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They just discovered a new kind of organism that isn't a virus or bacterium

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20|04|2024

I finally worked on a general plan of my study to do list for the next couple of months. As usual creating this kind of overview makes me feel way better because I feel like I have a clear idea of what I have to do. I spent the rest of the day reading and then out with my mom exploring old royal residences and birdwatching in a field.

📖: Nona The Ninth by Tamsyn Muir

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april 7th, 2024.

tomorrow marks my last ever week of undergraduate classes and it is so so bittersweet. :,)

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While looking through my 2023 journal I stumbled upon this cute little page of what I wanted for April 2024. The best thing about journaling is reading back over everything when you are an older and wiser version of yourself 🤍

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Allegedly it’s February now

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Greenhouse nursery tour 2.17.24. Kawahara, Floricultura, and Monterey Bay Nursury.

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found at work today

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Histone Modifications

Hello, hello! Today's topic is histone modifications. We are continuing on with the epigenetics theme after my previous educational post about DNA methylation. As described in that post, epigenetics is the study of heritable genetic modifications without a change in DNA sequence (Takuno & Gaut, 2012). Similarly to DNA methylation, histone modifications affect gene expression through regulation of accessibility of the DNA for transcription (Bartova et al, 2008). But before we get into these modifications, let's go over a bit of background information!

What is a histone, anyway? A histone is a type of protein involved in DNA compaction and organization. In order to fit a genome's worth of DNA into the nucleus of a cell, that stuff needs to be extremely tightly packed! Histones help with this by forming an octomer called a nucleosome, which the DNA wraps around. These nucleosomes then coil together to form a fiber known as chromatin, which goes on to make up a chromosome. When the chromatin is less tightly packed, it is known as euchromatin and it is available for transcription (Bartova et al, 2008). When it is more tightly packed, it is known as heterchromatin, and polymerase proteins cannot access and transcribe the DNA (Bartova et al, 2008). Histone modifications regulate the transition between heterochromatin and euchromatin (Bartova et al, 2008).

(Above image from humanoriginproject.com)

(Above image from Caputi et al, 2017)

The octomer core of a nucleosome is made up of two copies of each of four types of histones: H2A, H2B, H3, and H4 (Marino-Ramirez et al, 2017). Each of these histones includes an N-terminal tail structure, which is the main site of modification (Marino-Ramirez et al, 2017). The tails are modified through addition and removal of certain functional groups or other small structures. Types of modifications include acetylation by histone acetyltransferases, methylation by histone methyltransferases, phosphorylation by kinases, and ubiquitination (Marino-Ramirez et al, 2017). All of this information is used for naming specific histone modifications: Which histone is modified, which amino acid of the histone tail the modification is on, what type of modification is made, and in what amount. For example, H3K9me2 is the name for di-methylation of the 9th Lysine on an H3 histone's tail.

Some important histone modifications and their effects include:

H3K9me2: transcriptional activation + maintenance of CHG DNA methylation in plants

H3K9me3: transcriptional repression

H3K9ac: transcriptional activation

H3K4me1 & H3K4me3: transcriptional activation

H3K27me3: transcriptional repression

H4K16ac: transcriptional activation

H3S10p: DNA replication-related chromatin condensation

(He & Lehming, 2003)

Important Terms: histone, nucleosome, heterochromatin, euchromatin, transcription, epigenetics

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The Wind Rises (2013) Kiki's Delivery Service (1989) Porco Rosso (1992) My Neighbor Totoro (1988) Whisper of the Heart (1995)

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jan & feb 2024 w them

we love cheddar cheese rocket crackers

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first semester as a molecular bionics engineering student is over, so my location is at the lab for this week!!🥽

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2/7/2024

30nym challenge Day 3: What does your ideal study plan look like this week?

Next week I am tutoring M1 students about performing physical exams, so I’m planning to review the material and brainstorm some relevant fun facts to make it a bit more fun. Only about 20 min of studying/prepping per day.

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when the academically challenging degree is indeed challenging you.

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02 • 03 • 24

Finally Friday! I wrote my biology exam after studying a whole chunk of the content a night before… walked in there with no stress and finished with time to spare. I’m caught up! Today I’m taking a breather with my girlfriend, we’ll be going plant shopping and having a chill day. Taking advantage of every little break we have.

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In case you were wondering, the shiniest living thing in the world is Pollia condensata, a tropical African herb that only grows to a meter tall and can produce up to 40 berry-like fruits per cluster.

While they do not make a tasty treat, their orbs can retain their sparkle and hue for decades.