Nav: Home

Genes for speech may not be limited to humans

November 15, 2016

Our current understanding is that mice have either no -- or extremely limited -- neural circuitry and genes similar to those that regulate human speech. According to a recent study published in Frontiers in Behavioral Neuroscience, this understanding may be incorrect.

Dr. Jonathan Chabout is the lead author of the paper, whose principal investigator is Dr. Erich Jarvis.

Dr. Jarvis and colleagues report the results of their investigation into the effect of a genetic mutation in the Forkhead box protein #2 (FOXP2) on the vocalization patterns of adult male mice. FOXP2 regulates speech production in humans. Individuals with deficiencies in FOXP2 protein have difficulty forming complex syllables and complex sentence construction.

Although mice are unable to communicate using speech in the same way as humans, they do vocalize as a means of communicating with each other. Therefore this study sought to determine whether FOXP2 deficiencies have similar consequences for communication by mice as they do for humans.

They do.

Dr. Jarvis suggests that this study supports the "continuum hypothesis," which is that FOXP2 affects the vocal production of all mammals and not just humans.

Dr. Jarvis' team investigated twenty-six (26) male mice bred to have a FOXP2 mutation the same as that found in humans with speech deficits, and twenty-four (24) "wildtype" male mice (i.e., mice with a normal level of FOXP2 protein).

Both types of male mice (the heterozygous mice containing the FOXP2 mutation and the wildtype mice) were placed in several unique contexts -- housed with an active wildtype female mouse, in proximity of only the urine of wildtype females, or housed with a sleeping female or sleeping male mouse. These particular contexts derived from prior research published by Chabout and colleagues in 2015.

This past study found that in these various social contexts, healthy males produced differences in the sequence and duration of the ultrasonic vocalizations (USVs), which are high-pitched sounds inaudible to humans, that mice make. In their new study, the investigators wished to determine if there was an effect of a FOXP2 deficiency on the communication patterns of mice.

The results showed that the FOXP2 heterozygotes have difficulty producing the complex vocal communication patterns that wildtype mice can create with ease -- as measured both by syllable length and the number of unique syllables produced over time. These divergences are particularly strong when comparing the communication of FOXP2 heterozygotes and wildtype males while in the presence of active female mice. In this context, the wildtype males were 3 times as likely as heterozygotes to produce the most complex syllable types and sequences available for review. Dr. Jarvis' team performed intricate statistical analyses to validate this finding, and their conclusion held true.

Following the conclusion of all recordings, Dr. Jarvis' team used a process known as transsynaptic tracing from vocal larynx muscles to compare the vocal brain regions of wildtype and heterozygote FOXP2 mice. This study revealed that the heterozygote's vocal motor neurons were more widely distributed across the cortex than was the case for wildtype mice. This evidence suggests that the FOXP2 mutation affects both the placement and functioning of the neurons connected to effective communication, from mice all the way to humans.

Prior research has shown a more limited role for FOXP2 than what is now becoming apparent. As Dr. Jarvis observes, "We believe that FOXP2 already had a pre-existing role in regulating vocal communication before human language evolved."
-end-
Citation: Chabout J, Sarkar A, Patel SR, Radden T, Dunson DB, Fisher SE and Jarvis ED (2016) A Foxp2 Mutation Implicated in Human Speech Deficits Alters Sequencing of Ultrasonic Vocalizations in Adult Male Mice. Front. Behav. Neurosci. 10:197. doi: 10.3389/fnbeh.2016.00197

Frontiers

Related Genetic Mutation Articles:

Combination therapy targets genetic mutation found in many cancers
A study at The University of Texas MD Anderson Cancer Center has shown promise for effective treatment of therapy-resistant cancers caused by a mutation of the RAS gene found in many cancers.
Genetic mutation studies help validate new strategy for reducing lipids, cholesterol
A new strategy -- an injectable antibody -- for lowering blood lipids and thereby potentially preventing coronary artery disease and other conditions caused by the build-up of fats, cholesterol, and other substances on the artery walls, is supported by findings from two new studies from researchers in the Perelman School of Medicine at the University of Pennsylvania.
Genetic mutation trade-offs lead to parallel evolution
Researchers at the University of Illinois at Urbana-Champaign have shown how evolutionary dynamics proceed when selection acts on two traits governed by a trade-off.
Scientists find genetic mutation responsible for rare skin disease in Afrikaners
Researchers at the Sydney Brenner Institute for Molecular Bioscience and the Division of Human Genetics at Wits, in collaboration with peers in Europe, the US and Canada published this research in the May issue of the American Journal of Human Genetics.
OCD-like behavior linked to genetic mutation
A new Northwestern Medicine study found evidence suggesting how neural dysfunction in a certain region of the brain can lead to obsessive and repetitive behaviors much like obsessive-compulsive disorder (OCD).
Genetic mutation in whale eyes may increase mortality risks
The study of this whale species, which numbers less than 500 individuals remaining in the Western Atlantic Ocean, may also help scientists better understand how vision works in other mammals, including people.
New testing method developed for genetic mutation that causes pulmonary hypertension
Pulmonology and genetics experts from two Utah healthcare organizations have collaboratively developed a new diagnostic genomic testing method for a rare form of pulmonary hypertension caused by a genetic mutation they discovered three years ago.
Novel genetic mutation may lead to the progressive loss of motor function
Researchers from the National Institutes of Health and their colleagues identified the genetic cause and a possible therapeutic target for a rare form of pediatric progressive neuropathy.
Researchers discover new genetic mutation linked to osteonecrosis of the hip
Osteonecrosis or 'bone death' of the femoral head is a disease caused by interruption of blood flow in the hip bone.
Genetic mutation causes ataxia in humans and dogs
Cerebellar ataxia is a condition of the cerebellum that causes an inability to coordinate muscle movements.

Related Genetic Mutation Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".