Category: DNA

Posted on

Long-crowing chicken origins

You may have noticed a neat new feature on the blog. There’s a “Show on map” link after some of the latest postings which whisks you off to a pointer to the geographic location of the story. Jeremy will say a bit more about how he did it and why later on. I bring it up now because it was the reason why I stumbled on an interesting paper.

You remember that video of the long-crowing chicken from a few days back? Well, how do you geo-tag that? Where does the weird creature come from? The caption on MySapceTV says that it is a pure-bred Totenko cockerel. If you google that, one of the things you get pointed to is a DNA study that suggests that this and a couple of other long-crowers were bred on Okinawa from fighting cocks from southern China or Indochina. Want to see exactly where Okinawa is? Click below…

Posted on

How the cat became a pet

A DNA study of almost a thousand wild and domestic cats from around the world is helping to unravel the evolutionary history of this most numerous of household pets. There are five wild subspecies of nearest-relatives, including one in the Near East, from which all domesticated cats are derived, though there has been subsequent hybridization of house cats with local wild populations here and there. Modern cat breeds can trace their origin to at least five mothers domesticated in the Fertile Crescent around the same time as agriculture started, over 9,000 years ago. And, coincidentally, there’s news also today of archaeological evidence from nearby Cyprus backing up that date.

Posted on

It’s a wise grape that knows its own father

In the annals of plant breeding there are many stories that have achieved the status of Truth. Like the discovery of the original pink grapefruit, the parent tree marked forever with a P carved in its trunk, or the Red Delicious apple found in a ditch somewhere. Not quite so well known is the tale of Cardinal grapes. It is a delicious table grape that, so the story goes, was bred in 1939 at the Horticultural Field Station in Fresno, California, by E. Snyder and F. Harmon, by crossing Flame Tokay and Ribier.

Alas, it ain’t so.

Flame Tokay is normally considered a synonym — just another name — for Ahmer Bou Amer, an Algerian table grape. In the course of examining the DNA of a bunch of Mediterranean grape varieties, A. Akkak, P. Bocacci and R. Rotta ((Cardinal grape parentage: a case of a breeding mistake. Genome 50(3): 325-328 (2007) doi:10.1139/G06-145)) discovered that Flame Tokay could not possibly have been a parent of Cardinal, though they cannot show who is either. I don’t imagine E. Snyder or F. Harmon is still around to tell us what really happened. The researchers also prove that Flame Tokay is not merely a synonym of Ahmer Bou Amer but a mutant in at least one gene.

And in other grape news, two scientists in Switzerland are warning that the American Vitis rootstocks that saved the European wine industry from Phylloxera are threatening the survival of native wild European grapevines. ((Arrigo N, Arnold C (2007) Naturalised Vitis Rootstocks in Europe and Consequences to Native Wild Grapevine. PLoS ONE 2(6): e521. doi:10.1371/journal.pone.0000521)) Nils Arrigo and Claire Arnold say that:

The regrouping of naturalised rootstocks in interconnected populations tends to create active hybrid swarms of rootstocks. The rootstocks show characters of invasive plants. The spread of naturalised rootstocks in the environment, the acceleration of the decline of the European wild grapevine, and the propagation of genes of viticultural interest in natural populations are potential consequences that should be kept in mind when undertaking appropriate management measures.

In other words, watch out.

The American rootstocks have already displaced wild grapes from the flood plains of the Rhone, and there may be worse in store.