TY - JOUR
T1 - The multiple β-tubulin genes of Xenopus
T2 - Isolation and developmental expression of a germ-cell isotype β-tubulin gene
AU - Bieker, James J.
AU - Yazdani-Buicky, Mitra
PY - 1992
Y1 - 1992
N2 - In this report, we demonstrate the presence of multiple β-tubulin genes in Xenopus and begin to explore the regulation of isotypes within the β-tubulin family by focusing on the characterization of a specific β-tubulin cDNA derived from a Xenopus oocyte library. This clone (XLOT: Xenopus laevis oocyte β-tubulin) contains the entire protein coding and 3′-untranslated regions of the gene, and is only missing approximately eleven nucleotides from the start of transcription. The XLOT transcript is ubiquitously expressed, but steady-state amounts are highest in immature oocytes and in testes. Consistent with the present understanding of this type of autoregulation, levels of oocyte β-tubulin transcript vary in accordance with fluctuating polymeric/monomeric tubulin protein ratios both in the developing oocyte and as the late stage oocyte matures to an unfertilized egg. In addition, steady-state levels of the oocyte β-tubulin transcript do not increase as the total number of cells per embryo increase during embryogenesis. Although one major and three minor transcriptional start sites are utilized in immature oocytes and adult tissues, usage of each individual site varies during oogenesis and embryogenesis. The preferential expression in germ cells indicate that the oocyte β-tubulin transcript may provide a useful marker for gonadal differentiation in early amphibian development.
AB - In this report, we demonstrate the presence of multiple β-tubulin genes in Xenopus and begin to explore the regulation of isotypes within the β-tubulin family by focusing on the characterization of a specific β-tubulin cDNA derived from a Xenopus oocyte library. This clone (XLOT: Xenopus laevis oocyte β-tubulin) contains the entire protein coding and 3′-untranslated regions of the gene, and is only missing approximately eleven nucleotides from the start of transcription. The XLOT transcript is ubiquitously expressed, but steady-state amounts are highest in immature oocytes and in testes. Consistent with the present understanding of this type of autoregulation, levels of oocyte β-tubulin transcript vary in accordance with fluctuating polymeric/monomeric tubulin protein ratios both in the developing oocyte and as the late stage oocyte matures to an unfertilized egg. In addition, steady-state levels of the oocyte β-tubulin transcript do not increase as the total number of cells per embryo increase during embryogenesis. Although one major and three minor transcriptional start sites are utilized in immature oocytes and adult tissues, usage of each individual site varies during oogenesis and embryogenesis. The preferential expression in germ cells indicate that the oocyte β-tubulin transcript may provide a useful marker for gonadal differentiation in early amphibian development.
UR - http://www.scopus.com/inward/record.url?scp=0026684460&partnerID=8YFLogxK
U2 - 10.1111/j.1432-0436.1992.tb00481.x
DO - 10.1111/j.1432-0436.1992.tb00481.x
M3 - Article
C2 - 1379202
AN - SCOPUS:0026684460
SN - 0301-4681
VL - 50
SP - 15
EP - 23
JO - Differentiation
JF - Differentiation
IS - 1
ER -