Combination of L-systems: For Designing Human Olfactory Receptor Pseudo-gene, OR1D3P Sk. Sarif Hassan a, c , Pabitra Pal Choudhury a , Amita Pal b , R. L. Brahmachary c and Arunava Goswami c a Applied Statistics Unit, Indian Statistical Institute, 203 B. T. Road, Calcutta, 700108 India. pabitrapalchoudhury@gmail.com [P. P. C.]; sarimif@gmail.com [S. S. H.]; b Bayesian Interdisciplinary Research Unit (BIRU), Indian Statistical Institute, 203 B. T. Road, Calcutta, 700108 India. pamita@isical.ac.in [A. P.] c Biological Sciences Division, Indian Statistical Institute, 203 B. T. Road, Calcutta, 700108 India. agoswami@isical.ac.in [A.G.]. Keywords L-system Pseudo-gene Olfactory receptor Olfaction Footnotes To whom correspondence should be addressed E-mail: sarimif@gmail.com / agoswami@isical.ac.in Author contributions: A. G. conceptualized the experiments and performed entire research with S. S. H.; A. G. and S. S. H. acknowledges A. P., P. P. C. and R. L. B. and Ms. Rebecca French (Grad student of Prof. Michael Hochella) of Virginia Tech, USA for their enormous help while doing these series of experiments. Conflict of interest statement : The authors declare no conflict of interest. Abstract: Using a set of L-system mathematical rules, we have made a close relative of olfactory receptor sequence, OR1D3P and show that possibly pseudogene play an important role in either genome stability. These results might give clues to the reasons for presence of long stretches of non-coding regions of DNA in genome. Introduction: As per conservative estimate, approximately 51-105 Olfactory receptors (ORs) loci are present in human genome occur in clusters. These clusters are like unevenly spread mosaics and spread over 21 pair of human chromosomes. Recent studies have shown that 339 full length OR genes and 297 OR pseudogenes are present in these clusters (1). OR1D3P is one of such pseudogene located near a loci where OR1D2, OR1D4 and OR1D5 OR genes are present. Pseudogenes are known to have stop codons (TAA/TAG and TGA) in all three open reading frames. Still today, there are no valid