TY - JOUR
T1 - The telomere-specific non-LTR retrotransposons SART1 and TRAS1 are suppressed by Piwi subfamily proteins in the silkworm, Bombyx mori
AU - Tatsuke, Tsuneyuki
AU - Sakashita, Kosuke
AU - Masaki, Yuki
AU - Lee, Jae Man
AU - Kawaguchi, Yutaka
AU - Kusakabe, Takahiro
N1 - Funding Information:
Acknowledgements. This study was supported in part by the Program for Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN), by a grant from the Ministry of Agriculture, Forestry and Fisheries of Japan (Integrated research project for plant, insect and animal using genome technology INSECT-1201) and by Japan Society for the Promotion of Science (JSPS).
PY - 2010/3
Y1 - 2010/3
N2 - The telomere structures in Bombyx mori are thought to be maintained mainly by the transposition of the specialized telomeric retroelements SART and TRAS. The silkworm genome has telomeric TTAGG repeats and telomerase, but this telomerase displays little or no activity. Here, we report that the transcription of the telomeric retroelements SART1 and TRAS1 is suppressed by the silkworm Piwi subfamily proteins BmAgo3 and Siwi. The silkworm Piwi subfamily was found to be expressed predominantly in the gonads and early embryo, as in other model organisms, but in BmN4 cultured cells, these proteins formed granules that were separate from the nuage, which is a different behaviour pattern. The expression of TRAS1 was increased in BmN4 cells when BmAgo3 or Siwi were silenced by RNAi. Our results suggest that B. mori Piwi proteins are involved in regulating the transposition of telomeric retroelements, and that the functional piRNA pathway is conserved in BmN4 cultured cells.
AB - The telomere structures in Bombyx mori are thought to be maintained mainly by the transposition of the specialized telomeric retroelements SART and TRAS. The silkworm genome has telomeric TTAGG repeats and telomerase, but this telomerase displays little or no activity. Here, we report that the transcription of the telomeric retroelements SART1 and TRAS1 is suppressed by the silkworm Piwi subfamily proteins BmAgo3 and Siwi. The silkworm Piwi subfamily was found to be expressed predominantly in the gonads and early embryo, as in other model organisms, but in BmN4 cultured cells, these proteins formed granules that were separate from the nuage, which is a different behaviour pattern. The expression of TRAS1 was increased in BmN4 cells when BmAgo3 or Siwi were silenced by RNAi. Our results suggest that B. mori Piwi proteins are involved in regulating the transposition of telomeric retroelements, and that the functional piRNA pathway is conserved in BmN4 cultured cells.
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U2 - 10.2478/s11658-009-0038-9
DO - 10.2478/s11658-009-0038-9
M3 - Article
C2 - 19943120
AN - SCOPUS:76149100567
VL - 15
SP - 118
EP - 133
JO - Cellular and Molecular Biology Letters
JF - Cellular and Molecular Biology Letters
SN - 1425-8153
IS - 1
ER -