The recent in vitro derivation of gamete-like cells from mouse embryonic stem (mES) cells is a major breakthrough and lays down several challenges, both for the further scientific investigation and for the bioethical and biolegal discourse. We refer here to these cells as gamete-like (sperm-like or oocyte-like, respectively), because at present there is still no evidence that these cells behave...

the following 9 chapters summarize the most essential steps that through evolution led to the reproductive behaviour of humans. Hence, the text is not necessarily confined to our species. it is a brief personal view, written as background information for reproductive specialists and gynaecologists. the objective is to give a rough sketch of the evolutionary framework in which some current repro...

During fertilization in Chlamydomonas, gametes of opposite mating types interact with each other through sex-specific adhesion molecules on their flagellar surfaces. Flagellar adhesion brings the cell bodies of the gametes into close contact and initiates a signal transduction pathway in preparation for cell-cell fusion. We have identified a cDNA, gsp1, whose transcript levels are upregulated d...

Polyploidization has played a major role in the origin and evolution of polyploid species. In this article we outline the unique characteristics of 2n gametes and implications of their participation in the evolution of polyploid Solanum species. The genetic consequences of 2n gametes indicate that sexual polyploidization results in greater variability, fitness, and heterozygosity than does soma...

Fertilization in both animals and plants relies on the correct targeting of the male gametes to the female gametes. In flowering plants, the pollen tube carries two male gametes through the maternal reproductive tissues to the embryo sac, which contains two female gametes. The pollen tube then releases its two male gametes into a specialized receptor cell of the embryo sac, the synergid cell. T...

Under current UK law, an embryo cannot be transferred to a woman's uterus without the consent of both of its genetic parents, that is both of the people from whose gametes the embryo was created. This consent can be withdrawn at any time before the embryo transfer procedure. Withdrawal of consent by one genetic parent can result in the other genetic parent losing the opportunity to have their o...

Transmission-ratio distortion is a departure from a 1:1 segregation of alleles in the gametes of a heterozygous individual. The so-called driving allele is strongly selected regardless of its effect on the fitness of the carrying individual. It may then have an important impact on neutral polymorphism due to the genetic hitchhiking effect. We study this hitchhiking effect in the case of true me...

BACKGROUND Long-term follow-up on relationship quality in couples who use sperm donation is scarce. Therefore, this study aimed to analyse changes over time in satisfaction with relationship in heterosexual couples who were scheduled for treatment with sperm donation and IVF couples treated with their own gametes and to compare the two groups undergoing different treatment for infertility. ME...