alejandra manjarrez

Alejandra Manjarrez, PhD

Alejandra Manjarrez is a freelance science journalist who contributes to The Scientist. She has a PhD in systems biology from ETH Zurich and a master’s in molecular biology from Utrecht University. After years studying bacteria in a lab, she now spends most of her days reading, writing, and hunting science stories, either while traveling or visiting random libraries around the world. Her work has also appeared in Hakai, The Atlantic, and Lab Times.

Articles by Alejandra Manjarrez, PhD
A younger-looking mouse next to an older-looking one
Epigenetic Manipulations Can Accelerate or Reverse Aging in Mice
Alejandra Manjarrez, PhD | Jan 12, 2023 | 4 min read
Repairing damaged DNA appears to drive aging by causing the loss of epigenetic information, but restoring that information reverses such effects, a study finds.
Pink neutrophils on a white background.
Mucus-Eating Gut Bacteria May Promote Fever After Cancer Treatment
Alejandra Manjarrez, PhD | Jan 5, 2023 | 3 min read
The expansion of mucus-degraders in the mouse gut—possibly due to poor nutrition—thins the colon’s mucus layer and may weaken defenses against blood-infecting microbes.
Human hand with white glove holding a white mouse in a green background.
Study Traces a Neural Circuit Behind Green Light–Mediated Pain Relief
Alejandra Manjarrez, PhD | Dec 9, 2022 | 4 min read
A mouse study concludes color-detecting cones in the eye and a subset of neurons in the brain’s thalamus are why green light exposure has an analgesic effect.
Illustration of viruses represented with different colors overlapping each other.
What Happens When You Catch More than One Virus?
Alejandra Manjarrez, PhD | Dec 7, 2022 | 8 min read
The “tripledemic” shines a spotlight on viral interference, in which one infection can block another.
Image of a culture of <em >Entamoeba gingivalis</em> growing together with bacteria. There are two roundish amoeba cells surrounded by bacilli and other bacterial forms.
Recently Discovered Virus Family Infects a Human Oral Amoeba
Alejandra Manjarrez, PhD | Dec 1, 2022 | 3 min read
Redondoviruses, which have been associated with cases of periodontitis and other diseases, turn out to live inside the amoeba Entamoeba gingivalis.
A mouse in front of an open sack of grain.
Mice Fed a Highly Processed Diet Are More Susceptible to the Flu
Alejandra Manjarrez, PhD | Nov 18, 2022 | 3 min read
It’s not clear why grain-fed mice are better able to recover after infection, but a study’s findings suggest food type may skew the results of animal studies.
A nine-banded armadillo walking on dry grass.
Leprosy Bacterium Rejuvenates Armadillos’ Livers
Alejandra Manjarrez, PhD | Nov 15, 2022 | 4 min read
Mycobacterium leprae appeared to reprogram the animals’ livers to a state partially resembling early development, resulting in healthy organ growth.
Illustration of green fluorescent bacterial cells.
Cocaine Use Creates Feedback Loop with Gut Bacteria: Mouse Study
Alejandra Manjarrez, PhD | Nov 1, 2022 | 3 min read
A jolt of norepinephrine in the mouse gut facilitates colonization by certain microbes, which in turn deplete glycine, enhancing cocaine-induced behaviors.
illustration of human oocyte
Mammalian Oocytes Store mRNA in Newly Found Membraneless Structure
Alejandra Manjarrez, PhD | Oct 20, 2022 | 3 min read
The findings answer the longstanding question of where these cells hold the mRNA needed to cope with the transcriptional halt preceding meiosis.
A cross-section of a mouse hypothalamus, where cells of the arcuate nucleus are shown in bright green at the bottom.
Methylation in Young Brains May Be Key to Obesity: Mouse Study
Alejandra Manjarrez, PhD | Oct 19, 2022 | 4 min read
Epigenetic events, such as methylation, during early brain development in mice occur in genomic regions associated with BMI in humans, according to a new study.