Microcell Mediated Chromosome Transfer (or MMCT) is a technique used in cell biology and genetics to transfer a chromosome from a defined donor cell line into a recipient cell line. MMCT has been in use since the 1970s and has contributed to a multitude of discoveries including tumor, metastasis and telomerase suppressor genes as well as information about epigenetics, x-inactivation, mitochondrial function and aneuploidy. [1] [2] MMCT follows the basic procedure where donor cells (i.e. cells providing one or more chromosomes or fragments to a recipient cell) are induced to multinucleate their chromosomes. These nuclei are then forced through the cell membrane to create microcells, which can be fused to a recipient cell line. [1]
The term MMCT was first used by Fournier and Ruddle in 1977. [3] Their method was based on previous work from 1974 by Ege, Ringertz, Veomett and colleagues, [4] [5] synthesizing the techniques used at the time to induce multinucleation in cells, nuclear removal and cell-cell fusions. The next major step in MMCT came during the 1980s when new transfection techniques were utilized to introduce selectable markers onto chromosomes thus making it possible to select for the introduction of specific chromosomes and more easily create defined hybrids. [1]
Procedures for MMCT differ slightly but they all require: the induction of multinucleation, enucleation (nuclear removal), and fusion. Multinucleation is usually accomplished through causing prolonged mitotic arrest by colcemid treatment. Certain cells will then "slip" out of mitosis and form multiple nuclei. These nuclei can then be removed using cytochalasin B to disrupt the cytoskeleton and centrifugation in a density gradient to force enucleation. The newly created microcells can then be fused to recipient (target) cells by exposure to poly ethylene glycol, use of Sendai virus, or electrofusion. [1] [6]
Variations now allow construction of "humanized" mice with large pieces from human chromosomes [7] as well as new methods for human and mouse artificial chromosomes. [8]
Leukotriene C4 synthase is an enzyme that in humans is encoded by the LTC4S gene.
Frizzled-2 is a protein that in humans is encoded by the FZD2 gene.
Frizzled-5 is a protein that in humans is encoded by the FZD5 gene.
Frizzled-7 is a protein that in humans is encoded by the FZD7 gene.
Probable G-protein coupled receptor 144 is a protein that in humans is encoded by the GPR144 gene. This gene encodes a member of the adhesion-GPCR family of receptors. Family members are characterised by an extended extracellular region with a variable number of protein domains coupled to a TM7 domain via a domain known as the GPCR-Autoproteolysis INducing (GAIN) domain.
Gamma-crystallin D is a protein that in humans is encoded by the CRYGD gene.
LIM domain-binding protein 1 is a protein that in humans is encoded by the LDB1 gene.
Kinesin-like protein KIF22 is a protein that in humans is encoded by the KIF22 gene.
Rhombotin-1 is a protein that in humans is encoded by the LMO1 gene.
Thyroid hormone receptor-associated protein 3 is a protein that in humans is encoded by the THRAP3 gene.
DNA polymerase delta subunit 2 is an enzyme that in humans is encoded by the POLD2 gene. It is a component of the DNA polymerase delta complex.
Guanine nucleotide-binding protein G(t) subunit alpha-1 is a protein that in humans is encoded by the GNAT1 gene.
Olfactory receptor 6A2 is a protein that in humans is encoded by the OR6A2 gene.
Olfactory receptor 7C1 is a protein that in humans is encoded by the OR7C1 gene.
Olfactory receptor 2A4 is a protein that in humans is encoded by the OR2A4 gene.
Zinc finger protein 44 is a protein that in humans is encoded by the ZNF44 gene.
Kinesin-like protein KIF24 is a protein that in humans is encoded by the KIF24 gene.
Eukaryotic translation initiation factor 1A, Y-chromosomal is a protein that in humans is encoded by the EIF1AY gene.
Alkaline ceramidase 2 also known as ACER2 is a ceramidase enzyme which in humans is encoded by the ACER2 gene.
Guanine nucleotide-binding protein G(t) subunit alpha-3, also known as gustducin alpha-3 chain, is a protein subunit that in humans is encoded by the GNAT3 gene.