A Second “Lab Rat” has its Genome Mapped April 28, 2010Posted by ecogeeko10 in Behavior, Biology, Evolution, Genetics, Health, Neuroscience, Physiology.
trackback Many behavioral ecologists, geneticists, physiologists, etc. are familiar with the zebra finch (Taeniopygia guttata). In fact, many have considered it to be the avian version of the white lab rat. Because of this, these researchers should be excited to hear that scientists have just recently decoded the zebra finch’s genome.
A genome to explore behavior
The zebra finch isn’t the only bird to have its genome mapped (the chicken was completed first) and it’s only about one-third the size of the human genome. However, this was a unique find because it will greatly help behavioral ecologists to understand the underlying mechanisms that help baby songbirds learn how to sing from their parents. This isn’t something that could have been done with the chicken genome because chickens don’t learn how to “cluck” from their parents—they just do it. Zebra finches, on the other hand, are similar to humans because human children also learn how to speak from their parents.
The zebra finch genome gives us the opportunity to explore the influence of genetics on language development.
Researchers are already analyzing the genome and they are finding that a good portion of the bird’s DNA is actively participating in the hearing and singing of songs. What’s more, these short simple songs are rooted in a great deal of genetic complexity. To date, it has been understood that the very act of singing and hearing songs activates large, complex gene networks in the bird’s brain. However, the current genomic research is revealing there to be many more participating genes than once thought. Right now it seems that there may be approximately 800 total genes that are active in this process!
Genes not acting as genes
New evidence is also showing that many of the activated genes aren’t acting like genes in the traditional sense. Rather than coding for proteins, the DNA from these genes is transcribed into short stretches of non-coding RNA that control the expression of other genes involved in the zebra finch’s vocal communication. Since non-coding RNAs are very influential in the developmental processes in animals and since they are thought to be instrumental in the evolution of higher organisms, the vocal learning that is found in the higher organisms may use non-coding RNAs as their driving force.
The evolution of language
It is also worth noting that when comparing the newly mapped zebra finch genome with the chicken genome, there seems to be some obvious differences that may point towards the evolutionary pathway that gave rise to birds that are capable of vocal learning. For instance, the evolution of the ion channel genes—which are important players in behavior and neurological function—in the zebra finch brain were greatly accelerated; the expression of the male sex chromosome genes seems to have been modified; and the production of new variants of neurobiologically important genes have taken place. It is amazing to see how much has learned in such a short period of time!
From birds to humans
It took the combined effort of more than 20 institutions to map out the genome of this song bird and now everyone has the opportunity to reap the benefits from this work. The newly gathered information should prove to be instrumental in helping us to better understand how humans learn language and perhaps it will help neuroscientists to identify the genetic and molecular causes of certain speech disorders that are associated with various illnesses such as Parkinson’s disease, stroke, autism, etc. With the parrot genome scheduled to be completed by the end of this year, who knows what all we can learn about our little feathered friends and even ourselves!