For the first time in China, the evolutionary characteristics of fish egg births were analyzed

, Zhang Quanqi, a professor at China Ocean University, published research results revealing the evolutionary characteristics of fish egg life, which is the first time in China to analyze the evolutionary characteristics of fish egg birth, and provides an important reference for understanding the evolution of animal egg birth and fetal reproductive patterns. The results were supported by scientific research projects such as the basic scientific research business expenses of the central university and the "Blue Granary Science and Technology Innovation" of the national key research and development plan, which were jointly completed by Professor Zhang Quanqi's team in cooperation with Qingdao Huada Gene Research Institute.
This study confirms at the cellular and molecular levels that during embryonic development prior to the hatching of Xu's pingpackerfish, there is not only the nutrients provided by the ovaries, but also the nutritional supply from the ovaries, which are reproduced by a transition type from egg birth to true fetal evolution.
fish breeding methods are egg, egg and fetal, Xu's flat is the birth of eggs or fetal reproduction has not been determined. After the female and male fish of the species were handed over in November-December, the sperm entered the female's ovary cavity and waited until the 3-4 months of the following year before the eggs matured for fertilization, and after the embryo had hatched in the female ovaries for about 1 month, the mother produced the baby fish directly. This particular reproductive characteristic provides valuable material for studying the evolution of egg life in fish. Based on this, the team used genome-wide sequence and transcription analysis to analyze its genomic characteristics and ovarian expression spectrum at different stages of development, and used immunofluorescent hybridization and other techniques to locate sperm in the ovaries. The study found that Xu's -tailed sperm was fixed in a transparent band protein (ZP) layer on the surface of the egg membrane, and that the members of the hatching enzyme family gene (HCE1-like) in his genome expanded, making adequate preparation for digesting the transparent band protein to release sperm "The genes associated with the signaling path, as well as those associated with embryo implantation (e.g., placental formation, vascular formation, oxygen transport, etc.) are significantly rich or specifically highly expressive, and the ovaries are rich in vascular systems, which implies that Xu's flatovaries have uterine and placental functions similar to those of fetal animals, providing nutrients and oxygen to the embryo."