The scientists of the Weizmann Institute, together with an international team of researchers, decoded the genome of "Pharisee Darwin"

A joint effort of a number of large research teams from around the world, including Prof. Doron Lantz and Dr. Tzvia Olander from the Department of Molecular Genetics at the Weizmann Institute of Science, recently led to the determination of the complete genetic sequence of the Zebra Finch and its decoding

"Darwin's Pharisees" (which are, in fact, a group of 14 species of gibbons originating from the Galapagos Islands and the Cocos Islands) have a place of honor in the history of science, as those who inspired the development of the idea of ​​evolution through natural selection. Today, more than 150 years after Darwin's journey aboard the Beagle, it turns out that research on the Pharisees is still ongoing. A joint effort by a number of large research teams from around the world, including Prof. Doron Lantz and Dr. Tzvia Olander from the Department of Molecular Genetics at the Weizmann Institute of Science, recently led to the determination of the complete genetic sequence of the Zebra Finch and its decoding. The detailed genomic information about this songbird - published in the scientific journal Nature, is particularly significant for understanding the evolution of the process of learning language and speech. For Prof. Lantz and Dr. Olander, this is another step in the ongoing effort to decipher the evolution of the sense of smell.

Songbirds - like humans, and like a small number of other animals - are capable of sophisticated and varied communication through the production of sounds. The similarity between birdsong and human language makes it possible to use songbirds as a model for understanding how this ability developed, and to understand how it is implemented, what are the neural mechanisms that activate it, and which genes enable its existence. Decoding the genome of the zebra finch contributes to a detailed and deep understanding of the genetic basis for these abilities and behaviors, and how they evolved. Thus, for example, the research findings show that a significant portion of the genes expressed in the brain are related to vocal communication. In addition, the researchers found several genes (that produce microRNA) whose level of expression in the brain changes following exposure to singing. These findings imply that changes in these genes are involved, apparently in the songbirds' ability to learn new melodies.

"The senses are a sophisticated method of communicating with the environment, which is why they attract a lot of attention. We are mainly interested in the sense of smell," says Dr. Olander, who joined the project, together with Prof. Lantz, in order to map the genes that code for the olfactory receptors of the zebra finch. The identification of the bird's olfactory receptors is of special significance, since in the past there were disagreements in the scientific community regarding the very existence and usefulness of a sense of smell in birds. However, in some birds, evidence was found of the great importance of the sense of smell, as in the case of carrier pigeons, which find their way to the base of the "home", among other things, through smells.

One of the possibilities to resolve this dispute is to count the number of genes coding for odor receptors, and to determine - through computer analysis of the genetic sequence - what percentage of these genes actually produce an active receptor. Thus, for example, 500 receptor genes were found in the chicken, but only 70 of them produce a normal receptor. The zebra finch has almost the same total number of smell genes, but the number of active genes is three times greater: about 200 genes have the potential to create a normal receptor. These data support the belief that this bird does use the sense of smell.

In addition, comparing the genetic sequences of the zebra finch with those of birds of other species sheds light on the evolution of the sense of smell in winged animals: unlike mammals, where there is great similarity in the genetic sequence of the olfactory receptors in different species, it was found that 95% of the receptors in the finch are unique to this species. It seems, then, that in each species of bird a separate array of smell receptors was formed, and they were not derived from a common avian ancestor. Prof. Lantz: "This finding has implications for the function of smell in the nesting bird - it is possible that odorants are involved in unique communication between individuals of the same species, in addition to communication through song sounds."

For articles published by Doron Lantz in Barat Hidan