Sequence and genetic map of Meloidogyne hapla: A compact nematode genome for plant parasitism.
We have established Meloidogyne hapla as a tractable model plant-parasitic nematode amenable to forward and reverse genetics, and we present a complete genome sequence. At 54 Mbp, M. hapla represents not only the smallest nematode genome yet completed, but also the smallest metazoan, and defines a platform to elucidate mechanisms of parasitism by what is the largest uncontrolled group of plant pathogens worldwide. The M. hapla genome encodes significantly fewer genes than does the free-living nematode Caenorhabditis elegans (most notably through a reduction of odorant receptors and other gene families), yet it has acquired horizontally from other kingdoms numerous genes suspected to be involved in adaptations to parasitism. In some cases, amplification and tandem duplication have occurred with genes suspected of being acquired horizontally and involved in parasitism of plants. Although M. hapla and C. elegans diverged >500 million years ago, many developmental and biochemical pathways, including those for dauer formation and RNAi, are conserved. Although overall genome organization is not conserved, there are areas of microsynteny that may suggest a primary biological function in nematodes for those genes in these areas. This sequence and map represent a wealth of biological information on both the nature of nematode parasitism of plants and its evolution.
Opperman
Charles H
CH
Center for the Biology of Nematode Parasitism, Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA. warthog@ncsu.edu
Bird
David M
DM
Williamson
Valerie M
VM
Rokhsar
Dan S
DS
Burke
Mark
M
Cohn
Jonathan
J
Cromer
John
J
Diener
Steve
S
Gajan
Jim
J
Graham
Steve
S
Houfek
T D
TD
Liu
Qingli
Q
Mitros
Therese
T
Schaff
Jennifer
J
Schaffer
Reenah
R
Scholl
Elizabeth
E
Sosinski
Bryon R
BR
Thomas
Varghese P
VP
Windham
Eric
E
D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics; D002874:Chromosome Mapping; D019143:Evolution, Molecular; D020440:Gene Duplication; D022761:Gene Transfer, Horizontal; D049751:Genome, Helminth; D006790:Host-Parasite Interactions / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009876:Operon; D010802:Phylogeny; D010944:Plants / Q000469:parasitology*; D026801:Synteny; D014431:Tylenchoidea / Q000235:genetics*