Lu Yan Chan

Year of Award


Degree Type


Degree Name

Master of Philosophy (MPhil)


Department of Biology

Principal Supervisor

Zhao, Zhongying


Caenorhabditis elegans ; Cyclin-dependent kinases




It is well established that cyclin and cyclin-dependent kinase (CDK) form complex that plays a central role in driving cell cycle progression. The fundamental functions of CDK and cyclin are well conserved across eukaryotes. However, gene families encoding the two type of proteins are significantly expanded in multicellular organisms compared with single-cell species. Despite intensive studies on CDK and its associated cyclin in cultured cell lines, especially in cancer cell lines, the partnership between individual CDKs and cyclins remains elusive especially in vivo. Here I present our preliminary results on establishing the molecular function of a well-conserved cyclin L encoded by cyl-1 in C. elegans. Human cyclin L was demonstrated to form a complex with both CDK11 and CDK12, but its association with the latter remains controversial. Despite a possible function in both transcription and pre-mRNA splicing as suggested by in vitro studies or in yeast, the in vivo function of cyclin L has yet been established in any species. To study cyl-1's function in vivo, we generated multiple strains each expressing a chromosomally integrated single-copy transgenes consisting of CYL-1::GFP flanked by its native regulatory sequences using miniMos technique. The transgene demonstrates ubiquitous expression in nuclei across developmental stages and cell types with few exceptions, including maturing oocytes, in which gene activity is known to be shut down, consistent with its function in transcription and splicing. Co-immunoprecipitation followed by mass spectrometry reveals that CYL-1 interacts with both CDK-11 and CDK-12 along with some other uncharacterized factors. Functional validation of these interactions is underway.


Principal supervisor: Doctor Zhao Zhongying ; Thesis submitted to the Department of Biology ; Thesis (M.Phil.)--Hong Kong Baptist University, 2018


Includes bibliographical references (pages 65-69).