diff --git a/data/AB/59/ED/AB59ED17564AFFB6FCAEFB58FE63FED8.xml b/data/AB/59/ED/AB59ED17564AFFB6FCAEFB58FE63FED8.xml index c1d9793aee2..a96f6008753 100644 --- a/data/AB/59/ED/AB59ED17564AFFB6FCAEFB58FE63FED8.xml +++ b/data/AB/59/ED/AB59ED17564AFFB6FCAEFB58FE63FED8.xml @@ -1,47 +1,49 @@ - - - -Neurogenesis in directly and indirectly developing enteropneusts: of nets and cords + + + +Neurogenesis in directly and indirectly developing enteropneusts: of nets and cords - - -Author + + +Author -Wanninger, Sabrina Kaul-Strehlow Makoto Urata Takuya Minokawa Thomas Stach Andreas +Wanninger, Sabrina Kaul-Strehlow Makoto Urata Takuya Minokawa Thomas Stach Andreas -text - - -Organisms Diversity & Evolution +text + + +Organisms Diversity & Evolution - -2015 - -2015-01-31 + +2015 + +2015-01-31 - -15 + +15 - -2 + +2 - -405 -422 + +405 +422 - -http://dx.doi.org/10.1007/s13127-015-0201-2 + +http://dx.doi.org/10.1007/s13127-015-0201-2 -journal article -10.1007/s13127-015-0201-2 -1618-1077 -PMC4514687 -26225120 -12764142 +journal article +301538 +10.1007/s13127-015-0201-2 +1ba91a1f-2835-4bef-9a15-be24c3cd350b +1618-1077 +PMC4514687 +26225120 +12764142 - + @@ -53,28 +55,28 @@ Embryos at this stage are of elongate shape measuring approximately 700 μm in maximum length ( -Fig. 6a +Fig. 6a ). The anterior proboscis region is of ovoid shape with a tapering anterior tip and is subdivided from the posterior body regions by a deep circular constriction ( -Fig. 6a, d +Fig. 6a, d ). The proboscis region is covered by short cilia, whereas at the anterior tip, a ciliary tuft composed of long cilia is present ( -Fig. 6a, c, d +Fig. 6a, c, d ). A second, yet shallow circular groove is discernable within the prospective collar region ( -Fig. 6d +Fig. 6d ). The opisthotroch is composed of compound cilia of multiciliary cells and demarcates the posterior perianal field ( -Fig. 6a, d +Fig. 6a, d ). Serotonin-LIR reveals the presence of several bipolar neurons that are located circumferentially around the midlevel of the proboscis region ( -Fig. 6a +Fig. 6a ). These bipolar neurons project a proximal neurite into a basiepidermal plexus of the proboscis region. A distal neurite connects to the apical cell surface where a single cilium is present. α- Tubulin-LIR reveals an apical ciliary tuft at the anterior tip; yet, no serotonin-LIR somata are detectable within the apical region close to the apical tuft ( -Fig. 6a, c +Fig. 6a, c ). Throughout the prospective collar and trunk region, basiepidermal serotonin-LIR neurites form a loose network that thins out posteriorly into individual neurites within the perianal field ( -Fig. 6b +Fig. 6b ). No traces of a serotonin-LIR opisthotroch neurite bundle are present within the trunk region, although tubulin staining reveals the existence of an opisthotroch ( -Fig. 6a +Fig. 6a ). @@ -87,16 +89,16 @@ Serotonin-LIR reveals the presence of several bipolar neurons that are located c The 1-gill-slit hatchling measures between 800 μm and 1 mm in length when fully expanded ( -Fig. 6e, h +Fig. 6e, h ). The animals exhibit a conical proboscis with an apical tuft composed of long cilia at the anterior tip ( -Fig. 6f, h +Fig. 6f, h ). The opisthotroch is present within the trunk region, just posterior to the position of the first pair of dorsolateral gill pores ( -Fig. 6h +Fig. 6h ). The posterior trunk region including the perianal field is elongated ventrally to a total length of 150 μm ( -Fig. 6e, h +Fig. 6e, h ). - + Fig. 5 Neurogenesis in the 2-gill slit juvenile of @@ -126,17 +128,17 @@ Detail The serotonin-LIR nervous system comprises a welldeveloped basiepidermal plexus that extends throughout all three body regions ( -Fig. 6h, g +Fig. 6h, g ). Numerous serotoninLIR epithelial neurons are present throughout the epidermis of the proboscis. These bipolar neurons are evenly distributed except for the most anterior area around the apical ciliary tuft. Within a radius of approximately 65 μm from the central apical tuft, no serotonin-LIR somata are present ( -Fig. 6f, h +Fig. 6f, h ). A higher density of serotonin-LIR neurites characterizes a part of the proboscis plexus dorsally at the base of the proboscis ( -Fig. 6h +Fig. 6h ). Within the collar epidermis, serotonin-LIR somata are concentrated into two multi-rowed rings, encircling the anterior and middle collar region ( -Fig. 6h, i +Fig. 6h, i ). The soma is located within the apical part of the epidermis, and each bipolar neuron sends a long proximal neurite into the basiepidermal plexus of the collar region. Detection of serotonin-LIR in the collar region reveals a neurite bundle that passes through the neurulating collar cord ( -Fig. 6i +Fig. 6i ). While the posterior part is already clearly in a subepidermal position, the more anterior part shows dorsal connections to the basiepidermal plexus within the collar epidermis ( -Fig. 6i +Fig. 6i ). The collar cord in S. kowalevskii @@ -144,11 +146,11 @@ The serotonin-LIR nervous system comprises a welldeveloped basiepidermal plexus neurulates successively from posterior to anterior, leaving just a neuropore at the posterior and anterior margin of the collar region (for more details, see Kaul and Stach 2010 ). Tubulin-LIR reveals the opisthotroch within the trunk region that propels the living hatchlings through the water ( -Fig. 6h +Fig. 6h ). No serotonin-LIR opisthotroch neurite ring is present ( -Fig. 6h, g +Fig. 6h, g ). Serotonin-LIR at the ventroposterior pole of the trunk region shows the presence of approximately 10 to 15 epithelial bipolar neurons ( -Fig. 6h +Fig. 6h ). @@ -186,7 +188,7 @@ In transmission electron micrographs, numerous basiepidermal neurites of differe The juveniles at this stage of development resemble the adult acorn worms in many aspects ( -Fig. 6k, l +Fig. 6k, l ). Obvious differences are a lower number of gill slits and the presence of the postanal tail, a feature only present in juvenile acorn worms of the family Harrimaniidae ( @@ -197,16 +199,16 @@ The juveniles at this stage of development resemble the adult acorn worms in man the proboscis show that the former ciliary tuft is degraded ( -Fig. 6k, l +Fig. 6k, l ). The opisthotroch is partially altered and has transformed into a ventral creeping sole. Within the proboscis and collar region, a serotonin-LIR basiepidermal plexus is present. The concentration of neurites is denser at the dorsoposterior base of the proboscis, constituting the proboscis plexus ( -Fig. 6k, o +Fig. 6k, o ). Serotonin-LIR bipolar neurons are distributed throughout the epidermis of the proboscis with the exception of the most anterior region. Each soma has a bulbous central part containing the nucleus and a slender distal neurite reaching the apical cell surface, where a single cilium is present ( -Fig. 6n +Fig. 6n ). Basally from the bulbous part, each soma sends a proximal neurite into the basiepidermal plexus. The dorsal proboscis stem sends two serotonin-LIR neurite bundles posteriorly into the subepidermal collar cord, thereby passing the proboscis neck region. At the posterior end of the collar region, the serotonin-LIR becomes superficial again and continues into a dorsal neurite bundle ( - + Fig. 6m , o @@ -220,18 +222,18 @@ Fig. S. kowalevskii lacks mesocoelic pores as well as a prebranchial nerve ring at this stage of development. A vast number of serotonin-LIR bipolar neurons are present within the epidermis of the anterior half of the collar region ( -Fig. 6k, o +Fig. 6k, o ). The architecture of the serotonin-LIR nervous system within the trunk region differs considerably from that described for the preceding hatchling stage. Serotonin-LIR is present in a longitudinal ventral as well as dorsal neurite bundle along the trunk region ( -Fig. 6k, m +Fig. 6k, m ). The ventral bundle is more extensive and extends to the posterior end of the postanal tail. The dorsal serotonin-LIR neurite bundle is less voluminous and is composed of few neurites only. It runs along the dorsal midline to the anus, with an interruption of the serotonin-LIR signal in the middle region of the trunk ( -Fig. 6k, m +Fig. 6k, m ). Several serotonin-LIR bipolar neurons are present within the trunk region ( - + Fig. 6m ). The majority of the somata are located dorsolaterally, sending a proximal neurite into the ventral nerve cord ( - + Fig. 6m diff --git a/data/AB/59/ED/AB59ED17564EFFBAFCAEFE75FAE1FBF3.xml b/data/AB/59/ED/AB59ED17564EFFBAFCAEFE75FAE1FBF3.xml index 015b19a0287..d51e3c1dba8 100644 --- a/data/AB/59/ED/AB59ED17564EFFBAFCAEFE75FAE1FBF3.xml +++ b/data/AB/59/ED/AB59ED17564EFFBAFCAEFE75FAE1FBF3.xml @@ -1,47 +1,49 @@ - - - -Neurogenesis in directly and indirectly developing enteropneusts: of nets and cords + + + +Neurogenesis in directly and indirectly developing enteropneusts: of nets and cords - - -Author + + +Author -Wanninger, Sabrina Kaul-Strehlow Makoto Urata Takuya Minokawa Thomas Stach Andreas +Wanninger, Sabrina Kaul-Strehlow Makoto Urata Takuya Minokawa Thomas Stach Andreas -text - - -Organisms Diversity & Evolution +text + + +Organisms Diversity & Evolution - -2015 - -2015-01-31 + +2015 + +2015-01-31 - -15 + +15 - -2 + +2 - -405 -422 + +405 +422 - -http://dx.doi.org/10.1007/s13127-015-0201-2 + +http://dx.doi.org/10.1007/s13127-015-0201-2 -journal article -10.1007/s13127-015-0201-2 -1618-1077 -PMC4514687 -26225120 -12764142 +journal article +301538 +10.1007/s13127-015-0201-2 +1ba91a1f-2835-4bef-9a15-be24c3cd350b +1618-1077 +PMC4514687 +26225120 +12764142 - + @@ -240,34 +242,34 @@ Early settled (12-h postsettlement (ps)) have an elongated body of vermiform shape measuring approximately 1 mm in length ( -Fig. 4a, b +Fig. 4a, b ). The proboscis is pointed at the anterior tip and about 450 μm long. The collar region measures 200 μm in length and is subdivided by a circular constriction into a broader anterior and narrower posterior part. The trunk region has significantly increased in length, now being 430 μm long. One pair of dorsolateral gill pores is developed at the anterior margin just behind the collar region. The opisthotroch is still present and encircles the trunk region ( -Fig. 4b +Fig. 4b ). Numerous serotonin-LIR somata are distributed throughout the epidermis of the proboscis region, and the apical organ is still visible at the anterior tip; yet, the number of serotoninLIR cells is reduced ( -Fig. 4a +Fig. 4a ) compared to the Agassiz stage. The serotonin-LIR nervous system of the proboscis region differs from the Agassiz stage in having a neurite-rich plexus at the dorsomedian base of the proboscis ( -Fig. 4a, e +Fig. 4a, e ). This socalled proboscis stem comprises one of the most condensed areas of the adult enteropneust nervous system. Posterior of the proboscis plexus, two serotonin-LIR neurite bundles project into the collar region and pass through the collar on a subepidermal level ( -Fig. 4e +Fig. 4e ). Both serotonin-LIR bundles are part of the neurulated collar cord that forms at this stage. Although DAPI staining reveals numerous nuclei accompanying the collar cord, no soma stains positively for serotonin within the collar cord. At the posterior end of the collar, the two neurite bundles become basiepidermal again and project laterally ( -Fig. 4e +Fig. 4e ) into the prebranchial nerve ring (see below). Within the epidermis of the collar region, numerous serotoninLIR somata are intercalated between the epidermis cells. Each serotonin-LIR bipolar neuron sends a proximal neurite into the basiepidermal plexus. The majority of serotonin-LIR neurites within the collar region runs in longitudinal direction ( -Fig. 4d +Fig. 4d ) and project into one of the two circular serotoninLIR neurite bundles within the posterior half of the collar region ( -Fig. 4d +Fig. 4d , mcb and 4f, pnr). The more anterior circular neurite bundle runs basiepidermally at the level of the internal margin of the collar coelom (mesocoel) ( -Fig. 4d +Fig. 4d , mcb), whereas the more posterior ring, the prebranchial nerve ring, is present at the very posterior margin of the collar region. The prebranchial nerve ring forms a distinct network of serotonin-LIR neurites around the paired mesocoelic pores ( -Fig. 4f, g +Fig. 4f, g ). These mesocoelic pores connect the coeloms of the collar region, the mesocoels, to the opening of the first gill pore, and eventually to the exterior. At this stage of development, a basiepidermal plexus is detectable by serotonin-LIR throughout the entire trunk region ( -Fig. 4c +Fig. 4c ), however, with only few serotonin-LIR somata. The opisthotroch neurite ring is less condensed and comprises only a loose arrangement of circular neurites ( -Fig. 4a, c +Fig. 4a, c ). @@ -278,26 +280,26 @@ staining reveals numerous nuclei accompanying the collar cord, no soma stains po After approximately 1-day postsettlement, the majority of juveniles have lost the opisthotroch ( -Fig. 4h +Fig. 4h ). The proboscis shape has slightly changed into a blunt, rounded acorn, measuring between 250 and 350 μm in length. The collar region resembles that described for the previous stage and the trunk region is shorter than the previous stage ( -Fig. 4h, l +Fig. 4h, l ). Within the proboscis and collar region, serotonin-LIR reveals only few changes of the overall architecture of the nervous system. Along the anterior tip of the proboscis, the number of the serotonin-LIR somata within the former apical organ is further reduced ( -Fig. 4i, l +Fig. 4i, l ). Along the anterior-posterior axis of the proboscis region, distinct neurite bundles indicate the position of the former larval ciliary bands ( -Fig. 4i +Fig. 4i , cgn, l). Within the anterior two thirds of the collar region, two rings of numerous serotonin-LIR neurons are present ( -Fig. 4k +Fig. 4k ). These cells are long, slender bipolar neurons with the somata placed basally, centrally, or even apically within the epidermis ( -Fig. 4k +Fig. 4k ). At the posterior collar margin, a pair of prebranchial nerves runs circumferentially, passes the mesocoelic pores, and eventually connects to the ventral part of the nervous plexus ( -Fig. 4l +Fig. 4l , pnr). While the arrangement and orientation of the basiepidermal neurites within the proboscis and collar region have not changed much, the situation in the trunk region is considerably different. A plexus-like arrangement of serotonin-LIR neurites is only detectable in the anterior half of the trunk ( -Fig. 4l, m +Fig. 4l, m ), whereas in the posterior part of the trunk, individual circumferential neurites are present. These circular neurites project into a longitudinal neurite bundle that is present along the ventral midline ( -Fig. 4l +Fig. 4l , vnb). @@ -308,18 +310,18 @@ Within the proboscis and collar region, serotonin-LIR reveals only few changes o After about 3-day postsettlement, most of the juveniles exhibit two pairs of gill slits ( -Fig. 5a, b +Fig. 5a, b ). Both gill slits are U-shaped and heavily ciliated on the inside ( -Fig. 5b +Fig. 5b ). No synapticles are developed. The juveniles measure up to 1.5 mm in total length ( -Fig. 5a–c +Fig. 5a–c ). The proboscis shows the typical acorn shape, while the mesosome has developed into a 200-μm-long threelobed collar region ( -Fig. 5a +Fig. 5a ). Scanning electron micrographs and acetylated-α- tubulin-LIR reveal that the proboscis and collar region are evenly covered with cilia, whereas on the trunk region, only scattered tufts of cilia are present ( -Fig. 5a, c +Fig. 5a, c ). - + Fig. 4 Neurogenesis in early settled stages of @@ -368,33 +370,33 @@ Detail showing circular 5-HT+ neurites within the posterior part of the trunk wh Throughout the epidermis of the proboscis, numerous serotonin-LIR bipolar neurons are intercalated between the other epidermal cells ( -Fig. 5c, i +Fig. 5c, i ). Each soma projects a single proximal neurite into the basiepidermal plexus of the proboscis region ( -Fig. 5i +Fig. 5i ). The most condensed area of serotonin-LIR neurites is present dorsally at the base of the proboscis, comprising a part of the proboscis plexus ( -Fig. 5c, d +Fig. 5c, d ). This dense network of neurites measures approximately 200 μm in width and 100 μm in length. From here, three distinct serotonin-LIR neurite bundles leave the proboscis plexus posteriorly to pass through the subepidermal collar cord within the collar region ( -Fig. 5d +Fig. 5d ). These serotonin-LIR neurite bundles are part of the ventral layer of neurites of the collar cord ( -Fig. 5h +Fig. 5h ). The dorsal area of the collar cord is composed of numerous cells, presumably neurons, which do not show serotonin-LIR in any of the somata ( -Fig. 5h +Fig. 5h ). At the posterior pole of the collar region, the three serotonin-LIR neurite bundles become basiepidermal again and connect to the nervous system within the trunk region. The median neurite bundle, composed of 7–10 serotonin-LIR neurites, continues directly into the dorsal midline and is part of the dorsal nerve cord ( -Fig. 5f +Fig. 5f ). SerotoninLIR is detectable until the posterior pole of the animals, with a discontinuity of about 150 μm in the middle of the trunk region ( -Fig. 5f, g +Fig. 5f, g , double arrowheads). Several serotoninLIR bipolar neurons are located dorsolaterally close to the dorsal midline and project a short neurite into the dorsal neurite bundle ( -Fig. 5f +Fig. 5f ). The lateral pair of neurite bundles that leaves the collar cord posteriorly runs circumferentially to the ventral side ( -Fig. 5d +Fig. 5d ). At the level of the dorsolateral gill slits, the bilateral neurite bundles form a distinctive network around the mesocoelic pores as also described for younger stages ( -Fig. 5d +Fig. 5d ). The bilateral neurite bundles are part of the prebranchial nerve ring and project into the ventral nerve cord. Numerous serotonin-LIR neurites extend along the entire midline of the trunk region thereby running within the ventral nerve cord that is about 40 μm wide ( -Fig. 5c, e +Fig. 5c, e ). Several serotonin-LIR somata are interspersed throughout the trunk epidermis. The majority of these bipolar neurons project a proximal neurite running circumferential into the ventral nerve cord ( -Fig. 5e +Fig. 5e ). The serotonin-LIR somata of the very posterior end send a proximal neurite running radially into the ventral neurite bundle ( -Fig. 5e +Fig. 5e ). It should be noted that a serotonin-LIR basiepidermal plexus is only present in the epidermis of the proboscis and collar, but completely absent within the trunk region, where instead a condensed dorsal and ventral neurite bundle is present.