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Studies of transport modalities and expression of wild and mutant horn genes

Mutations can be viewed as a "noise" event at the molecular level. And there is lots of noise in Chennai - so there are many opportunities for mutation of mission-critical genes - insertion, deletion, replacement and post-translational alteration. Here are a few examples of noise making devices, the proteins resulting from altered gene expression in Chennai

We selected the horn gene because of its high prevelance, and the ease with which one can observe mutant events. Basically the horn gene expresses two subunits - the "bulb" and the "trumpet". At this point of our studies, its not clear whether expression of bulb and trumpet actually arises from a single expression of the horn gene or whether they are in fact, the result of co-expression of a bulb gene and a trumpet gene. In either case, expression of the horn gene results in a "horned" auto while failure to express results in the "hornless" auto. Within the class of horned autos, we have observed both gene products (bulb and trumpet) as well as bulbless and trumpless horns. Bulbs vary in size - while trumpets vary in configuration (see bottom of this page for examples).

In any study of noise, its necessary to first establish a baseline. We start with a summary of various modes of transport seen on the streets of Chennai. So here is a nice view of Mt Road with motorcycles and distant bus:

There is the usual spectrum of transport - ranging from the automobile to ladies (I never saw a man carrying something on his head). motorized 3 wheeler with driver:

There is the auto-rickshaw - a sort of three wheel contraption, equipped with noise-making horn and sometimes grumpy driver

There are bicycles

Then there are tricycles

and some unusual 2 wheet barrel transporter:

Here is a frequently seen transport - the oxcart - usually without ox. This one travels up and down TTK road, moving dirt between two locations. This morning - the driver stopped for a position in our photo-essay.

Finally, there is the real king of the law of large noises - the bus

and water trucks and lorries

Altered Expression and Regulation of Noise Making Device Genes

Horns on auto-rickshaws are quite varied - but - as with genes - there seems to be a theme, with variations based on insertion, deletion and replacements of components. First there is the hornless and horned auto, the result of expression or repression of the horned gene:

There are two primary components - the bulb, and the trumpet. Here, we can see insertion and deletion at work. note a bulbless:

and trumpetless horn:

Here are examples of mutant horns (bulbless [deletion] and broken):

With bulb, but broken

Here is an example of overexpression of the bulb gene and underexpression of the trumpet gene

Finally, here is an example of correct expression, but a post-translational alteration resulted in a spiral trumpet:

[Nore on Dec 18] Yesterday, I had the good fortune to catch an auto equipped with an overexpressed trumpet.

As seen form the inside - here is what the overexpressed bulb looked like

And you can get a very good impression of use - after viewing this photo taken along the longitudinal axis of the trumpet and then observing the driver's perpendicular arm angle when squeezing the bulb.

[Dec 19 2002] Today we discovered an interesting variant of the expressed products of the horn gene: the double-trumpet gene:

The double trumpet protein produces a trumpet with a treble sound - in constrast to the spiral trumpet described above (which makes a deep bass sound). The double trumpet is also played in a different manner than the spiral trumpet. I did not realize this until our long trip yesterday during which I was able to carefully watch the playing of the bulb and the resultant noise. The spiral trumpet bulb is played with individual fingers, creating depressions in the bulb, resulting in individual notes. The double trumpet bulb is played with the complete hand, creating a single depression in the bulb with a resultant dual-tone noise. Compare the placement of hand and fingers in the above photo of the spiral bass horn with the placement of hand and fingers of the double trumpet horn below. Shown here is the double trumpet horn, in the armed position and being played:

The result is quite interesting and when stopped, the double trumpet equipped auto is the source of admiration from local children:

Last Days - waking up with TTK Road

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This work is licensed under a Creative Commons License.

C. Frank Starmer