High impact information on Pola1

• Similarly, young human fibroblasts are also able to initiate DNA synthesis in heterokaryons with the ts Pola mutant at the two temperatures [1].
• The nature of the mutation in three of the non-Pola lines has not been determined but, like the Pola mutant cells, are inhibited in the G1 phase of the cell cycle when incubated at the nonpermissive temperature (39.5 degrees C) [1].
• In order to determine if complementation of the non-Pola mutants requires induction of serum responsive factors in the senescent cells, fusion studies of similar design were conducted with young and old human fibroblasts incubated in low serum (0.2%) for 48 hr prior to and after cell fusion [1].
• Pulsed-field mapping of a number of DNA markers in the Pola-Zfx region of the mouse X chromosome has established a genomic restriction map extending over 1.4 Mb [2].
• The mapping of Pola to region C-D of the mouse X chromosome adds a new marker in a conserved region between the mouse X chromosome and region Xp21-22.1 of the human X chromosome [3].

Biological context of Pola1

• Data from Southern blots of normal and transgenic DNA demonstrated that a large segment of DNA encompassing Arx and including part of Pola1 was duplicated as a result of the transgene insertion [4].
• A 1-Mb contig of BAC clones was assembled by using sequences flanking the transgene and revealed that the insertion lies close to Pola1 and Arx, a gene encoding a highly conserved homeobox protein known to be expressed in the developing forebrain of the mouse [4].

References