Figure 1. The
tra-4 Gene Encodes a PLZF-like Protein. (A) (Top) Genetic map. Genes and single-nucleotide polymorphisms (SNPs) used for mapping the mutation
bc45 on linkage group (LG) X are indicated. The numbers below the genetic map represent the fraction of the four recombination events identified between SNPs F55F1:6752 and F53B3:29540 that occurred between the loci indicated. (Middle) Physical map. Cosmids that cover the interval between SNPs F55F1:6752 and F53B3:29540 were tested for the rescue of
tra-4(
bc45) and are shown. (Bottom) Structure of part of cosmid F53B3 with predicted open reading frames (ORFs). The black boxes in ORFs represent untranslated sequences, and the white boxes represent coding sequences. Gray boxes in the coding sequence of ORF F53B3.1 indicate regions that code for C2H2-type zinc fingers. pBC291 contains a 5.7 kb XmaI fragment of F53B3 that rescues
tra-4(
bc45) (see below [B]). The position of mutation
bc45 and the extent of deletion
bc250 are indicated above and below, respectively, F53B3.1.(B)
tra-4(
bc45) rescue data. Three independent lines of transgenic
tra-4(
bc45) animals carrying pBC291 as an extrachomosomal array were generated, and rescue was scored as described in Experimental Procedures by using the reporter Ppkd-2gfp.(C) Expression of
tra-4. Transgenic
tra-4(
bc45) embryos in utero, expressing the functional transgene Ptra-4gfp-
tra-4 (bcEx282) starting from the 28-cell stage. Nomarski and epifluorescence image.(D) Alignment of the protein sequences of TRA-4 and human PLZF (hPLZF). The alignment was done by using the DIALIGN algorithm. The regions of the zinc fingers were aligned separately from the N-terminal parts of the sequences and corrected by hand to match the cysteines and histidines of the zinc finger domains. Identical amino acids have a black background, and amino acids with similar biochemical properties have a gray background. The box indicates the RD2 domain (amino acids 200-300 of hPLZF). The black bars above the TRA-4 sequence mark the positions of the seven zinc finger domains of TRA-4. The position at which the deletion
tra-4(
bc250) is predicted to truncate the TRA-4 protein is indicated by a black arrowhead above the TRA-4 sequence. The amino acid that is changed as a result of the
tra-4 mutation
bc45 (His493Tyr) is indicated by an asterisk (*).(E) Schematic representation of the TRA-4 and hPLZF proteins. The POZ domain of hPLZF is not found in TRA-4. The lines between the schematic proteins indicate domains that have high similarity. Also indicated are the truncated TRA-4 proteins TRA-4-C (amino acids 1-201) and TRA-4delN (amino acids 202-543) used for interaction studies in yeast.