The integration of hormone induction of young ewes,live oocyte collection,in-vitro fertilization and embryo transfer( JIVET),as a major breakthrough in livestock breeding technology,not only solves the problem of low ...The integration of hormone induction of young ewes,live oocyte collection,in-vitro fertilization and embryo transfer( JIVET),as a major breakthrough in livestock breeding technology,not only solves the problem of low oocytes obtained from adult ewes by hormone induction in production practice,but also significantly improves production efficiency. This technology can reduce the generation interval of cattle and sheep and speed up the acquisition of genes in genetic breeding. The application of this technology can help accelerate the cultivation process,shorten the generation interval,promote the industrialization and improve the economic benefits of beef cattle breed. This paper provides a reference for the research and application of new breeding and propagation techniques of beef cattle.展开更多
We investigated the early embryonic and larval development of the concave-eared torrent frogs, Odorrana tormota （Amphibia, Anura, Ranidae）. Embryos were derived from artificial fertilization of frogs’ eggs, and the...We investigated the early embryonic and larval development of the concave-eared torrent frogs, Odorrana tormota （Amphibia, Anura, Ranidae）. Embryos were derived from artificial fertilization of frogs’ eggs, and the staging of development was based on morphological and physiological characteristics. Two major periods of development were designated： i） early embryonic period, from fertilization to operculum completion stage, lasted for 324 h at water temperature （WT） 18 ？23℃; ii） larval period, from operculum completion stage to tail absorbed stage, took 1207 h at WT 20 ？ 24℃. Tadpoles of the concave-eared torrent frogs showed no evidence of abdominal sucker. Absence of this key characteristic supports the view from molecular systematics that concave-eared torrent frog does not belong to the genus Amolops. Two cleavage patterns were observed in embryos at 8-cell and 16-cell stages, with Pattern I2 （latitudinal cleavage at the 8-cell stage, and meridional cleavage at the 16-cell stage with two perpendicular meridional furrows） being the predominant pattern and only 1.5% belonging to Pattern II （meridional cleavage at the 8-cell stage and latitudinal cleavage at the 16-cell stage）. The factors affecting cleavage and hatching ratios, developmental speed, and ecological adaptation were discussed.展开更多
基金Supported by Qiqihar Agricultural Innovation Project (CNYG_2021015)Qiqihar Science and Technology Major Project (ZDTG-202201)。
文摘The integration of hormone induction of young ewes,live oocyte collection,in-vitro fertilization and embryo transfer( JIVET),as a major breakthrough in livestock breeding technology,not only solves the problem of low oocytes obtained from adult ewes by hormone induction in production practice,but also significantly improves production efficiency. This technology can reduce the generation interval of cattle and sheep and speed up the acquisition of genes in genetic breeding. The application of this technology can help accelerate the cultivation process,shorten the generation interval,promote the industrialization and improve the economic benefits of beef cattle breed. This paper provides a reference for the research and application of new breeding and propagation techniques of beef cattle.
基金supported by the National Natural Science Fundation of China(30730029)
文摘We investigated the early embryonic and larval development of the concave-eared torrent frogs, Odorrana tormota （Amphibia, Anura, Ranidae）. Embryos were derived from artificial fertilization of frogs’ eggs, and the staging of development was based on morphological and physiological characteristics. Two major periods of development were designated： i） early embryonic period, from fertilization to operculum completion stage, lasted for 324 h at water temperature （WT） 18 ？23℃; ii） larval period, from operculum completion stage to tail absorbed stage, took 1207 h at WT 20 ？ 24℃. Tadpoles of the concave-eared torrent frogs showed no evidence of abdominal sucker. Absence of this key characteristic supports the view from molecular systematics that concave-eared torrent frog does not belong to the genus Amolops. Two cleavage patterns were observed in embryos at 8-cell and 16-cell stages, with Pattern I2 （latitudinal cleavage at the 8-cell stage, and meridional cleavage at the 16-cell stage with two perpendicular meridional furrows） being the predominant pattern and only 1.5% belonging to Pattern II （meridional cleavage at the 8-cell stage and latitudinal cleavage at the 16-cell stage）. The factors affecting cleavage and hatching ratios, developmental speed, and ecological adaptation were discussed.
