PNAS is the world's most-cited multidisciplinary scientific serial. It publishes high-impact research reports, commentaries, perspectives, reviews, colloquium papers, and actions of the Academy. In ...

(PhysOrg.com) -- It had long been assumed that the human sperm cell’s mission in life ended once it had transferred its freight of parental DNA to the egg. More recently however, other components of ...

In the animal kingdom, sperm usually are considerably smaller than eggs, which means that males can produce far more of them. Large numbers of tiny sperm can increase the probability of successful ...

The DNA molecule is not naked in the nucleus. Instead, it is folded in a very organized way by the help of different proteins to establish a unique spatial organization of the genetic information.

It had long been assumed that the human sperm cell's mission in life ended once it had transferred its freight of parental DNA to the egg. More recently however, other components of sperm have been ...

In the first hours of life, all animals undergo a fascinating process. Following fertilization, two highly specialized cells, the egg and the sperm, unite to create an entirely new organism with its ...

An in depth discussion of contemporary topics related to reproduction and embryogenesis. Lecture material is supplemented with reading assignments in a recently published textbook and current ...

The fruit fly Drosophila bifurca is only a few millimeters in size but produces sperm that are almost six centimeters long. An international team of researchers headed by the University of Zurich now ...