Biologia Molecolare

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[84 ] Capitolo 4 GENI E GENOMI: ORGANIZZAZIONE E FUNZIONE
 4.1  LA FUNZIONE BIOLOGICA: IL PROGRAMMA DELLA VITAŽ ‰‡‘ƒ †‹ — ‘”‰ƒ‹•‘ ° †‡ˆ‹‹–‘ ‘‡ l’intero patrimonio genetico aploide contenuto
nelle celluleǡ ‡ ˆ‹•‹ ƒ‡–‡ ‘””‹•’‘†‡ ƒŽŽǯ‹–‡”ƒ •‡“—‡œƒ †‹ — Ž‡‘–‹†‹ †‡ŽŽ‡ ‘Ž‡ ‘Ž‡ †‹
ȋ‘ †‹ ‡Ž ƒ•‘ †‹ ƒŽ —‹ ˜‹”—•Ȍ ’”‡•‡–‹ ‡ŽŽ‡ ‡ŽŽ—Ž‡Ǥ Ž –‡”‹‡ genoma ° •–ƒ–‘ —•ƒ–‘
’‡” Žƒ ’”‹ƒ ˜‘Ž–ƒ †ƒŽ „‘–ƒ‹ ‘ –‡†‡• ‘ ƒ• ‹Ž‡” ‡Ž ͳͻʹͲǡ ‡ †‡”‹˜ƒ †ƒŽŽƒ ˆ—•‹‘‡ †‡‹ †—‡
–‡”‹‹ gene ‡ chromosome Ǥ Ž ‰‡‘ƒ ’—Ö ‡••‡”‡ ”‡Žƒ–‹˜ƒ‡–‡ •‡’Ž‹ ‡ ‘ ‘Ž–‘ ‘’Ž‡••‘ǡ
ƒ ‹ –—––‹ ‹ ƒ•‹ ‘–‹‡‡ Ž‡ ‹•–”—œ‹‘‹ ‘ ‹ˆ‘”ƒœ‹‘‹ ‡ ‡••ƒ”‹‡ ’‡” ‡•‡‰—‹”‡ ‡ ”‡‰‘Žƒ”‡ Ž‡
‘Ž–‡’Ž‹ ‹ ˆ—œ‹‘‹ †‡ŽŽ‡ ‡ŽŽ—Ž‡Ǥ —‹†‹ǡ Žƒ •—ƒ ˆ—œ‹‘‡ ’”‹ ‹’ƒŽ‡ ‡ —‹˜‡”•ƒŽ‡ ° “—‡ŽŽƒ †‹ ‘Ǧ
•–‹–—‹”‡ — Dz†‡’‘•‹–‘dz †‹ ‹ˆ‘”ƒœ‹‘‹ Š‡ •‹ƒ –”ƒ•‹••‹„‹Ž‡ ‘ ’‘ Š‡ ‡˜‡–—ƒŽ‹ ƒŽ–‡”ƒœ‹‘‹
ȋ—–ƒœ‹‘‹Ȍ ƒŽŽƒ ’”‘‰‡‹‡Ǥ ‘ Žǯƒ˜ƒœƒ”‡ †‡ŽŽ‡ ‘‘• ‡œ‡ǡ ’‡”Öǡ •‹ ° ‘’”‡•‘ Š‡ “—‡•–‘
Dz†‡’‘•‹–‘dz ‘ ° †ƒ ‹–‡†‡”•‹ ‘‡ “—ƒŽ ‘•ƒ †‹ •–ƒ–‹ ‘ǡ Š‡ ‹ƒ‰ƒœœ‹ƒ ‡ ƒŽŽǯ‘ ‘””‡œƒ
ˆ‘”‹• ‡ Ž‡ ‹•–”—œ‹‘‹ ‡ ‡••ƒ”‹‡ǡ “—ƒ–‘ ’‹—––‘•–‘ ƒ —ƒ ˆ‘–‡ †‹ ‹ˆ‘”ƒœ‹‘‹ †‹ƒ‹ ƒ Š‡
’—Ö ‡ ƒ ˜‘Ž–‡ †‡˜‡ ‘†‹ˆ‹ ƒ”•‹ ’‡” ”‡‰‘Žƒ”‡ Ž‡ ˆ—œ‹‘‹ †‡ŽŽǯ‘”‰ƒ‹•‘Ǥǯ‹’‘”–ƒœƒ ˆ‘†ƒ‡–ƒŽ‡ †‡Ž ‰‡‘ƒ ’‡” Žƒ ˜‹–ƒ ° ‡˜‹†‡œ‹ƒ–ƒ †ƒŽŽǯ‹’ƒ––‘ Š‡ Šƒ ƒ˜—–‘
•—ŽŽ‡ ‘•–”‡ ‘‘• ‡œ‡ ‡ –‡ ‘Ž‘‰‹‡ ‹Ž •‡“—‡œ‹ƒ‡–‘ †‡Ž ‰‡‘ƒ —ƒ‘Ǥ ƒ”–‹–‘ ‡‹ ’”‹‹
ƒ‹ ǯͻͲ †‡Ž •‡ ‘Ž‘ • ‘”•‘ǡ ‹Ž •‡“—‡œ‹ƒ‡–‘ †‡Ž ‰‡‘ƒ —ƒ‘ ° •–ƒ–‘ ‘’Ž‡–ƒ–‘ ƒŽŽǯ‹‹œ‹‘
†‹ “—‡•–‘ •‡ ‘Ž‘Ǥ —‡ ‘•‘”œ‹ †‹ ”‹ ‡” ƒ–‘”‹ ‡ ‡–‹ †‹ ”‹ ‡” ƒǡ —‘ ’—„„Ž‹ ‘ ‡ —‘ ’”‹˜ƒ–‘ǡ Šƒ‘
’—„„Ž‹ ƒ–‘ ‡Ž ʹͲͲͳ Žƒ •‡“—‡œƒ †‹ ‹” ƒ ŽǯͺͷΨ †‡Ž ‰‡‘ƒ —ƒ‘ •— Nature ‡ Scienceǡ †—‡ ”‹Ǧ
˜‹•–‡ • ‹‡–‹ˆ‹ Š‡ ‘Ž–‘ ’”‡•–‹‰‹‘•‡ ȋFigura 4.1ȌǤ  “—‡•–ƒ ˜‡”•‹‘‡ ’”‡Ž‹‹ƒ”‡ǡ ƒ ƒ˜ƒ‘
”‡‰‹‘‹ ”‹’‡–—–‡ ’‘˜‡”‡ †‹ ‰‡‹ǡ Š‡ ‘ ‡”ƒ‘ ƒŽŽ‘”ƒ ˆƒ ‹Ž‡–‡ •‡“—‡œ‹ƒ„‹Ž‹ ’‡” ”ƒ‰‹‘‹ –‡ Ǧ
‹ Š‡Ǥ Ž ‰‡‘ƒ —ƒ‘ — Ž‡ƒ”‡ ° †‹ ‹” ƒ ͵ǡ͵ ‹Ž‹ƒ”†‹ †‹ ‘’’‹‡ †‹ „ƒ•‹ǡ “—‹†‹ ‹Ö ˜—‘Ž †‹”‡
Š‡ ‹ —ƒ ‡ŽŽ—Žƒ •‘ƒ–‹ ƒ —ƒƒ Žǯ‹–‡”‘ ‘–‡—–‘ ȋ†‹’Ž‘‹†‡Ȍ †‹ — Ž‡ƒ”‡ ‘””‹•’‘†‡
ƒ ͸ǡ͸ ‹Ž‹ƒ”†‹ †‹ ‘’’‹‡ †‹ „ƒ•‹Ǥ Ž–”‡ ‹Ž — Ž‡ƒ”‡ǡ ‹Ž ‰‡‘ƒ †‹ —ƒ ‡ŽŽ—Žƒ ‡— ƒ”‹‘–‹ ƒ ‘Ǧ
’”‡†‡ ƒ Š‡ ‹Ž ‹–‘ ‘†”‹ƒŽ‡ ‡ †‡‹ Ž‘”‘’Žƒ•–‹ǡ ’‘‹ Š± “—‡•–‹ ‘”‰ƒ‡ŽŽ‹ ‘–‡‰‘‘ —
’”‘’”‹‘ Ǥ  “—‡•–‹ ƒ•‹ǡ ‘—“—‡ǡ Žƒ Ž—‰Š‡œœƒ †‡ŽŽƒ ‘Ž‡ ‘Žƒ †‹ ° ‘Ž–‘ ‹ˆ‡”‹‘”‡ †‹
“—‡ŽŽ‘ — Ž‡ƒ”‡ǡ ’‡” ‡•‡’‹‘ ‹Ž ‰‡‘ƒ ‹–‘ ‘†”‹ƒŽ‡ —ƒ‘ ° †‹ ͳ͸Ǥͷ͹ͳ ‘’’‹‡ †‹ „ƒ•‹Ǥ —‡”‘ ‘•¿ ‰”ƒ†‡ †‹ — Ž‡‘–‹†‹ †‡Ž ‰‡‘ƒ —ƒ‘ ° †‹ˆˆ‹ ‹Ž‡ †ƒ ‘’”‡†‡”‡ •—„‹–‘
‡ ’‘‡ †‡ŽŽ‡ †‹ˆˆ‹ ‘Ž– —‘˜‡ ’‡” ”‹—• ‹”‡ ƒ ƒ’‹”‡ Ž‡ •—‡ ˆ—œ‹‘ƒŽ‹–Ǥ ‡” ˆƒ”‡ —ǯƒƒŽ‘‰‹ƒ ‘Ǧ
•‹†‡”‹ƒ‘ “—‡•–‘ Ž‹„”‘ Š‡ ‘–‹‡‡ ‹” ƒ — ͳ ‹Ž‹‘‡ †‹ ƒ”ƒ––‡”‹ ƒŽˆƒ—‡”‹ ‹Ǣ “—‹†‹ǡ •‡
˜‘Ž‡••‹‘ • ”‹˜‡”‡ Žǯ‹–‡”ƒ •‡“—‡œƒ †‹ „ƒ•‹ †‡Ž ‰‡‘ƒ ƒ’Ž‘‹†‡ —ƒ‘ ‹ ˜‘””‡„„‡”‘ ’‹î ‘
‡‘ ͵͵ͲͲ Ž‹„”‹ †‡ŽŽƒ †‹‡•‹‘‡ †‹ “—‡•–‘Ǥ ‘ ’‡” Š± ‘’”‡†‡”‡ ‡ ‹–‡”’”‡–ƒ”‡ ’‹‡ƒǦ
‡–‡ ‹Ž ‰‡‘ƒ —ƒ‘ ° —ǯ‹’”‡•ƒ ‡‘”‡ǡ ‡ ‹ˆƒ––‹ǡ ‹Ž ʹͲͲͳ Šƒ •‡‰ƒ–‘ —‘ •’ƒ”–‹ƒ “—‡ –”ƒ
—ǯ‡”ƒ ’”‡Ǧ ‡ —ǯ‡”ƒ ’‘•–Ǧ‰‡‘‹ ƒǤ ƒ “—‡Ž ‘‡–‘ ‹Ž ‰‡‘ƒ †‹ — ‘”‰ƒ‹•‘ ° †‹˜‡—–‘ ‹Ž
’—–‘ †‹ ”‹ˆ‡”‹‡–‘ †‹ ‘Ž–‡ ‹†ƒ‰‹‹ • ‹‡–‹ˆ‹ Š‡ǡ ‡ ‹ „—‘ƒ ‹•—”ƒ —ƒ ˆ‹ƒŽ‹– ‹’‘”–ƒ–‡
‡ ‘—‡ ƒ ‘Ž–‹ ”‹ ‡” ƒ–‘”‹ ° Žƒ †‡ˆ‹‹œ‹‘‡ †‡‹ ‡ ƒ‹•‹ ‡ †‡ŽŽ‡ ˆ—œ‹‘ƒŽ‹– ‘’Ž‡••‡ †‡‹
‰‡‘‹Ǥ ‘Ž–”‡ǡ ‹Ž •‡“—‡œ‹ƒ‡–‘ †‡‹ ‰‡‘‹ ° •–ƒ–‘ ”‡•‘ ’‘••‹„‹Ž‡ †ƒ‰Ž‹ ‡‘”‹ ƒ˜ƒœƒ‡Ǧ
–‹ –‡ ‘Ž‘‰‹ ‹ ‡ ‹ˆ‘”ƒ–‹ ‹ ȋ•‹ ˜‡†ƒ ‹Ž ’ƒ”ƒ‰”ƒˆ‘ •— ‡••‹˜‘ȌǤ —‡•–‹ ƒ˜ƒœƒ‡–‹ –‡ ‘Ž‘‰‹ ‹
Šƒ‘ ”‹˜‘Ž—œ‹‘ƒ–‘ ‹Ž ‘†‘ †‹ ƒ “—‹•‹”‡ ‘‘• ‡œ‡ ƒ Š‡ ‹ ƒŽ–”‹ •‡––‘”‹ †‡ŽŽƒ „‹‘Ž‘‰‹ƒ ‘Ž‡Ǧ
‘Žƒ”‡ǡ ’‡” ‡•‡’‹‘ Žƒ –”ƒ• ”‹œ‹‘‡ ‡ Ž‡ ‹–‡”ƒœ‹‘‹ ’”‘–‡‹ƒǦƒ ‹†‘ — Ž‡‹ ‘Ǥ  ‡ˆˆ‡––‹ǡ Žǯ‡”ƒ ’‘•–Ǧ
‰‡‘‹ ƒ Šƒ ”‹˜‘Ž—œ‹‘ƒ–‘ –—––ƒ Žƒ „‹‘Ž‘‰‹ƒ ‡ Šƒ ‰‹ ’‡”‡••‘ —Ž–‡”‹‘”‹ ƒ˜ƒœƒ‡–‹ †‡ŽŽ‡ ‘Ǧ
‘• ‡œ‡ ‹ †‹˜‡”•‹ ƒ’‹ †‡ŽŽƒ „‹‘Ž‘‰‹ƒ ‡ †‡ŽŽ‡ „‹‘–‡ ‘Ž‘‰‹‡Ǥ  Š‡ ’‹î ‹ƒ––‡•‘ ° ˆ‘”•‡
Žǯ‹’ƒ––‘ •—ŽŽƒ ˜‹–ƒ “—‘–‹†‹ƒƒ †‹ ‘‰—‘ †‹ ‘‹ Š‡ Žƒ ‘‘• ‡œƒ †‡‹ ‰‡‘‹ Šƒ ƒ˜—–‘ǡ ‡ ’”‘Ǧ
‰”‡••‹˜ƒ‡–‡ ƒ˜” •‡’”‡ †‹ ’‹îǡ ‰”ƒœ‹‡ ƒŽŽ‘ •˜‹Ž—’’‘ †‡ŽŽ‡ „‹‘–‡ ‘Ž‘‰‹‡ ‹ —‡”‘•‹ •‡––‘”‹
†‡ŽŽƒ ˜‹–ƒ ‡ ‘‘‹ ƒ ‡ •‘ ‹ƒŽ‡ †‡ŽŽ‡ ’‘’‘Žƒœ‹‘‹ —ƒ‡Ǥ
FIGURA 4.1 X Le copertine di Nature e Science che celebra-
no la pubblicazione nel 2001 della prima versione del genoma
umano da parte del Consorzio di Istituzioni di ricerca Interna-
zionali e della Celera Genomics.