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PURPOSE. We previously used mRNA differential displayand identified a novel gene that is up regulated in the healing corneal epithelium.To understand the potential in vivo role of this gene, termed T4a,we cloned the full-length T4a cDNA and investigated its temporal and spatialtranscription expression in healing rat corneas, as well as in developingcornea and skin. METHODS. The displayed T4a cDNA was used to identify clones from a ratcDNA library derived from healing corneal epithelia. The cDNA clones weresequenced and the sequence was analyzed with the Blast program. In situ hybridization was performed using digoxigenin-labeled riboprobes andcryostat sections from healing and developing cornea as well as skin. RESULTS. The T4a cDNA had 2538 bp with an open reading frame of 2178 bp,consistent with a conceptual translation product of 725 amino acid residues,a calculated molecular mass of 83.1 kD and theoretical pI of 6.93. AlthoughT4a exhibited no sequence homology with known genes in the GenBank, it matcheda large number of Expressed Sequence Tags (ESTs) from human, mouse and rattissue cDNA libraries; more than half of the murine T4a ESTs were from embryonicDNA libraries. Sequence analysis revealed numerous phosphorylation and myristoylationsites in the deduced amino acid sequence of T4a. In the wounded rat cornea,intensive T4a mRNA staining was observed in the epithelium at all stages ofre-epithelialization indicating that the expression of T4a is wound-related.In 7 day old mice, an abundant level of T4a transcripts was found in the epidermisand hair follicles, as well as in the corneal epithelial layer. High levelsof T4a mRNA staining persisted in the developing postnatal corneal epithelia.In contrast, weak mRNA staining was only detected in the basal layer of theadult epidermis and corneal epithelium. CONCLUSION. These results indicate that T4a expression correlates withre-epithelialization of the cornea and maturation of the cornea and skin,suggesting... [ABSTRACT FROM AUTHOR]

Objective: To investigate the point mutations and polymorphisms of SIP1 gene in Hirschsprung disease(HSCR) and discuss the relationship between the feature of gene mutations and single nucleotide polymorphisms of SIP1 gene and HSCR., Methods: Polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP)and DNA direct sequencing were performed in 50 HSCR cases and 30 normal controls. All 10 exons of SIP1 gene were analyzed for point mutations and single nucleotide polymorphisms (SNPs)., Results: Loss of heterozygosity was observed in exon 7 in one patient. This variation leads to a nonsense mutation (L157L) and is an SNP. A missense mutation was detected in exon 8 in four patients, the frequency was 8%(4/50). PCR-SSCP was analyzed by silver staining. Identical patterns were observed in exon 2 for two cases, exon 7 for three cases, and exon 8 in seven patients., Conclusion: The mutations of SIP1 gene were detected in HSCR. The results suggest that SIP1 gene might play an important role in the pathogenesis of HSCR.