Characterization of hypoxia induced gene 1: expression during rat central
nervous system maturation and evidence of antisense RNA expression.

Bedo G, Vargas M, Ferreiro MJ, Chalar C, Agrati D.

Seccion Geneica Evolutiva, Facultad de Ciencias, Universidad de la Republica,
Montevideo, Uruguay. gbedo@fcien.edu.uy

Although recent studies have provided a detailed understanding of cellular
interactions occurring during the development of the CNS, little is known about
the molecular signals which during the peri and postnatal periods ensure its
maturation and functionality. Using the mammalian spinal cord as a model, we
have designed experiments to examine the main changes in gene expression
occurring during this critical transition. In this paper we describe the cloning
and characterization of the rat hypoxia induced gene-1 (Hig-1), its expression
pattern during spinal cord maturation and in situ localization of its mRNA. We
show an increase in Hig-1 expression between P1 and P15 in the spinal cord and a
differential spatial pattern. In the P1 spinal cord we observed preferential
expression in regions of dorsal laminae II and III and laminae IX ventrally;
while in P8, the distribution was more widespread and overall expression was
increased. Hig-1 is also widely expressed in the brain. Results of in situ
hybridization experiments, as well as particular features concerning ESTs, led
us to propose the expression of an antisense mRNA. Primer-specific RTPCR
demonstrates the presence of this aHig-1 transcript whose structure has not yet
been characterized. The high homology between putative rHig-1 protein and human-
and murine-predicted sequences, as well as its characteristic expression in the
Central Nervous System, are indicative of a specific role which could be related
to apoptosis signaling during postnatal maturation.