A Hungarian twin study on hand clasping, arm folding and tongue curling

A twin study was performed in adult Hungarian monozygotic and dizygotic pairs for hand clasping, arm folding and tongue curling. Genetic background of these traits could not be confirmed, although there appears to be a positive correlation between hand clasping type and handedness.     

Transmission and learning of tongue gymnastic ability

Observations were made for two weeks on the ability to roll, twist, and fold the tongue in the four members of an American family of northern European background. Photographs and questions were mailed to relatives, thus providing data for a total of 13 persons in three generations. It was found that ample time and example must be provided for learning tongue tricks, even if they be genetically determined. Also, there was evidence for the independent transmission of folding and rolling, and of transitory intermediate positions of the tongue before full expression of the abilities appeared.     

The genetic basis of tongue rolling

Tongue rolling is widely used in elementary biology education to illustrate simple genetics despite doubts about its validity. A survey was carried out to determine the extent to which apparent non-rollers can learn to roll their tongues and to discover what advantage the ability to roll the tongue or not might confer and thus offer an explanation for this apparent polymorphism.     

广东客家人5项舌运动类型的人类学研究

应用随机群体抽样方法对广东梅州地区203例客家人(其中男68例,女135例)的卷舌、叠舌、翻舌、尖舌、三叶舌5项体质人类学指标进行调查,与国内外族群资料进行比较,分析了5项指标间的相互关系。结果显示,1)广东客家人卷舌率为63.05%,叠舌率为6.90%,翻舌率为34.48%,尖舌率为67.98%,三叶舌率为3.45%。与国内族群比较,广东客家人卷舌率较低,叠舌率中等,翻舌率较高,尖舌率较低,三叶舌率低。2)广东客家人舌运动类型出现率与四川邛崃汉族最为接近,具有南方族群的特征。3)广东客家人只有卷舌-翻舌间存在着相关。卷舌基因与叠舌基因是相互独立的。     

Kinetics of tongue projection in Ambystoma tigrinum: Quantitative kinematics,muscle function,and evolutionary hypotheses

The projectile tongue of caudate amphibians has been studied from many perspectives, yet a quantitative kinetic model of tongue function has not yet been presented for generalized (nonplethodontid) terrestrial salamanders. The purposes of this paper are to describe quantitatively the kinnematics of the feeding mechanism and to present a kinetic model for the function of the tongue in the ambystomatid salamander Ambystoma tigrinum. Six kinematic variables were quantified from high-speed films of adult A. tigrinum feeding on land and in the water. Tongue protrusion reaches its maximum during peak gape, while peak tongue height is reached earlier, 15 ms after the mouth starts to open. Tongue kinematics change considerably during feeding in the water, and the tongue is not protruded past the plane of the gape. Electrical stimulation of the major tongue muscles showed that tongue projection in A. tigrinum is the combined result of activity in four muscles: the geniohyoideus, Subarcualis rectus 1, intermandibularis posterior, and interhyoideus. Stimulation of the Subarcualis rectus 1 alone does not cause tongue projection. The kinetic model produced from the kinematic and stimulation data involves both a dorsal vector (the resultant of the Subarcualis rectus 1, intermandibularis posterior, and interhyoideus) and a ventral vector (the geniohyoideus muscle), which sum to produce a resultant anterior vector that directs tongue motion out of the mouth and toward the prey. This model generates numerous testable predictions about tongue function and provides a mechanistic basis for the hypothesis that tongue projection in salamanders evolved from primitive intraoral manipulative action of the hyobranchial apparatus.     

A study of nine anthroposcopic traits among the three tribes of the Bastar District in Madhya Pradesh, India

Nine anthroposcopic traits, namely palmar and plantar digital formulae, hand-clasping, armfolding, handedness, tongue rolling and folding, ear lobe attachment and legfolding have been studied in the three tribal populations--Murias, Bisonhorn Marias and Halbas--from the Bastar District in Madhya Pradesh (Central India). An attempt has been made to compare the results of the present study with other population groups of Central India.     

Filiform papillae of human, rat and swine tongue

In order to study the structure of filiform papillae (FP), tissue specimens were taken from the anterior part of the tongues of 8 humans, 8 rats and 8 swine. The formalin-fixed samples were processed routinely for scanning electron microscopy (SEM) and light microscopy. With SEM, FP of human tongue contained 5-12 hairs which were covered with a massive plaque of micro-organisms. FP of rat tongue, on the other hand, contained one papillary projection with smooth surface structure. Colonization of micro-organisms was seen on the anterior part of the body of FP, but not on the hairs. In the cross-section of FP of the rat tongue, the cells of the papilla were close to each other and no micro-organisms were seen within the papillae. On the contrary, the spaces between the squamous epithelial cells of the hairs of human FP contained numerous micro-organisms. The structure of FP of the swine tongue resembled that of the rat tongue. The hairs were smooth, and some micro-organisms were seen on the cell surface of the interpapillary areas. The structure of FP is discussed from the standpoint of different keratinization and colonization of micro-organisms.     

Separate and distinctive roles for Wnt5a in tongue, lingual tissue and taste papilla development

Although canonical Wnt signaling is known to regulate taste papilla induction and numbers, roles for noncanonical Wnt pathways in tongue and taste papilla development have not been explored. With mutant mice and whole tongue organ cultures we demonstrate that Wnt5a protein and message are within anterior tongue mesenchyme across embryo stages from the initiation of tongue formation, through papilla placode appearance and taste papilla development. The Wnt5a mutant tongue is severely shortened, with an ankyloglossia, and lingual mesenchyme is disorganized. However, fungiform papilla morphology, number and innervation are preserved, as is expression of the papilla marker, Shh. These data demonstrate that the genetic regulation for tongue size and shape can be separated from that directing lingual papilla development. Preserved number of papillae in a shortened tongue results in an increased density of fungiform papillae in the mutant tongues. In tongue organ cultures, exogenous Wnt5a profoundly suppresses papilla formation and simultaneously decreases canonical Wnt signaling as measured by the TOPGAL reporter. These findings suggest that Wnt5a antagonizes canonical Wnt signaling to dictate papilla number and spacing. In all, distinctive roles for Wnt5a in tongue size, fungiform papilla patterning and development are shown and a necessary balance between non-canonical and canonical Wnt paths in regulating tongue growth and fungiform papillae is proposed in a model, through the Ror2 receptor.     

Sonic hedgehog exerts distinct, stage-specific effects on tongue and taste papilla development

Taste papillae are ectodermal specializations that serve to house and distribute the taste buds and their renewing cell populations in specific locations on the tongue. We previously showed that Sonic hedgehog (Shh) has a major role in regulating the number and spatial pattern of fungiform taste papillae on embryonic rat tongue, during a specific period of papilla formation from the prepapilla placode. Now we have immunolocalized the Shh protein and the Patched receptor protein (Ptc), and have tested potential roles for Shh in formation of the tongue, emergence of papilla placodes, development of papilla number and size, and maintenance of papillae after morphogenesis is advanced. Cultures of entire embryonic mandible or tongues from gestational days 12 to 18 [gestational or embryonic days (E)12-E18] were used, in which tongues and papillae develop with native spatial, temporal, and molecular characteristics. The Shh signaling pathway was disrupted with addition of cyclopamine, jervine, or the 5E1 blocking antibody. Shh and Ptc proteins are diffuse in prelingual tissue and early tongue swellings, and are progressively restricted to papilla placodes and then to regions of developing papillae. Ptc encircles the dense Shh immunoproduct in papillae at various stages. When the Shh signal is disrupted in cultures of E12 mandible, tongue formation is completely prevented. At later stages of tongue culture initiation, Shh signal disruption alters development of tongue shape (E13) and results in a repatterned fungiform papilla distribution that does not respect normally papilla-free tongue regions (E13-E14). Only a few hours of Shh signal disruption can irreversibly alter number and location of fungiform papillae on anterior tongue and elicit papilla formation on the intermolar eminence. However, once papillae are well formed (E16-E18), Shh apparently does not have a clear role in papilla maintenance, nor does the tongue retain competency to add fungiform papillae in atypical locations. Our data not only provide evidence for inductive and morphogenetic roles for Shh in tongue and fungiform papilla formation, but also suggest that Shh functions to maintain the interpapilla space and papilla-free lingual regions. We propose a model for Shh function at high concentration to form and maintain papillae and, at low concentration, to activate between-papilla genes that maintain a papilla-free epithelium.     

Heat transfer modeling of the tongue

The heat transfer mechanism of tongue was investigated on the basis of experimental and theoretical research. Firstly, the relationship between tongue temperature and blood perfusion was obtained from animal experiment that mainly carried out on porcine tongue, subordinate on human tongue. Secondly, a one-dimensional variable coefficients second-order inhomogeneous heat transfer equation is developed by simplifying tongue as fin cube and the analytical solution is got. The results show that the change regulations of temperature by blood perfusion rate are the same in human and porcine tongue, and also, there is a good agreement between calculation and experimental results. When checking the model with corresponding properties of human tongue, the result is also satisfied. In conclusion, predicting temperature distribution of tongue is feasible with the fin cube model.     

Models of tongue movement in the walrus (Odobenus rosmarus)

Three hypothetical models of tongue movement of the walrus during suction feeding are examined. These models encompass the entire range of simple tongue retraction movements possible by examining 1) movement of the tongue directly to the rear following the curvature of the palate, 2) to the rear and ventrally in a straight line, and 3) ventrally in a straight line. The percent of muscular force available from the hyoglossus, genioglossus, and styloglossus that could be applied toward retraction as predicted by each model is calculated. The resistance that the tongue would provide during retraction is calculated using projected tongue areas and is combined with the above data from the muscles to provide an estimate of the percent of the total available force that is needed to retract the tongue for each model. A separate examination of the direction of tongue-induced wear striations on the palatal and lingual aspects of the teeth is used to help support or reject the three models. The model where the tongue is moved directly to the rear is supported by studies of both muscle force and tooth wear. In the mammalian groups that were compared to the walrus, there is a great deal of interspecific variation in movements of the tongue during suction feeding; no two groups can be considered to have identical stereotyped tongue movements.     

Reanimation of the hemiparalytic tongue

Tongue hemiparesis is the inevitable result when the freshly severed 12th nerve is anastomosed to the trunk of a paralyzed 7th nerve in the technique commonly used by neurosurgeons, head and neck surgeons, otologists, and plastic surgeons to treat unilateral facial paralysis. This author has reactivated hemiparalytic tongues after research on cats. The technique has now been proved to be successful on two human beings. The reanimation is based on a simple Z-plasty of tongue muscle across the midline. Two principles are established: (1) placing a normal muscle in direct contact with a denervated muscle stimulates axons from the normal side to penetrate into the denervated side, eventually restoring function, and (2) transposition of a flap of muscle from the normal side containing extrinsic tongue muscles could provide a motor apparatus to activate the paralytic side. Biopsy slides taken from the paralyzed side of the cat tongues after 18 months showed sprouting of multiple nerves. Nerve sprouting can be found in human tongues 1 year after Z-plasties. The two patients who experienced atrophy and hemiparesis after the 12th-7th nerve hookup regained full range of tongue movements by 2 months and 4 months, respectively, demonstrating that with time, motor axons from the normal side innervated the atrophic muscle side to form new neuromotor junctions resulting in tongue movements. EMGs of the reanimated tongue showed normal activity in both sides of the tongue. Biopsies of the interface between the normal and former paralyzed side taken 1 year later showed nerves crossing the scar barrier. Apparently, the role of additional extrinsic muscle to the paralyzed side played a minor role.     

Brief communication: Noninvasive measuring of operational tongue length in callitrichids

Callitrichids use their tongue in various social, ecological, and hygienic contexts. Using a noninvasive measuring device, we obtained data on the operational tongue length (OTL) in seven species from the family Callitrichidae. OTL (defined as the maximum tongue extension into the device) varied significantly between species and the width of the device, but did not correlate with mandible length; it is smaller in relation to mandible length in Leontopithecus chrysomelas compared to species from the genera Saguinus and Callithrix. Current information does not allow concluding which of the various functions of the tongue is selecting for tongue length. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.     

内蒙古三个民族舌运动类型的遗传学研究

调查了内蒙古汉、蒙古、回族舌运动类型(卷舌、翻舌、叠舌、三叶舌与尖舌),共716例。研究结果显示:各种舌运动类型出现率性别间均无显著性差异;卷舌基因分别与叠、翻、尖、三叶舌基因间存在着互相作用关系,卷舌基因对叠舌基因是隐性上位基因,对翻舌、尖舌、三叶舌基因是修饰基因;内蒙古3个民族间卷、叠、尖舌出现率接近。本文首次调查并研究了尖舌性状。尖舌在过去国内外文献中未见报道。 Abstract:The tongue moving types(including tongue rolling,tongue twisting,tongue folding,clover-leaf tongue and pointed tongue)of 716 cases of Han,Mongol and Hui nationalities in Inner Mongolia were investigated.The results showed that no difference in the frequencies of various tongue moving types between male and female and that the frequencies of rolling,folding and pointed tongue were close to each other among the three nationalities of Inner Mongolia.However,some interactions between genes were revealed,that the rolling gene is a recessive epistatic gene to folding gene and a modifier gene to twisting,pointed and clover-leaf gene respectively.The research on pointed tongue in this paper has never been reported in China and abroad.     

A biomechanical model of sagittal tongue bending

The human tongue is a structurally complex and extremely flexible organ. In order to better understand the mechanical basis for lingual deformations, we modeled a primitive movement of the tongue, sagittal tongue bending. We hypothesized that sagittal bending is a synergistic deformation derived from co-contraction of the longitudinalis and transversus muscles. Our model of tongue bending was based on classical bimetal strip theory, in which curvature is produced when one muscle layer contracts more so than another. Contraction was modulated via mismatched thermal expansion coefficients and temperature change (to simulate muscular contraction). Our results demonstrated that synergistic contraction produced curvature and strain results which were in better correspondence to empirical results derived from tagging MRI than were the results of contraction of the longitudinalis muscle alone. This fundamental reliance of tongue bending on the synergistic contraction of its intrinsic fibers supports the muscular hydrostat theory of tongue function.     

The scaling of tongue projection in the veiled chameleon,Chamaeleo calyptratus

Within a year of hatching, chameleons can grow by up to two orders of magnitude in body mass. Rapid growth of the feeding mechanism means that bones, muscles, and movements change as chameleons grow while needing to maintain function. A previous morphological study showed that the musculoskeletal components of the feeding apparatus grow with negative allometry relative to snout–vent length (SVL) in chameleons. Here, we investigate the scaling of prey capture kinematics and muscle physiological cross-sectional area in the veiled chameleon, Chamaeleo calyptratus. The chameleons used in this study varied in size from approximately 3 to 18 cm SVL (1–200 g). Feeding sequences of 12 chameleons of different sizes were filmed and the timing of movements and the displacements and velocities of the jaws, tongue, and the hyolingual apparatus were quantified. Our results show that most muscle cross-sectional areas as well as tongue and hyoid mass scaled with isometry relative to mandible length, yet with negative allometry relative to SVL. Durations of movement also scaled with negative allometry relative to SVL and mandible length. Distances and angles generally scaled as predicted under geometric similarity (slopes of 1 and 0, respectively), while velocities generally scaled with slopes greater than 0 relative to SVL and mandible length. These data indicate that the velocity of jaw and tongue movements is generally greater in adults compared to juveniles. The discrepancy between the scaling of cross-sectional areas versus movements suggests changes in the energy storage and release mechanisms implicated in tongue projection.     

Functional morphology of tongue projection in Taricha torosa (Urodela: Salamandridae)

The kinematics of tongue projection by terrestrial adult California newts, Taricha torosa (Rathke, 1833), are described based upon high-speed cinematography. Tongue projection results from coupled anterior movements of the ceratohyals and branchial arches. Four distinct periods are defined during a projection sequence: preparation, tongue projection, tongue recovery and mouth closing. Key anatomical correlates of projection are described, with special emphasis on the mobility of the hyoid arch. Adult Taricha (Gray, 1850) have lost the mandibulo-hyoid ligament and reduced additional connective tissues present in larvae. These changes decouple the hyoid arch from mouth opening and release the ceratohyals to participate in a tongue projection system distinct from those of ambystomatids and plethodontids. These phylogenetic differences pose questions about the evolution of tongue projection systems in terrestrial urodeles. Currently available data are consistent with the interpretation that terrestrial urodeles have independently evolved specialized tongue projection systems at least twice: the ceratohyal-stable mode of plethodontids and the ceratohyal-mobile system of newts. In all cases, an essential underlying (= plesiomorphic) feature is the presence of the depressor mandibulae muscle. We regard this pathway for mouth opening as a prerequisite which liberated the hyobranchium for alternative function. Comprehensive studies of the mandibulo-hyoid ligament and depressor mandibulae will be vital to modelling the evolution of specialized tongue projection systems of urodeles.     

内蒙古达斡尔族舌运动类型的遗传学研究

调查了内蒙古达斡尔族舌运动类型（卷舌、叠舌、翻舌、尖舌、三叶舌）,共480例（男239例,女241例）。研究结果显示：（1）卷舌、叠舌、翻舌、尖舌、三叶舌出现率分别为80．42％、4．58％、31．25％、81．88％、31．46％;（2）卷舌、三叶舌出现率存在性别间明显差异;（3）卷舌基因与翻舌、三叶舌基因间存在互作关系,翻舌基因与叠舌、尖舌、三叶舌基因间存在互作关系;（4）卷舌、叠舌、翻舌、三叶舌的出现率存在民族间或种族间差异。     

Sliding posterior tongue flap

A modification of the hemitongue advancement flap is presented which provides greater extensibility to the base of the tongue. This technique allows for reconstruction of T2 tumor defects of the midlateral tongue ranging from 4 to 6 cm in length. Mobility of the tongue is minimally compromised, preserving good speech and deglutition. Excessive bulk is not present to impinge on the mandibular alveololingual sulcus, thus allowing early use of lower dentures without the need for adjustment and relining.