Identification and phylogenetic analysis of long terminal repeat elements of the human ehdogenous retrovims K family (HEW‐K) from a human brain cDNA library

Long terminal repeats (LTRs) of the human endogenous retrovirus K family (HERV‐K) have been found to be coexpressed with sequences of genes closely located nearby. We examined transcribed HERV‐K LTR elements in human brain tissue. Using cDNA synthesized from mRNA of the human brain, we performed PCR amplification and identified ten HERV‐K LTR elements. These LTR elements showed a high degree of sequence similarity (92.4–99.7%) with the human‐specific LTR elements. A phylogenetic tree obtained by the neighbor‐joining method revealed that HERV‐K LTR elements could be divided into two groups through evolutionary divergence. Some HERV‐K LTR elements (HKL‐B7, HKL‐B8, HKL‐B10) belonging to the group II from human brain cDNA were closely related to the human‐specific HERV‐K LTR elements. Our data suggest that HERV‐K LTR element are active in the human brain; they could conceivably play a pathogenic role in human diseases such as psychosis.

Key words:

• Long terminal repeat
• HERV‐K
• Human cDNA library
• Phylogeny
• Psychosis

Notes

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