Human-specific ARHGAP11B is necessary and sufficient for human-type basal progenitor levels in primate brain organoids

Jan Fischer, Jula Peters, Takashi Namba, Wieland B. Huttner, Michael Heide

Preprint posted on 1 October 2020

Fischer and colleagues directly address the role of the human-specific gene ARHGAP11B in primate cortical development, leveraging chimpanzee and human brain organoids.

Selected by Ana Uzquiano


The neocortex is the brain region responsible for our higher cognitive functions. Its development relies on diverse neural progenitor types, which generate the compendium of postmitotic neurons. There are two main types of cortical neural progenitors: apical progenitors (AP), residing in the germinal ventricular zone, close to the ventricles, and basal progenitors (BP), localized in the subventricular zone (SVZ), a germinal zone located in more basal regions of the developing cortex (Florio and Huttner, 2014). The proliferative capacity of these two neural progenitor types is thought to underlie the enlarged cortical size and increased number of neurons characteristic of the human neocortex, which is larger than in any other primate (Florio and Huttner, 2014).

Extensive work in animal models has provided fundamental knowledge about the conserved mechanisms driving corticogenesis. However, the study of primate, including human, cortical development has been challenging due to the protracted length of this process which happens mostly in utero. With the advent of the stem cell field and organoid models, brain organoids provide a window to study primate/human-specific processes of neocortical development. Brain organoids are small 3D structures grown from embryonic stem cells (ESCs) or induced pluripotent stem cells  (iPSCs) which recapitulate certain events of neocortical development (reviewed in Velasco et al, 2020). Additionally, a handful of studies have shown their potential to unravel human-specific features of corticogenesis. Brain organoids have thus arisen as promising models to further investigate primate/human brain development.

ARHGAP11B is a human-specific gene implicated in human neocortical development (Florio et al, 2015, Florio et al, 2016, Kalebic et al, 2018, Heide et al, 2020). Its role in neural cortical progenitors has been previously studied in the mouse, ferret and marmoset neocortex, where it was shown that overexpression (mouse, ferret) or physiological expression (marmoset) of ARHGAP11B increases BP proliferation. In this study, the goal of the authors was to directly address the role of ARHGAP11B in primate corticogenesis, capitalizing on the use of chimpanzee – our closest living relative – and human brain organoids.

Main results

The authors genetically manipulated human and chimpanzee brain organoids by microinjecting selected DNA constructs, followed by electroporation. They assessed  the proliferation state by BrdU pulses and performed the experiments at ~ 51-55 days of in vitro development.

First, in order to assess the specific role of ARHGAP11B in BP proliferative capacity in both species, a dominant-negative construct was microinjected in human and chimpanzee cerebral organoids. Microinjection of this dominant-negative construct led to a decrease of proliferating BPs in human organoids, down to the level observed in chimpanzee organoids. However, microinjection of this construct in chimpanzee organoids did not have any  effect on proliferative BPs, pointing to a human-specific role of ARHGAP11B to maintain proliferative BPs.

Then, the authors investigated if human ARHGAP11B would increase BP proliferation in chimpanzee organoids. Indeed, overexpression of this human-specific gene led to an increase in the abundance of cycling BPs in chimpanzee brain organoids, consistent with previous results obtained in the embryonic mouse (Florio et al, 2015), embryonic ferret (Kalebic et al, 2018) and fetal marmoset (Heide et al, 2020).

Finally, the authors examined if, as expected, neuronal production was compromised at the expense of the increased abundance of proliferating BPs in chimpanzee organoids. Indeed, a decrease of neurons, particularly deep-layer projection neurons, was observed when overexpressing ARHGAP11B in chimpanzee organoids, concomitantly with the increase of proliferating BPs.

In conclusion, by using chimpanzee and human brain organoids, this study shows that ARHGAP11B is required for human BP proliferation. This work also shows that overexpression of ARHGAP11B can lead to an increase of proliferating BPs in other primates such as the chimp. However, the introduction of the dominant-negative construct did not cause any effect on chimp BP proliferation, suggesting the absence of another protein that may act similarly to ARHGAP11B in chimps.

Why I choose this paper

Cerebral cortex development is a highly intricate process, in which different types of neural progenitors are responsible for the production of the final neuronal progeny. Although many studies over the last decade have investigated species-specific mechanisms of neural progenitor behavior, this question still remains open and more work is required to fully understand how the human cerebral cortex is built and what makes it so unique.

This work focuses on a human-specific gene with a known function in cortical development to further shed light into this highly relevant topic. Additionally, it contributes to the slowly growing  list of studies showing the potential of brain organoids to study aspects pertaining to brain evolution.

Questions for the authors

These experiments were performed at a very narrow window of in vitro development. Is there a time-window for ARHGAP11B’s role in corticogenesis? Would you expect similar results if you insert the dominant-negative construct or overexpress ARHGAP11B in human and chimpanzee organoids, respectively, at a different time point?

Have you done a deeper analysis of the identity of the BPs which are affected upon your genetic manipulations, both in human and chimpanzee organoids?



Tags: brain evolution, brain organoids, cortical development, neural progenitors

Posted on: 3 March 2021


Read preprint (No Ratings Yet)

Author's response

Wieland B. Huttner and Michael Heide shared

  • These experiments were performed at a very narrow window of in vitro development. Is there a time-window for ARHGAP11B’s role in corticogenesis?

We believe that the time-window for ARHGAP11B’s action corresponds to the time-window during corticogenesis when basal progenitors are active, self-renewing themselves and generating neurons.

  • Would you expect similar results if you insert the dominant-negative construct or overexpress ARHGAP11B in human and chimpanzee organoids, respectively, at a different time point?

Yes, if the experiments are carried out when the organoids contain basal progenitors. At very early stages of organoid development, i.e. before the generation of basal progenitors, and at very late stages of organoid development, when basal progenitors are scarce, we would not expect much of an effect of ARHGAP11B.

  • Have you done a deeper analysis of the identity of the BPs which are affected upon your genetic  manipulations, both in human and chimpanzee organoids?

Not in the manuscript that is on the preprint server. However, we are currently in the process of examining the effects of ARHGAP11B expression on basal radial glia vs. basal intermediate progenitors.



1 comment

2 years

Vasso Episkopou

excellent review and questions by Ana Uzquiano . Thank you Ana!
What I don’t like in this paper is the use of dominant negative construct. The function of such contracts is complicated, I wonder if loss of function experiments using RNAi has the same effect.

Have your say

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sign up to customise the site to your preferences and to receive alerts

Register here

preLists in the developmental biology category:

2nd Conference of the Visegrád Group Society for Developmental Biology

Preprints from the 2nd Conference of the Visegrád Group Society for Developmental Biology (2-5 September, 2021, Szeged, Hungary)


List by Nándor Lipták


The advances in fibroblast biology preList explores the recent discoveries and preprints of the fibroblast world. Get ready to immerse yourself with this list created for fibroblasts aficionados and lovers, and beyond. Here, my goal is to include preprints of fibroblast biology, heterogeneity, fate, extracellular matrix, behavior, topography, single-cell atlases, spatial transcriptomics, and their matrix!


List by Osvaldo Contreras

EMBL Synthetic Morphogenesis: From Gene Circuits to Tissue Architecture (2021)

A list of preprints mentioned at the #EESmorphoG virtual meeting in 2021.


List by Alex Eve

EMBL Conference: From functional genomics to systems biology

Preprints presented at the virtual EMBL conference "from functional genomics and systems biology", 16-19 November 2020


List by Jesus Victorino

Single Cell Biology 2020

A list of preprints mentioned at the Wellcome Genome Campus Single Cell Biology 2020 meeting.


List by Alex Eve

Society for Developmental Biology 79th Annual Meeting

Preprints at SDB 2020


List by Irepan Salvador-Martinez, Martin Estermann

FENS 2020

A collection of preprints presented during the virtual meeting of the Federation of European Neuroscience Societies (FENS) in 2020


List by Ana Dorrego-Rivas

Planar Cell Polarity – PCP

This preList contains preprints about the latest findings on Planar Cell Polarity (PCP) in various model organisms at the molecular, cellular and tissue levels.


List by Ana Dorrego-Rivas

Cell Polarity

Recent research from the field of cell polarity is summarized in this list of preprints. It comprises of studies focusing on various forms of cell polarity ranging from epithelial polarity, planar cell polarity to front-to-rear polarity.


List by Yamini Ravichandran

TAGC 2020

Preprints recently presented at the virtual Allied Genetics Conference, April 22-26, 2020. #TAGC20


List by Maiko Kitaoka et al.

3D Gastruloids

A curated list of preprints related to Gastruloids (in vitro models of early development obtained by 3D aggregation of embryonic cells). Updated until July 2021.


List by Paul Gerald L. Sanchez and Stefano Vianello

ASCB EMBO Annual Meeting 2019

A collection of preprints presented at the 2019 ASCB EMBO Meeting in Washington, DC (December 7-11)


List by Madhuja Samaddar et al.

EDBC Alicante 2019

Preprints presented at the European Developmental Biology Congress (EDBC) in Alicante, October 23-26 2019.


List by Sergio Menchero et al.

EMBL Seeing is Believing – Imaging the Molecular Processes of Life

Preprints discussed at the 2019 edition of Seeing is Believing, at EMBL Heidelberg from the 9th-12th October 2019


List by Dey Lab

SDB 78th Annual Meeting 2019

A curation of the preprints presented at the SDB meeting in Boston, July 26-30 2019. The preList will be updated throughout the duration of the meeting.


List by Alex Eve

Lung Disease and Regeneration

This preprint list compiles highlights from the field of lung biology.


List by Rob Hynds

Young Embryologist Network Conference 2019

Preprints presented at the Young Embryologist Network 2019 conference, 13 May, The Francis Crick Institute, London


List by Alex Eve

Pattern formation during development

The aim of this preList is to integrate results about the mechanisms that govern patterning during development, from genes implicated in the processes to theoritical models of pattern formation in nature.


List by Alexa Sadier

BSCB/BSDB Annual Meeting 2019

Preprints presented at the BSCB/BSDB Annual Meeting 2019


List by Dey Lab

Zebrafish immunology

A compilation of cutting-edge research that uses the zebrafish as a model system to elucidate novel immunological mechanisms in health and disease.


List by Shikha Nayar