Hermaphrodite hook up
The obliquely striated body wall muscles are arranged into strips in four quadrants, two dorsal and two ventral, along the whole length of the animal (Intro FIG 2A-F) (see Somatic Muscle System).
Smaller, nonstriated muscles are found in the pharynx and around the vulva, intestine and rectum (see Nonstriated Muscle System). Four cells situated on the ventral side of the posterior head make up the excretory system, which functions in osmoregulation and waste disposal.
The anatomical description of the whole animal has been completed at the electron microscopy level and its complete cell lineage, which is invariant between animals, has been established (Brenner, 1973; Byerly et al., 1976; Sulston et al., 1983; Wood, 1988a; Lewis and Fleming, 1995). Various tissues open to the outside through this cuticle (Intro FIG 3).
There are two sexes: a self-fertilizing hermaphrodite (XX) and a male (XO). The excretory pore is located at midline on the ventral side of the head (Intro FIG 3E).
The excretory system opens to the outside through the excretory pore (Intro FIG 3E) (see Excretory System).
feeds through a two lobed pharynx, which is nearly an autonomous organ with its own neuronal system, muscles, and epithelium (Intro FIG 1).
The apical surfaces of the intestinal cells carry numerous microvilli. is a small, free-living soil nematode (roundworm) that lives in many parts of the world and survives by feeding on microbes, primarily bacteria (Intro FIG 1). It is an important model system for biological research in many fields including genomics, cell biology, neuroscience and aging ( Electron microscopical reconstruction of the anterior sensory anatomy of the nematode (ed. The resulting diploid zygotes are stored in the uterus and laid outside thorough the vulva, which protrudes at the ventral midline (see Reproductive System: Somatic Gonad, Germ Line and Egg-laying Apparatus). larvae initially display the same simple cylindrical body plan as hermaphrodites, but from the L2 stage onward, the shape of their posterior half changes as their sexual organs begin to develop (Intro FIG 5) (Sulston and Horvitz, 1977; Sulston et al., 1980; Nguyen et al., 1999). The animal can be maintained in the laboratory where it is grown on agar plates or liquid cultures with as the food source. It can be examined at the cellular level in living preparations by differential interference contrast (DIC) microscopy, because it is transparent throughout its life cycle. A collagenous cuticle, secreted by the underlying epithelium, surrounds the worm on the outside and also lines the pharynx and rectum (see Cuticle). Changing synaptic specificities in the nervous system of : Differentiation of the DD motoneurons. Among its many advantages for study are its short life cycle, compact genome, stereotypical development, ease of propagation and small size. The adult body plan is anatomically simple with about 1000 somatic cells. has an unsegmented, cylindrical body shape that is tapered at the ends (Intro FIG 1; Intro MOVIE 1). The narrow space between the pharynx and the surrounding tissues anterior to the NR can be considered an accessory pseudocoelom because the main pseudocoelom is sealed off by the GLRs at the NR level. Two much narrower openings on the lateral sides of the tail whip exist for the phasmid sensilla at the junction of the seam cells and the tail hypodermis (Intro FIG 4C). (Image reprinted with permission: Juergen Berger and Ralf Sommer, Max Planck-Institute for Developmental Biology, Tübingen, Germany.) B. neurons are located in the head around the pharynx. This is the typical nematode body plan, with an outer tube and an inner tube separated by the pseudocoelomic space (Intro FIG 2). Body wall (outer tube) is separated from the inner tube (alimentary system, gonad) by a pseudocoelom. Alimentary canal opens to outside through anus at ventral midline (). In the body, a continuous row of neuron cell bodies lies at the midline, adjacent to the ventral hypodermis.