What is the Snail/Slug family of gene repressors?

[Bill Angel]

Here is a title and abstract from a review paper. It mentions that the Snail/Slug family of gene repressors figure in the understanding of the development of cancer.

Can anyone explain a bit what the Snail/Slug family of gene repressors are and what they have to do with snails and slugs?

A copy of the review paper is attached to this message.

Snail/Slug family of repressors: slowly going into the fast lane of development and cancer
The existence of homologous genes in diverse species is intriguing. A detailed comparison of the structure and function of gene families may provide important insights into gene regulation and evolution. An unproven assumption is that homologous genes have a common ancestor. During evolution, the original function of the ancestral gene might be retained in the different species which evolved along separate courses. In addition, new functions could have developed as the sequence began to diverge. This may also explain partly the presence of multipurpose genes, which have multiple functions at different stages of development and in different tissues. The Drosophila gene snail is a multipurpose gene; it has been demonstrated that snail is critical for mesoderm formation, for CNS development, and for wing cell fate determination. The related vertebrate Snail and Slug genes have also been proposed to participate in mesoderm formation, neural crest cell migration, carcinogenesis, and apoptosis. In this review, we will discuss the Snail/Slug family of regulators in species ranging from insect to human. We will present the protein structures, expression patterns, and functions based on molecular genetic analyses. We will also include the studies that helped to elucidate the molecular mechanisms of repression and the relationship between the conserved and divergent functions of these genes. Moreover, the studies may enable us to trace the evolution of this gene family.

 

Thanks.

hemavathy2000.pdf

[CharonY]

Ah the joy of name gene loci. As far as I recall one of the first member of this family was functionally characterized by Nuesslein-Vollhard in Drosophila melanogaster (i.e. fruit fly). I do not know precisely how the name was coined, though one should keep in mind that the naming conventions in those days (around the 80s) were much looser than after the all the genome sequencing projects. I believe it was initially termed sna (though I cannot really tell what the origin of that was). I guess that either it was colloquially called snail (e.g. based on using SNAI as the protein name) and it stuck. A different member of the same family was subsequently named esg (escargot) and a members of a new subfamily were termed slug.

So basically they have little to do with actual snails. That being said, they are zinc finger (a special domain involved in DNA binding) proteins that regulate expression of genes that are involved in cell movement. Initially discovered for their role in embryogenesis (which requires significant cell rearrangements). Cancer cells share many similarities of undifferentiated (embryonic) cells and these regulators appear to be involved in this.

Anything specific that you are wondering about?

[Bill Angel]

Thanks for the informative reply. What prompted the query was a discussion I encountered about this news article:
Feds Spending $880,000 to Study Benefits of Snail Sex

As you pointed out, there is a connection between the Snail/Slug family of gene regulators and cancer activity. I had hoped that there was a connection between the study of these gene regulators and the study of snails and slugs, as such a connection would bolster the argument that studying the biology of these animals (including their reproductive activities) could be of benefit in improving the health of humans.

Can't blame biologists for having a little fun in choosing names. In physics there are name associations that also are intriguing:
A Weakly Interacting Massive Particle is known as a WIMP, while a
Massive Astrophysical Compact Halo Object, is designated as a MACHO

[CharonY]

The question with regards to the benefits of sexual reproduction is a fairly fundamental one and as such does not easily lead into questions of medical research. That being said, understanding physiology and genetics of other animals greatly benefits our understanding of human physiology and genetics, as the example of the snail genes in Drosophila have shown (and many, many other examples).

 

It is a bit sad if fundamental research is often being slashed in favor of immediate applied research. I always feel that we really should do more to address biological fundamentals instead of aiming straight for cancer cure without properly understanding the underlying cell biology.