Thursday 7 January 2016

Hour 16: Splitting headaches

Mitosis is an essential process in the lives of cells, as it allows them to replicate (become two individual cells). This is a highly regulated process, as there a lot of things that need to be doubled before either 'daughter' cell can exist independently. During mitosis, the DNA of a cell is distributed equally among daughter cells. However, before this can happen, the cell needs to double in size, double all of its organelles (cell organs) and, most importantly, make an exact copy of its DNA. As you can imagine, keeping track of all this doubling can get confusing, so scientists have found a way to subdivide this whole process into several distinct steps. These include interphase, Gap1 (G1), Synthesis (S), Gap 2, and finally, mitosis. Most of you will have covered all of this in your school years, maybe in a time long-forgotten, or maybe you are stuck trying to memorize it now. But before you turn away in disgust (bleargh, biology) and contemplate clicking onto the next more frivolous web-site, I ask you this: have you ever wondered what mitosis would feel like?

For the school students, who are wondering 'what is the point of learning this since I will never use it again in my life', I have included some simplified biology details that should help you pass your dreaded biology exam. Hang in there, soon you will be part of the people who can comfortably forget biology details without any significant consequence to their lives.

The Gap 1 (G1) phase, is the step that comes after interphase. Essentially, all that happens in G1 is that the cell increases in size and gets ready for DNA replication. To do this, the cell increases its supply of proteins and number of organelles, such as mitochondria (the cellular equivalent of lungs, they breathe and use the oxygen to produce energy) and ribosomes (essential to the cell as they make protein). It can last a variable amount of time. 

I waited and waited in the gloom. My body seemed to grow with the drumming of the heart-beat. But I was darkness and I was barely aware of my size. I was anger, and disappointment and pain. I wasn't any different from my fellow cancer cells. I was a monster, too. I let myself sink deeper into my misery. I didn't deserve an escape. I felt my sides push against my neighbouring cells, and I let them, revelling in the feeling of discomfort. I don't know how much time had passed as I grew, impassive. It could've been hours, or minutes, or days. Time seemed to have lost its value, as it led me to my atrocious fate. Abruptly, everything stalled. I glanced down, disinterested, noticing how my inside organs seemed to have doubled. Maybe I had finally lost my mind, and I was just seeing double. I noted I was huge, towering over my fellow cells. I wondered if this was how Hulk felt on a daily basis. I briefly wondered if I should feel some sympathy for him, and then remembered I didn’t care.

The synthesis (S) phase, is the stage where the DNA is replicated. On any other day, a cell’s DNA looks like a bowl of spaghetti. You can imagine how hard it would be to pick out individual spaghetti pieces and try to duplicate them without making a mess (please do not try this at home). Cells have found a way to ‘tidy-up’ the DNA into chromosomes just for this purpose. Essentially, they make the bowl of spaghetti look like baguette bread loafs. Each bread loaf (chromosome) is duplicated and then left to lie next to the original baguette. To avoid making a new mess, and forgetting what’s what, each baguette copy is tied to the original with a tooth-pick in its centre (scientists call this the ‘centromere’). When two baguettes(chromosomes) are tied like that, scientists like to call them ‘sister chromatids’, because they want to confuse you. You can call them ‘brother baguettes’ to get right back at them.  DNA synthesis (replication) is completed as quickly as possible, so as not to expose the fresh baguettes to mutagenic factors before they are completed. Mutations cause cancers. Cancers are bad.

 I suddenly realised there was a faint cheering in the background. Scours of cancerous evil eyes were watching my progress, elated. I felt nauseated, and attempted to return to the blackness, the numbness. I closed my eyes, and revelled in the feeling of the oxygen seeping into my pores. But the solace of darkness didn't envelop me. Instead, I felt a faint tugging in my nucleus. The nucleus contains the DNA, like a skull would a brain, if I were human.  It controls our every move, our every thought. I guess the feeling I was experiencing could be compared to a migraine, or a strong headache. The pain jolted me out of my depression, and I grimaced, confused. I tried in vain to ascertain what was happening inside my nucleus. But like a man wouldn't be able to look into its own brain, I was unable to make the slightest progress. The pain got stronger, clouding my brain. Every thought had to travel through a thick fog before becoming coherent. I tried to shake my head, but realised I couldn't. I had no head. I was a cell. A sticky, huge cell, who couldn't budge. The nearby cancer cells seemed to notice my discomfort, and started cheering louder. 'Here comes the DNA synthesis' one cell said, ecstatic. Her words raced through my muddled thoughts, their meaning sinking into the depth of my soul. The fear they brought was stronger than the pain. Survival instincts kicked in, as I realised I was about to have two sets of DNA, a second brain. I was about to become two cells. I wondered in horror, whether I would lose myself as I became two. Was this the end of me? 'I'm not afraid.' I thought. 'I'm not afraid, I'm not afraid, I'm not afraid.' I repeated these words over and over in my mind, clinging to their meaning, chanting them to the fear that was slowly building at the edges on my mind. But I wouldn't, I couldn't let it win. If I was to go as a monster, I wouldn't let myself be a coward too. The edges of my thoughts were becoming clouded, and I chanted, louder and louder, challenging the pain, resisting my nature. But the clouds didn't recede, and I realised with a jolt that my thoughts had now become weak whispers of fear, as I mumbled 'I'm not afraid' one last time. I felt a final blinding tug in my nucleus, as if my brain was being opened up and split into two, and I felt myself sink into the darkness. Through the rumbling in my ears I thought I heard a pleading voice, clear as an angel, whisper my name. 'Selena.' I thought. And then it all went black.

The Gap 2 (G) phase, is just a gap between DNA synthesis and mitosis. Impossibly, the cell continues to grow in size.

I slowly slipped back to consciousness, faintly aware of a strong pain gradually subsiding. My thoughts were still muddled, and I noticed there seemed to be an echo to the voices within me. I felt like I was screaming inside an empty cave, my every scream doubled back at me. As if sound was looking at itself in the mirror. I tried to recall what was happening, but thinking was becoming so hard. There seemed to be too many thoughts conflicting with each other...Like two minds in one body. This realisation hit me like a lightning bolt, and I understood that my cloudy state of mind was due to me having one nucleus with two sets of DNA, like one head with two brains. Both of my minds froze in unison. Then, a faint pressure on my membrane broke me out of my reverie: impossibly, I was still getting bigger.  I felt a second part of me rejoice in the notion of splitting. Like I had somehow unearthed an evil side. I got muddled up in a mixture of happiness and awe, terror and fear. When would this nightmare end? I closed my eyes again, attempting to clear my mind. I longed for the silence, for a mind at peace. There were too many thoughts, too many evil thoughts. I felt crowded. And then, as abruptly as it had stopped, the pain seared again.

Cell X