Disease relevance of En2

• In the present study, we show that viable and fertile mice, heterozygous null for Engrailed-1 and homozygous null for Engrailed-2 (En1+/-;En2-/-), have an adult phenotype that resembles key pathological features of Parkinson's disease [1].
• We have tested this hypothesis by using a recombinant replication-competent retrovirus to overexpress the En-1 or En-2 genes in the developing tectum [2].
• We then generated transgenic mice expressing human Pax5 under control of the Engrailed-2 promoter, which is expressed in the cerebellar external granule cell layer and in medulloblastomas [3].

Psychiatry related information on En2

• Deficits in social behavior were detected in En2(-/-) mice across maturation that included decreased play, reduced social sniffing and allogrooming, and less aggressive behavior [4].

High impact information on En2

• To assess HNF-3 beta function, the gene has been ectopically expressed in the midbrain/hindbrain of transgenic embryos using an En-2 promoter/enhancer [5].
• This corresponds to the region where two transcription factors encoded by the mouse engrailed genes (En-1 and En-2) are normally expressed [6].
• Production of a mutation in mouse En-2 gene by homologous recombination in embryonic stem cells [7].
• Our hybridization analysis in situ has revealed that expression of En-2 is restricted to a specific domain of the developing central nervous system from 8 days of development on, indicating a role for the gene in establishing spatial domains in the brain [7].
• Rescue of the En-1 mutant phenotype by replacement of En-1 with En-2 [8].

Biological context of En2

• In mutant mice homozygous null for En1 and En2, the neurons are generated in the ventral midbrain, become postmitotic, and begin to express their neurotransmitter phenotype [9].
• The homeobox transcription factors Engrailed-1 and Engrailed-2 are required for the survival of mesencephalic dopaminergic neurons in a cell-autonomous and gene-dose-dependent manner [1].
• A minimum En-2 1.0 kb enhancer fragment was defined and found to contain multiple positive and negative regulatory elements that function in concert to establish the early embryonic mid-hindbrain expression [10].
• Engrailed-2 also affects the transient mediolateral (M/L) pattern of En-1 and Wnt-7b expression seen in late embryogenesis [11].
• We have examined three markers of cerebellar compartmentation in En-2 mutant mice: the Zebrin II and Ppath monoclonal antibodies and the transgene L7lacZ [11].

Anatomical context of En2

• The En2 knock-out mouse harbors cerebellar abnormalities that are similar to those found in autistic individuals and, as we report here, has a distinct anterior shift in the position of the amygdala in the cerebral cortex [12].
• Null alleles of the mouse Engrailed-2 gene, a molecular homolog of the fly gene engrailed, have demonstrable effects on the anteroposterior (A/P) patterning of cerebellum as reflected in the disruption of the normal process of foliation of the cerebellar cortex and the alteration of transgene expression boundaries in the adult [11].
• In mammals, two engrailed homologues exist, engrailed-1 and engrailed-2, which are expressed in a broad band around the isthmus at an age when the serotonergic and noradrenergic neurons in mid/hindbrain are generated [13].
• Antisense targeting of En-2 expression of early somite stages produced few alterations in development, although approximately one third of the embryos exhibited a series of lateral folds in the spinal cord at the level of the forelimb-bud.(ABSTRACT TRUNCATED AT 250 WORDS)[14]
• Selective disruption of "late onset" sagittal banding patterns by ectopic expression of engrailed-2 in cerebellar Purkinje cells [15].

Associations of En2 with chemical compounds

• Moreover, we also show that there is a correlation between the M-L clusters established by the birth date-related Purkinje cells and the domains of engrailed-2, Wnt-7B, L7/pcp2, and EphA4 receptor tyrosine kinase expression [16].
• Nontumorigenic mammary cell lines engineered to ectopically express En-2 have a marked reduction in their cycling time, lose cell contact inhibition, become sensitive to 17-AAG treatment, fail to differentiate when exposed to lactogenic hormones and induce mammary tumors when transplanted into cleared mammary glands of syngeneic hosts [17].

Physical interactions of En2

• The two Pax2/5/8-binding sites were deleted from the En2 locus and replaced with the bacterial neo gene by homologous recombination in mouse embryonic stem cells [18].

Regulatory relationships of En2

• En-2 is expressed in a subset of cells expressing En-1 [19].
• Additional findings indicate that En-1 and En-2 regulate expression of alpha-synuclein, a gene that is genetically linked to Parkinson's disease [20].
• Engrailed-2 negatively regulates the onset of perinatal Purkinje cell differentiation [21].

Other interactions of En2

• These results indicate the existence of a molecular hierarchy in which FGF8 signalling establishes the graded expression of En-2 within the tectum [22].
• In interspecific crosses, the segregation of either mutation was followed in relation to polymorphic alleles of Msx1, Il6, and En2, to give a fine map around the mutant loci [23].
• Our experiments show that the interaction between these two proteins is required for the positioning of the isthmic organizer genes Fgf8, Pax2 and En2 [24].
• En-2 enhancer activity in the first arch requires a combination of cis-acting sequences that includes a motif which is identical to one found in the Otx2 enhancer and which is sufficient to direct expression in the first arch [25].
• Shh mapped to a position 0.6 cM distal to En2 and 1.9 cM proximal to Il6 on mouse chromosome 5 [26].

Analytical, diagnostic and therapeutic context of En2

• Significantly, no change in the Engrailed-2 mutant phenotype occurs after a similar background switch, and whole-mount in situ hybridization reveals identical En2 expression patterns in wild-type C57BL/6J and 129/Sv mice [27].
• To determine whether these contrasting phenotypes reflect differences in temporal expression or biochemical activity of the En proteins, En-1 coding sequences were replaced with En-2 sequences by gene targeting [8].
• When grafted ectopically into the diencephalon of a chick host embryo, a portion of met-mesencephalon straddling the met-mesencephalic constriction has the capacity to induce En-2 expression in the surrounding host tissue [28].
• The antiserum detects both the En-1 and En-2 proteins in mouse, chick and Xenopus embryos by Western blot analysis [29].

References