Expression of TLR2/4 on Epididymal Spermatozoa of the Chinese Soft‐Shelled Turtle Pelodiscus sinensis During the Hibernation Season

Abstract

Spermatozoa are known to be stored in the epididymis of the Chinese soft-shelled turtle Pelodiscus sinensis for long periods during hibernation, but the mechanism that underlies the sperm storage is poorly understood. This study was carried out to confirm the presence of TLR2/4 (Toll-like receptor 2/4) in epididymal spermatozoa during the hibernation season and to analyze whether TLRs play a role in sperm storage. The structure and ultrastructure of a spermatozoon during the hibernation stage were investigated using light- and transmission electron-microscopy. RT-PCR was used to analyze mRNA expression, while protein expression was determined via Western blot. TLR2/4 mRNA and proteins were detected in spermatozoa. Immunofluorescence staining was used to confirm TLR2/4 localization in the spermatozoon, and TLR2/4 were localized in the midpiece and the posterior segment of the head of the spermatozoon, which corresponded to the cytoplasmic droplets (CDs) of the turtle spermatozoon. As TLRs play critical roles in detecting and responding to invading pathogens, this study provided molecular evidence that TLR2/4 might contribute to sperm storage in the epididymides. Anat Rec, 299:1578-1584, 2016. © 2016 Wiley Periodicals, Inc.

In Vivo Autophagy Up-Regulation of Small Intestine Enterocytes in Chinese Soft-Shelled Turtles during Hibernation

“…Hibernation is an adaptive survival strategy in response to cold and foodless winter seasons, mostly found in mammals and birds [1]. Previously, our research group addressed the life cycle of the Chinese soft-shelled turtle that consists of a hibernation period, which starts from the early days of December and continues into March, and a nonhibernation period from May to October [2,3]. Hibernation is a way that some animals, including Chinese soft-shelled turtles, cope with unfavorable ecological conditions by dramatically reducing their body activity [4,5], metabolic rate [6], and physiological parameters such as body temperature and heart and respiratory rate compared to nonhibernation [7,8].…”

“…Hibernation is a way that some animals, including Chinese soft-shelled turtles, cope with unfavorable ecological conditions by dramatically reducing their body activity [4,5], metabolic rate [6], and physiological parameters such as body temperature and heart and respiratory rate compared to nonhibernation [7,8]. Hibernation is an energy-limiting period [6], as during this period the animals are sedentary, and the demand for oxygen is reduced severely, thus eliminating the need for food during cold seasons [2,9]; although, animals face different kinds of challenges in these critical situations. However, animal bodies have developed different physiological defense mechanisms against any stressor that could enter into the animals along with nutrients in the digestive system [10].…”

Differential expression of TLRs and AKAP3 in cigarette smoked mice testis

“…TLRs play broad roles in testicular function and inflammation and innate immune responses to alloantigens (Hedger, ). MyD88 signalling would activate TLR in spermatozoa and then reduce sperm motility (Zhu et al, ), and TLR2/4 may play roles in sperm storage in the epididymides (Hu et al, ). In order to further illustrate the role of TLR in spermatogenesis, we detected the expression of TLRs and its signalling pathway genes in cigarette smoked mice testis.…”

Hepatic lipid droplet breakdown through lipolysis during hibernation in Chinese Soft-Shelled Turtle (Pelodiscus sinensis)

“…Hibernation is an energy-limited period, during which organisms lower their metabolic rate to adapt to a colder winter or food restriction. The Chinese Soft-Shelled Turtle ( Pelodiscus sinensis ) usually started to hibernate in the middle of November and come out of hibernation in the middle of April [3,4]. Before hibernation, the amount of triglyceride (TG) stored as LD in the liver of hibernating animals is significantly increased [5].…”