Characterization of heterogeneity in Ty1-copia GROUP retrotransposons in chickpea (Cicer arietinum L.).

Retrotransposons represent a major fraction of the plant genome and play a significant role in the molecular evolution through sequence re-organization. In order to access the diversity in Ty1-copia group of retrotransposons in chickpea, reverse transcriptase (RT) conserved domain specific primers were selected to amplify RT conserved sequences. Thirty-six amplified fragments were cloned and characterized. On the basis of deduced amino acid homology among them, these sequences were grouped into five families. These sequence families showed from 34 to 81% inter-family homology at the amino acid level. Although these sequences belong to a highly conserved region no two sequences were identical. The results show that there is a high degree of heterogeneity among the Ty1-copia group of retroelements in chickpea. The genomic Southern hybridization with one of the reverse transcriptase sequences as a probe shows the presence of a large population of the Ty1-copia group of retrotransposons in chickpea.