The Trichoplax genome and the nature of placozoans.
As arguably the simplest free-living animals, placozoans may represent a primitive metazoan form, yet their biology is poorly understood. Here we report the sequencing and analysis of the approximately 98 million base pair nuclear genome of the placozoan Trichoplax adhaerens. Whole-genome phylogenetic analysis suggests that placozoans belong to a 'eumetazoan' clade that includes cnidarians and bilaterians, with sponges as the earliest diverging animals. The compact genome shows conserved gene content, gene structure and synteny in relation to the human and other complex eumetazoan genomes. Despite the apparent cellular and organismal simplicity of Trichoplax, its genome encodes a rich array of transcription factor and signalling pathway genes that are typically associated with diverse cell types and developmental processes in eumetazoans, motivating further searches for cryptic cellular complexity and/or as yet unobserved life history stages.
Srivastava
Mansi
M
Center for Integrative Genomics and Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA. msrivast@berkeley.edu
Begovic
Emina
E
Chapman
Jarrod
J
Putnam
Nicholas H
NH
Hellsten
Uffe
U
Kawashima
Takeshi
T
Kuo
Alan
A
Mitros
Therese
T
Salamov
Asaf
A
Carpenter
Meredith L
ML
Signorovitch
Ana Y
AY
Moreno
Maria A
MA
Kamm
Kai
K
Grimwood
Jane
J
Schmutz
Jeremy
J
Shapiro
Harris
H
Grigoriev
Igor V
IV
Buss
Leo W
LW
Schierwater
Bernd
B
Dellaporta
Stephen L
SL
Rokhsar
Daniel S
DS
D000818:Animals; D002448:Cell Adhesion; D017124:Conserved Sequence; D005109:Extracellular Matrix / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D016678:Genome / Q000235:genetics*; D005854:Germ Cells; D006801:Humans; D007448:Invertebrates / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics* / Q000502:physiology*; D010802:Phylogeny; D012098:Reproduction / Q000235:genetics; D017422:Sequence Analysis, DNA; D012723:Sex; D015398:Signal Transduction; D026801:Synteny; D014157:Transcription Factors / Q000235:genetics
D014157:Transcription Factors