The Corynorhinus mexicanus bat provides an interesting experimental model for the study of epididymal sperm maturation because after testicular regression, this bat stores sperm in epididymal cauda for several months. Earlier research conducted by our group suggested that sperm maturation in this specie must be completed in the caudal region of the epididymis, although the precise factor linked with this phenomenon is unknown. Therefore, the aim of this work was to analyze changes in the distribution of N-acetylglucosamine and/or sialic acid, Fucose and Mannose carbohydrates in different membrane domains of sperm cells as they change from the caput to the cauda of the epididymis, as well as, their changes in different dates of capture. The sperm cells present a redistribution of N-acetylglucosamine and/or sialic when they arrived in the caudal region (September 11), but after storage until October 22 the distribution of N-acetylglucosamine and/or sialic acid changed. Mannose residues were found predominantly towards the acrosome during their entry into and transit through the three regions of the epididymis. The flow cytometry assay indicated that fluorescence intensity due to the presence of of N-acetylglucosamine and/or sialic acid on the sperm decreases as the sperm pass through the epididymal duct and as storage time in the cauda goes on. The Mannose fluorescence intensity, decreased in corpus and cauda from September 24 to October 8, though no differences appeared on the latter date. The presence of Fucuse was corroborated only by flow cytometry. In conclusion, the carbohydrate distribution on sperm membrane can be considered as part of the process of epididymal sperm maturation and is associated with the phenomenon of prolonged sperm storage that is characteristic of this specie. This adaptation allows the males to synchronize with the period of receptivity of the females, and then, carry out the matings.
The mammary gland has long drawn the attention of the scientific community due to the limited knowledge of some fundamental aspects involved in the control of its function. Myotis velifer, a microchiropteran species, provides an interesting model to study some of the regulatory factors involved in the control of the mammary gland cycle. Having an asynchronous, monoestrous reproductive pattern, female M. velifer bats undergo drastic morphological changes of the breast during the reproductive cycle. Current research on non-chiropteran mammals indicates that serotonin (5-HT) plays a major role in the intraluminal volume homeostasis of the mammary gland during lactation; however, an analysis of both the expression and localization of the main components of the serotonergic system in the bat mammary gland is lacking. Thus, the objectives of the present study were: to describe the gross and histological anatomy of the mammary gland of M. velifer to establish the lactation period for this species; to analyze the distribution and expression of the main serotonergic components in the mammary tissues of these bats under the physiological conditions of lactation, involution and the resting phase; and to provide information on the involvement of 5-HT in the regulation of the physiological function of this organ. To assess the expression and localization of serotonergic components, multiple immunofluorescence, Western blot and HPLC methods were used. 5-HT and the enzyme that catalyzes its synthesis (TPH) were located in both myoepithelial and luminal epithelial cells, while the enzyme responsible for the catabolism of this neurohormone (MAO A) was found in luminal epithelial cells as well as in secreted products. We also found an increased expression of serotonergic components during lactation, indicating that elements of the serotonergic system may play an important role in lactation in this species of bat in a way similar to that of other mammal species.
Obtener el grado de Doctor es un éxito personal al que se llega como resultado de la realización de grandes esfuerzos y dedicación permanente, para concluir los estudios propios de una carrera académica. Pero, para realizar un recorrido exitoso por una carrera académica, es necesario el apoyo de instituciones y de personas, enlazados y estimulados todos, por un fin básico común, la obtención de conocimientos.Es por ello, que deseo expresar mis mas sinceros agradecimientos a las siguientes instituciones: el
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