Sample records for spermatids
from WorldWideScience.org

Sample records 1 - 8 shown.



1

Características ultra-estruturais e diferenciativas das espermátides de piracanjuba (Brycon orbignyanus) durante a espermiogênese/ Ultrastructural features and differentiation of the spermatids in Brycon orbignyanus during the spermiogenesis

AIRES, Eduardo Duarte; STEFANINI, Maíra Aparecida; ORSI, Antonio Marcos
2000-01-01

Resumo em português A espermiogênese que ocorre em piracanjuba Brycon orbignyanus pode ser dividida em quatro etapas morfológicas, cujas características principais consistem em reduções dos volumes citoplasmático, nuclear e celular, e compactação da cromatina nuclear das espermátides, sendo que as etapas espermiogenéticas ocorrem simultaneamente. Ao final da espermiogênese, quando as espermátides atingem nível elevado de diferenciação, os núcleos se tornam mais compactos e os (mais) citoplasmas se tornam reduzidos. Estas modificações resultam na formação de células altamente diferenciadas, os espermatozóides com cabeça, peça intermediária e flagelo bem definidos. As espermátides e os espermatozóides foram observados em cistos germinativos, mas também podem ser encontrados na luz dos túbulos seminíferos. Resumo em inglês Spermiogenesis in Brycon orbignyanus may be divided in four stages, which consist mainly in reduction of cytoplasmic, nuclear and cellular volumes and compactation of the nuclear chromatin, whose stages of the process occur simultaneously. At the end of the spermiogenesis, when the spermatids reach high levels of differentiation, the nuclei become more compact and cytoplasms become reduced. These modifications result in the formation of new highly differentiated cells, th (mais) e spermatozoa. Spermatozoa may be observed predominantly in cysts, like spermatids, or inside the lumen of the seminiferous tubules. Ultrastructurally, three different parts have been clearly identified in Brycon orbignyanus spermatozoon: head, middle-piece and flagellum.

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2

Comportamento dos cromossômios sexuais do Dysdercus mendesi na segunda divisão dos espermatócitos

Jor, S. de Toledo Piza
1947-01-01

Resumo em inglês In a previous, publication (3) the author described the behaviour of the sex-chromosomes, of Dysdercus mendesi Blöte Following conversation with Dr. Luiz O. T. Mendes, the author was simulated to reexamine the, slides and to study another new series of slides" As a result of these observations the¹ writer now concludes that in the division of the 2nd spermatocytes the sex-chromosomes pass undivided to one pole. Thus half of the spermatids receives a single compound elem (mais) ent and half receives none. This is believed to be; similar to the conclusions reached by. Dr.. Luiz O. T. Mendes. Further studies will be made with respect to the nature of the compound element.

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3

Citologia aspirativa por agulha fina (CAAF), em testículo de onça pintada (Panthera onca), utilizada como ferramenta no diagnóstico de infertilidade/ Testicular fine needle aspiration cytology as a diagnostic tool in jaguar (Panthera onca) infertility

Paz, Regina Celia Rodrigues da; Leme, Denise Pereira; Züge, Roberta Mara; Pessuti, Cecília; Santos, Eliana Ferraz; Barnabe, Renato Campanarut
2003-01-01

Resumo em português Técnicas de biópsia, caracterizadas pela remoção de segmentos de órgãos e tecidos para análise histopatológica, não são indicadas no auxílio diagnóstico de alterações testiculares para animais ameaçados de extinção, por não serem totalmente isentas de riscos. Neste sentido, é de grande interesse que se desenvolvam técnicas de biópsia testicular cada vez mais seguras e com o mínimo de conseqüências negativas. Com este intuito três onças pintadas ( (mais) Panthera onca) foram submetidas a exames de Citologia Aspirativa por Agulha Fina (CAAF). Amostras foram obtidas através da punção aspirativa dos testículos, esfregaços foram confeccionados, corados com Panótico e analisados sob Microscopia Óptica. Simultaneamente foram realizadas coletas de sêmen para avaliação do volume, pH, concentração, motilidade, vigor e morfologia espermáticas. Quanto à avaliação espermática, os animais apresentaram valores semelhantes aos encontrados na literatura quanto ao volume, pH, motilidade, vigor e morfologia espermáticas. Quanto a concentração espermática os animais apresentaram valores abaixo dos encontrados na literatura. Nos exames de CAAF, todas as gerações de células germinativas foram identificadas, indicando espermatogênese normal em todos os animais, com exceção das espermátides finais duplas que ainda não foram relatadas como achados em punções testiculares de outras espécies, o que vem confirmar a elevada porcentagem de células teratológicas encontradas nesses animais. Desta forma, podemos concluir que a CAAF testicular é um método diagnóstico auxiliar importante na detecção de alterações testiculares em casos de sub ou infertilidade, podendo ser utilizados na rotina de investigação do trato reprodutivo masculino, quando o exame histopatológico, por ser um método altamente invasivo, é desaconselhável. Resumo em inglês Several methods of testicular punch biopsy were proposed for obtaining material for histologic or cytologic evaluation, but did not received enough clinical acceptance because it was considered to be too traumatizing. The fine Needle Aspiration (FNA) is considered a useful, simple and fast method to obtain samples from tissues. Regarding the importance of FNA in wild animals, this technique was tried in captive adult jaguar (Panthera onca) aiming the evaluation and possib (mais) le causes of infertility. Using a needle and disposable syringe, the testis were aspirated. The whole aspirated was smeared onto a microscope slide and stained with Diff-quick method. Semen samples were collected by electroejaculation and analyzed for pH, total volume, motility, status, total spermatozoa count and morphology. Evaluation of sperm volume, pH, motility vigor and morphology were normal. However, was found below concentration. Cytologic quantification revealed germinative cells in all testicles. Among serial types of morphological normal spermatogenesis cells, there were found theratological forms of double final spermatids. These anomalous forms of final spermatids have not been noticed yet in FNA papers. So, we concluded that FNA together with other techniques, provides a useful tool in male infertility diagnostics, mainly when related to endangered species.

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4

Desenvolvimento testicular, espermatogênese e concentrações hormonais em touros Angus/ Testicular development, spermatogenesis and hormonal concentrations in Angus bulls

Aguiar, Gyselle Viana; Araújo, Airton Alencar; Moura, Arlindo de Alencar Araripe
2006-08-01

Resumo em português Este estudo foi realizado com a finalidade de avaliar a evolução das secreções hormonais e do epitélio seminífero em touros da raça Angus de 10 a 38 semanas de idade. Foram castrados 1 a 5 animais em intervalos de quatro semanas (total de 25 touros) para coleta de amostras do parênquima testicular e do plasma sanguíneo. As variáveis relacionadas ao crescimento testicular, aos aspectos quantitativos da espermatogênese e aos níveis hormonais foram transformadas (mais) em logaritmo e avaliadas por meio de análise de variância. O diâmetro dos testículos e túbulos seminíferos e o peso testicular apresentaram variações mais acentuadas após 26 semanas de idade. A porcentagem do parênquima testicular ocupado pelos túbulos seminíferos aumentou de 49,3 para 75,2% durante o experimento. A maioria dos túbulos (>90%) apresentou-se com células de Sertoli somente entre 10 e 14 semanas, mas na 18ª (13,8±1,7%) e 22ª semanas (19±1%), o número de túbulos com gonócitos e espermatogônias aumentou em relação às semanas iniciais. Espermatogônias intermediárias e B predominaram na 26ª semana (24,5±8,2%) e a porcentagem de túbulos com espermatócitos foi mais elevada na 30ª semana (42,3±9,9%). Espermátides arredondadas foram detectadas partir da 26ª semana e, na 38ª semana, 62,3±1,5% dos túbulos seminíferos continham espermátides alongadas ou maduras. As variações mais acentuadas no crescimento testicular e, principalmente, no peso testicular após as 26 semanas coincidiram com o estabelecimento da meiose, com as alterações morfológicas do núcleo e nucléolo das células de Sertoli (indicativos do processo de diferenciação das mesmas), com os níveis reduzidos de androstenediona e os incrementos significativos de testosterona e estradiol 17beta. As associações entre o crescimento testicular e os níveis de FSH e LH na circulação periférica foram menos evidentes. Resumo em inglês This study aimed to evaluate changes in hormone secretion and in seminiferous epithelium of Angus bulls between 10 and 38 weeks of age. Samples of testicular parenchyma and blood were collected from 25 animals castrated in 4 week intervals. Traits associated to testicular development and quantitative aspects of spermatogenesis and hormonal concentrations were transformed by logarithm before analyses of variance. Changes in testis and seminiferous tubule diameter and testi (mais) s weight were more pronounced after 26 weeks of age. The percentage of testicular parenchyma occupied by seminiferous tubules increased from 49.3 to 75.2% from 10 to 38 weeks. Most tubules (>90%) had only Sertoli cells at 10 and 14 weeks, but the number of tubules with gonocytes and A spermatogonia increased at 18 (13.8±1.7%) and 22 weeks (19±1%). Tubules with B and intermediate spermatogonia became predominant at 26 weeks (24.5±8.2%) and those with spermatocytes as the most advanced germ cell type were more evident at 30 weeks (42.3±9.9%). Round spermatids were detected at 26 weeks and at 38 weeks of age, 62.3±1.5% of all tubules had either elongate or mature spermatids. Variations in testis growth (specially testis weight) after 26 weeks were coincident with the establishment of meiosis in the seminiferous tubules, morphological alterations in nucleus and nucleolus of the Sertoli cells (indicators of Sertoli cell differentiation), lower levels of androstenedione and significant increases in testosterone and estradiol 17beta. Associations between testis development and concentrations of FSH and LH were less evident.

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5

Análise citológica e cariométrica da ação da colchina sôbre a espermatogênese dos hemípteros/ Cytologic and caryometric analysis of the action of colchicine on the spermatogenesis in hemiptera

Schreiber, G.; Pellegrino, J.
1951-03-01

Resumo em inglês The action of colchicine upon the spermatogenesis of Triatoma infestans, (Hemipt. Heteroptera), has been studied and the different categories of giant spermatids that appear during the treatment have been compared with the nuclear volumes of the whole series of normal spermatogenetic stages. The following facts have been ascertained: 1) 4 hours after the treatment the gonial mitotic metaphases, and the 1st. and 2nd. metaphases of meiosis are stopped. The prophasic stages (mais) of meiosis and diakynesis appear to be normal. After 9 days of treatment, all the tetrads are broken in the meiotic metaphases and the cells appear with 44 and 22 chromosomes respectively, scattered in the cytoplasm. 2) At 9 days, practically all spermatogenetic stages have disappeared except for a few cysts of spermatogonia, and practically the whole testicle is full of cysts of spermatozoa and spermatid, with some large zones of necrosis with pycnotic nuclei. The spermatids appear to be of different sizes and the statistical analysis of the nuclear volumes gives a polymodal hystogram with 4 modes, whose volumes are in the ratio of 1:2:4:8. Ripe spermatozoa seem to have a certain volume variability, that has not been possible to analyse quantitatively. All these facts confirm what DOOLEY found in the colchicinized Orthoptera testicle. 3) The caryometric analysis conducted statistically on the normal stages of the spermatogenesis (resting spermatogonia, gonial prophases, leptotene, "confused stage", diakynesis, and spermatid) revealed the following facts: a) Considering the volume of the resting, spermatogonia as 1, their mitotic prophases have a volume of 2. Some rare prophases appear to have a volume of 4 and probably belong to tetraployd spermatogonia normally present in the testicle of Hemiptera. b) The first spermatocyte at the beginning of the auxocitary growth (leptotene) has a volume of 2, which is equal to that of them gonial prophase. It grows further during the "confused stage" and reduplicates, reaching thus the volume of 4. Diakynesis has a rather variable nuclear volume and it is higher than volume 4. This is probably of physico-chemical nature and not a growth increase. c) The spermatid at the beginning of the spermiogenetic process has a volume of 1 which is very constant and homogeneous. 4) These results can be summarized concluding that the meiotic process begins from a spermatogonium at the end of his mitotic interphasic growth (vol. 2) and instead of entering into the mitotic prophase transforms itself into the leptotene spermatocyte. During the diplotene ("confused stage") the volume of the nucleus doubles once more and reaches volume 4. In consequence of the two successive meiotic divisions the spermatid, although having an haploid number of chromosomes, has a nuclear volume of 1, just like the diploid spermatogonium. The interpretation of this strange result probably comes from the existence of the "tertiary split" in the chromosomes of the haploid set, that has been illustrated in the Hemiptera by HUGUES SCHRADER and in Orthoptera by MICKEY and co-workers. The tertiary split indicates that the chromosomes of the haploid set are constituted from almost two chromonemata, and this double constitution corresponds to the double cycle of reduplication that takes place during the spermatogenesis starting from the resting gonia. In Triatoma infestans the tertiary split appears in the chromosomes in the 1st. and 2nd. metaphases and in the diakynesis. In the blocked metaphases at the 9th. day of colchicinization some of the 44 elements scattered in the cytoplasm, show, when properly oriented, the split very clearly. Some new and strange facts revealed by SCHRADER and LEUCHTEMBERGER in Arvelius suggest the possibility of other interpretations of the rhythmic growth in special cases. There appears the necessity of more knowledge about the multiple or simple constitution of the chromosomes in somatic and spermatogonial mitosis.

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6

Espermiogênese em Eupemphix nattereri (Anura, Leiuperidae): aspectos ultra-estruturais/ Spermiogenesis in Eupemphix nattereri (Anura, Leiuperidae): ultrastructural aspects

Zieri, Rodrigo; Taboga, Sebastião R.; Oliveira, Classius de
2008-06-01

Resumo em português A maturação dos espermatozóides envolve um extenso e complexo processo que começa com a proliferação e diferenciação das espermatogônias, passa pela meiose e finaliza com a espermiogênese. Nessa fase, eventos envolvendo alterações morfológicas e bioquímicas transformam espermátides em espermatozóides. Aspectos ultra-estruturais da espermiogênese e do espermatozóide do anuro Eupemphix nattereri (Steindachner, 1863) foram analisados através de microscopia (mais) eletrônica de transmissão. A espermiogênese envolve condensação da cromatina e alongamento nuclear, com visível eliminação de citoplasma. Nesse estágio, grande quantidade de microtúbulos e glicogênio podem ser visualizados no citoplasma das células de Sertoli, rodeando cada espermátide. O espermatozóide é fusiforme e o acrossomo forma uma capa na região anterior do núcleo. A bainha mitocondrial é encontrada ao redor da porção proximal da cauda. A cauda apresenta o axonema com o modelo 9+2, uma fibra axonemal, a membrana ondulante e ausência de bastão axial. Esta organização apresenta algumas similaridades com espécies do gênero Physalaemus (Leiuperidae) como P. biligonigerus (Cope, 1861), P. gracilis (Boulenger, 1883) e P. fuscomaculatus (Steindachner, 1864). Resumo em inglês Spermatozoon maturation involves an extense and complex process beginning with proliferation and differentiation of spermatogonia, passing through meiosis, and ending with spermiogenesis. The later event involves morphological and biochemical changes in order to transform spermatids into spermatozoa. Ultrastructural aspects of the spermiogenesis and testicular spermatozoa of the anuran Eupemphix nattereri (Steindachner, 1863) were analyzed by transmission electron microsc (mais) opy. Spermiogenesis involves chromatin condensation and nuclear elongation, with visible cytoplasmic elimination. At this stage, a large amount of microtubules and glycogen can also be seen in Sertoli cell cytoplasm, surrounding each spermatid. The spermatozoon is fusiform and the acrossome forms a cap in the anterior region of the nucleus. A mitochondrial sleeve is found around the proximal portion of the tail. The tail presents an axonema with a 9+2 pattern, a justaxonemal fiber, an undulating membrane, and the absence of axial rod. This organization shows some similarities with species of the genus Physalaemus (Leiuperidae) such as P. biligonigerus (Cope, 1861), P. gracilis (Boulenger, 1883) and P. fuscomaculatus (Steindachner, 1864).

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7

Sôbre a meiose de Dysdercus mendesi bloete (1937) - Hemiptera, pyrrhocoridæ

Mendes, Luiz O. T.
1947-01-01

Resumo em inglês 1 - The spermatogonia of Dysdercus mendesi Bloete have 16 chromosomes : 7 pairs of autosomes and 2 sex-chromosomes. 2 - After the last spermatogonia! division, the chromatin of the autosomes diffuses and the nucleoplasm assumes an uniform granulai- aspect ; each sex-chromosome is involved by a vesicle and stands well colored. 3 - While the chromatin of the autosomes starts to condense again, to form the long threads (that finnally are seen in a paired condition) the cycle (mais) of the sex-chromosomes is as follows : a) yet contained in the vesicles, they grow in size and become long rods ; b) the vesicles disappear, the sex-chromosomes move inside the nucleoplasm and come to be disposed longitudinally, close together. c) they touch each other, become fissured, and a tetradlike chromatic element is formed, which contracts itself, remaining always well colored. 4 - The hetero-pycnosis of the sex-chromosomes is observed through the whole grow phase of the spermatocyte I. 5 - The separation of the sex-chromosome tetrad, originating two independent sex-chromosomes, is observed in the early grow phase of the spermatocyte as well as during any other period of this phase. The latest separation is observed during the diffuse stage of the nucleus. 6 - When the autosomes are in diakinesis, the sex-chromosomes assume the aspect of chromosomes in pachytene. 7 - In metaphase I the autosomic tetrads are in a more condensed and colored condition than the sex-chromosomes. The sex-chromosomes move to the center of the autosome-forming circle, but there is no contact between them. 8 - In anaphase I it is observed 2 interzonal connections between each autosomic dyad ; some exceptions are observed. Only one interzonal connection is observed between the separating sex-chromosomes. Moving to the poles the sex-chromosomes also approximate one to the other. 9 - In telophase I the sex-chromosome touch each other, and fuse side-by-side, forming only one chromatic element. The line of fusion is well visible through the subsequent stages of meiosis. 10 - In metaphase II the autosomes are disposed at the equator. The sex-chromosome, dyad is also disposed at the equator, as well as at any other position. 11 - In anaphase II the separation of the auto.somes is normal, and it is seen only one interzonal connection between its halves. The sex-chromosome dyad do not separate and moves to one pole, always in precession. 12 - There are two classes of spermatids : a) with 7 autosomes ; b) with 7 autosomes plus the sex-chromosome dyad. 13 - During the first phases of the spermatogeneses the 7-autosomc containing nucleus presents a reticulated aspect ; the sex-chromosome-dyad containing nucleus shows this chromatic element well colored inside the reticulated nucleoplasm. 14 - The male of Dysdercus mendesi Bloete has 7 AA + XX chromosomes. NOTE - A discussion on the movements of the sex-chromosome and its cycle. as well as on some aspects of the pairing of the autosomes, is being prepared. It will be published in the near future. The female of Dysdercus mendesi Bloete has 2n = 14A+4X.

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8

Índice e histologia gonadal em reprodutores de frangos de corte da linhagem Avian Farm submetidos à restrição alimentar/ Testicular index and histology in breeder broilers of the lineage Avian Farm submitted to the feed restriction

Drummond, Cristina Delarete; Murgas, Luis David Solis; Bertechini, Antonio Gilberto; Rodenas, Carolina Elizabeth O.; Maciel, Mônica Patrícia; Alvarenga, Ana Luisa N.; Sousa, Sara Zardini de
2004-12-01

Resumo em português Nos reprodutores de frangos de corte, a restrição alimentar precoce é usada para limitar o ganho de peso corporal e otimizar o desempenho reprodutivo. Conduziu-se este trabalho com o objetivo de avaliar o efeito da utilização da restrição alimentar no período de 14 a 121 dias de idade das aves sobre o índice gonadal e histologia testicular em galos reprodutores de corte. Foram avaliados os seguintes tratamentos: controle; 6 dias de alimentação e 1 não (6:1); e (mais) 5 dias de alimentação e 2 não (5:2). Foram utilizados 36 animais da linhagem Avian Farm, avaliando-se o peso corporal, o peso gonadal, o índice gonadal, procedendo-se à avaliação histológica testicular de 6 animais por tratamento aos 54 e 121 dias de idade. Foi usado um DIC em estrutura fatorial 2x3 (idade x restrição). Não foram observadas diferenças significativas (P>0,05) para as variáveis analisadas entre os tratamentos à idade de 54 dias. O peso testicular e o índice gonadal foram menores (P Resumo em inglês In breeder broilers the feed restriction is used to limit the gain of corporal weight and to optimize the reproductive performance. It is necessary to moderate the rate of precocious growth through programs of feed restriction. This work had as objective to evaluate the effect of the use of the feed restriction on the testicular index and histology in breeder broilers males. They were evaluated the following treatments: control; 6 days of feeding and 1 day without feeding (mais) (6:1); and 5 days of feeding and 2 day without feeding (5:2). 36 animals of the lineage Avian Farm were used being evaluated the corporal weight, the testicular weight, the testicular index and histology testicular evaluation of 6 animals for treatment to the 54 and 121 days of age. A factorial structure 2x3 (age x feed restriction) was used for test the effects of treatments. Significant differences were not observed (P>0.05), for the analyzed variables, among the treatments to the age of 54 days. The testicular weight and the testicular index were smaller (P

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