Plant Transcription factor database - Universität Potsdam
version: 3.0

Chlamydomonas reinhardtii VARL Family


Duncan, et al. 2007: Chlamydomonas reinhardtii, Volvox carteri, and their relatives in the family Volvocaceae provide an excellent opportunity for studying how multicellular organisms with differentiated cell types evolved from unicellular ancestors. While C. reinhardtii is unicellular, V. carteri is multicellular with two cell types, one of which resembles C. reinhardtii cytologically but is terminally differentiated. Maintenance of this "somatic cell" fate is controlled by RegA, a putative transcription factor. We recently showed that RegA shares a conserved region with several predicted V. carteri and C. reinhardtii proteins and that this region, the VARL domain, is likely to include a DNA-binding SAND domain. As the next step toward understanding the evolutionary origins of the regA gene, we analyzed the genome sequences of C. reinhardtii and V. carteri to identify additional genes with the potential to encode VARL domain proteins. Here we report that the VARL gene family, which consists of 12 members in C. reinhardtii and 14 in V. carteri, has experienced a complex evolutionary history in which members of the family have been both gained and lost over time, although several pairs of potentially orthologous genes can still be identified. We find that regA is part of a tandem array of four VARL genes in V. carteri but that a similar array is absent in C. reinhardtii. Most importantly, our phylogenetic analysis suggests that a proto-regA gene was present in a common unicellular ancestor of V. carteri and C. reinhardtii and that this gene was lost in the latter lineage.

Members of this family
  SHOULD possess VARL domain

Domain alignments


There are 12 gene models in this family

Gene modelDescriptionDomains
141155 Chlre2_kg.scaffold_8000326 VARL
144938 Chlre2_kg.scaffold_12000132 VARL
145132 Chlre2_kg.scaffold_13000045 VARL
146989 Chlre2_kg.scaffold_1000813 VARL
146990 Chlre2_kg.scaffold_1000814 VARL
196800 FER_4324623 VARL
20566 fgenesh1_pg.C_scaffold_59000022 VARL Involucrin
36449 estExt_fgenesh1_pg.C_490081 VARL
400512 pasa_Sanger_mRNA28639 VARL
406248 pasa_Sanger_mRNA256 VARL
409369 pasa_Sanger_mRNA18034 VARL
415440 pasa_Sanger_mRNA21120 VARL

General references

Duncan, L; Nishii, I; Harryman, A; Buckley, S; Howard, A; Friedman, NR; Miller, SM. 2007. The VARL gene family and the evolutionary origins of the master cell-type regulatory gene, regA, in Volvox carteri. J. Mol. Evol. 65(1):1-11 PUBMEDID:17646893