Gephyrin

The gephyrin yin and yang sequences are prevalent today in populations representing every major human ancestry.

[11] Positive antibody staining for gephyrin at a synapse is most of the time consistent with the presence of glycine and/or GABAA receptors.

Nevertheless, some exceptions can occur like in neurons of Dorsal Root Ganglions where gephyrin is absent despite the presence of GABAA receptors.

[20] In animal models, a total lack of gephyrin results in stiff muscles and death immediately after birth.

[18] At some point in human history, there was a DNA sequence encompassing gephyrin that split and followed two divergent evolutionary paths.

[10] These types of splits can occur when two populations become isolated from each other or when a chromosomal region does not experience recombination events.

This happened in a relatively short time on an evolutionary scale, as hundreds of mutations were fixed in distinct ‘yin’ and ‘yang’ sequences prior to human migration to Asia.

[10] The existence of this massive yin-yang pattern suggests that two completely divergent evolutionary paths rapidly progressed during human history, presumably achieving the common goal of enhancing regulation of gephyrin.

Yin-yang DNA sequences encompassing human gephyrin gene. Yin-yang haplotypes arise when a stretch of DNA evolves to present two divergent forms. This image shows the states for ~1000 markers in the genomic region centered on gephyrin for 934 individuals in eight global populations. Humans carry pairs of chromosomes, so each individual possesses two copies of the gephyrin gene. Dark blue and red horizontal lines in the yin-yang region represent individuals carrying two yin and two yang haplotypes, respectively, and light blue represents individuals carrying both a yin and a yang haplotype.