Defective development of secretory neurones in the hypothalamus of Arnt2-knockout mice

Tomonori Hosoya, Yoshihito Oda, Satoru Takahashi, Masanobu Morita, Shimako Kawauchi, Masatsugu Ema, Masayuki Yamamoto, Yoshiaki Fujii-Kuriyama

Research output: Contribution to journalArticlepeer-review

95 Citations (Scopus)


Background: Within the basic region-helix-loop-helix (bHLH)-PAS family of transcription factors, Arnt and Arnt2 play unique roles; these two factors not only heterodimerize with themselves, but also with other members of this family and they act as transcription regulators which bind to specific DNA elements. Whereas Arnt is broadly expressed in various tissues, the expression of Arnt2 is known to be limited to the neural tissues. Results: To elucidate the function of Arnt2 in detail, we cloned the mouse Arnt2 gene and its gene structure was determined. We subsequently generated germ line Arnt2 mutant mice by gene targeting technology. Heterozygous Arnt2 mice were viable, but homozygous Arnt2 gene knockout mice died shortly after birth. Histological and immunological analyses revealed that the supraoptic nuclei (SON) and the paraventricular nuclei (PVN) are hypocellular. Moreover, secretory neurones identified by the expression of neurosecretory hormone such as arginine vasopressin, oxytocin, corticotrophin-releasing hormone and somatostatin are completely absent in SON and PVN in the mutant Arnt2 mice. Consistent with these observations, prospective SON and PVN neurones which express Brn2 appeared around E13.5 in the mantle zone, but no neurones which expressed the neurosecretory hormones were found in the SON and PVN regions. Conclusions: These data show that the transcription factor Arnt2 controls the development of the secretory neurones at the later or final stages of differentiation rather than at the beginning stage. Strikingly similar observations have been reported with the Sim1 deficient mice. Taken together, our results demonstrate that Arnt2 is an indispensable transcription factor for the development of the hypothalamus, and suggest that Arnt2 is an obligatory partner molecule of Sim1 in the developmental process of the neuroendocrinological cell lineages.

Original languageEnglish
Pages (from-to)361-374
Number of pages14
JournalGenes to Cells
Issue number4
Publication statusPublished - 2001


Dive into the research topics of 'Defective development of secretory neurones in the hypothalamus of Arnt2-knockout mice'. Together they form a unique fingerprint.

Cite this