Starting with tiny pycno eggs, each a little larger than a grain of sand, she microinjected little pieces of microscopic bacterial DNA known as plasmids, which contained a copy of the growth hormone gene. The plasmid DNA would be acting like little drug factories, producing small amounts of the hormone in the pycno on a daily basis. Usually, hormones were naturally occurring trace substances produced by glands—they served as chemical messengers carried by the blood to various target organs. In the genetically engineered organism, the tiny plasmid DNA took the place of the glands. The plasmid DNA would integrate itself into the host animal's normal genetic sequence, and the growth hormone levels would rise.
To obtain the proper plasmids, Martha wrote to the University of Maryland and asked for a small sample of the bacteria containing the growth hormone genes. She told the researchers she wished to sequence and study the entire plasmid but not to use it in any test organism. She of course was lying.
Within a week she received a package marked
NON-HAZARDOUS BIOLOGICAL SPECIMENS
in bright red letters. A few years ago, packages of this type were marked “BIOHAZARD,” but this tended to make the mail departments dangerously excited and, as a result, packages were often never shipped. In any case, the bacterial strains Martha had requested were not really considered hazardous because they did not contain any agent infectious to humans. The brown box she received contained a small plastic vial of soft agar along with the bacterium E. coli containing growth hormone plasmids. The box also contained a note which reminded her it was illegal and potentially dangerous to use the plasmids in a host organism without governmental approval. The Maryland researchers also asked that their names be on any scientific papers Martha might publish as a result of her sequencing work.
“Sure.” Martha chuckled when she read the last part of their letter. It read:
Of course should any patent arise from your use of our plasmids, or any commercial use of the plasmid be discovered, your legal department and ours would be expected to sign a contractual agreement.
Martha's idea to transform the sea spiders into bigger specimens depended on the theory that the growth hormones from flies should have an effect on the pycnos. Not a crazy idea, she told herself. After all, Auburn University scientists recently had shown that genetically engineered catfish containing extra copies of the human growth hormone gene grew at abnormally fast rates. And the Department of Agriculture had been experimenting with transgenic carp and succeeded in breeding fish that were twice the normal size. If it worked for catfish and carp, why not for the pycnos?
Martha scraped the contents of the vial into a glass petri dish which contained a nutrient gel on the bottom. Inside the dish, the bacteria containing the growth hormone plasmid genes would reproduce. Interestingly, the petri dish contained an agar gel that was laced with an antibiotic called ampicillin. Not only did the plasmids carry the growth hormone gene but they also contained antibiotic resistance genes, so any bacteria that grew in the disk were guaranteed to have the plasmid with the growth hormone gene. Any other bacteria that would try to grow in the dish would simply die. Martha also created huge stocks of E. coli. with the plasmid by growing giant bacterial colonies in gallon size flasks of liquid growth media.
After she had a significant stock, she microinjected purified DNA from the plasmids directly into fertilized pycnogonid eggs, some of which integrated the fly growth hormone genes of the plasmid into their own cellular genetic code. She carefully worked under a microscope, slowly manipulating a microneedle as it punctured an egg and allowed the new DNA to flow into the egg. If the method worked, Martha could mate the genetically engineered pycnogonids. Some of their offspring would contain the extra DNA coding for growth hormone and also grow to colossal proportions.
Normally when pycnogonids reproduced, the male fertilized the eggs as they passed out of the female. Then the male collected the eggs into masses on his smaller ovigerous legs. Glands on the femurs of these appendages formed a secretion for attaching the egg masses. It was at this point that Martha removed eggs, microinjected them, and then placed them back on the father pycno. Unfortunately, this was much easier to plan than to accomplish; the pycnos did not understand what she was doing, and were decidedly uncooperative. She could tie the spider down, and collect the eggs, and she could replace them. But when she released the creatures, they sensed the foreign nature of the eggs, and scraped them off. She got so angry once that she squashed one flat—then spent days in remorse. These were not human beings, after all; they didn't deserve to be destroyed out of hand. She had to find a way to anesthetize the rebellious spiders for long enough to let the modified eggs settle in, as it were, so that they no longer seemed foreign.
After a few months of trial and error, Martha found that genetically engineered fly growth hormone did produce pycnogonids that grew at rates much faster than normal. She estimated that if the current rates of growth continued, they would mature to elephant size in just two years. Sometimes she found it remarkable that hormones from a fly could have any effect at all on a pycno. It seemed a little like substituting water for gasoline in a car and expecting it to have a beneficial effect. However, the growth hormone molecules apparently were similar enough so that the fly molecules would have a noticeable effect on a member of this related, but different, species.
This was not to say that Martha's goal of producing huge pycnos was a simple or straightforward one. She soon found that when the pycno got very large, it had difficulty breathing, because the amount of surface area available for exchanging oxygen and carbon dioxide became smaller in proportion to the huge volume the creature now had. Not all the cells inside its body could satisfy their need for life-giving oxygen.
To solve this problem, Martha selectively bred species which contained, as infants, an unusually high level of hemocyanin, the compound which carried oxygen in the blood of pycnos. Just by chance, about 1 out of every 100 infant spiders had a slightly elevated level of hemocyanin in its blood. She bred these creatures to one another, and their offspring also had a slightly higher level of hemocyanin. The process was repeated for several generations of pycnos until the final specimens had very high levels of hemocyanin and blood corpuscles. Of course, all of this selective breathing was done with normal sized specimens to make the process quick and easy. It was with these better breathers that Martha again began her growth hormone experiments. The process of selecting these better breathers was not unlike the methods used by agriculturists to select disease-resistant plants or plants that could tolerate drought.
Martha also found it necessary to strengthen the hard outer material which served both as skin and skeleton for the creature. Unlike mammals and other higher organisms which had an internal skeleton, many creatures such as insects, lobsters and pycnogonids wore their skeleton on the outside. This outer skeleton, or exoskeleton, served several functions. It gave animals their external shape—particularly important for larger arthropods which needed rigid skeletons to retain their shape out of water. Secondly, the exoskeleton provided support for the muscles. Finally, it provided protection against predators and various forces of impact, buckling, and bending.
As a student of biochemistry in college, Martha learned that the hard bony exoskelton of arthropods was made of chitin—a long polymer, or chain, of N-acetylglucosamine molecules. Martha knew that although chitin was pretty incredible stuff, the heavy load that would be placed on the exoskeleton for an elephant-sized creature made it impossible to simply grow the pycnos to elephant size and expect them to function normally, particularly out of water. Their buoyancy in water would normally help support the weight of the creatures. The exoskeleton would simply not be able to bear the stress unless she could make it stronger or thicker.
Martha found, however, that she could produce a super-hard armorlike exoskelton by accelerating the rate at which the enzyme chitin synthase built the final chitin polymer. She also added chemical variants of the small molecule, N-acetylg
lucosamine, which were linked together to form the final molecular chain. This helped to further strengthen the pycnogonid's external coverings.
“Eureka,” she screamed when she first hit a fist-sized pycno with a hammer and found she could not crack its exoskelton. The hammer bounced off the body as if it had struck a creature made of metal.
That had led to mischief. Her hireling Lisa, then somewhat bony and awkward, in contrast to what two years were to do for her, heard her cry and thought there had been an accident. She dashed back to the lab section, and it was all Martha could do to persuade her that there was no emergency. Fortunately the adolescent was not unduly inquisitive, and had no interest in spiders of any kind, so the secret of Martha's researches was preserved.
Unfortunately for Martha, the stronger exoskeltons were so rigid that they sometimes confined the body tissues in a vise-like prison that did not permit proper growth. Normally, during the pycno's growth, the hard exoskeleton allowed little room for expansion and so, like with other arthropods, pycnos had to shed their coverings periodically by molting to permit additional growth. A new skeleton then had to be secreted to replace the one discarded. This molting process was under hormonal control.
With the new, stronger exoskeletons, baby pycnos had great difficulty periodically shedding their skeletons. To solve this problem Martha placed the naturally occurring molt-accelerating hormones on the same bacterial plasmids as the growth hormone. The elevated levels of molting hormone did the trick, and the molting and growth process occurred fairly normally. Occasionally there were mishaps: pycnos with body tissues bursting through the joints of the exoskeletons which did not shed at the proper intervals, or animals with so much exoskeleton that they looked more like spherical lumps of marble than functioning sea spiders. But such things were part of the normal course, and were routinely selected out.
There was another type of problem. The defective things were horrible, but how could they be blamed for this? They reminded her too much of herself: freakish, compared to the common mode. Surely they would be cruelly attacked by their more normal fellows, if ever put in with them. She wished she could spare them death, but she lacked the facilities to maintain her failures, even if they should prove to be capable of survival. So after considerable and pained reflection, she gently put such misfits out of their misery by overdosing them with anesthetic, with an uncharacteristic tear in her eye.
Her last step in creating the pycnogonids of monstrous proportions was to increase the pycnos’ strength so that they could move their huge bodies. To create more powerful muscles, Martha strengthened the actin and myosin molecules which were the basis for all muscle actions in animals. As a result, the muscles were several times as strong as in normal pycnos. Naturally, these stronger muscles needed additional energy to function so Martha also increased the levels of the energy rich substances phosocreatine and the enzyme phosphocreatine kinase. Phosphocreatine supplied the energy for muscle contraction.
But before they grew to their full new size, she put the more muscly versions through their paces: stress tests, pulling objects, finally even showing them off to the girl Lisa, who was suitably appalled. Lisa had no notion of the significance of these creatures; all she knew was that spiders were horrible. She came close to freaking out more than once, and that pleased Martha. “If you ever tell anyone else about my private experiments, I'll put some in your underwear,” she said, and was gratified to see the girl almost faint. Of course it was a bluff; the little pycnos couldn't survive for long out of the water yet, and would be just as freaked out by human underwear as Lisa was at the idea of having them there. But Lisa didn't know that, and anyway, a dead water spider would frighten her almost as much as a live one.
All of her biological manipulations had initially been enhancements to the pycnogonid's natural body architecture and biochemistry—and did not actually provide any new biological features. She did, however, want to make it possible for the pycno to easily see above water without having to lift its entire body out of the ocean. To do this, she had a plan to add two new functional eyes near the end of the proboscis. The process required a few months of experimentation to solve. In the end, she simply implanted pycno eye tissue under the exoskeleton of the proboscis when it was beginning to form during its embryonic stage. The additional tissue sent out biochemicals to the surrounding tissue and began a cascade of biochemical and physical events that eventually induced the formation of retina and optic nerves beneath each new eye.
The process of biochemical induction occurred normally during the course of embryonic development. One embryonic tissue had a chemical effect on a neighbor so that the developmental course of the responding tissue was drastically changed from what it would have been in the absence of the inductor. One of the classic examples of embryonic induction was the formation of the lens of the eye as a result of the inductive action of the optic cup upon the overlying tissue.
With the pycnos, nine out of ten times, the new optic nerves were able to grow and find their way back to the creature's forward brain, where they made a functional connection. Although Martha could have extended her discoveries and technologies to the implantation of new eyes in humans, she was not very concerned with humans. She didn't like humans very much. But she loved her new pycnos.
CHAPTER 20
Lisa
ELMO NEVER MADE a third trip to the hospital. A hospital clerk called him with the news that his mother was dead. “We'll need your authorization for the disposition of the body,” she said with marvelous insensitivity.
“I will have to check with my sister,” he said numbly. He had known this was coming, but still found himself unprepared.
“Of course,” the clerk said disapprovingly.
He made his way to the store. He didn't know what Martha's reaction would be, but he had to tell her. She was in a general way alienated from the species of mankind, having suffered more rejection at a more formative age than he had, and the death of their mother might have the effect of cutting her the rest of the way free. Or it might not affect her at all, she being long since alienated from Mrs. Samules. But he had to have her okay to arrange for the cremation; she was after all the closest blood kin available.
He approached the store, paused, nerved himself, and entered. The young woman, Lisa, was behind the counter, talking to a customer. Elmo hung back, waiting for the store to clear before getting to his ugly business. “You will have to speak to Martha,” she was saying.
“Well, where is she?” the man demanded.
“She's out at the moment, but I expect her back in an hour.”
“I can't wait a damn hour! These are bad fish she sold me, and I want a refund now.”
Bad fish? Elmo had his differences with his sister, but one thing she would never do was sell inferior fish. This had to be a confusion. But it wasn't his business.
“I'm sorry,” Lisa said, evidently flustered. “I'm not allowed to give refunds. It's against store policy.” Her eyes flicked to the posted sign, but the man ignored the signal. “They have to be handled by Martha herself,” Lisa continued somewhat doggedly. “If you can just come back in an hour—”
“No! These are bad fish, and I want my money back now.”
Lisa blinked. Elmo was surprised to see that she was evidently near tears. She was young, and innocent, and didn't know how to handle obnoxiousness. She had also suffered a recent bereavement. So he stepped forward, knowing that he would probably regret it. “Perhaps I can help,” he said.
The man whirled on him. “Who the hell are you?”
“Elmo Samules, a fishery officer for Trinity Bay.”
The customer didn't seem to pick up on the name, perhaps because Martha Samules seldom used any but her first name. “You got a refund?”
“No, but I do know something about fish.” He looked at the plastic container the man held. “When did you buy those?”
“Two days ago. And now they're dead.”
“You left them i
n that container throughout?”
“Yeah. Got to take them on the ferry south tomorrow. But not any more. They must have been diseased.”
“No. They died from oxygen deprivation. You should have put them immediately into an aerated aquarium. Didn't Martha tell you that?”
“Of course I know fish need oxygen to survive. I opened the container every four hours. And no, Martha didn't say a thing about the fish being in a sealed container.”
“She did!” Lisa interjected. “I remember. And anyway, opening the container once every four hours is far too seldom.”
“Well, when I get home, she said. But I'm not home yet. I live in New York. So I kept them here.”
Elmo shook his head. “Sir, you killed those fish. No sense waiting for Martha; she won't give you any refund. In fact, I'd advise you to be far away when she learns of this. Those are valuable fish.”
“I'll say! I paid a mint for them! And I want it back. Now.”
“You are out of luck,” Elmo said firmly. “You should not be buying fish until you learn something about them.”
“What I learned is that this is a gyp joint!” the man said, getting red in the face. He turned back to Lisa. “Now listen, you little bitch—”
Elmo reached up, gripped the man's shoulder with thumb and fingers, and squeezed. “There is no call for that kind of language. Please leave now.”
“Listen, buster, you can't—” But the man broke off as Elmo increased the pressure of his grip. It was becoming apparent that there was a lot of power in that hand. Then he dropped the container, turned, and stalked out. Elmo let him go.
Lisa was already rushing to the fish container. It was stoutly constructed, and had not burst. She picked it up as if it were a baby. “Thank you, sir,” she said gratefully. Then her eyes brightened with recognition as she stood, hugging the container. “Haven't we met?”
Spider Legs Page 13
