爱爱小说网 > 其他电子书 > jurassic.park >

第18章

jurassic.park-第18章

小说: jurassic.park 字数: 每页3500字

按键盘上方向键 ← 或 → 可快速上下翻页,按键盘上的 Enter 键可回到本书目录页,按键盘上方向键 ↑ 可回到本页顶部!
————未阅读完?加入书签已便下次继续阅读!



ting insects that have sucked blood from larger animals。〃
    〃Sucked the blood;〃 Grant repeated。 His mouth fell open。 〃You mean sucked the blood of dinosaurs。
    〃Hopefully; yes。〃
    〃And then the insects are preserved in amber。 。 。 。〃 Grant shook his head。 〃I'll be damned…that just might work。〃
    〃I assure you; it does work;〃 Wu said。 He moved to one of the microscopes; where a technician positioned a piece of amber containing a fly under the microscope。 On the video monitor; they watched as he inserted a long needle through the amber; into the thorax of the prehistoric fly。
    〃If this insect has any foreign blood cells; we may be able to extract them; and obtain paleo…DNA; the DNA of an extinct creature。 We won't know for sure; of course; until we extract whatever is in there; replicate it; and test it。 That is what we have been doing for five years now。 It has been a long; slow process…but it has paid off。
    〃Actually; dinosaur DNA is somewhat easier to extract by this process than mammalian DNA。 The reason is that mammalian red cells have no nuclei; and thus no DNA in their red cells。 To clone a mammal; you must find a white cell; which is much rarer than red cells。 But dinosaurs had nucleated red cells; as do modern birds。 It is one of the many indications we have that dinosaurs aren't really reptiles at all。 They are big leathery birds。〃
    Tim saw that Dr。 Grant still looked skeptical; and Dennis Nedry; the messy fat man; appeared pletely uninterested; as if he knew it all already。 Nedry kept looking impatiently toward the next room。
    〃I see Mr。 Nedry has spotted the next phase of our work;〃 Wu said。 〃How we identify the DNA we have extracted。 For that; we use powerful puters。〃
    They went through sliding doors into a chilled room。 There was a loud humming sound。 Two six…foot…tall round towers stood in the center of the room; and along the walls were rows of waist…high stainless…steel boxes。 〃This is our high…tech laundromat;〃 Dr。 Wu said。 〃The boxes along the walls are all Hamachi…Hood automated gene sequencers。 They are being run; at very high speed; by the Cray XMP superputers; which are the towers in the center of the room。 In essence; you are standing in the middle of an incredibly powerful genetics factory。〃
    There were several monitors; all running so fast it was hard to see what they were showing。 Wu pushed a button and slowed one image。


1 GCGTTGCTGG CGTTTTTCCA TAGGCTCCGC CCCCCTGACG AGCATCACAA AAATCGACGC
61 GGTGGCGAAA CCCGACAGGA CTATAAAGAT ACCAGGCGTT TCCCCCTGGA AGCTCCCTCG
121 TGTTCCGACC CTGCCGCTTA CCGGATACCT GTCCGCCTTT CTCCCTTCGG GAAGCCTGGC
181 TGCTCACGCT GTAGGTATCT CAGTTCGGTG TAGGTCGTTC GCTCCAAGCT GGGCTGTGTG
241 CCGTTCAGCC CGACCGCTGC GCCTTATCCG GTAACTATCG TCTTGAGTCC AACCCGGTAA
301 AGTAGGACAG GTGCCGGCAG CGCTCTGGGT CATTTTCGGC GAGAACCGCT TTCGCTGGAG
361 ATCGGCCTGT CGCTTGCGGT ATTCGGAATC TTGCACGCCC TCGCTCAAGC CTTCGTCACT
421 CCAAACGTTT CGGCGAGAAG CAGGCCATTA TCGCCGGCAT GGCGGCCGAC GCGCTGGGCT
481 GGCGTTCGCG ACGCGAGGCT GGATGGCCTT CCCCATTATG ATTCTTCTCG CTTCCGGCGG
541 CCCGCGTTGC AGGCCATGCT GTCCAGGCAG GTAGATGACG ACCATCAGGG ACAGCTTCAA
601 CGGCTCTTAC CAGCCTAACT TCGATCACTG GACCGCTGAT CGTCACGGCG ATTTATGCCG
661 CACATGGACG CGTTGCTGGC GTTTTTCCAT AGGCTCCGCC CCCCTGACGA GCATCACAAA
721 CAAGTCAGAG GTGGCGAAAC CCGACAGGAC TATAAAGATA CCAGGCGTTT CCCCCTGGAA
781 GCGCTCTCCT GTTCCGACCC TGCCGCTTAC CGGATACCTG TCCGCCTTTC TCCCTTCGGG
841 CTTTCTCAAT GCTCACGCTG TAGGTATCTC AGTTCGGTGT AGGTCGTTCG CTCCAAGCTG
901 ACGAACCCCC CGTTCAGCCC GACCGCTGCG CCTTATCCGG TAACTATCGT CTTGAGTCCA
961 ACACGACTTA ACGGGTTGGC ATGGATTGTA GGCGCCGCCC TATACCTTGT CTGCCTCCCC
1021 GCGGTGCATG GAGCCGGGCC ACCTCGACCT GAATGGAAGC CGGCGGCACC TCGCTAACGG
1081 CCAAGAATTG GAGCCAATCA ATTCTTGCGG AGAACTGTGA ATGCGCAAAC CAACCCTTGG
1141 CCATCGCGTC CGCCATCTCC AGCAGCCGCA CGCGGCGCAT CTCGGGCAGC GTTGGGTCCT
1201 GCGCATGATC GTGCT。。。。。。。。。。。。。 CCTGTCGTTG AGGACCCGGC TAGGCTGGCG GGGTTGCCTT
1281 AGAATGAATC ACCGATACGC GAGCGAACGT GAAGCGACTG CTGCTGCAAA ACGTCTGCGA
1341 AACATGAATG GTCTTCGGTT TCCGTGTTTC GTAAAGTCTG GAAACGCGGA AGTCAGCGCC


    〃Here you see the actual structure of a small fragment of dinosaur DNA;〃 Wu said。 〃Notice the sequence is made up of four basic pounds…adenine; thymine; guanine; and cytosine。 This amount of DNA probably contains instructions to make a single protein…say; a hormone or an enzyme。 The full DNA molecule contains three billion of these bases。 If we looked at a screen like this once a second; for eight hours a day; it'd still take more than two years to look at the entire DNA strand。 It's that big。〃
    He pointed to the image。 〃This is a typical example; because you see the DNA has an error; down here in line 1201。 Much of the DNA we extract is fragmented or inplete。 So the first thing we have to do is repair it…or rather; the puter has to。 It'll cut the DNA; using what are called restriction enzymes。 The puter will select a variety of enzymes that might do the job。〃


1 GCGTTGCTGGCGTTTTTCCATAGGGTCCGCCCCCCTGACGAGCATCACAAAAATCGACGC
61 GGTGGCGAAACCCGACAGGACTFITAAAGATACCAGGCGTTTCCCCCTGGAAGCTCCCTCG
NspO4
121 TGTTCCGACCCTGCCGCTTACCGGATACCTGTCCGCCTTTCTCCCTTCGGGAAGCGTGGC
181 TGCTCACGCTGTAGGTATCTCAGTTCGGTGTAGGTCGTTCGCTCCASGCTGGGCTGTGTG
BrontIV
241 CCGTTCAGCCCGACCGCTGCGCCTTATCCGGTAACTATCGTCTTGAGTCCAACCCGGTAA
301 AGTAGGACAGGTGCCGGCAGCGCTCTGGGTCATTTTCGGCGAGGACCGCTTTCGCTGGAG
434 DnxTl           AoliBn
361 ATCGGCCTGTCGCTTGCGGTATTCGCAATCTTGCACGCCCTCGCTCAAGCCTTCGTCACT
421 CCAAACGTTTCGGCGAGAAGCAGGCCATAATCGCCGGCATGGCGGCCGACGCGCTGGGCT
481 GGCGTTCGCGACGCGAGGCTGGATGGCCTTCCCCATTATGATTCTTCTCGCTTCCGGCGG
541 CCCGCGTTGCAGGCCATGCTGTCCAGGCAGGTAGATGACGHCCATCAGGGACAGCTTCAA
601 CGGCTCTTACCAGCCTAACTTCGATCACTGGACCGCTGATCGTCACGGCGATTTATGCCG
Nsp04
661 CACATGGACCCGTTGCTGGCGTTTTTCCATAGGCTCCGCCCCCCTGACGAGCATCACAAA
721 CAAGTCAGAGGTGGCGAAACCCOACAGOACTATAAAGATACCAOOCOTTTCCCCCTGGAA
924 Caoll I   DinoLdn
781 GCGCTCTCCTOTTCCOACCCTOCCOCTTACCOGATACCTOTCCOCCTTTCTCCCTTCGGG
841 CTTTCTCAATOCTCACOCTGTABGTATCTCAGTTCGGTOTAGGTCGTTCOCTCCAAOCTO
901 ACGAACCCCCCOTTCAGCCCGACCGCTGCGCCTTATCCGGTAACTATCGTCTTGAOTCCA
961 ACACOACTTAACCOOTTOOCATGGATTGTAGGCGCCGCCCTATACCTTGTCTOCCTCCCC
1021 GCGGTGCATGOAOCCOGOCCACCTCGACCTGAATOGAAGCCGOCGOCACCTCOCTAACOG
1081 CCAAGAATTGGAGCCAATCAATTCTTGCGGAGAACTGTGAATGCGCAAACCAACCCTTGG
1141 CCATCGCGTCCGCCATCTCCAGCAGCCGCACGCGGCGCATCTCGGGCAGCGTTGGGTCCT
1416 DnxTI 
SSpd4
1201 GCGCATGATCGTGCT:+=:CCTGTCGTTGAGGACCCGGCTAGGCTGGCGGGGTTGCCTTACT
1281 ATGAATCACCGATACGCGAGCGAACGTGAAGCGACTGCTGCTGCAAAACGTCTGCGACCT
    

    〃Here is the same section of DNA; with the points of the restriction enzymes located。 As you can see in line 1201; two enzymes will cut on either side of the damaged point。 Ordinarily we let the puters decide which to use。 But we also need to know what base pairs we should insert to repair the injury。 For that; we have to align various cut fragments; like so。〃
    〃Now we are finding a fragment of DNA that overlaps the injury area; and will tell us what is missing。 And you can see we can find it; and go ahead and make the repair。 The dark bars you see arc restriction fragments…small sections of dinosaur DNA; broken by enzymes and then analyzed。 The puter is now rebining them; by searching for overlapping sections of code。 It's a little bit like putting a puzzle together。 The puter can do it very rapidly。〃

   
1 GCGTTGCTGGCGTTTTTCCATAGGCTCCGCCCCCCTGACGAGCATCACAAAAATCGACGC
61 GGTGGCGAAACCCGACAGGACTATAAAGATACCAGGCGTTTCCCCCTGGAAGCTCCCTCG
121 TGTTCCGACCCTGCCGCTTACCGGATACCTGTCCGCCTTTCTCCCTTCGGGAAGCCTGGC
181 TGCTCACGCTGTAGGTATCTCAGTTCGGTGTAGGTCGTTCGCTCCAAGCTGGGCTGTGTG
241 CCGTTCAGCCCGACCGCTGCGCCTTATCCGGTAACTATCGTCTTGAGTCCAACCCGGTAA
301 AGTAGGACAGGTGCCGGCAGCGCTCTGGGTCATTTTCGGCGAGAACCGCTTTCGCTGGAG
361 ATCGGCCTGTCGCTTGCGGTATTCGGAATCTTGCACGCCCTCGCTCAAGCCTTCGTCACT
421 CCAAACGTTTCGGCGAGAAGCAGGCCATTATCGCCGGCATGGCGGCCGACGCGCTGGGCT
481 GGCGTTCGCGACGCGAGGCTGGATGGCCTTCCCCATTATGATTCTTCTCGCTTCCGGCGG
541 CCCGCGTTGCAGGCCATGCTGTCCAGGCAGGTAGATGACGACCATCAGGGACAGCTTCAA
601 CGGCTCTTACCAGCCTAACTTCGATCACTGGACCGCTGATCGTCACGGCGATTTATGCCG
661 CACATGGACGCGTTGCTGGCGTTTTTCCATAGGCTCCGCCCCCCTGACGAGCATCACAAA
721 CAAGTCAGAGGTGGCGAAACCCGACAGGACTATAAAGATA CCAGGCGTTTCCCCCTGGAA
781 GCGCTCTCCTGTTCCGACCCTGCCGCTTACCGGATACCTGTCCGCCTTTCTCCCTTCGGG
841 CTTTCTCAATGCTCACGCTGTAGGTATCTC AGTTCGGTGTAGGTCGTTCGCTCCAAGCTG
901 ACGAACCCCCCGTTCAGCCCGACCGCTGCGCCTTATCCGGTAACTATCGTCTTGAGTCCA
961 ACACGACTTAACGGGTTGGCATGGATTGTAGGCGCCGCCCTATACCTTGTCTGCCTCCCC
1021 GCGGTGCATGGAGCCGGGCCACCTCGACCTGAATGGAAGCCGGCGGCACCTCGCTAACGG
1081 CCAAGAATTGGAGCCAATCAATTCTTGCGGAGAACTGTGAATGCGCAAACCAACCCTTGG
1141 CCATCGCGTCCGCCATCTCCAGCAGCCGCACGCGGCGCATCTCGGGCAGCGTTGGGTCCT
1201 GCGCATGATCGTGCTAGCCTGTCGTTGAGGACCCGGCTAGGCTGGCGGGGTTGCCTT
1281 AGAATGAATCACCGATACGCGAGCGAACGTGAAGCGACTG CTGCTGCAAAACGTCTGCGA
1341 AACATGAATGGTCTTCGGTTTCCGTGTTTC GTAAAGTCTGGAAACGCGGAAGTCAGCGCC
    

    〃And here is the revised DNA strand; repaired by the puter。 The operation you've witnessed would have taken months in a conventional lab; but we can do it in seconds。〃
    〃Then are you working with the entire DNA strand?〃 Grant asked。
    〃Oh no;〃 Wu said。 〃That's impossible。 We've e a long way from the sixties; when it took a whole laboratory four years to decode a screen like this。 Now the puters can do it in a couple of hours。 But; even so; the DNA molecule is too big。 We look only at the sections of the strand that differ from animal to animal; or from contemporary DNA。 Only a few percent of the nucleotides differ from one species to the next。 That's what we analyze; and it's still a big job。〃

Dennis Nedry yawned。 He'd long ago concluded that InGen must be doing something like this。 A couple of years earlier; when InGen had hired Nedry to design the park control systems; one of the initial design parameters called for data records with 3 X 109 fields。 Nedry just assumed that was a mistake; and had called Palo Alto to verify it。 But they had told him the Spec was correct。 Three billion fields。
    Nedry had worked on a lot of large systems。 He'd made a name for himself setting up worldwide telephone munications for multinational corporations。 Often those systems had millions of records。 He was used to that。 But InGen wanted something so much larger。 。 。 。 
    Puzzled; Nedry had gone to see Barney Fellows over at Symbolics; near the M。I。T。 campus in Cambridge。 〃What kind of a database has three billion records; Barney?〃
    〃A mistake;〃 Barney said; laughing。 〃They put in an extra zero or two。〃
    〃It's not a mistake。 I checked。 It's what they want。〃
    〃But that's crazy;〃 Barney said。 〃It's not workable。 Even if you had the fastest processors and blindingly fast algorithms; a search would still take days。 Maybe weeks。〃
    〃Yeah;〃 Nedry said。 〃I know。 Fortunately I'm not being asked to do algorithms。 I'm just being asked to reserve storage and memory for the overall system。 But still 。 。 。 what could the database be for?〃
    Barney frowned。 〃You operating under an ND?〃
    〃Yes;〃 Nedry said。 Most of his jobs required nondisclosure agreements。
    〃Can you tell me anything?〃
    〃It's a bioengineering firm。〃
    〃Bioengineering;〃 Barney said。 〃Well; there's the obvious。 。 。 。〃
    〃Which is?〃
    〃A DNA molecule。〃
    〃Oh; e on;〃 Nedry said。 〃Nobody could be analyzing a DNA molecule。〃 He knew biologists wer

返回目录 上一页 下一页 回到顶部 0 2

你可能喜欢的