From the moment embryo transfer takes place up until the day when a woman takes a pregnancy test, a set of events aimed at achieving implantation (adherence of the embryo to the uterus) take place in the uterus and embryo. The process has traditionally been described as a dialogue and this is, indeed, a good way of explaining […]
What are genetics and epigenetics?
Genetics and epigenetics are two, closely-related branches of biology. The former is much more well known and consists of studying how hereditary characteristics are passed on from generation to generation. DNA is the molecule in which genetic information is stored in a 4-letter code: A, C, G and T. The combination of letters is not a matter of chance. On the contrary, they combine in a precise manner because, in living things, the 4 letters make up the code for generating the instructions (genes) for synthesising all proteins. This DNA is in the nucleus of the cells linked to the histones around which DNA wraps itself, as if it were a spool of thread. […]
Spermatozoa production takes place in the testicular seminiferous tubules and the process is known as spermatogenesis. At the end of this process, a germ cell generates 4 mature spermatozoa which will survive in the human body for between 62 and 75 days. The final stage in spermatogenesis, known as spermiogenesis, is a cell differentiation and maturation process consisting of the change from spermatids to spermatozoa. As can be seen in the picture, the spermatids develop from secondary spermatocites and have already undergone Meiosis I and II division. They have a normal set of chromosomes (haploid) which means that fertilisation of a mature egg can take place. Therefore, and despite the fact that they are immature cells, they can be used in assisted reproduction techniques using ICSI when there are no mature sperm in samples taken from the ejaculate or testicles. […]