Shunli Wang, Zhaorui Li, Feng Yuan, François Varray
The projected transverse angle and the nonprojected intrusion angle can be used to describe the radial orientation of local cardiomyocytes in the left ventricle wall, although to date their descriptive relevance has not been demonstrated. This paper compares the evolution of the transverse angle and the intrusion angle in five left ventricle wall samples, and investigates in more detail their respective behaviors when the nonprojected helical angle varies. We show that the intrusion angle avoids the “projection” effect, and contrary to the transverse angle, it remains stable whatever the values taken by the nonprojected helical angle, even when this approaches 90°. The intrusion angle is the better choice, rather than the transverse angle, in describing the radial orientation of local cardiomyocytes. Furthermore, the oscillation of the intrusion angle in the samples is assessed, whose results indicate that the intrusion angle's oscillation amplitude and period are regional and related to the local tissue architecture.
{"title":"Use of the intrusion angle to describe the radial orientation of local cardiomyocytes in the left ventricle","authors":"Shunli Wang, Zhaorui Li, Feng Yuan, François Varray","doi":"10.1002/jmor.21650","DOIUrl":"10.1002/jmor.21650","url":null,"abstract":"<p>The projected transverse angle and the nonprojected intrusion angle can be used to describe the radial orientation of local cardiomyocytes in the left ventricle wall, although to date their descriptive relevance has not been demonstrated. This paper compares the evolution of the transverse angle and the intrusion angle in five left ventricle wall samples, and investigates in more detail their respective behaviors when the nonprojected helical angle varies. We show that the intrusion angle avoids the “projection” effect, and contrary to the transverse angle, it remains stable whatever the values taken by the nonprojected helical angle, even when this approaches 90°. The intrusion angle is the better choice, rather than the transverse angle, in describing the radial orientation of local cardiomyocytes. Furthermore, the oscillation of the intrusion angle in the samples is assessed, whose results indicate that the intrusion angle's oscillation amplitude and period are regional and related to the local tissue architecture.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135821658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present new reconstructions of subcephalic musculature for the stem chondrichthyan Pucapampella, the tetrapodomorph fish Eusthenopteron, and the Devonian tetrapod Ichthyostega. These reconstructions are based on macroscopic dissections of the head muscles of an archaic shark Heptranchias and an archaic actinopterygian Polypterus, that are combined with functional considerations and a reappraisal of not widely known theoretical concepts from the past. The subcephalic, as well as the supracephalic, musculature is formed by four anterior myomeres. They are continuous with subsequent myomeres of the trunk, but are innervated by ventral nerve roots of the medulla oblongata and thus belong to the head. The fourth subcephalic myomere ends with its posterior myoseptum on the occiput in osteichthyans, but on the first vertebra in chondrichthyans. The original function of subcephalic and supracephalic muscles in basal gnathostomes supposedly was to hold together anterior and posterior parts of the neurocranium during interaction with prey, such as the backward-ripping prey dissection, hypothesized for Pucapampella. In sarcopterygian osteichthyans, subcephalic musculature is involved in active depression of the anterior part of the neurocranium; specialization of this mechanism resulted in a complete separation of m. subcephalicus from trunk myomeres in Latimeria. Fusion of anterior and posterior parts of the neurocranium has resulted in reduction of the subcephalic musculature in the majority of cartilaginous and bony fishes. However, hexanchid sharks retain three posterior subcephalic myomeres for backward-ripping prey dissection. Polypterus and Chauliodus have retained the subcephalic musculature, but its function has shifted to a depression of the whole neurocranium.
{"title":"Reconstructing the subcephalic musculature in Pucapampella and Ichthyostega","authors":"Alexander N. Kuznetsov, Nadezhda V. Kryukova","doi":"10.1002/jmor.21648","DOIUrl":"10.1002/jmor.21648","url":null,"abstract":"<p>We present new reconstructions of subcephalic musculature for the stem chondrichthyan <i>Pucapampella</i>, the tetrapodomorph fish <i>Eusthenopteron</i>, and the Devonian tetrapod <i>Ichthyostega</i>. These reconstructions are based on macroscopic dissections of the head muscles of an archaic shark <i>Heptranchias</i> and an archaic actinopterygian <i>Polypterus</i>, that are combined with functional considerations and a reappraisal of not widely known theoretical concepts from the past. The subcephalic, as well as the supracephalic, musculature is formed by four anterior myomeres. They are continuous with subsequent myomeres of the trunk, but are innervated by ventral nerve roots of the <i>medulla oblongata</i> and thus belong to the head. The fourth subcephalic myomere ends with its posterior myoseptum on the occiput in osteichthyans, but on the first vertebra in chondrichthyans. The original function of subcephalic and supracephalic muscles in basal gnathostomes supposedly was to hold together anterior and posterior parts of the neurocranium during interaction with prey, such as the backward-ripping prey dissection, hypothesized for <i>Pucapampella</i>. In sarcopterygian osteichthyans, subcephalic musculature is involved in active depression of the anterior part of the neurocranium; specialization of this mechanism resulted in a complete separation of <i>m. subcephalicus</i> from trunk myomeres in <i>Latimeria</i>. Fusion of anterior and posterior parts of the neurocranium has resulted in reduction of the subcephalic musculature in the majority of cartilaginous and bony fishes. However, hexanchid sharks retain three posterior subcephalic myomeres for backward-ripping prey dissection. <i>Polypterus</i> and <i>Chauliodus</i> have retained the subcephalic musculature, but its function has shifted to a depression of the whole neurocranium.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135320691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jessica L. Dobson, Thomas W. Pike, Jose Gonzalez-Rodriguez, Carl D. Soulsbury
Colourful signals have long been implicated as indicators of individual quality in animals. Bare-skin signals are an understudied aspect of avian colouration compared with plumage studies, despite displaying rapid changes in size and colour in response to different environmental or physiological stressors. Even fewer studies have focused on the underlying histology of these structures and the importance this plays in the resulting skin colour. Using the Black Grouse (Lyrurus tetrix), we identified the underlying structure of individual dermal spikes, which make up the red supra-orbital comb (a known integumentary signal of male quality), and highlight visual structural differences between combs of different sizes. In addition, we used Raman spectroscopy to indicate the presence of carotenoids within the tissue, something that had previously only been inferred through characteristic reflectance patterns. An increased understanding of the structural basis of colour of featherless parts of the skin opens up exciting new avenues for interpreting the information content of integumentary signals.
{"title":"Identifying and locating carotenoids in supra-orbital combs of male black grouse (Lyurus tetrix) using Raman and transmission electron microscopy: A histological study using rehydrated tissue samples","authors":"Jessica L. Dobson, Thomas W. Pike, Jose Gonzalez-Rodriguez, Carl D. Soulsbury","doi":"10.1002/jmor.21652","DOIUrl":"https://doi.org/10.1002/jmor.21652","url":null,"abstract":"<p>Colourful signals have long been implicated as indicators of individual quality in animals. Bare-skin signals are an understudied aspect of avian colouration compared with plumage studies, despite displaying rapid changes in size and colour in response to different environmental or physiological stressors. Even fewer studies have focused on the underlying histology of these structures and the importance this plays in the resulting skin colour. Using the Black Grouse <i>(Lyrurus tetrix)</i>, we identified the underlying structure of individual dermal spikes, which make up the red supra-orbital comb (a known integumentary signal of male quality), and highlight visual structural differences between combs of different sizes. In addition, we used Raman spectroscopy to indicate the presence of carotenoids within the tissue, something that had previously only been inferred through characteristic reflectance patterns. An increased understanding of the structural basis of colour of featherless parts of the skin opens up exciting new avenues for interpreting the information content of integumentary signals.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68180708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many tetrapod vertebrates have two distinct olfactory organs, the olfactory epithelium (OE) and vomeronasal organ (VNO). In turtles, the olfactory organ consists of two types of sensory epithelia, the upper chamber epithelium (UCE; corresponding to the OE) and the lower chamber epithelium (LCE; corresponding to the VNO). In many turtle species, the UCE contains ciliated olfactory receptor cells (ORCs) and the LCE contains microvillous ORCs. To date, several transcription factors involved in the development of the OE and VNO have been identified in mammals. Fez family zinc-finger protein 1 and 2 (Fezf1 and 2) are expressed in the OE and VNO, respectively, of mouse embryos, and are involved in the development and maintenance of ORCs. B-cell lymphoma/leukemia 11B (Bcl11b) is expressed in the mouse embryo OE except the dorsomedial parts of the nasal cavity, and regulates the expression of odorant receptors in the ORCs. In this study, we examined the expression of Fezf1, Fezf2, and Bcl11b in the olfactory organs of embryos in three turtle species, Pelodiscus sinensis, Trachemys scripta elegans, and Centrochelys sulcata, to evaluate their involvement in the development of reptile olfactory organs. In all three turtle species, Bcl11b was expressed in the UCE, Fezf2 in the LCE, and Fezf1 in both the UCE and LCE. These results imply that the roles of the transcription factors Fezf1, Fezf2, and Bcl11b in olfactory organ development are conserved among mammals and turtles.
{"title":"Expression patterns of the transcription factors Fezf1, Fezf2, and Bcl11b in the olfactory organs of turtle embryos","authors":"Shoko Nakamuta, Hideki Noda, Hideaki Kato, Takuya Yokoyama, Yoshio Yamamoto, Nobuaki Nakamuta","doi":"10.1002/jmor.21655","DOIUrl":"10.1002/jmor.21655","url":null,"abstract":"<p>Many tetrapod vertebrates have two distinct olfactory organs, the olfactory epithelium (OE) and vomeronasal organ (VNO). In turtles, the olfactory organ consists of two types of sensory epithelia, the upper chamber epithelium (UCE; corresponding to the OE) and the lower chamber epithelium (LCE; corresponding to the VNO). In many turtle species, the UCE contains ciliated olfactory receptor cells (ORCs) and the LCE contains microvillous ORCs. To date, several transcription factors involved in the development of the OE and VNO have been identified in mammals. Fez family zinc-finger protein 1 and 2 (Fezf1 and 2) are expressed in the OE and VNO, respectively, of mouse embryos, and are involved in the development and maintenance of ORCs. B-cell lymphoma/leukemia 11B (Bcl11b) is expressed in the mouse embryo OE except the dorsomedial parts of the nasal cavity, and regulates the expression of odorant receptors in the ORCs. In this study, we examined the expression of <i>Fezf1, Fezf2</i>, and <i>Bcl11b</i> in the olfactory organs of embryos in three turtle species, <i>Pelodiscus sinensis</i>, <i>Trachemys scripta elegans</i>, and <i>Centrochelys sulcata</i>, to evaluate their involvement in the development of reptile olfactory organs. In all three turtle species, <i>Bcl11b</i> was expressed in the UCE, <i>Fezf2</i> in the LCE, and <i>Fezf1</i> in both the UCE and LCE. These results imply that the roles of the transcription factors Fezf1, Fezf2, and Bcl11b in olfactory organ development are conserved among mammals and turtles.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21655","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49678530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The neuromast is a sensory structure of the lateral line system in aquatic vertebrates, which consists of hair cells and supporting cells. Hair cells are mechanosensory cells, generally arranged with bidirectional polarity. Here, we describe a neuromast with hair cells arranged radially instead of bidirectionally in the first cranial neuromast of four teleost species: red seabream (Pagrus major), spotted halibut (Verasper variegatus), brown sole (Pseudopleuronectes herzensteini), and marbled sole (Pseudopleuronectes yokohamae). In these four species, this polarity was identified only in the first cranial neuromast, where it appeared at the rostral edge of the otic vesicle before hatching. We investigated the initial appearance and fate of this unique neuromast using scanning electron microscopy. We also assessed characteristics of radial neuromast pertaining to morphogenesis, development, and innervation using a vital fluorescent marker and immunohistochemistry in V. variegatus. The kinocilium initially appears at the center of each hair cell, then moves to its outer perimeter to form radial polarity by around 7 days postfertilization. However, hair cells arranged radially disappear about 15 days after hatching. This is followed by the appearance of bidirectionally arranged hair cells, indicating that polarity replacement from radial to bidirectional has occurred. In P. herzensteini, both afferent and efferent synapses between the nerve fibers and hair cells were observed by transmission electron microscopy, suggesting that radial neuromast is functional. Our discovery suggests that neuromasts with radial polarity could enable larval fish to assimilate multiaxial stimuli during this life stage, potentially assisting them in detecting small water vibrations or water pressure changes.
{"title":"Radial polarity in the first cranial neuromast of selected teleost fishes","authors":"Machiko Otsuka, Shoei Sugita, Daisuke Shimizu, Masato Aoyama, Masaru Matsuda","doi":"10.1002/jmor.21654","DOIUrl":"10.1002/jmor.21654","url":null,"abstract":"<p>The neuromast is a sensory structure of the lateral line system in aquatic vertebrates, which consists of hair cells and supporting cells. Hair cells are mechanosensory cells, generally arranged with bidirectional polarity. Here, we describe a neuromast with hair cells arranged radially instead of bidirectionally in the first cranial neuromast of four teleost species: red seabream (<i>Pagrus major</i>), spotted halibut (<i>Verasper variegatus</i>), brown sole (<i>Pseudopleuronectes herzensteini</i>), and marbled sole (<i>Pseudopleuronectes yokohamae</i>). In these four species, this polarity was identified only in the first cranial neuromast, where it appeared at the rostral edge of the otic vesicle before hatching. We investigated the initial appearance and fate of this unique neuromast using scanning electron microscopy. We also assessed characteristics of radial neuromast pertaining to morphogenesis, development, and innervation using a vital fluorescent marker and immunohistochemistry in <i>V. variegatus</i>. The kinocilium initially appears at the center of each hair cell, then moves to its outer perimeter to form radial polarity by around 7 days postfertilization. However, hair cells arranged radially disappear about 15 days after hatching. This is followed by the appearance of bidirectionally arranged hair cells, indicating that polarity replacement from radial to bidirectional has occurred. In <i>P. herzensteini</i>, both afferent and efferent synapses between the nerve fibers and hair cells were observed by transmission electron microscopy, suggesting that radial neuromast is functional. Our discovery suggests that neuromasts with radial polarity could enable larval fish to assimilate multiaxial stimuli during this life stage, potentially assisting them in detecting small water vibrations or water pressure changes.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49678533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Timea P. Neusser, Bastian Brenzinger, Michael Schrödl, Katharina M. Jörger
The freshwater slugs of the genus Acochlidium (Heterobranchia, Gastropoda, and Acochlidimorpha) are peculiar, one to two centimeter sized animals found only in small coastal rivers and streams of Southeast Asian and Western Pacific islands. When first described by Bücking, the author observed a branching “net of dendritic vessels connected to the heart,” which he assumed to have replaced the original gastropod gill. In the present study, we compare the renopericardial systems of four Acochlidium species in microanatomical, histological and ultrastructural detail and identify where exactly the enigmatic, subepidermal “dorsal vessels” connect to the renopericardial system to examine if they can really function as a gill. Acochlidium have elaborate renopericardial systems compared to their ancestrally marine and also freshwater relatives. The primary site of ultrafiltration is the epicardium of the atrium with podocytes as usual for gastropods. The “dorsal vessels” in Acochlidium are extensions of the outer epithelium of the pericardial cavity and represent true vessels, that is, coelomatic channels, having an endothelium with podocytes. Hence, they considerably enlarge the site of ultrafiltration increasing the pericardial surface. “Dorsal vessels” in Acochlidium are therefore not homologous to externally similar morphological structures in Sacoglossa (marine panpulmonate slugs and snails). The multiplication of renopericardioducts in Acochlidium is a unique feature within Mollusca that enhances the negative pressure necessary for ultrafiltration in the thin, tube-like dorsal vessels and as a consequence the transport of primary urine from the pericardium to the kidney. The circulatory and excretory systems in Acochlidium are adaptations to a lifestyle in their freshwater environment in which snail bodies are hyposmotic and accrue considerable influx of surplus water into the body, which needs to be expelled.
{"title":"Really a “secondary gill under the skin”? Unveiling “dorsal vessels” in freshwater slugs (Mollusca, Panpulmonata, Acochlidimorpha)","authors":"Timea P. Neusser, Bastian Brenzinger, Michael Schrödl, Katharina M. Jörger","doi":"10.1002/jmor.21653","DOIUrl":"10.1002/jmor.21653","url":null,"abstract":"<p>The freshwater slugs of the genus <i>Acochlidium</i> (Heterobranchia, Gastropoda, and Acochlidimorpha) are peculiar, one to two centimeter sized animals found only in small coastal rivers and streams of Southeast Asian and Western Pacific islands. When first described by Bücking, the author observed a branching “net of dendritic vessels connected to the heart,” which he assumed to have replaced the original gastropod gill. In the present study, we compare the renopericardial systems of four <i>Acochlidium</i> species in microanatomical, histological and ultrastructural detail and identify where exactly the enigmatic, subepidermal “dorsal vessels” connect to the renopericardial system to examine if they can really function as a gill. <i>Acochlidium</i> have elaborate renopericardial systems compared to their ancestrally marine and also freshwater relatives. The primary site of ultrafiltration is the epicardium of the atrium with podocytes as usual for gastropods. The “dorsal vessels” in <i>Acochlidium</i> are extensions of the outer epithelium of the pericardial cavity and represent true vessels, that is, coelomatic channels, having an endothelium with podocytes. Hence, they considerably enlarge the site of ultrafiltration increasing the pericardial surface. “Dorsal vessels” in <i>Acochlidium</i> are therefore not homologous to externally similar morphological structures in Sacoglossa (marine panpulmonate slugs and snails). The multiplication of renopericardioducts in <i>Acochlidium</i> is a unique feature within Mollusca that enhances the negative pressure necessary for ultrafiltration in the thin, tube-like dorsal vessels and as a consequence the transport of primary urine from the pericardium to the kidney. The circulatory and excretory systems in <i>Acochlidium</i> are adaptations to a lifestyle in their freshwater environment in which snail bodies are hyposmotic and accrue considerable influx of surplus water into the body, which needs to be expelled.</p>","PeriodicalId":16528,"journal":{"name":"Journal of Morphology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/jmor.21653","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49678534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}