Animals ; Humans ; Organogenesis ; physiology ; Sex Determination Processes ; Vertebrates ; physiology

Although it is generally understood that the testes recruited kidney ducts for reproductive function during the evolution of vertebrates, little is understood of the biological significance of the adaptation. In the context of the evolution of the mammalian epididymis, this report provides evidence that a major role of the epididymis is to enhance a male's chance of achieving paternity in a competitive mating system. A unique example of sperm cooperation in monotremes is used as evidence that the epididymis produces sperm competition proteins to form groups of 100 sperm into bundles that have a forward motility nearly thrice that of individual spermatozoa. As it required 3-h incubation in vitro under capacitation conditions to release motile sperm from the bundles, it is suggested that the monotremes provide an example of capacitation that is quite different from capacitation in higher mammals. It is suggested that variation between species in the intensity of sperm competition could explain the variation that occurs between species in the amount of post-testicular sperm maturation and storage in the epididymis, an explanation of why the human epididymis does not play as important a role in reproduction as the epididymis of most mammals.
Acclimatization ; Animals ; Biological Evolution ; Echidna ; Epididymis ; physiology ; secretion ; ultrastructure ; Humans ; Male ; Mammals ; Spermatozoa ; physiology ; Vertebrates

Arbovirus is a group of virus transmitted by blood-sucking arthropod bites, which infects both arthropods and vertebrates. More than 600 arboviruses have been characterized worldwide until now, including 65 highly pathogenic viruses, which pose a high threat to public health. The risk of arbovirus transmission is increasing due to climate change, international trade and urbanization. The review summarizes the discovery and distribution of emerging and reemerging arboviruses and novel arboviruses with potential pathogenic risks, and proposes responses to the arbovirus transmission risk, so as to provide insights into the research and management of arboviruses and arthropod-borne infectious diseases in China.
Animals ; Humans ; Arboviruses/physiology* ; Commerce ; Internationality ; Arbovirus Infections/prevention & control* ; Vertebrates

Academies and Institutes/history* ; Animals ; Biostatistics/history* ; China ; Ecology/history* ; History, 20th Century ; Humans ; Insecta/physiology* ; Vertebrates/physiology* ; Zoology/history*