Genetic replacement of cyclin D1 function in mouse development by cyclin D2.
D cyclins (D1, D2, and D3) are components of the core cell cycle machinery in mammalian cells. It is unclear whether each of the D cyclins performs unique, tissue-specific functions or the three proteins have virtually identical functions and differ mainly in their pattern of expression. We previously generated mice lacking cyclin D1, and we observed that these animals displayed hypoplastic retinas and underdeveloped mammary glands and a presented developmental neurological abnormality. We now asked whether the specific requirement for cyclin D1 in these tissues reflected a unique pattern of D cyclin expression or the presence of specialized functions for cyclin D1 in cyclin D1-dependent compartments. We generated a knock-in strain of mice expressing cyclin D2 in place of D1. Cyclin D2 was able to drive nearly normal development of retinas and mammary glands, and it partially replaced cyclin D1's function in neurological development. We conclude that the differences between these two D cyclins lie mostly in the tissue-specific pattern of their expression. However, we propose that subtle differences between the two D cyclins do exist and they may allow D cyclins to function in a highly optimized fashion. We reason that the acquisition of multiple D cyclins may allow mammalian cells to drive optimal proliferation of a diverse array of cell types.
Carthon
Bradley C
BC
Department of Cancer Biology, Dana-Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, USA. peter_sicinski@dfci.harvard.edu
Neumann
Carola A
CA
Das
Manjusri
M
Pawlyk
Basil
B
Li
Tiansen
T
Geng
Yan
Y
Sicinski
Piotr
P
D000818:Animals; D002490:Central Nervous System / Q000378:metabolism* / Q000473:pathology; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism*; D056742:Cyclin D2; D016213:Cyclins / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D008321:Mammary Glands, Animal / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D012160:Retina / Q000378:metabolism* / Q000473:pathology; D014018:Tissue Distribution / Q000502:physiology
C486196:Ccnd2 protein, mouse; D056742:Cyclin D2; D016213:Cyclins; D019938:Cyclin D1