Palaeontology News Thread

Lt. Killer M · 27-03-2009, 14:28

In this thread I'll post news from palaeontology and other related disciplines whenever I have time and find something of interest. There will be separate debate threads for topic where I expect debate.

THREAD RULES:

1) Please take your SPAM elsewhere, in order not to clutter up this thread. Use, e.g., the debate threads instead

2) Creationist are welcome to post their opinions. However, I demand that they
2a) do not c&p from elsewhere
2b) are willing to debate, not just post&run
2c) refrain from using religious texts as sources for scientific issues (asides from historical studies)

3) I'll make more rules up as I go along

Lt. Killer M · 27-03-2009, 14:33

Shared developmental mechanisms pattern the vertebrate gill arch and paired fin skeletons

http://www.pnas.org/content/early/2009/03/23/0810959106

ABSTRACT: Here, we describe the molecular patterning of chondrichthyan branchial rays (gill rays) and reveal profound developmental similarities between gill rays and vertebrate appendages. Sonic hedgehog (Shh) and fibroblast growth factor 8 (Fgf8) regulate the outgrowth and patterning of the chondrichthyan gill arch skeleton, in an interdependent manner similar to their roles in gnathostome paired appendages. Additionally, we demonstrate that paired appendages and branchial rays share other conserved developmental features, including Shh-mediated mirror-image duplications of the endoskeleton after exposure to retinoic acid, and Fgf8 expression by a pseudostratified distal epithelial ridge directing endoskeletal outgrowth. These data suggest that the skeletal patterning role of the retinoic acid/Shh/Fgf8 regulatory circuit has a deep evolutionary origin predating vertebrate paired appendages and may have functioned initially in patterning pharyngeal structures in a deuterostome ancestor of vertebrates.

So what does this all mean?
It tells us that the genetic toolkit used by vertebrates, including sharks, to create limbs is also used to create gill rays in sharks. The latter are much older, and it has long been suspected that limbs/fins are developed from them. Now, we know that however limbs arose, the genes controlling their development are an edited copy of that defining gill ray development.

Matrix · 27-03-2009, 16:57

Why does this remind me of Ross from Friends?

barbu1977 · 20-05-2009, 14:39

Is this news a scientist seeking attention or is it accurate?

http://www.nydailynews.com/news/us_w...light_on_.html

Shabbaman · 20-05-2009, 14:59

I know Sonic the Hedgehog, but I've never heared of the game Fibroblast growth factor. It must be a long running franchise, already the 8th edition!

27-03-2009, 14:28	#1
Lt. Killer M Emperor Join Date: Mar 2003 Location: HAWK!. Posts: 4,365	Palaeontology News Thread In this thread I'll post news from palaeontology and other related disciplines whenever I have time and find something of interest. There will be separate debate threads for topic where I expect debate. THREAD RULES: 1) Please take your SPAM elsewhere, in order not to clutter up this thread. Use, e.g., the debate threads instead 2) Creationist are welcome to post their opinions. However, I demand that they 2a) do not c&p from elsewhere 2b) are willing to debate, not just post&run 2c) refrain from using religious texts as sources for scientific issues (asides from historical studies) 3) I'll make more rules up as I go along __________________ One more turn..... just one more turn... one MORE! Last edited by Lt. Killer M; 27-03-2009 at 14:33.

27-03-2009, 14:33	#2
Lt. Killer M Emperor Join Date: Mar 2003 Location: HAWK!. Posts: 4,365	Shared developmental mechanisms pattern the vertebrate gill arch and paired fin skeletons http://www.pnas.org/content/early/2009/03/23/0810959106 ABSTRACT: Here, we describe the molecular patterning of chondrichthyan branchial rays (gill rays) and reveal profound developmental similarities between gill rays and vertebrate appendages. Sonic hedgehog (Shh) and fibroblast growth factor 8 (Fgf8) regulate the outgrowth and patterning of the chondrichthyan gill arch skeleton, in an interdependent manner similar to their roles in gnathostome paired appendages. Additionally, we demonstrate that paired appendages and branchial rays share other conserved developmental features, including Shh-mediated mirror-image duplications of the endoskeleton after exposure to retinoic acid, and Fgf8 expression by a pseudostratified distal epithelial ridge directing endoskeletal outgrowth. These data suggest that the skeletal patterning role of the retinoic acid/Shh/Fgf8 regulatory circuit has a deep evolutionary origin predating vertebrate paired appendages and may have functioned initially in patterning pharyngeal structures in a deuterostome ancestor of vertebrates. So what does this all mean? It tells us that the genetic toolkit used by vertebrates, including sharks, to create limbs is also used to create gill rays in sharks. The latter are much older, and it has long been suspected that limbs/fins are developed from them. Now, we know that however limbs arose, the genes controlling their development are an edited copy of that defining gill ray development. __________________ One more turn..... just one more turn... one MORE!

27-03-2009, 16:57	#3
Matrix Administrator Join Date: Mar 2003 Location: Tampere, Finland Posts: 4,828	Why does this remind me of Ross from Friends? __________________

20-05-2009, 14:39	#4
barbu1977 Emperor Join Date: Apr 2004 Location: Blame Canada!. Posts: 3,501	Is this news a scientist seeking attention or is it accurate? http://www.nydailynews.com/news/us_w...light_on_.html __________________ Postcount = Postcount + 1; //Postcount++

20-05-2009, 14:59	#5
Shabbaman Administrator Join Date: Mar 2003 Location: Costa La Haya Posts: 8,494	I know Sonic the Hedgehog, but I've never heared of the game Fibroblast growth factor. It must be a long running franchise, already the 8th edition! __________________ "Our spam is backed with COMETS!"