African Journal of Biotechnology Vol. 2 (10), pp. 341-344, October 2003

ISSN 1684-5315  © 2003 Academic Journals

Full Length Research Paper

Sequence heterogeneity of the envelope-like domain in the Egyptian cotton Gossypium barbadense

Abdel Ghany A. Abdel Ghany¹ and Essam A. Zaki^2*

¹Institute of Efficient Productivity, Zagazig University, El Zagazig, Egypt.

²Genetic Engineering and Biotechnology Research Institute, GEBRI, Research Area, Borg El Arab, Post Code 21934, Alexandria, Egypt.

*Corresponding author; Essam A. Zaki, Current Address: Department of Biological Sciences, 1392 Lilly Hall of Life Sciences, West Lafayette, IN 47907-1392, Phone (765) 494-9837 Fax (765) 496-1496, E-mail: ezaki@purdue.edu.

Abbreviations; LTR: long terminal repeat, ORF: open-reading frame, PCR: polymerase chain reaction, RT: reverse transcriptase gene.

Accepted 15 September 2003  

The current study aimed to investigate the evolution of env-like sequences in the Egyptian cotton Gossypium barbadense. DNA sequence determination and analysis of env-like sequences revealed that these sequences are heterogeneous in G. barbadense. The observed sequence diversity, however, seems to preserve the coding information. Phylogenetic analysis demonstrated that plant env-like sequences group together, suggesting their monophyletic origin. Gossypium env-like sequences are, however, more closely related to elements present in other plant species.  Our result suggests that env-like sequences in cotton have evolved under functional constraint and likely to play a role in the life cycle of these elements.

Key words: Envelope, Gossypium, gypsy, plant retroviruses, retrotransposons, retroviruses, reverse transcriptase.