Transcriptional Characterisation of Human Musculoskeletal Development in vivo and in vitro

The musculoskeletal system is affected by a wide range of diseases throughout life, often affecting young, economically active people. These diseases are the leading cause of morbidity worldwide. Despite this, this organ system is rarely the focus of large scientific initiatives. For example, it was absent from the original Human Cell Atlas (HCA) white paper; a global project which aims to compile a reference map of all human cell types to better understand health and disease. Applying the technologies used by the HCA to study the development of the musculoskeletal system at the level of individual cells could further our understanding of diseases that affect it, ranging from congenital limb malformations, which affect one in five hundred live births, to degenerative diseases such as osteoarthritis, which affects eight million individuals in the United Kingdom. This gap in our knowledge was the main stimulus for the work performed in this thesis. Chapter 1 aims to summarise recent developments in methods used to characterise the transcriptome of human tissues, in particular spatial transcriptomics, single cell RNA sequencing and in-situ sequencing, and discuss their application to date in the musculoskeletal system. In Chapter 2, I form a detailed healthy reference tissue ‘atlas’ of the human first trimester hindlimb across a range of gestational ages, and use spatial transcriptomics to explore links between gene expression patterns during limb morphogenesis and congenital limb malformation. In Chapter 3, I extend my investigation of patterning by profiling the development of the human spine along its entire craniocaudal axis, shedding new light on the rostrocaudal expression patterns of HOX genes and exploring their role in organising the dorsoventral axis of the embryonic spinal cord. In Chapter 4, I enrich the ‘atlas’ of healthy fetal limb development for the osteochondral compartment through sequencing of fetal long bones in order to address an important question in musculoskeletal science: how faithfully does the development of in vitro chondrocytes recapitulate that of their in vivo counterparts? This chapter presents a framework for pursuing high fidelity tissue engineering, using single cell data from human development to drive improvement. I believe this approach holds great promise for understanding the pathophysiology of a broad range of musculoskeletal diseases. I summarise how I plan to build on the work performed during this PhD in the discussion section of this thesis.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2024

Author dc:creator

• Lawrence, John

Advisors dc:contributor.advisor

• Teichmann, Sarah
• Behjati, Sam

• musculoskeletal
• human development
• ossification
• limb malformation
• HOX genes

Licence

• https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/ca3c1807-69da-4e4a-8adb-fc0ab5a9c91a/download
• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

eng

DOI dc:identifier.doi

https://doi.org/10.17863/CAM.113994

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/376975