Evolutionary diversification of DYX1C1 gene transcripts by HERV-H LTR integration event Results & Discussion Abstract DYX1C1 (dyslexia susceptibility 1 candidate 1) gene on human chromosome 15q21.3 is a candidate gene for developmental dyslexia. The DYX1C1 shows three alternatively spliced transcripts in GenBank database. We found that one of transcripts is related to HERV-H LTR element that could affect the protein-coding region. The HERV-H LTR element on human DYX1C1 gene seems to have been integrated into our common ancestor genome after the divergence of Old World monkeys and New World monkeys. RT-PCR analysis of HERV-H LTR-related transcript shows that five different alternative transcripts are expressed in several human tissues. Five different alternative splicing forms are also identified in various rhesus monkey tissues. From the sequencing analysis of various primate DNA samples, we found the lineage specific tandem repeated sequences of Old World monkeys in protein coding region. However, the formation of tandem repeated sequences did not affect the amino acid sequences. Taken together, integration event of the HERV-H LTR element contributed to the DYX1C1 gene diversification by affecting protein coding region during the primate evolution.………………………………………………………………………..… Yun-Ji Kim 1, Jae-Won Huh 1, Dae-Soo Kim 2, Hong-Seok Ha 1, Kung Ahn 1, Ja-Rang Lee 1, Min-In Bae 1, and Heui-Soo Kim 1, 2 1 Division of Biological Sciences, College of Natural Sciences, Pusan National University, Busan , Republic of Korea 2 PBBRC, Interdisciplinary Research Program of Bioinformatics, College of Natural Sciences, Pusan National University, Busan , Republic of Korea Materials & Methods Plasmid DNA Isolation Transformation-Inoculation Ligation Electrophoresis-Gel purification Polymerase Chain Reaction (PCR) Gene Cloning Genomic DNAs & cDNA PCR & RT-PCR Bioinformatics QIAEX II gel extraction kit(Qiagen) High Pure plasmid isolation kit HumanMonkey NCBI,BLAST,MEGA3 Introduction Chr.15 q21.3 NM_ EXON NM_ NM_ EXON NEW TRANSCRIPTS EXON V1 V1-1 V2 V3 V1-2 V1-3 V1-4 7’7’ 8’8’ 8’8’ S AS S M HU CH GO OR GI JM RH NM SQ CM 799 bp 1.Sin HS, Huh JW, Kim DS, Kang DW, Min DS, Kim TH, Ha HS, Kim HH, Lee SY, Kim HS. (2006) Transcriptional control of the HERV-H LTR element of the GSDML gene in human tissues and cancer cells. Arch Virol. 151(10): Okahara G, Matsubara S, Oda T, Sugimoto J, Jinno Y, Kanaya F. (2004) Expression analyses of human endogenous retroviruses (HERVs): tissue-specific and developmental stage-dependent expression of HERVs. Genomics. 84(6): References V1 V1-3 V1-4 V1-1,V1-2 GAPDH 120 bp V3 V2 Number Tissuesadrenal glandcerebellumheartkidneyliverlungtestistrachea Human Intergation Time LTR in CDS DYX1C1 HU DYX1C1 CH DYX1C1 GO DYX1C1 GI 100 DYX1C1 JM DYX1C1 RH DYX1C1 CM DYX1C1 SQ DYX1C1 NM LTR7 M GAPDH 120 bp V1 V1-3 V1-4 V1-1,V1-2 GAPDH 120 bp V3 V2 Model for DYX1C1 gene evolution Rhesus Coding region Untranslated region LTR7 M Retroelement Retroposon SINE Retrotransposon LINE RNA intermediate - LTR element+ LTR element - env+ env - RT+ RT Yeast Ty1/copia/truncated HERVs LTRORF1ORF2LTR Human THE1 P Poly(A) Human Alu ORF1ORF2P Poly(A) L1 Retrovirus gagpolenvLTR Full-length HERVs/exogenous retrovirus Human Common ancestor Rodents ancestor Primate ancestor MouseRat New World monkey Old World monkey LTR 7 PB1D9 B1F Tandem duplication