Characteristics Of Telocytes In The Oviduct Of Chinese Soft Shelled Turtle,Pelodiscus Sinensis

The oviduct is a vital reproductive organ that is involved in the transport and maturation of the eggs in a well prescribed and regulated way.It is also known to as the fallopian tube or ovarian tube or uterine tube.It is the site where the embryos/eggs-the future animals are developed.The escalating demand of the current world for the animal origin proteins has made it decisive to develop strategies for the increased production from animal’s species.Chinese soft-shelled turtle is an ancient type of reptile found in China;as well as in many other countries especially in Asia.The Chinese soft-shelled turtle is of great importance in aquaculture and as a food item,and is,of significant economic and pharmacological value.It is of great importance to understand the normal functioning of the female reproductive system in this species because it will be very helpful to plan healthy and more productive animals in the future.Recent studies have confirmed the presence and recognized many roles of telocytes in almost all the vital organs of mammals.The information on the localization of these cells in the oviducts of reptiles is widely missing.In the present study we have demonstrated the presence of telocytes in the different parts of oviduct of Chinese soft-shelled turtle,also characterized these cells on the basis of their ultrastructure and distribution.Furthermore the molecular confirmation of the regulation of telocytes at gene level has also been investigated.Thus,the results of the current study have broadened our knowledge and for the meantime have given a new perspective on the oviduct functionality in the Chinese soft-shelled turtle.Moreover,it provides the initial work at the structural level to study the important processes of the fertilization,formation and transportation of eggs in the reptile’s species.Future studies will be mandatory to scrutinize these phenomenons on the genetic/molecular and functional grounds.(Experiment Ⅰ)Ultrastructural and immunohistochemical characteristics of telocytes in the vagina of the Chinese soft-shelled turtle,Pelodiscus sinensisTelocytes,a novel type of interstitial cell first identified by Popescu and his coworkers,have been reported in many different type of tissue and organs,but not yet in vagina.(www.telocytes.com).This study aims to investigate the existence,ultrastructure,and distribution of telocytes,as well as whether they have any contact with surrounding cells in the vagina of the Chinese soft-shelled turtle,Pelodiscus sinensis.We used transmission electron microscopy and CD34 Immunohistochemistry to demonstrate the existence of telocytes in the turtle vagina.Telocytes were mainly located in the lamina propria beneath the simple columnar epithelium,situated close to the secretory glands,mast cells,and collagen fibers.The complete morphology of telocytes and telopodes was clearly observed.Our data confirmed the existence of telocytes in the vagina of Pelodiscus sinensis.In conclusion we showed the presence and distribution of telocytes in the turtle vagina,which may offer new insights for understanding the function of the vagina and preventing and treating vaginal disorders.(Experiment Ⅱ)Identification and characterization of telocytes in the uterus of the oviduct in the Chinese soft-shelled turtle,Pelodiscus sinensisTelocytes(Tcs)are cells with telopodes(Tps),which are very long cellular extensions with alternating thin segments podomers and dilated bead-like thick regions known as podoms.Telocytes are a distinct category of interstitial cells and have been identified in many mammalian organs including heart,lung and kidney.The reptile’s oviduct is composed of 5 segments or regions(from anterior to posterior),viz.,infundibulum,magnum,isthmus,shell gland(uterus)and vagina.The present study investigates the existence,ultrastructure,distribution and contacts of Tc with surrounding cells in the uterus(shell gland)of the oviduct of the Chinese soft-shelled turtle,Pelodiscus sinensis.Samples from the uterine segment of the oviduct were examined by transmission electron microscopy and CD34 Immunohistochemistry.Tcs were mainly located in the lamina propria beneath the simple columnar epithelium of the uterus and were situated close to nerve endings,capillaries,collagen fibers and secretory glands.The complete morphology of Tcs and Tps was clearly observed and our data confirmed the existence of Tcs in the uterus of the Chinese soft-shelled turtle Pelodiscus sinensis.Our results suggest these cells contribute to the function of the secretory glands and contraction of the uterus.(Experiment Ⅲ)Identification and Ultrastructural characterization of telocytes in the Isthmus of the oviduct of Chinese soft shelled turtle,Pelodiscus sinensisTelocytes(TCs)are a distinctive type of interstitial cells described in many tissues and organs.A TC is characterized by a small cell body and extremely long and thin telopodes(Tps),with alternating regions of podomers and podoms.Tps release three types of extracellular vesicles:exosomes,ectosomes and multi vesicular cargos,which take part in paracrine signaling.The present study was carried out to investigate the ultrastructure,distribution,contact of telocytes with surroundings in the isthmus by TEM and CD34 Immunohistochemistry in the oviduct of Chinese soft-shelled turtle,Pelodiscus sinensis.Different shaped telocytes depending on the number of prolongations were found,closely related to or established many junctions in the Isthmus,located in lamina propria beneath the simple columnar epithelium.Also found involved in the secretion of extracellular vesicles.Their complete morphology was observed.Present study added new facts for the existence and distribution of telocytes in the isthmus of the oviduct in Chinese soft-shelled turtle,Pelodiscus sinensis.(Experiment Ⅳ)The Expression of CD34 mRNA in the Oviduct of Chinese soft shelled turtle,Pelodiscus sinensis.Hematopoietic progenitor cell antigen CD34 also known as CD34 antigen is believed as a specific marker of the telocytes.By using the quantitative real-time polymerase chain reaction(RT-qPCR),we have confirmed the mRNA expression of CD34 gene in the 4 segments of the Chinese soft shelled turtle oviduct,the magnum,isthmus,uterus(shell gland),and vagina.The TEM observations revealed high number of telocytes in the lamina propria of the Chinese soft shelled turtle oviduct.We used the samples from four segment of the oviduct to determine the CD34 expression.The CD34 mRNA was expressed throughout the oviduct,with regional variations in the levels of expression.The highest level of CD mRNA expressed was found in the uterus segment of the oviduct followed by the vagina.Moderate levels of expression were seen in the isthmus while the magnum segment showed low level of expression of the CD34 gene.The regional variation in the relative expression of the CD34 gene among different segments of the oviduct may have some functional grounds in control of motility of the oviduct and transportation of egg throughout the whole length of oviduct.