Effects of gravity,microgravity or microgravity simulation on early mouse embryogenesis:A review of the first two space embryo studies

Many simulated micro-gravity(micro-G)experiments on earth suggest that micro-G conditions are not compatible with early mammalian embryo development.Recently,the first two“space embryo”studies have been published showing that early mouse embryo development can occur in real microgravity(real micro-G)conditions in orbit.In the first of these studies,published in 2020,Lei and collaborators developed automated mini-incubator(AMI)devices for mouse embryos facilitating cultivation,microscopic observation,and fixation1.Within these AMI apparatuses,3400 non-frozen 2-cell embryos were launched in a recoverable satellite,experiencing sustained microgravity(~0.001G)for 64 h post-orbit before fixation in space and recovery on earth.In a subsequent study,in 2023,Wakayama and colleagues2 devised Embryo Thawing and Culturing(ETC)devices,enabling manual thawing,cultivation,and fixation of frozen 2-cell mouse embryos by a trained astronaut aboard the International Space Station(ISS).Within the ETCs,a total of 7202-cell mouse embryos underwent thawing and cultivation for 4 days on the ISS,subject to either microgravity(n?360)and simulated-1G(n?360)conditions.The primary findings from both space embryo experiments indicate that mouse embryos can progress through embryogenesis from the 2-cell stage to the blastocyst stage under real micro-G conditions with few defects.Collectively,these studies propose the potential for mammalian reproduction under real micro-G conditions,challenging earlier simulated micro-G research suggesting otherwise.

Effect of gravistimulation on amino acid profile of pea,rice,corn,wheat during early growth stages

The amino acids are one of the major cellular components of plants,which are involved in different metabolic pathways.In present study,effect of artificial gravistimulation on amino acid profiles of pea,rice,corn,wheat during early growth stages was investigated.One-axis clinostat was used for gravistimulation application,which was applied at embryonic stage.Amino acid profile was measured in 10-days old seedlings of pea,rice,corn and wheat cultivars.The effect of clinostat rotation was also evaluated under salt stress and MS medium supplement.Germinated pea,rice,corn and wheat seedlings were grown under the gravity condition for specific time interval.Corn and wheat seeds showed slowgermination as compared to pea and rice cultivars.The rate of amino acid formation under gravity condition was significantly higher than control(un-treated seedling).The variation in amino acid profile of pea,rice,corn and wheat cultivars vary deferentially.Results revealed that gravistimulation applied through clinostat has positive effect on amino acid profile in plant tissue and future studies should be focused on growth,biochemical,physiological at lateral stages of growth.

Cell responses of Dunaliella salina FACHB 435 (Green Alga) to microgravitational stimulation by clinorotation

Clinorotation experiments were established to simulate microgravity on ground. It was found that there were obvious changes of Dunaliella salina FACHB435 cells and their metabolic characteristics during clinorotation. The changes included the increases of glycerol content, the rate of H + secretion and PM H + ATPase activity, and the decrease of ratio of the plasma membrane (PM) phospholipid to PM protein. These results indicated that microgravity was a stress environment to Dunaliella salina . It is deduced that it would be possible to attribute the effect of microgravity on algal cells to the secondary activation of water stress.