نتایج جستجو برای: gamete
تعداد نتایج: 2451 فیلتر نتایج به سال:
With the increase in survivorship following cancer for women in their reproductive years, as well as an increase in survivorship with childhood cancers, there is a demand for perfecting current fertility preservation methods and generating new options for patients who are unable to pursue the conventional course of fertility treatments. Cryopreservation using a slow-cooling method for embryos i...
The role of the male gamete-the sperm cell-in the process of fertilization is to recognize, adhere to, and fuse with the female gamete. These highly specialized functions are expected to be controlled by activation of a unique set of genes. However, male gametic cells traditionally have been regarded as transcriptionally quiescent because of highly condensed chromatin and a very reduced amount ...
An increasing number of molecular studies are indicating that, in a wide variety of species, genes directly related to fertilization evolve at extraordinarily high rates. We try to gain insight into the dynamics of this rapid evolution and its underlying mechanisms by means of a simple theoretical model. In the model, sexual selection and sympatric speciation act together in order to drive rapi...
Marine species with high dispersal potential often have huge ranges and minimal population structure. Combined with the paucity of geographic barriers in the oceans, this pattern raises the question as to how speciation occurs in the sea. Over the past 20 years, evidence has accumulated that marine speciation is often linked to the evolution of gamete recognition proteins. Rapid evolution of ga...
Reproductive isolation is pivotal to maintain species separation and it can be achieved through a plethora of mechanisms. In addition, the development of barriers to gamete interaction may drive speciation. Such barriers to interspecific gamete interaction can be prezygotic or postzygotic. Considering the great diversity in animal species, it is easy to assume that regulation of the early steps...
Both gamete competition and gamete limitation can generate anisogamy from ancestral isogamy, and both sperm competition (SC) and sperm limitation (SL) can increase sperm numbers. Here, we compare the marginal benefits due to these two components at any given population level of sperm production using the risk and intensity models in sperm economics. We show quite generally for the intensity mod...
Kin selection on one hand, and gamete interactions in post-ejaculatory sexual the other are two major research themes that have risen to prominence over past half century simultaneously developed into central fields of evolutionary biology. There is a natural connection between two: when gametes interact with each other, very commonly many them originate from same parent thus siblings. For exam...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید