Feed aggregator

Growing demand for oil will lead to shortage and high prices in 2020s

Genetics - Tue, 2018-11-13 02:01
Even if governments step up action on energy, fossil fuel consumption will keep growing for at least another 20 years according to a major new report
Categories: Biology

Spore-autonomous fluorescent protein expression identifies meiotic chromosome mis-segregation as the principal cause of hybrid sterility in yeast

PLOS Biology (new articles) - Tue, 2018-11-13 00:00

by David W. Rogers, Ellen McConnell, Jasmine Ono, Duncan Greig

Genome-wide sequence divergence between populations can cause hybrid sterility through the action of the anti-recombination system, which rejects crossover repair of double strand breaks between nonidentical sequences. Because crossovers are necessary to ensure proper segregation of homologous chromosomes during meiosis, the reduced recombination rate in hybrids can result in high levels of nondisjunction and therefore low gamete viability. Hybrid sterility in interspecific crosses of Saccharomyces yeasts is known to be associated with such segregation errors, but estimates of the importance of nondisjunction to postzygotic reproductive isolation have been hampered by difficulties in accurately measuring nondisjunction frequencies. Here, we use spore-autonomous fluorescent protein expression to quantify nondisjunction in both interspecific and intraspecific yeast hybrids. We show that segregation is near random in interspecific hybrids. The observed rates of nondisjunction can explain most of the sterility observed in interspecific hybrids through the failure of gametes to inherit at least one copy of each chromosome. Partially impairing the anti-recombination system by preventing expression of the RecQ helicase SGS1 during meiosis cuts nondisjunction frequencies in half. We further show that chromosome loss through nondisjunction can explain nearly all of the sterility observed in hybrids formed between two populations of a single species. The rate of meiotic nondisjunction of each homologous pair was negatively correlated with chromosome size in these intraspecific hybrids. Our results demonstrate that sequence divergence is not only associated with the sterility of hybrids formed between distantly related species but may also be a direct cause of reproductive isolation in incipient species.
Categories: Biology, Journals

An extinct monkey evolved to live like a sloth in the Caribbean

Genetics - Mon, 2018-11-12 22:00
Jamaica was once home to a sloth-like monkey – now we know it was a strange descendant of South America’s titi monkeys that adapted to island life
Categories: Biology

An extinct monkey evolved to live like a sloth in the Caribbean

HIV and AIDS - Mon, 2018-11-12 22:00
Jamaica was once home to a sloth-like monkey – now we know it was a strange descendant of South America’s titi monkeys that adapted to island life

An extinct monkey evolved to live like a sloth in the Caribbean

Genetically modified organisms (GMO) - Mon, 2018-11-12 22:00
Jamaica was once home to a sloth-like monkey – now we know it was a strange descendant of South America’s titi monkeys that adapted to island life
Categories: Science and society

Earliest known animal might have inflated its body like a balloon

Genetics - Mon, 2018-11-12 18:40
Dickinsonia lived about 560 million years ago and may have been the first animal – but it seems to have inflated its body in a way no animals do today
Categories: Biology

Earliest known animal might have inflated its body like a balloon

HIV and AIDS - Mon, 2018-11-12 18:40
Dickinsonia lived about 560 million years ago and may have been the first animal – but it seems to have inflated its body in a way no animals do today

Earliest known animal might have inflated its body like a balloon

Genetically modified organisms (GMO) - Mon, 2018-11-12 18:40
Dickinsonia lived about 560 million years ago and may have been the first animal – but it seems to have inflated its body in a way no animals do today
Categories: Science and society

Pluto’s weird ridges may be glacial landforms unlike any on Earth

Genetics - Mon, 2018-11-12 18:00
Next to Pluto’s heart-shaped plains are strange rolling hills unlike anything we’ve seen on Earth, and they may be left over from receding ancient glaciers
Categories: Biology

Pluto’s weird ridges may be glacial landforms unlike any on Earth

HIV and AIDS - Mon, 2018-11-12 18:00
Next to Pluto’s heart-shaped plains are strange rolling hills unlike anything we’ve seen on Earth, and they may be left over from receding ancient glaciers

Pluto’s weird ridges may be glacial landforms unlike any on Earth

Genetically modified organisms (GMO) - Mon, 2018-11-12 18:00
Next to Pluto’s heart-shaped plains are strange rolling hills unlike anything we’ve seen on Earth, and they may be left over from receding ancient glaciers
Categories: Science and society

We’ve discovered a whole new defence system against germs in our noses

HIV and AIDS - Mon, 2018-11-12 14:00
Billions of tiny sacs filled with weapons and warning signals to other cells are released into the lining of our noses when dangerous bacteria are detected

The day a Siberian tiger nearly killed me

Genetically modified organisms (GMO) - Mon, 2018-11-12 14:00
Pavel Fomenko patrols the icy and dangerous forests of Russia’s far east to protect its big cats. But the worst happened when he least expected it
Categories: Science and society

We’ve discovered a whole new defence system against germs in our noses

Genetically modified organisms (GMO) - Mon, 2018-11-12 14:00
Billions of tiny sacs filled with weapons and warning signals to other cells are released into the lining of our noses when dangerous bacteria are detected
Categories: Science and society

The day a Siberian tiger nearly killed me

Genetics - Mon, 2018-11-12 14:00
Pavel Fomenko patrols the icy and dangerous forests of Russia’s far east to protect its big cats. But the worst happened when he least expected it
Categories: Biology

We’ve discovered a whole new defence system against germs in our noses

Genetics - Mon, 2018-11-12 14:00
Billions of tiny sacs filled with weapons and warning signals to other cells are released into the lining of our noses when dangerous bacteria are detected
Categories: Biology

The Wider Earth review – Darwin’s Beagle days make a gripping play

Genetically modified organisms (GMO) - Mon, 2018-11-12 11:00
An unusual venue stages an intriguing play about Darwin's Beagle days as London's Natural History Museum turns theatrical–with superb puppets as exotic wildlife
Categories: Science and society

The Wider Earth review – Darwin’s Beagle days make a gripping play

Genetics - Mon, 2018-11-12 11:00
An unusual venue stages an intriguing play about Darwin's Beagle days as London's Natural History Museum turns theatrical–with superb puppets as exotic wildlife
Categories: Biology

Monkeys and dogs judge humans by how they treat others

Genetics - Sat, 2018-11-10 12:00
Experiments show that both canines and capuchins prefer those of us who help other people, hinting that morality may have a more-ancient origin than thought
Categories: Biology

Monkeys and dogs judge humans by how they treat others

Genetically modified organisms (GMO) - Sat, 2018-11-10 12:00
Experiments show that both canines and capuchins prefer those of us who help other people, hinting that morality may have a more-ancient origin than thought
Categories: Science and society