The genus Nanopterodectes Mironov, 2009 (Acari, Proctophyllodidae), with descriptions of three new species from antbirds (Passeriformes: Thamnophilidae) in Brazil

Three new species of the recently discovered, and hitherto monotypic, feather mite genus Nanopterodectes Mironov, 2009 are described: N. acutirostris n. sp. from Stymphalornis acutirostris Bornschein, Reinert & Teixeira, N. mentalis n. sp. from Dysithamnus mentalis (Temminck), and N. leucopterus n. sp. from Pyriglena leucoptera (Vieillot). This feather mite genus is currently restricted to passerine birds of the Neotropical family Thamnophilidae in Brazil. A key to the known species of Nanopterodectes is presented for both sexes.     

Knuckle-walking and the evolution of hominoid hands

Knuckle-walking is a pattern of digitigrade locomotion unique to African apes among Primates. Only chimpanzees and gorillas are specially adapted for supporting weight on the dorsal aspects of middle phalanges of flexed hand digits II–V. When forced to the ground, most orangutans assume one of a variety of flexed hand postures, but they cannot knuckle-walk. Some orangutans place their hands in palmigrade postures which are impossible to African apes. The knuckle-walking hands and plantigrade feet of African apes are both morphologically and adaptively distinct from those of Pongo, their nearest relative among extant apes. These features are associated with a common adaptive shift to terrestrial locomotion and support placing chimpanzees and gorillas in the same genus Pan. It is further suggested than Pan comprises the subgenera (a) Pan, including P. troglodytes and pygmy chimpanzees, and (b) Gorilla, including mountain and lowland populations of P. gorilla. African apes probably diverged from ancestral pongids that were specially adapted for distributing their weight in terminal branches of the forest canopy. Early adjustments to terrestrial locomotion may have involved fist-walking which later evolved into knuckle-walking. Orangutans continued to adapt to feeding and locomotion in the forest canopy and their hands and feet became highly specialized for four-digit prehension. Although chimpanzees retained arboreal feeding and nesting habits, they moved from tree to tree by terrestrial routes and became less restricted in habitat. While adapting to a diet of ground plants gorillas increased in size to the point that arboreal nesting is less frequent among them than among chimpanzees and orangutans. Early hominids probably diverged from pongids that had not developed prospective adaptations to knuckle-walking, and therefore did not evolve through a knuckle-walking stage. Initial adjustments to terrestrial quadrupedal locomotion and resting stance probably included palmigrade hand posturing. Their thumbs may have been already well developed as an adaptation for grasping during arboreal climbing. A combination of selection pressures for efficient terrestrial locomotor support and for object manipulation further advanced early hominid hands toward modern human configuration.     

Palmar and plantar pads and flexion creases of genetic polydactyly mice (Pdn)

Attempts to gain a better understanding of the relationship between the epidermal ridge patterns (dermatoglyphics) and flexion creases on the volar aspects of human hands and feet and specific medical disorders led to a search for a suitable animal model, allowing studies of the fetal development of the pertinent structures. A common experimental animal, the rat (Rattus norvegicus), was found to be an excellent candidate, owing to the strong resemblance of the volar pads and flexion creases on its palmar and plantar surfaces to those of human subjects. A hereditary preaxial polydactyly mouse (Pdn) provides an opportunity to study the effects of this malformation on the surrounding morphological structures and, specifically, on the volar pads, i.e., the sites over which the dermatoglyphic patterns develop. The hands and feet of the wild‐type (+/+) mice show no anomalies, and their major pad and flexion crease configurations correspond to those of normal rats. The heterozygous (Pdn/+) mice, in spite of having a thumb/big toe with a duplicated distal phalanx on their hands/feet, did not display any alterations in palmar/plantar pads. The homozygous (Pdn/Pdn) mice have a protrusion in the thenar area and one to three supernumerary digits on the preaxial portion of both the hands and feet. The effect of these anomalies was found to be limited to the pad and flexion crease configurations in the preaxial areas; the postaxial sites were not affected. The original number of pads on the thenar/first interdigital areas of Pdn/Pdn mice was apparently identical to that of the +/+ and Pdn/+ mice. The preaxial protrusion, however, affected the number, size, and location of the pads observed in the newborn mice, resulting in varying pad configurations, such as fused and scattered pads or a pad cluster formed by gathering the neighboring pads. These pad modifications were induced by the preaxial plantar/palmar protrusion only and were not affected by the presence of supernumerary preaxial digits. In view of the similarities in the morphology and fetal development of human and mouse distal limbs, the present study is relevant to human subjects, particularly to the understanding of the significance of dermatoglyphic variations in individuals with specific medical disorders. Future studies of naturally occurring or experimentally induced limb malformations in mice or rats should provide valuable insights into the development of human hands and feet and into factors contributing to their congenital anomalies. J. Morphol. 239:87–96, 1999. © 1999 Wiley‐Liss, Inc.     

Novel homozygous mutations in the WNT10B gene underlying autosomal recessive split hand/foot malformation in three consanguineous families

Split-hand/split-foot malformation (SHFM), representing variable degree of median clefts of hands and feet, is a genetically heterogeneous group of limb malformations with seven loci mapped on different human chromosomes. However, only 3 genes (TP63, WNT10B, DLX5) for the seven loci have been identified.     

Grasping primate development: Ontogeny of intrinsic hand and foot proportions in capuchin monkeys (Cebus albifrons and Sapajus apella)

Young primates have relatively large hands and feet for their body size, perhaps enhancing grasping ability. We test the hypothesis that selection for improved grasping ability is responsible for these scaling trends by examining the ontogeny of intrinsic hand and foot proportions in capuchin monkeys (Cebus albifrons and Sapajus apella). If selection for improved grasping ability is responsible for the observed patterns of hand and foot growth in primates, we predicted that fingers and toes would be longer early in life and proportionally decline with age. We measured the lengths of manual and pedal metapodials and phalanges in a mixed‐longitudinal radiographic sample. Bone lengths were (a) converted into phalangeal indices (summed non‐distal phalangeal length/metapodial length) to test for age‐related changes in intrinsic proportions and (b) fit to Gompertz models of growth to test for differences in the dynamics of phalangeal versus metapodial growth. Manual and pedal phalangeal indices nearly universally decreased with age in capuchin monkeys. Growth curve analyses revealed that metapodials generally grew at a faster rate, and for a longer duration, than corresponding phalanges. Our findings are consistent with the hypothesis that primates are under selection for increased grasping ability early in life. Relatively long digits may be functionally adaptive for growing capuchins, permitting a more secure grasp on both caregivers and arboreal supports, as well as facilitating early foraging. Additional studies of primates and other mammals, as well as tests of grasping performance, are required to fully evaluate the adaptive significance of primate hand and foot growth.     

Body shape and life style of the extinct rodent Canariomys bravoi (Mammalia,Murinae) from Tenerife,Canary Islands (Spain)

A three-dimensional reconstruction of the skeleton of the giant rat of Tenerife (Canary Islands, Spain) Canariomys bravoi was obtained by computerized microtomography. Body size, body mass, and body shape were estimated, and limb morphofunctional indices used to infer the style of life of this recently extinct rat. A sample of recent Murinae, including the Philippines endemic giant cloud rat Phloeomys cumingi, was used for comparison. It appears that C. bravoi differed from most continental rats by its relatively large size, body proportions, and tail length. Among its distinctive features, claws almost similarly developed on fore and hind limbs, and feet longer than hands evoke an intermediate body shape between rats and arboreal murines like Phloeomys. C. bravoi was a strong and powerfully muscled rat able to move on different substrates from floor to trees, and probably had digging skills.     

Convergence of forelimb and hindlimb Natural Pendular Period in baboons (Papio cynocephalus) and its implication for the evolution of primate quadrupedalism

The patterns of muscle mass distribution along the lengths of limbs may have important effects on the mechanics and energetics of quadrupedalism. Specifically, Myers and Steudel (J. Morphol. 234 (1997) 183) have shown that fore- and hindlimb Natural Pendular Periods (NPPs) may affect quadrupedal kinematics and must converge to reduce locomotor energetic costs. This study quantifies patterns of limb mass distribution in a live sample of Papio cynocephalus using limb inertial properties (mass, center of mass, mass moment of inertia, and radius of gyration). These inertial properties are calculated using a geometric modeling technique similar to that of Crompton et al. (Am. J. phys. Anthrop. 99 (1996) 547). The inertial properties in Papio are compared to those of Canis from Myers and Steudel (J. Morphol. 234 (1997) 183). The Papio sample has convergent fore- and hindlimb NPPs. Additionally, these limb NPPs are relatively large compared to those of Canis due to the relatively distally distributed limb mass in the Papio sample (relatively large limb masses, relatively distal centers of mass and radii of gyration, and relatively large limb mass moments of inertia). This relatively distal limb mass appears related to the grasping abilities of their hands and feet. Causal links are explored between limb shape adaptations for grasping hands and feet and the kinematics of primate quadrupedalism. In particular, if primates in general follow Papio's limb mass distribution pattern, then relatively large limb NPPs may lead to the relatively low stride frequencies already documented for primates. The kinematics of primate quadrupedalism appears to have been strongly influenced by both selection for grasping hands and feet and selection for reduced locomotor energetic costs.     

Deletion and Point Mutations of PTHLH Cause Brachydactyly Type E

Autosomal-dominant brachydactyly type E (BDE) is a congenital limb malformation characterized by small hands and feet predominantly as a result of shortened metacarpals and metatarsals. In a large pedigree with BDE, short stature, and learning disabilities, we detected a microdeletion of ∼900 kb encompassing PTHLH, the gene coding for parathyroid hormone related protein (PTHRP). PTHRP is known to regulate the balance between chondrocyte proliferation and the onset of hypertrophic differentiation during endochondral bone development. Inactivation of Pthrp in mice results in short-limbed dwarfism because of premature differentiation of chondrocyte. On the basis of our initial finding, we tested further individuals with BDE and short stature for mutations in PTHLH. We identified two missense (L44P and L60P), a nonstop (X178WextX^∗54), and a nonsense (K120X) mutation. The missense mutation L60P was tested in chicken micromass culture with the replication-competent avian sarcoma leukosis virus retroviral expression system and was shown to result in a loss of function. Thus, loss-of-function mutations in PTHLH cause BDE with short stature.     

Positional dependence of scale size and shape in butterfly wings: Wing-wide phenotypic coordination of color-pattern elements and background

Butterfly wing color-patterns are a phenotypically coordinated array of scales whose color is determined as cellular interpretation outputs for morphogenic signals. Here we investigated distribution patterns of scale shape and size in relation to position and coloration on the hindwings of a nymphalid butterfly Junonia orithya. Most scales had a smooth edge but scales at and near the natural and ectopic eyespot foci and in the postbasal area were jagged. Scale size decreased regularly from the postbasal to distal areas, and eyespots occasionally had larger scales than the background. Reasonable correlations were obtained between the eyespot size and focal scale size in females. Histological and real-time individual observations of the color-pattern developmental sequence showed that the background brown and blue colors expanded from the postbasal to distal areas independently from the color-pattern elements such as eyespots. These data suggest that morphogenic signals for coloration directly or indirectly influence the scale shape and size and that the blue “background” is organized by a long-range signal from an unidentified organizing center in J. orithya.     

They Wallop Like They Gallop: Audiovisual Analysis Reveals the Influence of Gait on Buttress Drumming by Wild Chimpanzees (Pan troglodytes)

The role learning plays in the acquisition of communicative gestures by wild chimpanzees (Pan troglodytes) is unclear. We aimed to evaluate the likelihood that social experience influences the structure of chimpanzee buttress drumming displays by examining whether individuals differed in the way they used their hands and feet to strike trees. We analyzed digital video recordings of 245 bouts by 9 adult males from Gombe National Park, Tanzania, frame by frame in conjunction with acoustic analysis. We investigated 1) how limb sequences used to approach drumming trees influenced limb use during drumming, 2) the relative use of hands vs. feet in drumming, and 3) the relative amplitude of beats produced by hands vs. feet. We found that the chimpanzees most often approached trees at a gallop and usually initiated drumming bouts with limb sequences that were identical to gait limb sequences. All individuals produced more beats with their feet than with their hands, and foot beats were higher in relative amplitude than hand beats. In only one instance did an individual produce a bout with hands only, whereas in three of nine observations of drumming on resonant camp equipment, the individuals primarily used their hands rather than their feet. We suggest that although chimpanzees may, by observing others, learn to use buttresses as tools to generate loud sounds, it is unlikely that learning influences the structure of displays because they result from innately determined gait patterns deployed to generate sound from comparatively nonresonant substrates.     

The species of Aspidorhynchus Agassiz, 1833 (Neopterygii,Aspidorhynchiformes) from the Jurassic plattenkalks of Southern Germany

The fishes of the genus Aspidorhynchus (Aspidorhynchidae) are among the most abundant predators in the palaeolagoons of the Solnhofen archipelago (Late Jurassic, southern Germany). They have been known since the end to the nineteenth century and the last revision of the genus was published more than 20 years ago. During these last two decades, numerous complete and excellently preserved specimens have been collected. The high morphological diversity shown by the new material made a new revision of these fishes necessary. This new taxonomic revision led us to revalidate the species A. ornatissimus Agassiz, 1834, which has hitherto been considered a junior synonym of the type species of the genus, A. acutirostris (Blainville, 1818), as well as to recognize high intraspecific variation in the latter species. These results helped to improve the distinction and, thus, the diagnoses of A. acutirostris, A. ornatissimus, and A. sanzenbacheri Brito and Ebert, 2009, which are the three valid species of this genus in the Solnhofen archipelago. We have been able to explain most of the intraspecific diversity of A. acutirostris by means of patterns of ontogenetic variation that encompass most of the other nominal species, thus largely reflecting early taxonomic hypotheses. Furthermore, the detailed morphological study led us to the recognition of some important anatomical structures previously unknown for aspidorhynchids: a connection between the temporal, infraorbital and supraorbital sensory canals in the frontal bone, the presence of an Y-shaped antorbital bone, and the presence of an interoperculum.     

Prevalence of tinea pedis,tinea unguium of toenails and tinea capitis in school children from Barcelona

ObjectiveTo evaluate the prevalence of tinea capitis, tinea pedis, and tinea unguium in children from several schools of Barcelona city.MethodsDuring the period of 2003–2004, a prospective cross-sectional study was carried out in 1,305 children (9% immigrant population) between the ages 3 and 15 in 17 schools in Barcelona. A systematic examination of the feet, (including nails and scalp), was performed to identify lesions compatible with tinea. Cultures of scalp and feet samples were done and analysis of environmental samples was performed for dermatophyte isolation.ResultsDermatophytes were isolated in 2.9% of the samples with a prevalence of 2.5% in feet, 0.23% in scalp, and 0.15% in nails of the feet. The predominant etiologic agents in feet were Trichophyton mentagrophytes in 45.7% of the cases and Trichophyton rubrum in 31.4%. In the nails, T. rubrum and Trichophyton tonsurans were isolated, while T. mentagrophytes (2 cases) and Trichophyton violaceum (1 case) were identified in scalp samples. Forty-five per cent of dermatophytes were isolated from healthy feet, the majority of cases in children 13–15 years old (p<0.05). Microsporum gypseum was the only agent identified in the environmental samples, and was also found in one of the cases of tinea pedis.ConclusionThe results of this study demonstrate a low prevalence of tinea capitis and tinea unguium in school children of Barcelona. On the contrary, high prevalence of dermatophytes in feet was found. It highlights the high prevalence of healthy carriers of dermatophytes in feet.     

Onychomycosis in Rome,Italy

This report presents the results of a study conducted between 1985 and 1994 on onychomycosis observed in the city of Rome. Six thousand six hundred and eighty eight patients were examined during this period. Among them 1,762 (26.3%) were affected by fungal nail infections. Because the etiologic agents could not be isolated in 105 cases (6%), the results refer to 1,657 subjects (24.8% of the total), presenting with positive microscopic and cultural examinations. Thirty eight patients (2.3%) had onychomycosis of both their hands and feet.From an etiological point of view, 59.1% of the nail infections were caused by yeasts, 23.2% were infected with dermatophytes and 17.6% by non-dermatophytic fungi. The etiology of onychomycosis of the hands differed from that of the feet. Yeasts were primarily responsible for onychomycosis of the hands (86.2%), while dermatophytes caused tinea unguium peduum (48%). Fungal fingernail infections by Candida spp. were the most common (50.3%), followed by those of the feet by dermatophytes (20%). Candida albicans was responsible for 70.6% of the hand infections but for only 15.9% of those of the feet. Trichophyton rubrum and T mentagrophytes were the most common dermatophytes, mainly causing toenail infections (23.4% and 21%, respectively), while Aspergillus spp., Scopulariopsis brevicaulis, Acremonium spp. and Aspergillus niger were the most common non-dermatophytes observed.With regard to sex, the fungal nail infections were more widespread in women (72.1%) and in subjects of both sexes over the age of 50.     

Handedness in the echolocating Schreiber's Long-Fingered Bat (Miniopterus schreibersii)

Bats, in terms of variety of species and their absolute numbers, are the most successful mammals on earth. The anatomical and functional peculiarities of Microchiroptera are not confined only to the auditory system; the wings (hands) of bats are unique both from an anatomical point of view as from a sensorial one. They are much thinner than those of birds and their bony structure is much more similar to a primate hand than to the forelimb of other mammals of the bat's size; the thumb, is very small and on its distal end there is a little claw that bats use for crawling and manipulating food. However, despite this very frequent use of the hands for food catching and for walking, nothing is known about the existence of a preferential use of the hands in Microchiroptera. The present study investigates the existence of handedness in the Schreiber's Long-Fingered Bat by recording the preferential use of the hand while climbing the walls of a plastic cylinder. This bat species is lateralized at population level and shows a left forelimb bias when using hands for climbing/grasping. This result is the first evidence of population-level handedness in an echolocating bat species.     

New conditions and intraspecific variation of some muscles of hands and feet of Dendropsophus labialis (Peters, 1863) (Anura,Hylidae)

Systematics of frogs have been based on osteological and molecular characters; however, the morphology of the muscles of hands and feet has proven to be an important complement to these studies, but it has not been sufficiently studied. This study presents undescribed conditions based on the origin, insertion or arrangement of 18 muscles of hands and feet of Dendropsophus labialis, and intraspecific variation. Muscles of four specimens (two males and two females) were examined to observe both sides of each specimen determining new conditions, and comparing them with documented species of Dendropsophus. Four intraspecific variant categories were established: Minor, unique, explosive and mimicking. Mainly mimicking, explosive and unique variations were found. Our results show the need to expand intraspecific studies in more species of Dendropsophus and to assess its value in the phylogeny of the genus. The family Hylidae may be identifiable based upon the combination of character states of some of these muscles: the m. flexor indicis superficialis proprius and the group of tendines superficialis digitorum of hands and foot, the m. extensor brevis superficialis Digiti III of the hand, the m. extensor brevis superficialis Digiti IV in hands and the mm. extensores breves profundi Digiti III in hands.     

Interspecific and Ontogenetic Variation in Proximal Pedal Phalangeal Curvature of Great Apes (Gorilla gorilla, Pan troglodytes, and Pongo pygmaeus)

Considerable attention has been devoted to understanding phalangeal curvature in primates, particularly with regard to locomotion. Previous work has found that increased phalangeal curvature may be indicative of increased grasping during suspensory and climbing behaviors, but the details of this relationship, particularly as regards feet, is still unclear. Using behavioral studies to predict an interspecific gradient of variation in pedal phalangeal curvature, I collected digital data from the third and fifth digit proximal pedal phalanges in adult Gorilla gorilla, Pan troglodytes, and Pongo pygmaeus and calculated included angles of phalangeal curvature to assess the appropriateness of pooling digits within taxa and evaluate the association between variation in pedal phalangeal curvature and frequency of climbing behavior. I also used an ontogenetic sample of Pan troglodytes to evaluate the postnatal relationship between variation in phalangeal curvature and grasping behaviors. I found intraspecific variation in phalangeal curvature suggesting among-digit variation in grasping behaviors. Curvature of Pongo was significantly greater than of both Pan and Gorilla. In contrast, Pan was significantly more curved than Gorilla only in comparison of third digits. Ontogenetic decreases in pedal phalangeal curvature among Pan troglodytes accorded well with postnatal decreases in documented climbing frequency. These findings largely support earlier work regarding the association between arboreal grasping and phalangeal curvature, and provide a unique intraspecific analysis that illuminates a number of areas where our knowledge of the behavioral and biomechanical determinants of phalangeal curvature should be explored further, particularly with respect to the role of among-digit variation in phalangeal curvature.     

Effects of limb mass distribution on the ontogeny of quadrupedalism in infant baboons (Papio cynocephalus) and implications for the evolution of primate quadrupedalism

Primate quadrupedal kinematics differ from those of other mammals. Several researchers have suggested that primate kinematics are adaptive for safe travel in an arboreal, small-branch niche. This study tests a compatible hypothesis that primate kinematics are related to their limb mass distribution patterns. Primates have more distally concentrated limb mass than most other mammals due to their grasping hands and feet. Experimental studies have shown that increasing distal limb mass by adding weights to the limbs of humans and dogs influences kinematics. Adding weights to distal limb elements increases the natural period of a limb's oscillation, leading to relatively long swing and stride durations. It is therefore possible that primates' distal limb mass is responsible for some of their unique kinematics. This hypothesis was tested using a longitudinal ontogenetic sample of infant baboons (Papio cynocephalus). Because limb mass distribution changes with age in infant primates, this project examined how these changes influence locomotor kinematics within individuals. The baboons in this sample showed a shift in their kinematics as their limb mass distributions changed during ontogeny. When their limb mass was most distally concentrated (at young ages), stride frequencies were relatively low, stride lengths were relatively long, and stance durations were relatively long compared to older ages when limb mass was more proximally concentrated. These results suggest that the evolution of primate quadrupedal kinematics was tied to the evolution of grasping hands and feet.     

四肢手足对称多指趾发育的基因特征与显微镜手术预后的相关性

目的:探讨四肢手足对称多指趾发育的基因特征与显微镜手术预后的相关性。方法:2016年2月至2020年1月选择在本院诊治的四肢手足对称多指趾患儿110例作为研究对象,所有患儿都给予显微手术治疗,记录预后情况。采用PCR方法检测HOXD13基因突变情况并进行相关性分析。结果:在110例患儿中,HOXD13基因突变45例,突变率为40.9%。突变组的性别、年龄、体重指数、血压、Wassel分型等与非突变组对比差异无统计学意义(P>0.05)。术后3个月突变组的疗效优良率为77.8%,显著低于非突变组的96.9%(P<0.05)。术后3个月突变组的肌腱粘连、切口感染、皮肤坏死、指趾间关节偏斜等并发症发生率为28.9%,显著高于非突变组的3.1%(P<0.05)。Pearson分析显示HOXD13基因突变与预后疗效、并发症等都存在相关性(P<0.05);多因素logistic回归分析分析显示HOXD13基因突变也是影响患儿预后疗效、并发症的主要因素(P<0.05)。结论:四肢手足对称多指趾患儿多伴随有HOXD13基因突变,显微手术具有很好的可行性,HOXD13基因突变与显微手术预后有显著相关性。     

Mutations in PIEZO2 Cause Gordon Syndrome,Marden-Walker Syndrome,and Distal Arthrogryposis Type 5

Gordon syndrome (GS), or distal arthrogryposis type 3, is a rare, autosomal-dominant disorder characterized by cleft palate and congenital contractures of the hands and feet. Exome sequencing of five GS-affected families identified mutations in piezo-type mechanosensitive ion channel component 2 (PIEZO2) in each family. Sanger sequencing revealed PIEZO2 mutations in five of seven additional families studied (for a total of 10/12 [83%] individuals), and nine families had an identical c.8057G>A (p.Arg2686His) mutation. The phenotype of GS overlaps with distal arthrogryposis type 5 (DA5) and Marden-Walker syndrome (MWS). Using molecular inversion probes for targeted sequencing to screen PIEZO2, we found mutations in 24/29 (82%) DA5-affected families and one of two MWS-affected families. The presence of cleft palate was significantly associated with c.8057G>A (Fisher’s exact test, adjusted p value < 0.0001). Collectively, although GS, DA5, and MWS have traditionally been considered separate disorders, our findings indicate that they are etiologically related and perhaps represent variable expressivity of the same condition.