Influence of Different Evolutive Forces on GDF5 Gene Variability

Area of Science:

• Human population genetics
• Molecular anthropology
• Genetics of skeletal development

Background:

• The GDF5 gene plays a crucial role in skeletal development, synovial joint formation, and connective tissues.
• Specific GDF5 gene polymorphisms, rs143384 and rs143383, have been linked to osteoarticular diseases and muscle flexibility.
• Understanding the evolutionary forces shaping GDF5 polymorphism distribution is key to comprehending human adaptation and disease susceptibility.

Purpose of the Study:

• To investigate whether the global distribution of the GDF5 rs143384 polymorphism is a product of natural selection or genetic drift.
• To analyze population structure and genetic differentiation using Sardinian population data.
• To assess selective pressures on GDF5 gene regions encompassing rs143384 and rs143383 SNPs.

Main Methods:

• Genotyping of the GDF5 rs143384 polymorphism in a Sardinian cohort.
• Calculation of genotype and allele frequencies.
• Population genetic analyses including Multidimensional Scaling (MDS) and Population Branch Statistic (PBS).

Main Results:

• Observed genotype frequencies in Sardinians: 28.72% AA, 13.83% GG, 57.45% AG.
• Allele frequencies in Sardinians: A=0.574, G=0.426.
• MDS analysis revealed heterogeneity in African populations and strong differentiation from other groups, with Sardinians clustering with Europeans.
• Low PBS values for both rs143384 and rs143383 suggest no significant selective pressure in these GDF5 gene regions.

Conclusions:

• The distribution of the GDF5 rs143384 polymorphism appears to be primarily influenced by genetic drift rather than positive selection.
• Population genetic analyses confirm distinct clustering of Sardinian populations within the broader European genetic landscape.
• The findings contribute to understanding the evolutionary history of GDF5 and its role in human skeletal diversity.