|ZFIN ID: ZDB-PUB-020220-9|
Alternative transcripts of a polyhomeotic gene homolog are expressed in distinct regions of somites during segmentation of zebrafish embryos
Kawamura, A., Yamada, K., Fujimori, K., and Higashinakagawa, T.
|Source:||Biochemical and Biophysical Research Communications 291(2): 245-254 (Journal)|
|Registered Authors:||Kawamura, Akinori|
|Keywords:||polycomb group; polyhomeotic; somite; tailbud; zebrafish|
|PubMed:||11846397 Full text @ Biochem. Biophys. Res. Commun.|
Kawamura, A., Yamada, K., Fujimori, K., and Higashinakagawa, T. (2002) Alternative transcripts of a polyhomeotic gene homolog are expressed in distinct regions of somites during segmentation of zebrafish embryos. Biochemical and Biophysical Research Communications. 291(2):245-254.
ABSTRACTHere we describe isolation and characterization of two zebrafish cDNAs, designated ph2[alpha] and ph2[beta], which were identified as structural homologs of the Drosophila polyhomeotic, mouse Mph2, and human HPH2 genes, collectively termed the Polycomb group. The [alpha] and [beta] transcripts shared a 1.9-kb sequence at their 3[prime prime or minute]-termini. [alpha] had an additional 1.6-kb sequence extending toward its 5[prime prime or minute]-terminus. Only a short 0.1-kb segment was unique to [beta]. Sequencing of a genomic clone corresponding to the two cDNAs indicated that the mRNAs were transcribed from a single gene locus by alternative promoters. Northern blots revealed expression of [alpha] transcripts during the segmentation period, while [beta] expression occurred at all developmental stages examined. Whole-mount in situ hybridizations with an [alpha]-specific probe and a probe recognizing both transcripts revealed distinct spatio-temporal expression patterns along developing somites. [alpha] transcripts were detected initially at the 7--8 somite stage; [beta] transcripts appeared in the first somites. As segmentation proceeded, [alpha] and [beta] expression shifted position toward the tailbud in parallel with the formation of each somite. Within individual somites, the signal corresponding to [alpha] was strongest at the posterior border and weakest in the anterior region. Conversely, that corresponding to [beta] was strongest at the anterior border and weakest in the posterior region. The data support the idea that Ph2[alpha] and Ph2[beta] are involved in spatio-temporal generation of somites as well as in specification of antero-posterior regional differences within individual somites.