TY - JOUR
T1 - Mate searching in Caenorhabditis elegans
T2 - A genetic model for sex drive in a simple invertebrate
AU - Lipton, Jonathan
AU - Kleemann, Gunnar
AU - Ghosh, Rajarshi
AU - Lints, Robyn
AU - Emmons, Scott W.
PY - 2004/8/25
Y1 - 2004/8/25
N2 - Much of animal behavior is regulated to accomplish goals necessary for survival and reproduction. Little is known about the underlying motivational or drive states that are postulated to mediate such goal-directed behaviors. Here, we describe a mate-searching behavior of the Caenorhabditis elegans male that resembles the motivated behaviors of vertebrates. Adult C. elegans males, if isolated from mating partners, will leave the area of a food source and wander about their environment in an apparent search for a mate. When mating partners are present on the food source, males do not wander but remain with them. This behavior is sexually dimorphic for C. elegans and two additional male/hermaphrodite species studied; for these species, hermaphrodites leave food significantly slower than males. In contrast, for three male-female species examined, both males and females left food, in two cases with similar frequency, suggesting coordinate evolution of behavioral dimorphism with hermaphroditism. We use a quantitative behavioral assay to show that C. elegans male mate searching is regulated by signals from hermaphrodites and by physiological signals indicating nutritional and reproductive status. We identify genes in the serotonin, insulin, and sex determination pathways that affect the rate of mate searching. These genes may contribute to physiological and reproductive regulatory mechanisms. Our results establish C. elegans as a model genetic animal with a simple nervous system in which neural pathways leading to a motivated behavior may be genetically dissected.
AB - Much of animal behavior is regulated to accomplish goals necessary for survival and reproduction. Little is known about the underlying motivational or drive states that are postulated to mediate such goal-directed behaviors. Here, we describe a mate-searching behavior of the Caenorhabditis elegans male that resembles the motivated behaviors of vertebrates. Adult C. elegans males, if isolated from mating partners, will leave the area of a food source and wander about their environment in an apparent search for a mate. When mating partners are present on the food source, males do not wander but remain with them. This behavior is sexually dimorphic for C. elegans and two additional male/hermaphrodite species studied; for these species, hermaphrodites leave food significantly slower than males. In contrast, for three male-female species examined, both males and females left food, in two cases with similar frequency, suggesting coordinate evolution of behavioral dimorphism with hermaphroditism. We use a quantitative behavioral assay to show that C. elegans male mate searching is regulated by signals from hermaphrodites and by physiological signals indicating nutritional and reproductive status. We identify genes in the serotonin, insulin, and sex determination pathways that affect the rate of mate searching. These genes may contribute to physiological and reproductive regulatory mechanisms. Our results establish C. elegans as a model genetic animal with a simple nervous system in which neural pathways leading to a motivated behavior may be genetically dissected.
KW - Behavioral mutant
KW - Insulin
KW - Motivation
KW - Serotonin
KW - Sex drive
KW - Sexual behavior
UR - http://www.scopus.com/inward/record.url?scp=4444303159&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=4444303159&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.1746-04.2004
DO - 10.1523/JNEUROSCI.1746-04.2004
M3 - Article
C2 - 15329389
AN - SCOPUS:4444303159
SN - 0270-6474
VL - 24
SP - 7427
EP - 7434
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 34
ER -