Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Meiosis I

Meiosis I

Meiosis is the division of a diploid cell into haploid cells forming sperm and eggs in animals through differentiation. Meiosis I is the first stage of meiosis, where the genetic recombination of homologous chromosomes and the reduction of the ploidy level by half occurs.
Prophase I is the most extended and complex step of meiosis I characterized by synapsis, chromosome pairing, and recombination of the homologous chromosomes. This process is facilitated by a proteinaceous structure called the...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Transcriptome analysis across reproductive stages in peripheral blood of female brown bears: a pilot study.

Scientific reports·2026

Same author

Antemortem diagnosis combining computed tomography and air sac fluid aspiration for aspergillosis: a case report in a gentoo penguin (Pygoscelis papua).

The Journal of veterinary medical science·2026

Same author

Plasma Atrial Natriuretic Peptide Concentrations and Associated Factors in Captive Dolphins: Potential Implications for Cardiovascular Assessment.

Animals : an open access journal from MDPI·2026

Same author

Enrichment of T: A→A: T substitutions in the TP53 gene in esophageal carcinoma with high Fusobacterium burden.

Scientific reports·2026

Same author

Distinct difference of pancreatic tissue-specific microbiome in autoimmune pancreatitis and pancreatic ductal adenocarcinoma.

Scientific reports·2026

Same author

Seroprevalence of tuberculosis and hematological variations in captive and orphaned wild elephants (Elephas maximus maximus) in Sri Lanka.

Veterinary research communications·2026

Search research articles

Related Experiment Video

Updated: Jun 29, 2026

A Noninvasive Hair Sampling Technique to Obtain High Quality DNA from Elusive Small Mammals

A Noninvasive Hair Sampling Technique to Obtain High Quality DNA from Elusive Small Mammals

Published on: March 13, 2011

Less-invasive age estimation using hair based on DNA methylation in brown bears.

Shiori Nakamura¹, Jumpei Yamazaki^1,2, Naoya Matsumoto³

¹Faculty of Veterinary Medicine, Hokkaido University, Kita-18, Nishi-9, Kita-ku, Sapporo, 060-0818, Hokkaido, Japan.

Scientific Reports

|December 30, 2025

Summary

This summary is machine-generated.

Researchers developed a new, non-invasive method to estimate the age of brown bears using DNA methylation levels found in hair. This breakthrough allows for better wildlife conservation and management by simplifying sample collection from wild populations.

Keywords:

Age estimation Aging Brown bear DNA methylation Epigenetic clock Wildlife management

More Related Videos

Sample Preparation to Bioinformatics Analysis of DNA Methylation: Association Strategy for Obesity and Related Trait Studies

Sample Preparation to Bioinformatics Analysis of DNA Methylation: Association Strategy for Obesity and Related Trait Studies

Published on: May 6, 2022

Optimized Bone Sampling Protocols for the Retrieval of Ancient DNA from Archaeological Remains

Optimized Bone Sampling Protocols for the Retrieval of Ancient DNA from Archaeological Remains

Published on: November 30, 2021

Related Experiment Videos

Last Updated: Jun 29, 2026

A Noninvasive Hair Sampling Technique to Obtain High Quality DNA from Elusive Small Mammals

A Noninvasive Hair Sampling Technique to Obtain High Quality DNA from Elusive Small Mammals

Published on: March 13, 2011

Sample Preparation to Bioinformatics Analysis of DNA Methylation: Association Strategy for Obesity and Related Trait Studies

Sample Preparation to Bioinformatics Analysis of DNA Methylation: Association Strategy for Obesity and Related Trait Studies

Published on: May 6, 2022

Optimized Bone Sampling Protocols for the Retrieval of Ancient DNA from Archaeological Remains

Optimized Bone Sampling Protocols for the Retrieval of Ancient DNA from Archaeological Remains

Published on: November 30, 2021

Area of Science:

Wildlife biology
Genetics
Conservation science

Background:

Chronological age is crucial for wildlife life history, conservation, and management.
DNA methylation methods offer alternatives to traditional tooth-based aging in bears.
Current DNA methylation methods require blood or skin, limiting samples to captured or deceased animals.

Purpose of the Study:

To establish the first hair-based age estimation model using DNA methylation in brown bears.
To enable less-invasive age assessment in wild brown bear populations.
To facilitate future ecological research and conservation efforts.

Main Methods:

Collected and analyzed DNA methylation levels from brown bear hair roots using bisulfite pyrosequencing.
Identified cytosine-phosphate-guanine (CpG) sites correlated with age near VGF, KCNK12, and ELOVL2 genes.
Developed and validated an age estimation model using the most significant CpG sites.

Main Results:

DNA methylation levels at specific CpG sites adjacent to VGF and KCNK12 genes correlated with chronological age.
The best age estimation model achieved a mean absolute error of 3.2 years and a median absolute error of 2.2 years.
The model utilized three CpG sites from two genes (VGF and KCNK12).

Conclusions:

A novel, non-invasive method for estimating brown bear age from hair DNA methylation was successfully developed.
This hair-based method simplifies sample collection, eliminating the need to capture bears.
Widespread application of this technique can significantly improve understanding of wild bear population structures, aiding conservation and management.