Review Article

Molecular and Cellular Basis of Autosomal Recessive Primary Microcephaly

Table 2

Animal models of MCPH.

GeneModelMethodPhenotype

MCPH1 MICROCEPHALIN MouseKnock-out (deletion of exon 2)Genomic instability, growth retardation, male infertility, and increased radiation sensitivity
MouseKnock-out (gene trap)Shorter life span, improper chromosome condensation
MouseConditional knock-out (recombination)Specific reduction of the cerebral cortex at birth
FlyKnock-out (p-element excision)Abnormal spindles during embryonic cell cycle

WDR62 RatshRNA knock-downPremature differentiation of neuroprogenitors into neurons
ZebrafishMorpholino-mediated knock-downReduction in head and eye size
MouseKnock-out (deletion of the WDR62 locus)Reduced brain size

CDK5RAP2 FlyKnock-out (chemical mutagenesis)Disconnection between centrosome and PCM
MouseshRNA knock-downPremature neuronal differentiation
Hertwig’s anemia mouseInversion of exon 4Reduced brain size

ASPM ZebrafishMorpholino-mediated knock-downReduction in head and eye size
MousesiRNA knock-downPremature differentiation of telencephalic neuroprogenitor cells
MouseKnock-out (removal of exons 2 and 3)Reduced brain size
MouseKnock-out (gene trap)Mild microcephaly, massive loss of germ cells
FlyMutagenesis (x-irradiation)Spindle positioning defects, increased apoptosis

CENPJ MouseConditional knock-out (truncated mRNA)Intrauterine growth retardation
FlyKnock-out (transposon insertion)Loss of centrioles, abnormal spindle
WormsiRNA knock-downLoss of centrioles, abnormal centrosome size/organization

STIL MouseKnock-out (removal of exons 3 to 5)Embryonic lethality
ZebrafishMorpholino-mediated knock-downEmbryonic lethality

CEP135 FlyKnock-out (transposon insertion)Abnormal centrioles, immotile cilium
AlgaInsertion mutagenesisAbnormal centrioles, abnormal cell division, and slow growth
ProtozoasiRNA knock-downAbnormal centrioles

CEP152 FlyChemical mutagenesisDefective centrosomes, no zygotic division
ZebrafishMorpholino-mediated knock-downCiliary defects

ZNF335 MouseshRNA knock-downImpaired progenitor cell proliferation
MouseKnock-out (removal of promoter and exons 1 and 2)Severely reduced cortical size
MouseKnock-out (gene trap insertion)Embryonically lethal

CDK6 MouseKnock-out (removal of 1st coding exon)Viable, develop normally, hematopoiesis slightly impaired