From chimps to chickens: how a little DNA can make a lot of difference

06 Sunday Jan 2013

Posted by sedeer in Development, Evolution, Genetics

Tags

alternative splicing, animals, biology, DNA, Gene, Genome, mammal, Messenger RNA, Popular science, RNA sequencing, RNA splicing, science, Species, Transcriptome, vertebrate

Humans and chimpanzees famously share more than 98% of their genome and yet the two species look and behave quite differently. This apparent paradox stretches well beyond our little corner of the tree of life; we share more than half our genes with chickens and those we share are 75% identical. Two studies published together in the December issue of Science tackled this perplexing discrepancy by showing that there may be more to a genome than meets the eye. Continue reading →

Gut bacteria and diabetes: the saga continues

26 Friday Oct 2012

Posted by sedeer in Bacteria, Genetics, Humans

≈ 4 Comments

Tags

Bacteria, biology, diabetes, Diabetes mellitus type 2, Gut flora, Health, metagenome, Metagenomics, Popular science, science, sequence

Type 2 diabetes is a serious global epidemic, having grown from 30 million cases to nearly 300 million over the past three decades. Although several recent studies have shown a link between type 2 diabetes and our gut bacteria, we’re still only at the dawn of learning about the microbiome. There’s a great deal we don’t yet know, including what kinds of bacteria live in our gut and how they go about making a living there. In a paper published in the September issue of Nature, a team of scientists from China and Denmark used whole genome sequencing technologies to overcome these gaps in our knowledge and get some more clues about the relationship between our gut bacteria and this disease. Continue reading →

Telling left from right: which side gets the heart?

23 Tuesday Oct 2012

Posted by sedeer in Development, Evolution, Form, Genetics, Vertebrates

≈ 3 Comments

Tags

animals, biology, Cytoskeleton, emergence, Popular science, science, shape, symmetry, Tubulin

This was originally a guest post on The Trenches of Discovery. Thanks, Shaun!

One out of every 8,000 humans is born with some of their internal organs on the wrong side of their body, a condition which can have serious medical consequences. Although we’re usually described as symmetric, that’s only superficially true. Like other vertebrates, we look symmetric from the outside but our internal organs show left-right asymmetry; unless you happen to be a Time Lord, you have only one heart which is normally located on the left side of your chest. Changes to the organization of the internal organs can lead to cardiac defects, misalignment of the bowel and other serious problems. Many genes are known to play a role in establishing this asymmetry, but we still don’t fully understand its evolutionary and developmental origins. Earlier this year, a paper published in the journal PNAS described how this asymmetry is established by subcellular components early in embryonic development.

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How short can genes get?

20 Saturday Oct 2012

Posted by sedeer in Form, Genetics

≈ 2 Comments

Tags

biology, DNA, Gene, Gene expression, genetic regulation, Polyadenylation, Popular science, Regulation of gene expression, RNA, RNA processing, science, terminator

A team of scientists at Aarhus University in Denmark reported a remarkable discovery in this month’s issue of the journal Genes & Development. Genetic regulation is a complex and intricate affair carefully orchestrated by an array of proteins and other factors. While the basics are well understood, the researchers discovered that the length of the gene itself may also have a role, adding another twist to the already complex and intricate story of genetic regulation.

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Blond Melanesians: what else are we missing?

05 Friday Oct 2012

Posted by sedeer in Evolution, Genetics, Humans

≈ 5 Comments

Tags

biology, Blond, diversity, Europeans, Genetics, Genome, Melanesians, Popular science, science, science and society, Science in Society, Solomon Islands

On the Solomon Islands in the south-eastern Pacific, it’s not uncommon to come across Melanesian children with dark skin and remarkably blond hair. While most people might take this unusual trait as a sign of European ancestry, Sean Myles wasn’t convinced. Curious to understand how the darkest skinned people outside of Africa could also have the highest frequency of blond hair outside of Europe, he led a team of scientists to unravel the genetics behind this mystery. The striking results of their research should serve as a note of caution about what we’re learning from the rapidly growing field from human genomics.
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What did we actually learn about GM foods and tumors?

26 Wednesday Sep 2012

Posted by sedeer in Genetics, Mammals

≈ 8 Comments

Tags

animals, Genetically modified food, Genetically modified maize, GMO, Monsanto, Popular science, Roundup, science, science and society, Science communication, Science in Society, Statistics

There’s been a great furor recently about a study which purports to show that rats fed GM corn develop more tumors than rats fed regular corn. I’m actually a bit late to this party; scientists and science writers across the web have already picked apart the flaws in this study, from shoddy statistics to poor design, and Carl Zimmer has called the whole thing “a rancid, corrupt way to report about science“. I don’t have much to add to the chorus; what I’d like to do with this post is to make clear to the layperson what we mean by “bad statistics” and why that makes the study unconvincing.

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