Female annual reproductive cycle ofRhinolophus ferrumequinum korai(Chiroptera: Rhinolophidae): morphological changes and prolonged sperm storage and sperm fate of the female reproductive tract according to month

Abstract

Morphological changes and prolonged sperm storage and loss of female reproductive tract per year and site as well as reproductive cycle were investigated by using an optical microscope, scanning electron microscope and transmission electron microscope in Rhinolophus ferrumequinum korai. The size and morphological characteristics of the uterus were found to be highly relevant to mating and the delivery period. In particular, some of the sperm ejaculated to the female reproductive tract became extinct due to phagocytosis by leukocytes starting from the end of August, which continued until the end of February. Accordingly, this period may be called the cleansing period. The sperm became extinct mainly in the uterine lumen, and an extremely small amount of sperm became extinct by secretion from the uterine gland and the phagocytosis by leukocytes. Such phagocytosis seemed to result in maintaining the clean intrauterine environment to facilitate the implantation of the fertilized egg. Also, phagocytosis by leukocytes was considered as a physiological mechanism to kill the sperm breaking into the female reproductive tract by recognizing them as alien materials, to maintain an appropriate number of sperm at the fertilization site of the fallopian tubes, so as to improve fertility. Only the sperm reaching the caudal isthmus of oviduct were found to be involved in fertilization in the next year. Ovulation and fertilization occurred approximately at the end of March. Embryogenesis appeared consecutively with implantation. The pregnancy period was approximately 70 days; delivery occurred approximately early-and middle June; and the nurturing period was approximately 80 days.

Springing into caves: the dynamics of cave roost use by bats in the Central Himalayas of Nepal.

“…All the species used microsites inside caves with higher mean temperature in late-winter and spring as compared to midwinter. These warmer sites could, potentially, be used to facilitate ovulation, fertilization, gestation, and pup-rearing cycles during late winter and early spring (Barlas & Yamaç, 2019;Cotterill, 1998;Furey et al, 2011;Lee, 2020;Reiter, 2004). As expected in late winter and early spring, pregnant R. a nis, R. macrotis, and R cf.…”

Assessment of Sperm Binding Capacity in the Tubal Reservoir Using a Bovine Ex Vivo Oviduct Culture and Fluorescence Microscopy

“…The formation of the sperm reservoir, which differs between species [1-4], is a complex process involving multiple receptors [5], glycans [6] and endocrine signaling [7] to prolong the survival of spermatozoa, select for acrosome-intact cells and limit the chances of polyspermy [8,9]. In most species, the majority of spermatozoa will bind to the isthmus of the oviduct [10][11][12], but some will also bind to the ampulla, the site of fertilization [13,14]. The oviductal glycans responsible for sperm binding in cattle include fucose [3], hyaluronan [15] and Lewis-a trisaccharide [16].…”

Evidencias de maduración espermática durante el almacenamiento prolongado en hembras del murciélago Corynorhinus Mexicanus

“…Una de las estrategias reproductivas, que diversos ordenes de quirópteros han adoptado, es el almacenamiento de gametos, que consiste en mantener a los gametos masculinos por largos periodos de tiempo (Birkhead & Møller, 1993;Crichton, 2000;Jones & Murdoch, 1996). Para mantenerse viables hasta que la ovulación ocurra, los espermatozoides deben adecuar diferentes procesos fisiológicos para que su vida fértil se prolongue, algunos de estos procesos son los de maduración espermática (Krishna & Roy, 2017;Lee, 2018Lee, , 2020.…”

“…Este proceso de eliminación y baja calidad espermática continua en el tracto reproductor de la hembra de esta especie donde los espermatozoides que no son aptos para mantenerse almacenados son liberados por las células del epitelio endometrial, donde se encontraban anclados para su protección, fagocitados por leucocitos (Lee, 2018(Lee, , 2020. En condiciones óptimas este proceso de eliminación permite mantener el ambiente intrauterino limpio y listo para la implantación del óvulo.…”

“…En condiciones óptimas este proceso de eliminación permite mantener el ambiente intrauterino limpio y listo para la implantación del óvulo. Sin embargo, con los cambios en la temperatura se observó una disminución del número espermatozoides que llegaron al sitio de fertilización (Lee, 2020). En C. mexicanus, se observó que tras la modificación a la técnica descrita por León-Galván y colaboradores en 1999, con la que reportan una concentración de 2.5 x 10 6 /mL de espermatozoides almacenados, obtuvimos una concentración espermática (Fig.…”