Limb Cells Can Evolve Into Genitals In The Lab

These sea vertebrates did not require external organs for sex, while their land counterparts did. The study under consideration here discusses how these land dwelling animals developed their sex organs. This Nature research suggests that the origin of the genetic organs actually lies in the limbs – at least with lizards and snakes. In order to develop their sex organs, the snakes turn on a certain signaling center called the hemipenes. The initial stages of their genital development very closely resembles the limb development in other reptiles.

In the lab, these scientists therefore experimented with the phenomenon and found that the limb cells of these reptiles, i.e. snakes and lizards, could be turned into genitals. Similar could be done with the bud cells of mice.

It was done when these researchers moved the position of the signaling source (discussed above) called the hemipenes. The movement demonstrated flexibility, hence showing the type of cells that can be recruited for the development of genitalia. The researchers were therefore, able to show that if this signaling source was ectopically transplanted into a tail bud or the limb, they could respond in the development of the genitals.

We may also say that by misplacing the molecular signals, you could actually misguide their development.

Then the genetic components of the embryonic cells were analyzed in order to find out which genes were turned off or on by picking out the sequencing RNA. In addition, it was also found in the same process that the development of the sex organs in mice took place in their tail bud. It was solely because of the different position of the signaling source. This study hence, also defies the previous researches, which said that the limbs and the genitals had a different homology.

Co-author of this paper, Professor Martin Cohn from the Maryland Howard Hughes Medical Institute said that there was  tremendous diversity seen in the anatomical form of the external genitals as their evolution was faster than any other organ. On an overall, he suggests that the papers highlight a deep evolutionary conservation of the first steps of the genital development. These genomic and molecular tools not only helps them compare the level of relatedness between the development of various organisms but also their genetic pathways.