Newly identified small-RNA pathway defends genome against the enemy within
Reproductive cells, such as an egg and sperm, join to form stem cells that can mature into any tissue type. But how do reproductive cells arise? We humans are born with all of the reproductive cells that ...
Study: Marmoset success with twin gestation
(Phys.org) —How can the tiny marmoset – a New World monkey – regularly successfully bear twins and sometimes triplets and quadruplets when much larger humans often face a difficult pregnancy and delivery?
Two Y genes can replace the entire Y chromosome for assisted reproduction in mice
The Y chromosome is a symbol of maleness, present only in males and encoding genes important for male reproduction. But live mouse offspring can be generated with assisted reproduction using germ cells from ...
Long-held assumption about emergence of new species questioned
Darwin referred to the origin of species as "that mystery of mysteries," and even today, more than 150 years later, evolutionary biologists cannot fully explain how new animals and plants arise.
Resurrecting ancient proteins, team finds just two mutations set stage for evolution of modern hormone signaling
Evolution, it seems, sometimes jumps instead of crawls. A research team led by a University of Chicago scientist has discovered two key mutations that sparked a hormonal revolution 500 million years ago.
Viruses impaired if their targets have diverse genes
When a viral infection spread through five genetically identical mice in a row, the virus replicated faster and became more virulent or severe. But when the infection spread one-by-one through five genetically ...
Sperm wars: Evolutionary biologist compiles international special issue on sperm competition
Why do male animals need millions of sperms every day in order to reproduce? And why are there two sexes anyway? These and related questions are the topic of the latest issue of the research journal Molecular Hu ...
That pregnant feeling makes a fly start nesting
Across the animal kingdom, it's not uncommon for pregnancy to change an expectant mom's behavior. Even female flies have their own rudimentary way of "nesting," which appears to be brought on by the stretch ...
Study sheds light on 'reinforcement' in wildflowers
Plants or animals using color to attract a mate is fairly common in nature, but for Phlox drummondii, a wildflower commonly known as Drummond's phlox, just the opposite is true.
Deploying exosomes to win a battle of the sexes
There are many biological tools that help animals ensure reproductive success. A new study in The Journal of Cell Biology provides further detail into how one such mechanism enables male fruit flies to imp ...
Population density and testes size: More than meets the eye
A team of researchers has discovered that changes in population density can affect the size of animals' testes and therefore impact on reproduction.
How plants may be evolving to the lack of bees
Plants which used to have two types of male reproductive organs – to increase their chances for fertilisation – are reverting back to one type. And in some cases, they are becoming self-fertilising.
Flower's bellows organ blasts pollen at bird pollinators
A small tree or shrub found in mountainous Central and South American rainforests has a most unusual relationship with the birds that pollinate its flowers, according to a study reported in the journal Current Bi ...
Breakthrough study solves plant sex mystery
A team of biologists from the University of Leicester has solved a mystery surrounding how plants have sex.