Graduation Year

2019

Date of Submission

12-2018

Document Type

Campus Only Senior Thesis

Degree Name

Bachelor of Arts

Department

Neuroscience

Reader 1

Lauren A. Weiss, Ph.D.

Reader 2

Thomas Borowski, Ph.D.

Terms of Use & License Information

Terms of Use for work posted in Scholarship@Claremont.

Rights Information

© 2018 Adrienne Y Jo

Abstract

The 16p11.2 copy-number variant (CNV) represents a well-characterized, high-risk factor for autism spectrum disorder that additionally predisposes deletion carriers (16pdel) to increased head circumference, known as macrocephaly. The 16p11.2 CNV consists of 29 known genes, many of which are associated with neurobiological processes relevant for macrocephaly such as cell proliferation and apoptosis, differentiation and cell growth. Our lab’s previous work has demonstrated that induced pluripotent stem cell (iPSC)-derived neurons from 16pdel carriers show altered cellular morphology related to growth, which include increased soma size, total dendritic length and dendritic complexity. However, specific CNV genes responsible for these phenotypes have not been established. Here, we investigate the relationship between three 16p11.2 genes and the observed cellular phenotypes. We differentiated neurons from control iPSC-derived neural progenitor cells (NPCs) and used short hairpin RNA (shRNA) to reduce the expression of these CNV genes: KCTD13, MAPK3 and C16ORF53. We then assessed neuronal morphology by evaluating soma size, total dendritic length and dendritic complexity. We demonstrate that knocking down KCTD13 and C16ORF53 increases soma size and total dendrite length, respectively, similar to that observed in 16pdel iPSC-derived neurons. For this reason, we speculate that these genes may have a role in cell growth and might underlie macrocephaly. Thus, our study investigates genes in the 16p11.2 CNV that contribute to neuronal morphology, which may have a role in influencing brain size.

This thesis is restricted to the Claremont Colleges current faculty, students, and staff.

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