226 research outputs found
Follicle Stimulating Hormone, Luteinizing Hormone and Testicular Leydig Cell Responses to Estradiol Immunization in Ile-de-France Rams
Active immunization of Ile-de-France rams against estradiol (E2) resulted in the production of E2-neutralizing antibodies and an elevation in the plasma concentrations of FSH, LH, and testosterone. The presence of E2 antibodies did not affect the testosterone metabolic clearance rate, indicating that the immunization-mediated 10-fold increase in plasma testosterone was the result of a 10-fold increase in testicular testosterone production. Testis weights, as well as nuclear and cytoplasmic volumes of individual peritubular and perivascular Leydig cells, were greater in E2-immunized rams than in albuminimmunized controls. Leydig cell numbers were not affected by treatment. The E2 antibodies were capable not only of neutralizing the inhibitory effects of endogenous E2 on gonadotropin levels in intact rams, but were able to block the effects of exogenously administered E2 on their FSH and Lii secretory response to castration. It is concluded that circulating E2 in the ram is involved in pituitary-testicular endocrine homeostasis and that E2 immunoneutralization can be employed to enhance testosterone secretion in this species
Morphometry and histomorphometry of the testis in crossbred pigs fed diets with different protein levels
Discovery of Potential piRNAs from Next Generation Sequences of the Sexually Mature Porcine Testes
Piwi- interacting RNAs (piRNAs), a new class of small RNAs discovered from mammalian testes, are involved in transcriptional silencing of retrotransposons and other genetic elements in germ line cells. In order to identify a full transcriptome set of piRNAs expressed in the sexually mature porcine testes, small RNA fractions were extracted and were subjected to a Solexa deep sequencing. We cloned 6,913,561 clean reads of Sus Scrofa small RNAs (18–30 nt) and performed functional characterization. Sus Scrofa small RNAs showed a bimodal length distribution with two peaks at 21 nt and 29 nt. Then from 938,328 deep-sequenced small RNAs (26–30 nt), 375,195 piRNAs were identified by a k-mer scheme and 326 piRNAs were identified by homology searches. All piRNAs predicted by the k-mer scheme were then mapped to swine genome by Short Oligonucleotide Analysis Package (SOAP), and 81.61% of all uniquely mapping piRNAs (197,673) were located to 1124 defined genomic regions (5.85 Mb). Within these regions, 536 and 501 piRNA clusters generally distributed across only minus or plus genomic strand, 48 piRNA clusters distributed on two strands but in a divergent manner, and 39 piRNA clusters distributed on two strands in an overlapping manner. Furthermore, expression pattern of 7 piRNAs identified by homology searches showed 5 piRNAs displayed a ubiquitous expression pattern, although 2 piRNAs were specifically expressed in the testes. Overall, our results provide new information of porcine piRNAs and their specific expression pattern in porcine testes suggests that piRNAs have a role in regulating spermatogenesis
Reproductive biology of the pampas deer (Ozotoceros bezoarticus): a review
The pampas deer (Ozotoceros bezoarticus) is a South American grazing deer which is in extreme danger of extinction. Very little is known about the biology of the pampas deer. Moreover, most information has not been published in peer-reviewed scientific journals, and is only available in local publications, theses, etc. Therefore, our aim was to update and summarize the available information regarding the reproductive biology of the pampas deer. Moreover, in most sections, we have also included new, unpublished information. Detailed descriptions are provided of the anatomy of both the female and the male reproductive tract, puberty onset, the oestrous cycle and gestational length. Birthing and the early postpartum period are described, as are maternal behaviour and early fawn development, seasonal distribution of births, seasonal changes in male reproduction and antler cycle, reproductive behaviour, semen collection, and cryopreservation. Finally, an overview is given and future directions of research are proposed
Evolution de la gonade male et de l'epithelium seminifere des mammiferes avec l'age
* INRA, Physiologie de la Reproduction, Nouzilly Diffusion du document : INRA, Physiologie de la Reproduction, NouzillyNational audienc
Contrôle gonadotrope des cellules somatiques et de la spermatogénèse des vertébrés
National audienc
L'epithelium seminifere des mammiferes : fonctionnement normal et pathologique
National audienc
L'epithelium seminifere des mammiferes : fonctionnement normal et pathologique
National audienc
L'epithelium seminifere des mammiferes : fonctionnement normal et pathologique
National audienc
Evolution de la gonade male et de l'epithelium seminifere des mammiferes avec l'age
* INRA, Physiologie de la Reproduction, Nouzilly Diffusion du document : INRA, Physiologie de la Reproduction, NouzillyNational audienc
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