Estimation of evolutionary distance between nucleotide sequences
A mathematical formula for estimating the average number of nucleotide substitutions per site (delta) between two homologous DNA sequences is developed by taking into account unequal rates of substitution among different nucleotide pairs. Although this formula is obtained for the equal-input model of nucleotide substitution, computer simulations have shown that it gives a reasonably good estimate for a wide range of nucleotide substitution patterns as long as delta is equal to or smaller than 1. 
Long-range correlations in nucleotide sequences
DNA SEQUENCES have been analysed using models, such as an it-step Markov chain, that incorporate the possibility of short-range nucleotide correlations1. We propose here a method for studying the stochastic properties of nucleotide sequences by constructing a 1:1 map of the nucleotide sequence onto a walk, which we term a ‘DNA walk’. We then use the mapping to provide a quantitative measure of the correlation between nucleotides over long distances along the DNA chain. Thus we uncover in the nucleotide sequence a remarkably long-range power law correlation that implies a new scale-invariant property of DNA. We find such long-range correlations in intron-containing genes and in nontranscribed regulatory DNA sequences, but not in complementary DNA sequences or intron-less genes. 
Estimation of evolutionary distances between homologous nucleotide sequences
By using two models of evolutionary base substitutions–“three-substitution-type” and “two-frequency-class” models–some formulae are derived which permit a simple estimation of the evolutionary distances (and also the evolutionary rates when the divergence times are known) through comparative studies of DNA (and RNA) sequences. These formulae are applied to estimate the base substitution rates at the first, second, and third positions of codons in genes for presomatotropins, preproinsulins, and alpha- and beta-globins (using comparisons involving mammals). Also, formulae for estimating the synonymous component (at the third codon position) and the standard errors are obtained. It is pointed out that the rates of synonymous base substitutions not only are very high but also are roughly equal to each other between genes even when amino acid-altering substitution rates are quite different and that this is consistent with the neutral mutation-random drift hypothesis of molecular evolution. 
Genotyping and Nucleotide Sequences of Growth Hormone Releasing Hormone and Its Receptor Genes in Egyptian Buffalo
Aim: The hypothalamic hormone, growth hormone-releasing hormone, is the principal stimulator of pituitary growth hormone (GH) synthesis and secretion. GHRH and its receptor (GHRHR) provide important functions in the regulation of the GH axis and in the development and proliferation of pituitary somatotropic axis. This study aimed to identify the genotypes and nucleotide sequences of two multifunctional genes; growth hormone-releasing hormone (GHRH) and its receptor (GHRHR) in Egyptian buffalo. 
Sequence Variations of Human Papillomavirus Type 16 E6 and E7 Genes in Cervical Cancer Isolates from Gabon
Aims: HPV-16 variants distribution is reported to differ geographically and in their oncogenic potential for progression to cervical cancer. In this study, we investigated the HPV 16 variants distribution among women from Gabon.
Methodology: Amplification of E6 and E7 genes of 29 HPV-16 isolates was performed by using type-specific primers PCR and then directly sequenced. The sequences obtained were aligned with the HPV-16 GenBank reference sequences. 
 Tajima, F. and Nei, M., 1984. Estimation of evolutionary distance between nucleotide sequences. Molecular biology and evolution, 1(3), pp.269-285.
 Peng, C.K., Buldyrev, S.V., Goldberger, A.L., Havlin, S., Sciortino, F., Simons, M. and Stanley, H.E., 1992. Long-range correlations in nucleotide sequences. Nature, 356(6365), pp.168-170.
 Kimura, M., 1981. Estimation of evolutionary distances between homologous nucleotide sequences. Proceedings of the National Academy of Sciences, 78(1), pp.454-458.
 E. Othman, O., F. Abdel-Samad, M., A. Abo El-Maaty, N. and M. Sewify, K. (2014) “Genotyping and Nucleotide Sequences of Growth Hormone Releasing Hormone and Its Receptor Genes in Egyptian Buffalo”, Biotechnology Journal International, 5(2), pp. 62-71. doi: 10.9734/BBJ/2015/11619.
 Assoumou, S. Z., Boumba, L. M., Mbiguino, A., Mabika, B., Belembaogo, E., Khattabi, A. and Ennaji, M. (2016) “Sequence Variations of Human Papillomavirus Type 16 E6 and E7 Genes in Cervical Cancer Isolates from Gabon”, Microbiology Research Journal International, 8(2), pp. 386-394. doi: 10.9734/BMRJ/2015/17225.