‘The combination of organoids with other organoids or with different specialized cell types in self-organizing 3D cultures results in emergent features of the system..’
‘Assembloids are obtained by: incorporating different organoids into multi-region assembloids, such as when combining dorsal with ventral forebrain, cerebral cortex with striatum, or cerebral cortex with thalamus; integrating neural or non-neural cells…’
‘Assembloids can be generated from organoids derived from different individuals, to create inter-individual assembloids, or different species, to create inter-species assembloids’
‘individual organoids can be generated from mixtures of cell lines derived from different species to create inter-species organoids.’
From our recent @Nature—a few recommissions [part 6 & last]:
‘The term cerebral organoid has sometimes been used broadly in the field, but it should be restricted to organoids that predominantly contain cells of the cerebrum.’
‘Claiming bona fide identity of in vitro-derived organoids or assembloids requires rigorous benchmarking to primary human tissue’
‘We recommend thoughtfulness in labelling cell types, taking into account their gene expression profiles, electrophysiological properties, activity-dependent states, areal identities and developmental trajectories.’
From our recent @Nature— thoughtfulness in the language used [part 5]:
‘It was felt strongly by all authors that the names mini-brain, brain-in-a-dish and whole-brain organoid to describe neural organoids should be avoided.’
‘These terms do not accurately inform the type of organoid produced, and they have proved to be confusing…’
‘Similarly, the term humanized animals to describe animal models with neural organoid-derived grafts should be avoided as it raises concerns about conferring advanced cognitive and behavioural abilities.’
‘We recognize two main categories of neural organoids on the basis of the level of guidance provided during the differentiation of pluripotent stem cells into organoids.’
‘By guidance we mean the addition of small molecules or factors intended to generate a particular region or collection of cell types’
‘when instructive signals are used to guide the generation of organoids composed of more regionally specific cell types, we call them regionalized neural organoids, which can recapitulate cellular, molecular or anatomical features of particular domains of the nervous system.’
From our recent @Nature— outlining key terms [part 1]
‘We define #organoids as in vitro-generated cellular systems that emerge by self-organization, include multiple cell types, and exhibit some cytoarchitectural and functional features reminiscent of an organ or organ region.’
‘Organoids can be generated as 3D cultures or by a combination of 3D and 2D approaches (also known as 2.5D)…For the nervous system, they are generally constructed from pluripotent stem cells but can also be derived from donor tissues with growth potential…’
‘We refer to nervous system organoids by the major anatomic region they model, such as cortical organoids, retinal organoids, hypothalamic organoids or spinal cord organoids’
Self-organizing systems have been one of the most exciting recent advances in stem cell research
However, many names & classifications are used making it challenging to convey the science
We now got together as a field to provide a nomenclature framework
Out in @Nature today👇1/9
Hundreds of genes have been associated with autism & neurodev disorders
But how do these genes impact specific stages in human development?
In a new preprint, @XianglingM took a bold approach & developed CRISPR screens in #assembloids to map 425 genes on interneuron dev stages 👇
To achieve this, @XianglingM & our team generated and screened over 1000 forebrain #assembloids built from parts derived from human pluripotent stem cells
This approach revealed that 46 out of a 425 autism spectrum disorder & other neurodevelopmental disease genes (~11%) expressed in the ventral forebrain interfere with either human GABAErgic cortical interneuron generation or interneuron migration