{"id":10158,"date":"2018-05-02T17:10:45","date_gmt":"2018-05-02T10:10:45","guid":{"rendered":"http:\/\/ttud.com.vn\/?p=10158"},"modified":"2018-05-02T17:10:45","modified_gmt":"2018-05-02T10:10:45","slug":"phat-hien-cau-truc-dna-hoan-toan-moi-tren-nguoi-khong-xoan-kep-va-khong-tuan-theo-nguyen-tac-bo-sung-a-t-g-c","status":"publish","type":"post","link":"https:\/\/casta.ttud.com.vn\/index.php\/phat-hien-cau-truc-dna-hoan-toan-moi-tren-nguoi-khong-xoan-kep-va-khong-tuan-theo-nguyen-tac-bo-sung-a-t-g-c\/","title":{"rendered":"Ph\u00e1t hi\u1ec7n c\u1ea5u tr\u00fac DNA ho\u00e0n to\u00e0n m\u1edbi tr\u00ean ng\u01b0\u1eddi, kh\u00f4ng xo\u1eafn k\u00e9p v\u00e0 kh\u00f4ng tu\u00e2n theo nguy\u00ean t\u1eafc b\u1ed5 sung A-T G-C"},"content":{"rendered":"

L\u1ea7n \u0111\u1ea7u ti\u00ean, c\u00e1c nh\u00e0 khoa h\u1ecdc x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a m\u1ed9t c\u1ea5u tr\u00fac DNA ho\u00e0n to\u00e0n m\u1edbi, ch\u01b0a t\u1eebng th\u1ea5y trong c\u00e1c t\u1ebf b\u00e0o s\u1ed1ng.<\/p>\n

C\u1ea5u tr\u00fac n\u00e0y r\u1ea5t kh\u00e1c so v\u1edbi nh\u1eefng g\u00ec ch\u00fang ta \u0111\u01b0\u1ee3c h\u1ecdc v\u1ec1 DNA trong s\u00e1ch gi\u00e1o khoa th\u1eddi ph\u1ed5 th\u00f4ng. N\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t s\u1ee3i DNA d\u1ea1ng xo\u1eafn k\u00e9p. Trong \u0111\u00f3, c\u00e1c nucleotide (A,T,G,C) c\u0169ng kh\u00f4ng c\u1ea7n tu\u00e2n th\u1ee7 theo nguy\u00ean t\u1eafc b\u1ed5 sung (A-T, G-C).<\/p>\n

C\u00e1c nh\u00e0 khoa h\u1ecdc \u0111\u00e3 nh\u00ecn th\u1ea5y hai nucleotide C-C b\u1eaft c\u1eb7p v\u1edbi nhau, th\u1eadm ch\u00ed \u0111\u00f3 c\u00f2n l\u00e0 2 nucleotide tr\u00ean c\u00f9ng m\u1ed9t s\u1ee3i DNA. K\u1ebft qu\u1ea3, \u0111i\u1ec1u \u0111\u00f3 \u0111\u00e3 t\u1ea1o n\u00ean m\u1ed9t c\u1ea5u tr\u00fac DNA d\u1ea1ng n\u00fat tr\u00f4ng \u201cd\u1ecb<\/i>\u201d nh\u01b0 th\u1ebf n\u00e0y:<\/p>\n

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\"Ph\u00e1t<\/div>\n
\n

Ph\u00e1t hi\u1ec7n c\u1ea5u tr\u00fac DNA ho\u00e0n to\u00e0n m\u1edbi tr\u00ean ng\u01b0\u1eddi, kh\u00f4ng xo\u1eafn k\u00e9p v\u00e0 kh\u00f4ng tu\u00e2n theo nguy\u00ean t\u1eafc b\u1ed5 sung A-T G-C<\/p>\n<\/div>\n<\/div>\n

“Khi ngh\u0129 v\u1ec1 DNA, h\u1ea7u h\u1ebft ch\u00fang ta s\u1ebd t\u01b0\u1edfng t\u01b0\u1ee3ng ra nh\u1eefng xo\u1eafn k\u00e9p<\/i>“, ti\u1ebfn s\u0129 Daniel Christ, tr\u01b0\u1edfng khoa Tr\u1ecb li\u1ec7u kh\u00e1ng th\u1ec3 thu\u1ed9c Vi\u1ec7n Nghi\u00ean c\u1ee9u Y khoa Garvan, Australia cho bi\u1ebft. “Nghi\u00ean c\u1ee9u m\u1edbi n\u00e0y nh\u1eafc nh\u1edf ch\u00fang ta v\u1ec1 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a c\u00e1c c\u1ea5u tr\u00fac DNA ho\u00e0n to\u00e0n kh\u00e1c \u2013 v\u00e0 s\u1ef1 \u0111a d\u1ea1ng trong c\u1ea5u tr\u00fac DNA c\u00f3 th\u1ec3 r\u1ea5t quan tr\u1ecdng v\u1edbi c\u00e1c t\u1ebf b\u00e0o c\u1ee7a con ng\u01b0\u1eddi”.<\/i><\/p>\n

C\u1ea5u tr\u00fac DNA m\u1edbi m\u00e0 nh\u00f3m nghi\u00ean c\u1ee9u c\u1ee7a ti\u1ebfn s\u0129 Christ x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 c\u1ea5u tr\u00fac i-motif. Th\u1ef1c ra, n\u00f3 \u0111\u00e3 \u0111\u01b0\u1ee3c ph\u00e1t hi\u1ec7n v\u00e0o nh\u1eefng n\u0103m 1990 trong m\u00f4i tr\u01b0\u1eddng \u1ed1ng nghi\u1ec7m (in vitro). \u0110\u00e2y l\u00e0 l\u1ea7n \u0111\u1ea7u ti\u00ean c\u00e1c nh\u00e0 khoa h\u1ecdc t\u00ecm th\u1ea5y n\u00f3 tr\u00ean t\u1ebf b\u00e0o s\u1ed1ng c\u1ee7a con ng\u01b0\u1eddi.<\/p>\n

Kh\u00e1c v\u1edbi c\u1ea5u tr\u00fac xo\u1eafn k\u00e9p th\u00f4ng th\u01b0\u1eddng c\u1ee7a DNA (\u0111\u01b0\u1ee3c hai nh\u00e0 khoa h\u1ecdc Watson v\u00e0 Crick ph\u00e1t hi\u1ec7n v\u00e0o n\u0103m 1953 v\u00e0 n\u1ed5i ti\u1ebfng \u0111\u1ebfn t\u1eadn b\u00e2y gi\u1edd), c\u1ea5u tr\u00fac i-motif c\u00f3 th\u1ec3 g\u00e2y b\u1ea5t ng\u1edd cho nhi\u1ec1u ng\u01b0\u1eddi.<\/p>\n

N\u00f3 kh\u00e1c v\u1edbi t\u1ea5t c\u1ea3 nh\u1eefng g\u00ec b\u1ea1n \u0111\u00e3 t\u1eebng h\u1ecdc trong s\u00e1ch gi\u00e1o khoa th\u1eddi ph\u1ed5 th\u00f4ng. C\u1ea5u tr\u00fac i-motif c\u0169ng kh\u00f4ng tu\u00e2n th\u1ee7 theo nguy\u00ean l\u00fd b\u1ed5 sung, n\u00f3i r\u1eb1ng c\u00e1c c\u1eb7p nucleotile c\u01a1 s\u1edf s\u1ebd ph\u1ea3i li\u00ean k\u1ebft theo c\u1eb7p A-T v\u00e0 G-C.<\/p>\n

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\"Ph\u00e1t<\/div>\n
\n

Trong c\u1ea5u tr\u00fac i-motif, hai nucleotide C tr\u00ean c\u00f9ng m\u1ed9t chu\u1ed7i DNA c\u00f3 th\u1ec3 li\u00ean k\u1ebft l\u1ea1i v\u1edbi nhau<\/p>\n<\/div>\n<\/div>\n

“i-motif l\u00e0 m\u1ed9t n\u00fat 4 s\u1ee3i c\u1ee7a DNA<\/i>“, nh\u00e0 di truy\u1ec1n h\u1ecdc Marcel Dinger, \u0111\u1ed3ng t\u00e1c gi\u1ea3 nghi\u00ean c\u1ee9u gi\u1ea3i th\u00edch. “Trong c\u1ea5u tr\u00fac n\u00fat, hai nucleotide C [cytosine] tr\u00ean c\u00f9ng m\u1ed9t chu\u1ed7i DNA li\u00ean k\u1ebft l\u1ea1i v\u1edbi nhau – v\u00ec v\u1eady \u0111i\u1ec1u n\u00e0y r\u1ea5t kh\u00e1c so v\u1edbi m\u1ed9t xo\u1eafn k\u00e9p, trong \u0111\u00f3 c\u00e1c nucleotide tr\u00ean hai s\u1ee3i \u0111\u1ed1i di\u1ec7n nhau m\u1edbi li\u00ean k\u1ebft \u0111\u01b0\u1ee3c v\u1edbi nhau v\u00e0 C ch\u1ec9 li\u00ean k\u1ebft \u0111\u01b0\u1ee3c v\u1edbi G [guanines]<\/i>“.<\/p>\n

Theo t\u00e1c gi\u1ea3 d\u1eabn \u0111\u1ea7u nghi\u00ean c\u1ee9u Mahdi Zeraati, c\u0169ng \u0111\u1ebfn t\u1eeb Vi\u1ec7n Nghi\u00ean c\u1ee9u Y khoa Garvan, i-motif ch\u1ec9 l\u00e0 m\u1ed9t trong s\u1ed1 c\u00e1c c\u1ea5u tr\u00fac DNA kh\u00f4ng mang d\u1ea1ng xo\u1eafn k\u00e9p. Ngo\u00e0i ra, ch\u00fang ta c\u00f2n c\u00f3 A-DNA, Z-DNA, triplex DNA v\u00e0 Cruciform DNA c\u0169ng l\u00e0 c\u00e1c c\u1ea5u tr\u00fac DNA kh\u00f4ng xo\u1eafn c\u00f3 th\u1ec3 t\u1ed3n t\u1ea1i trong c\u01a1 th\u1ec3 con ng\u01b0\u1eddi.<\/p>\n

N\u0103m 2013, c\u00e1c nh\u00e0 khoa h\u1ecdc c\u00f2n d\u1ef1 \u0111o\u00e1n th\u00eam s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a m\u1ed9t c\u1ea5u tr\u00fac DNA l\u1ea1 kh\u00e1c \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 G-quadruplex (G4), v\u1edbi c\u00e1c nucleotide li\u00ean k\u1ebft v\u1edbi nhau tr\u00ean c\u00f9ng m\u1ed9t s\u1ee3 DNA, c\u0169ng kh\u00f4ng tu\u00e2n th\u1ee7 theo nguy\u00ean t\u1eafc b\u1ed5 sung.<\/p>\n

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\"Ph\u00e1t<\/div>\n
\n

C\u1ea5u tr\u00fac G-quadruplex (G4) v\u00e0 i-motif c\u1ee7a DNA<\/p>\n<\/div>\n<\/div>\n

\u0110\u1ebfn nay, ph\u00e1t hi\u1ec7n v\u1ec1 s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a c\u1ea5u tr\u00fac DNA i-motif trong t\u1ebf b\u00e0o ng\u01b0\u1eddi m\u1edbi ch\u1ec9 l\u00e0 d\u1ea5u m\u1ed1c ban \u0111\u1ea7u \u0111\u1ec3 ch\u00fang ta t\u00ecm hi\u1ec3u v\u1ec1 n\u00f3. C\u00e1c nh\u00e0 khoa h\u1ecdc ch\u01b0a hi\u1ec3u g\u00ec v\u1ec1 ho\u1ea1t \u0111\u1ed9ng c\u1ee7a i-motif, ch\u1ec9 bi\u1ebft r\u1eb1ng n\u00f3 th\u01b0\u1eddng h\u00ecnh th\u00e0nh mu\u1ed9n trong v\u00f2ng \u0111\u1eddi c\u1ee7a t\u1ebf b\u00e0o.<\/p>\n

C\u00e1c c\u1ea5u tr\u00fac i-motif c\u0169ng c\u00f3 khuynh h\u01b0\u1edbng xu\u1ea5t hi\u1ec7n trong nh\u1eefng v\u00f9ng \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 ‘promoter<\/i>‘ – c\u00e1c v\u00f9ng DNA ki\u1ec3m so\u00e1t s\u1ef1 bi\u1ec3u hi\u1ec7n hay c\u00f2n g\u1ecdi l\u00e0 \u201cb\u1eadt<\/u><\/i>\u201d ho\u1eb7c \u201ct\u1eaft<\/i>\u201d gen. Ngo\u00e0i ra, n\u00f3 c\u0169ng c\u00f3 m\u1eb7t trong telomere, v\u00f9ng DNA li\u00ean quan \u0111\u1ebfn qu\u00e1 tr\u00ecnh l\u00e3o h\u00f3a.<\/p>\n

“Ch\u00fang t\u00f4i ngh\u0129 s\u1ef1 xu\u1ea5t hi\u1ec7n v\u00e0 bi\u1ebfn m\u1ea5t c\u1ee7a c\u00e1c c\u1ea5u tr\u00fac i-motif l\u00e0 m\u1ed9t \u0111\u1ea7u m\u1ed1i cho ch\u1ee9c n\u0103ng c\u1ee7a ch\u00fang<\/i>“, Zeraati n\u00f3i. C\u00f3 th\u1ec3 i-motif \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn s\u1ef1 bi\u1ec3u hi\u1ec7n c\u1ee7a gen, qu\u00e1 tr\u00ecnh phi\u00ean m\u00e3 v\u00e0 d\u1ecbch m\u00e3.<\/p>\n

B\u00e2y gi\u1edd, c\u00e1c nh\u00e0 khoa h\u1ecdc \u0111\u00e3 x\u00e1c nh\u1eadn d\u1ea1ng DNA m\u1edbi n\u00e0y t\u1ed3n t\u1ea1i trong c\u00e1c t\u1ebf b\u00e0o. Nhi\u1ec7m v\u1ee5 ti\u1ebfp theo c\u1ee7a h\u1ecd l\u00e0 ch\u1ec9 ra nh\u1eefng g\u00ec m\u00e0 i-motif \u0111ang l\u00e0m b\u00ean trong c\u01a1 th\u1ec3 con ng\u01b0\u1eddi. Theo d\u1ef1 \u0111o\u00e1n c\u1ee7a Zeraati, c\u00e1c c\u1ea5u tr\u00fac n\u00e0y c\u00f3 \u00fd ngh\u0129a r\u1ea5t quan tr\u1ecdng v\u1edbi c\u00e1c protein trong t\u1ebf b\u00e0o.<\/p>\n

“V\u00ec v\u1eady, s\u1ef1 h\u00ecnh th\u00e0nh c\u00e1c c\u1ea5u tr\u00fac n\u00e0y c\u00f3 th\u1ec3 c\u1ef1c k\u1ef3 quan tr\u1ecdng \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng c\u1ee7a t\u1ebf b\u00e0o. V\u00e0, b\u1ea5t k\u1ef3 l\u1ed7i n\u00e0o trong c\u00e1c c\u1ea5u tr\u00fac n\u00e0y c\u00f3 th\u1ec3 \u0111\u1ec3 l\u1ea1i m\u1ed9t h\u1eadu qu\u1ea3 b\u1ec7nh l\u00fd<\/i>“, \u00f4ng n\u00f3i.<\/p>\n

Tham kh\u1ea3o\u00a0ScienceAlert<\/i><\/p>\n

Tr\u00ed Th\u1ee9c Tr\u1ebb<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

L\u1ea7n \u0111\u1ea7u ti\u00ean, c\u00e1c nh\u00e0 khoa h\u1ecdc x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c s\u1ef1 t\u1ed3n t\u1ea1i c\u1ee7a m\u1ed9t c\u1ea5u tr\u00fac DNA ho\u00e0n to\u00e0n m\u1edbi, ch\u01b0a t\u1eebng th\u1ea5y trong c\u00e1c t\u1ebf b\u00e0o s\u1ed1ng. C\u1ea5u tr\u00fac n\u00e0y r\u1ea5t kh\u00e1c so v\u1edbi nh\u1eefng g\u00ec ch\u00fang ta \u0111\u01b0\u1ee3c h\u1ecdc v\u1ec1 DNA trong s\u00e1ch gi\u00e1o khoa th\u1eddi ph\u1ed5 th\u00f4ng. N\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 […]<\/p>\n","protected":false},"author":18,"featured_media":10159,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[],"class_list":["post-10158","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tin-tuc"],"_links":{"self":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/10158","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/users\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/comments?post=10158"}],"version-history":[{"count":1,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/10158\/revisions"}],"predecessor-version":[{"id":10160,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/posts\/10158\/revisions\/10160"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/media\/10159"}],"wp:attachment":[{"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/media?parent=10158"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/categories?post=10158"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/casta.ttud.com.vn\/index.php\/wp-json\/wp\/v2\/tags?post=10158"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}