and late spermatids (50% and 24.5%, respectively). In this case, the results of both FNAC could demonstrate a partial recovery of spermatogenesis activity. Two months later, the stallion had mated two mares successfully and they became pregnant. In conclusion, the adequate treatment allowed a complete recovery of the stallion's reproductive function, and since semen collection was impossible during treatment, testicular FNAC showed to be an efficient diagnostic method for evaluating acute damage in the spermatogenesis.

Cytological identification and quantification of testicular cell types using fine needle aspiration in horses

Fifteen stallions of different breeds, age 3-11 years, had their right testicles evaluated by fine needle aspiration cytology (FNAC). Cytological analysis showed the following spermatogenic cell types: spermatogonia (1.6% +/- 1.1); spermatocyte I (3.4% +/- 2.2); spermatocyte II (0.8% +/- 0.7); early spermatids (25.5% +/- 9.5); late spermatids (37.0% +/- 9.3). Spermatozoal numbers were expressed as the spermatic index (SI = 31.5% +/- 8.5) and Sertoli cells mere expressed as the Sertoli cell index (SEI = 20.9% +/- 17.0) (means +/- s.d). Identification of cell types was relatively easy and no immediate adverse effects of aspiration were noted. The results suggest that FNAC of testis may assist clinical diagnosis in the study of male equine infertility.

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.