Transcription regulatory networks in Caenorhabditis elegans

zip-3 encodes a bZip transcription factor.

zmp-3 encodes a protein with two C-terminal noncanonical C2H2 zinc-fingers whose paralogs include HIM-8, ZIM-1/-2, and C02F5.12; ZIM-3 is specifically required for homolog pairing, synapsis, and segregation of chromosomes I and IV during meiosis; zim-3(tm2303) oocytes ending prophase have ~4 bivalents and ~4 univalents, the latter of which are consistently chromosomes I and IV; ZIM-3 associates with the right end of chromosome I and the left end of chromosome IV, which may indicate an association with their pairing centers; while the C-terminal region of ZIM-3 most closely resembles those of its orthologs in other Caenorhabditis species, its N-terminal region instead most closely resembles those of its paralogs in C. elegans, indicating coevolving, species-specific functions; ZIM-3 foci, like HIM-8 foci, associate with the nuclear envelope during meiotic prophase; zim-3 mutants also have some defective segregation of the X chromosome (yielding a Him phenotype), but this may be an indirect effect of autosomal asynapsis.

zim-1 encodes a protein with two C-terminal noncanonical C2H2 zinc-fingers whose paralogs include HIM-8, ZIM-2/-3, and C02F5.12; ZIM-1 specifically required for homolog pairing, synapsis, and segregation of chromosomes II and III during meiosis; zim-1(tm1813) oocytes ending prophase have ~4 bivalents and ~4 univalents, the latter of which are consistently chromosomes II and III; ZIM-1 associates with the left ends of chromosomes II and III, which may indicate an association with their pairing centers; while the C-terminal region of ZIM-1 most closely resembles those of its orthologs in other Caenorhabditis species, its N-terminal region instead most closely resembles those of its paralogs in C. elegans, indicating coevolving, species-specific functions; ZIM-1 foci, like HIM-8 foci, associate with the nuclear envelope during meiotic prophase; zim-1 mutants also have some defective segregation of the X chromosome (yielding a Him phenotype), but this may be an indirect effect of autosomal asynapsis.

zig-2 encodes a predicted secreted protein that is a member of the immunoglobulin superfamily of proteins; a zig-2::gfp reporter fusion is expressed in the PVT interneuron and weakly in 4-6 additional head neurons.

zeel-1 encodes a large (917-residue) putative membrane protein, probably enriched in male soma, that is required for compatibility between the Bristol N2 and Hawaiian CB4856 strains of C. elegans; ZEEL-1 has a ~200-residue N-terminal region with six predicted transmembrane sequences, followed by a ~700-residue C-terminal region with normal (globular) amino acid composition but with no known protein motifs; the globular domain of ZEEL-1 has at least 18 C. elegans paralogs, and is divergently related to ZYG-11 and its metazoan orthologs; ZEEL-1 is required zygotically for the viability of embryos also carrying a paternal peel-1(CB4856) allele; a naturally occurring zeel-1 deletion in CB4856, a Hawaiian C. elegans strain, is zygotically lethal with paternal peel-1(Hawaii), and thus is genetically incompatible with C. elegans N2 Bristol; zeel-1 alleles from N2 and CB4856 are embedded in haplotypes that are both present in C. elegans wild populations, and are likely to comprise a balanced polymorphism under some (unknown) form of continuing positive selection; zeel-1 transcripts are enriched in male somatic tissues; other than lethality with paternal peel-1(Hawaii), zeel-1 deletion mutants have no known phenotype, and ZEEL-1 has no obvious function in mass RNAi assays.