EVOLUTIONARY RELATIONSHIP OF LOW DENSITY LIPOPROTEIN RECEPTOR (LDLR) GENE
Fauzia Imtiaz, Nusrat Jabeen, Mushtaq Hussain
Department of Molecular Pathology, DDRRL, Dow University of Health Sciences,Karachi-Pakistan.
Abstract:
Introduction: Low-density lipoprotein is essential constituent part of cholestrol metabolism. Normally LDL enters into the cell via specific receptor ascribed as Low Density Lipoprotein Receptor (LDLR). Truncation of the said gene(s) may result in the impairment of the LDLR receptor that entails the increased concentration of cholestrol in blood (hypercholesteroleamia). The condition may render premature heart attacks, artherosclerosis, xanthometa and xantholesma formation etc.
Objective: The present study is designed to unravel the evolutionary history of the said genes among different phylogenetic groups of life forms.
Study Design: The study is based on in-silico analysis of gene variations.
Place and Period of Study: Department of Molecular Pathology, DDRRL, Dow University of Health Sciences, Karachi-Pakistan. (March- September 2011)
Methods: The gene sequeunce of LDLR was retrieved from NCBI database and subjected to non-redundant blasting of 1000 hits. Multiple sequence alignment of the selected sequences was conducted and phylogenetic tree was constructed by UPGMA and/or Neighbor joining methods. Boot strapping was exploited to calculate lineage distance.
Results: The cladogram indicates the ancestral presence of the LDLR genes among different taxonomic groups of animals. Important structural and functional variations have been noticed among primates, chordates and invertebrates. The sequential variations have been found increased according to the evolutionary placement of the group to which the organism(s) belong.
Conclusion: The findings suggest that phylogenetic tree based on LDLR may be explored for the classification of animals as earlier based on 23srRNA tree. Additionally, it may also provide more insights regarding the ancestral root of the anomalies associated with LDLR.
Keywords:LDLR, Cholesterol, Evolution and Hypercholesteroleamia.