Camels (especially dromedaries) have exceptional heat tolerance, surviving desert temperatures often exceeding 40–50°C (104–122°F) with minimal water. While whole-body adaptations like fat-storing humps, thick fur for insulation/shade, low sweating, and heterothermy (allowing body temperature to fluctuate daily, e.g., up to 41–42°C) are well-known, recent research highlights cellular and molecular mechanisms.

A 2026 study in BMC Genomics compared skin fibroblasts (connective tissue cells) from humans and one-humped camels under different temperatures. Researchers developed a new analytical framework focusing on gene expression variability and consistency across individuals (rather than just up/down regulation), enabling insights even with smaller datasets.

Mammalian cells use a three-part genetic system for heat response:

1. Stable genes — Anchor and control the overall response.
2. Heat-responsive genes — Activate specifically during temperature shifts.
3. Erratic genes — Reflect system stress and variability.

Camel cells show greater resilience and a more flexible, coordinated response, maintaining cellular “well-being” and homeostasis better at both normal body temperature (98.6°F/37°C) and elevated heat (105.8°F/41°C). Human cells respond more rigidly, making them less adaptable under stress.

This flexibility helps camel cells stay balanced despite disruptions, contributing to overall thermotolerance.

Heat shock proteins (HSPs) are a highly conserved family of molecular chaperones produced by cells in response to stressors like heat, helping maintain protein homeostasis (proteostasis). They prevent misfolding/aggregation of proteins, assist in refolding damaged ones, and promote cell survival under stress.

HSPs are classified by molecular weight (e.g., HSP70, HSP90, HSP60, small HSPs like HSP27).

Under normal conditions, many HSPs are constitutively expressed at low levels. Heat (or other stresses) triggers rapid transcriptional activation via heat shock factors (HSFs), leading to massive HSP accumulation. This is part of the broader heat shock response (HSR), which temporarily halts most protein synthesis to prioritize stress protection.

In desert-adapted mammals like camels, HSPs are crucial for thermotolerance, enabling survival at high body temperatures (up to ~41–42°C) with minimal water loss.

HSP induction is energy-intensive and not a complete solution—prolonged extreme stress can still overwhelm it, leading to apoptosis. In camels, HSPs integrate with other adaptations (e.g., resilient RBCs, efficient water conservation, flexible gene regulatory networks) for superior overall resilience.

HSP research in camels (e.g., reviews by Hoter et al., studies on somatic cells by Saadeldin et al.) positions them as models for understanding thermotolerance, with potential applications in livestock breeding and human heat-related diseases. For the newest gene-network insights tying into HSPs, see the 2026 BMC Genomics paper.

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New approaches to discovering epigenetic rules of homeostasis in diverse mammal species

Traditional differential expression analysis (identifying genes that go significantly up or down) often fails with small sample sizes (few biological replicates), which is common in studies of non-model or large mammals like camels.

The authors (led by Jorge Gonzalez, with collaborators from FAU, Broad Institute, and others) introduce a new framework focused on epigenetic/homeostatic rules:

They emphasize inter-individual variability in gene expression. Genes that preserve or reduce variability under stress (e.g., temperature change) are interpreted as contributing to homeostasis-preserving mechanisms for that species. This is a key novel idea, usable even with limited replicates via simple non-statistical criteria.

Data came from skin fibroblast cell cultures (homogeneous cells) exposed to different temperatures, comparing species like humans (tight thermoregulation) vs. dromedary camels (wide daily body temperature swings).

Mammalian cells respond to temperature perturbations via three main gene groups that function like a simple organizing system:

Stable genes — Act as anchors, maintaining overall control and homeostasis.

Heat-responsive genes — Activate or change specifically during temperature shifts.

Erratic genes — Show increased variability, reflecting system stress or disruption.

They identify four extreme subgroups of differentially expressed genes (DEGs) based on expression changes and variability, then build an intuitive neural network architecture that best interpolates the data and models the principal response “rules” for each species.

Camels consistently rank higher than humans in cellular well-being under both normal (32°C) and heat-stress (41°C) conditions. Camel cells show more flexible, coordinated, and resilient responses, better maintaining balance despite disruptions. Human cells are more rigid.

Published: BMC Genomics (2026) open access

DOI: 10.1186/s12864-026-12823-7

Authors: Jorge Gonzalez, 
Diane P. Genereux, 
Kristin Crouse, 
Bradley Frishman, 
Allyson G. Hindle, 
Elinor Karlsson, 
Carla B. Madelaire, 
Lucas Moreira & 
Valery Forbes 

Abstract
Background: While the cells of some mammals, such as humans, maintain their internal
temperature within tightly controlled ranges, the cells of others, such as dromedary camels,
experience wide ranges of temperature variation. In order to understand these differences, it
is critical to identify differentially expressed genes (DEGs) and their interactions; however,
the data available are often insufficient to obtain statistically significant results.
Results: We develop an explanatory model to understand the mechanisms of response of
mammalian species to environmental perturbation on the basis of empirical gene expression
data. Our approach is motivated by the novel idea that approximately preserved or reduced
inter-individual variability of expression levels upon environmental change is an indicator
that a given gene contributes to a homeostasis-preserving mechanism for the species. To
identify such genes, we use a simple non-statistical criterion that is suitable even when the
number of replicates is limited. We then identify four extreme subgroups of the DEGs,
and from these construct an intuitive neural network architecture that best interpolates
the data and describes the principal response rules of the considered species. Finally, we
propose measures of the robustness of homeostasis (well-being) from these networks based
on perturbation analysis and entropy computations. The data used to develop the model
were collected from homogeneous cell cultures of skin fibroblasts.
Conclusions: Even with data available for just a few individuals, our model identi
f
ies extreme response sets of genes, using inter-individual variability to provide a faithful
representation of the response of the species to environmental perturbations. Sets of genes
identified as relevant in individual species are useful for comparing responses across species.
All the measures of cellular well-being introduced in this work rank camels higher than
humans for both the 32° and 41° treatments.
Keywords: inter-individual variability of genes, differential expression, stress response
model

The paper combines empirical RNA-seq data, novel analytical criteria, network modeling, and robustness metrics into a practical pipeline for comparative mammalian physiology and epigenetics. For the full details (methods, specific gene sets, math appendices, supplementary figures), read the open-access article directly.