Tarsal Fold Research Articles

Cell proliferation and Notch signaling coordinate the formation of epithelial folds in the Drosophila leg.

The formation of complex three-dimensional organs during development requires precise coordination between patterning networks and mechanical forces. In particular, tissue folding is a crucial process that relies on a combination of local and tissue-wide mechanical forces. Here, we investigate the contribution of cell proliferation to epithelial morphogenesis using the Drosophila leg tarsal folds as a model. We reveal that tissue-wide compression forces generated by cell proliferation, in coordination with the Notch signaling pathway, are essential for the formation of epithelial folds in precise locations along the proximo-distal axis of the leg. As cell numbers increase, compressive stresses arise, promoting the folding of the epithelium and reinforcing the apical constriction of invaginating cells. Additionally, the Notch target dysfusion plays a key function specifying the location of the folds, through the apical accumulation of F-actin and the apico-basal shortening of invaginating cells. These findings provide new insights into the intricate mechanisms involved in epithelial morphogenesis, highlighting the crucial role of tissue-wide forces in shaping a three-dimensional organ in a reproducible manner.

A new species of terrestrial toad of the Rhinellafestae group (Anura, Bufonidae) from the highlands of the Central Cordillera of the Andes of Colombia.

The genus Rhinella (Bufonidae) comprises 92 species of Neotropical toads. In Colombia, Rhinella is represented by 22 recognized species, of which nine belong to the Rhinellafestae group. Over the past decade, there has been increasing evidence of cryptic diversity within this group, particularly in the context of Andean forms. Specimens of Rhinella collected in high Andean forests on both slopes of the Central Cordillera in Colombia belong to an undescribed species, Rhinellakumandaysp. nov. Genetic analyses using the mitochondrial 16S rRNA gene indicated that the individuals belong to the festae species group. However, they can be distinguished from other closely related species such as Rhinellaparaguas and Rhinellatenrec by a combination of morphological traits including the presence of tarsal fold, a moderate body size, and substantial genetic divergence in the 16S rRNA gene (> 5%). Through this integrative approach, the specimens from the Central Cordillera of Colombia are considered an evolutionary divergent lineage that is sister to R.paraguas, and described as a new species. Rhinellakumandaysp. nov. is restricted to the Central Cordillera of Colombia inhabiting both slopes in the departments of Caldas and Tolima, in an elevational range between 2420 and 3758 m. With the recognition of this new species, the genus Rhinella now comprises 93 species with 23 of them found in Colombia, and ten species endemic to the country.

A new species of Pristimantis Jimnez de la Espada, 1870 (Anura: Strabomantidae) from the Brejos de Altitude in Northeast Brazil.

Pristimantis is the most diverse Neotropical genus of terrestrial vertebrates and is distributed from Central America to Argentina. The last few years have seen the description of several new species of the genus, suggesting that its diversity is still underestimated. After decades of uncertainties about the taxonomic status of populations of Pristimantis from the Brejos de Altitude of the state of Cear, Northeast Brazil, we finally found morphological, acoustic and molecular evidence confirming their distinctiveness from other Atlantic Forest species. The new species is characterized by the following: shagreen dorsal skin with small-scattered tubercles, absence of dorsolateral fold, presence of tarsal fold, advertisement call composed of 18 pulsed notes, (25 pulses per note), and dominant frequency located in the second energy band, ranging from 36174220 Hz. Phylogenetic analysis placed the new species in the Pristimantis conspicillatus species group and the sister lineage of the Atlantic Forest clade comprising P. ramagii, P. paulodutrai and the P. vinhai species complex.

A new species of Pristimantis (Amphibia, Anura, Strabomantidae) from the Pui Pui Protected Forest (central Peru), with comments on Pristimantis albertus Duellman & Hedges, 2007.

We describe a new Pristimantis species from the eastern Andes, Región Junín, Peru following an integrative taxonomic approach. The description is based on three adult males (snout-vent length 25.7–28.8 mm) collected in two montane forests between 1615 and 1800 m a.s.l. in the Pui Pui Protected Forest and its close surroundings. The new species is mainly characterised by absence of tympanum, presence of inner tarsal fold, broad horizontal red band across iris, ventre mottled black and cream and ventral surfaces of thighs salmon and grey mottled. Amongst the Amazonian and montane forest Pristimantis that have the ventre and groin contrastingly black and cream mottled, P. sinschisp. nov. is morphologically most similar to P. lindae and P. ventrimarmoratus. However, DNA barcoding revealed a clear distinction between these three species and placed P. sinschisp. nov. as sister taxon of P. lindae. We designate a lectotype for P. ventrimarmoratus and restrict the type locality of this species to “El Topo, R. Pastaza, [Provincia Tungurahua,] E. Ecuador, 4200 feet”. Pristimantis albertus and P. sagittulus are recorded for the first time in the Región Junín. Additional data on morphology and systematics are provided for P. albertus.

The transcription factor Dysfusion promotes fold and joint morphogenesis through regulation of Rho1.

The mechanisms that control tissue patterning and cell behavior are extensively studied separately, but much less is known about how these two processes are coordinated. Here we show that the Drosophila transcription factor Dysfusion (Dysf) directs leg epithelial folding and joint formation through the regulation of Rho1 activity. We found that Dysf-induced Rho1 activity promotes apical constriction specifically in folding epithelial cells. Here we show that downregulation of Rho1 or its downstream effectors cause defects in fold and joint formation. In addition, Rho1 and its effectors are sufficient to induce the formation of epithelial folds when misexpressed in a flat epithelium. Furthermore, as apoptotic cells can actively control tissue remodeling, we analyzed the role of cell death in the formation of tarsal folds and its relation to Rho1 activity. Surprisingly, we found no defects in this process when apoptosis is inhibited. Our results highlight the coordination between a patterning transcription factor and the cellular processes that cause the cell shape changes necessary to sculpt a flat epithelium into a three dimensional structure.

A new species of Hyloscirtus (Anura, Hylidae) from the Colombian and Venezuelan slopes of Sierra de Perijá, and the phylogenetic position of Hyloscirtus jahni (Rivero, 1961).

A new species of Hyloscirtus, belonging to the H. bogotensis species Group, is described from the Venezuelan and Colombian slopes of the Sierra de Perijá. The new species can be readily distinguished from its congeners by the combination of the following characters: mental gland present, disc-shaped and small; ulnar, outer, and inner tarsal folds present; calcar tubercle absent; whitish stripes on external border of upper eyelids and supratympanic folds, longitudinally on the mid-dorsum, on supracloacal fold, outer ulnar folds, inner and outer tarsal folds, and also on dorsal internal surface of shanks. We estimate phylogenetic relationships based on mtDNA (spanning fragments of 12S rRNA, tRNA-Val and 16S rRNA), of all Hyloscirtus species available in Genbank, as well as the new species described herein, H. callipeza, H. jahni, and H. platydactylus, all of which have not been previously sequenced. Our molecular data support the hypothesis of the new species as sister species of H. callipeza and indicates that H. jahni does not belong to the H. bogotensis species Group, but rather is sister species of all other Hyloscirtus (sensu Faivovich et al. 2005). Based on this last result we propose a new species group for H. jahni and the synonymy of Colomascirtus in Hyloscirtus. We also provide the first description of the advertisement call of H. callipeza. With the new species described herein, the number of Hyloscirtus species increases to 37.

Diversity of marsupial frogs (Anura: Hemiphractidae: Gastrotheca) in the northern Cordillera Central, Peru, with the descriptions of two new species

Two new species of Gastrotheca are represented by adult females, genomic data of these are included in a phylogenetic analysis, whereby they are placed in the northern clade of the subgenus Gastrotheca. One new species, G. spectabilis, is unique within the genus in having a color pattern consisting of white labial, rostral, and canthal stripes. The second new species, G. oresbios, has a dorsal color pattern of dark paravertebral markings and canthal stripe, but no pale labial stripe; thus it resembles G. abdita, which differs by having an inner tarsal fold, a wider interorbital distance, and smooth skin on the dorsum lacking scattered tubercles as in G. oresbios. Of the nine species of Gastrotheca in the northern Cordillera Central, only G. spectabilis, G. ossilaginis, and G. oresbios lack an inner tarsal fold. The third species is represented by two juveniles; it is briefly described but not named. Of the nine species of Gastrotheca known from the high elevations in the northern part of the Cordillera Central in northern Peru, only two are members of the subgenus Duellmania that occurs principally north of the Huancabamba Depression. Only one of the nine species of species of Gastrotheca in the northern part of the Cordillera Central is shared with the Cordillera Occidental in Peru, and none of the species is shared with the Ecuadorian ranges of the Andes

A new species of Pristimantis (Amphibia, Anura, Craugastoridae) from the foothills of the Andes in Manu National Park, southeastern Peru.

We describe a new species of Pristimantis from the humid sub-montane forest of the Región Cusco in Peru. Pristimantis pluvialis sp. n. was collected in the Kosñipata and Entoro valleys at elevations from 740 to 1110 m a.s.l., near the borders of Manu National Park and within the Huachiperi Haramba Queros Conservation Concession. The new species can be distinguished from other members of the genus Pristimantis by its rostral tubercle, smooth dorsal skin, and by its advertisement call. Pristimantis lacrimosus and Pristimantis waoranii superficially most resemble the new species, but Pristimantis pluvialis sp. n. differs from both species by having a rostral tubercle (absent in Pristimantis waoranii and variable in Pristimantis lacrimosus) and larger size, from Pristimantis lacrimosus by its call emitted at a lower frequency, and from Pristimantis waoranii for its dorsal coloration with dark markings. Two other species have partially overlapping distributions and resemble the new species, Pristimantis mendax and Pristimantis olivaceus, but they produce advertisement calls with much higher dominant frequencies than the advertisement call of the new species. Furthermore, Pristimantis mendax differs from the new species by lacking a rostral tubercle and by having a sigmoid inner tarsal fold, whereas Pristimantis olivaceus differs by being smaller and by having dorsal skin shagreen with scattered tubercles. The new species has snout-vent length of 21.8–26.9 mm in males (n = 12) and 28.8 mm in a single female.

The Australasian frog family Ceratobatrachidae in China, Myanmar and Thailand: discovery of a new Himalayan forest frog clade.

In an effort to study the systematic affinities and specieslevel phylogenetic relationships of the enigmatic anurans variably assigned to the genera Ingerana or Limnonectes (family Dicroglossidae), we collected new molecular sequence data for five species including four Himalayan taxa, Limnonectes xizangensis, Lim. medogensis, Lim. alpina, [corrected] Ingerana borealis and one southeast Asian species, I. tasanae, and analyzed these together with data from previous studies involving other ostensibly related taxa. Our surprising results demonstrate unequivocally that Lim. xizangensis, Lim. medogensis and Lim. alpina [corrected] form a strongly supported clade, the sister-group of the family Australasian forest frog family Ceratobatrachidae. This discovery requires an expansion of the definition of Ceratobatrachidae and represents the first record of this family in China. These three species are distinguished from the species of Ingerana and Limnonectes by the: (1) absence of interdigital webbing of the foot, (2) absence of terminal discs on fingers and toes, (3) absence of circumarginal grooves on the fingers and toes, and (4) absence of tarsal folds. Given their phylogenetic and morphological distinctiveness, we assign them to the oldest available generic name for this clade, Liurana Dubois 1987, and transfer Liurana from Dicroglossidae to the family Ceratobatrachidae. In contrast, Ingerana tasanae was found to be clustered with strong support with the recently described genus Alcalus (Ceratobatrachidae), a small clade of otherwise Sundaic species; this constitutes a new record of the family Ceratobatrachidae for Myanmar and Thailand. Finally, Ingerana borealis clustered with the "true" Ingerana (family Dicroglossidae), for which the type species is I. tenasserimensis.

Contributions to the Morphology of Plectrohyla mykter (Anura: Hylidae), with Comments on Some Controversial Characters and the Diagnosis of this Species

<p>We describe the tadpole, juveniles, and two adult specimens of Plectrohyla mykter. The tadpole of this species is unique among Plectrohyla by having labial tooth row formula 4(4)/6. We found that tarsal fold, thoracic fold, and rostral keel are present in P. mykter but not evident in adults, and that the skin thickness is intermediate in comparison to other species of Plectrohyla. We conclude that these characters are not useful for the diagnosis of P. mykter and propose a new diagnosis for this species.</p>

A Second Species of Trachycephalus Tschudi (Anura: Hylidae) with a Single Vocal Sac from the Brazilian Amazon

A new species of Trachycephalus from the Brazilian Amazon Rain Forest, morphologically similar to T. hadroceps (Duellman and Hoogmoed), is described. This new species is characterized by having the skin not co-ossified with the skull; skin on dorsum bearing many low and medium round tubercles; a vocal sac not externally visible; well-developed paratoid gland; snout rounded in profile; third finger disc almost the same size of the eye; absence of tarsal fold; iris pinkish-beige with a horizontal dark gray bar; dorsal color pattern in life light brownish-orange with scattered brown dots. Trachycephalus hadroceps is restricted to the left margin (north) of the Amazon River, in the Guiana Shield, and possibly in the adjacent Brazilian Amazon Rain Forest, and the new species occurs on the right margin (south) of the Amazon River. It is a canopy treefrog, which probably uses treeholes filled with water as breeding sites.

A new species of Pristimantis (Amphibia: Anura: Strabomantidae) from the Río Abiseo National Park, Peru.

We describe a new species of Pristimantis from the Río Abiseo National Park in the Andes of northern Peru. Specimens were collected from 2650 to 3000 m elevation. The new species has a snout-vent length of 24.9-34.2 mm (n = 7) in adult females, and 15.3-23.5 mm (n = 29) in adult males. It differs from other species of Pristimantis in having the snout with a broad, slightly upwards curved, fleshy process. The most similar species, P. phoxocephalus has the snout with a vertical fleshy keel, but differs from the new species by being larger (female SVL up to 38.4 mm vs. 34.2 mm), by having prominent dentigerous processes of vomers (minute in the new species), by lacking an inner tarsal fold (present), by lacking heel tubercles (present), and by having the dorsum in life grey, red or brown and the groin with black and orange or yellow mottling, whereas in the new species the dorsum is rusty reddish-brown with lighter blotches or tannish-brown chevrons, and the groin tan with pale brown flecks.

A New Technique of Upper Eyelid Blepharoplasty Using the Orbicularis Muscle Flap

Blepharoplasty of the upper eyelids is one of the most commonly performed procedures in aesthetic plastic surgery. The orbicularis muscle flap technique provides good results for patients with atonic skin and an atonic orbicularis muscle when there is excessive fullness in the lateral aspect of the upper lid. This flap also can be used to contain a prominent lacrimal gland or retro-orbicularis oculi fat (ROOF) without dangerous removal of the last one. A total of 30 patients underwent upper lid blepharoplasty through a supratarsal incision approach. Dissection of the orbicularis muscle flap was made 5-8mm above the supratarsal fold. Before the muscle flap suspension, the excess skin and fat pad were removed. The flap suspension was achieved with its rotation and motion of a tunnel in the suborbicularis plane, which anchored it on the periosteum of the orbital lateral rim of the frontal bone with a permanent suture. This technique restores the sharp and crisp tarsal folds and pretarsal show with deepening of the orbitopalpebral sulcus. The orbicularis muscle flap also can be proposed for cases with a ptosis of the lateral upper lid. The authors believe this technique reduces the risk for "rounding" of the eyelid and produces better contact of the lid with the ocular globe. The orbicularis muscle flap procedure is a feasible technique that can be used reliably to reshape the lateral upper lid. It would be a useful addition to the armamentarium of the plastic surgeon who is called on to perform upper blepharoplasty.

A New Species of the Craugastor rugulosus Series (Anura: Craugastoridae) from West-Central Panama

We describe a new species of anuran from the Cordillera Central, El Copé, Coclé Province, Panama. The species is assigned to the Craugastor rugulosus species series of Neotropical stream-dwelling frogs, which contains 33 species and which ranges from Mexico to central Panama. The new species differs from all other members of the C. rugulosus species series by the combination of the absence of vocal slits and nuptial pads, and the presence of strong toe webbing and a large flap-like tarsal fold. This species experienced population declines in central Panama in 2004 and no remaining populations are known.

A new species of Hyalinobatrachium (Anura: Centrolenidae) from the Amazonian slopes of the central Andes, with comments on the diversity of the genus in the area

We describe a new species of Hyalinobatrachium from the Amazonian slopes of the Andes in Peru and Bolivia on the basis of morphological, bioacoustic and genetic characteristics. Hyalinobatrachium carlesvilai sp. nov. can be distinguished from other species of Hyalinobatrachium by the combination of the following characters: (1) truncate snout in dorsal and lateral view; (2) white pericardium; (3) enameled dorsal, tarsal and cloacal folds; (4) hand webbing formula III 2 – – 1 + IV; (5) iris cream; (6) advertisement call consisting of a single, frequency-modulated note with a pulsed section followed by a tonal section. The new species had been previously identified as Hyalinobatrachium munozorum and H. bergeri. The advertisement call of the new species was previously assigned to H. bergeri. Here we describe the previously unknown call of Hyalinobatrachium bergeri. Additionally, we study the taxonomic status of H. lemur and H. pellucidum and place the former as synonym of the later. We extend the distribution of H. pellucidum to Departamento Cusco in southern Peru.

Diversity of small Amazonian Dendropsophus (Anura: Hylidae): another new species from northern Bolivia

A new small species of Dendrospsophus is described from lowland Amazonia of the Departamento Pando, northern Bolivia. The new species is mainly characterized by smooth dorsal skin with scattered minute tubercles, relatively large distal subarticular tubercle on first toe, lack of tarsal folds, light brown to dark reddish or purple brown dorsum with numerous small dark markings and spots, dark colouration of loreal-tympanic region sharply outlined and contrasting against dorsal head colouration, one or two small white spots below the eye, yellow vocal sac in life, and advertisement call consisting of two notes with strong amplitude modulation. The new species is tentatively grouped with species placed in the Dendropsophus microcephalus group. It has rather arboreal habits and occurs in the tree canopy along swampy or flooded shores of smaller streams running through terra firme rainforest.

A new species of the Eleutherodactylus lacrimosus assemblage (Anura, Brachycephalidae) from the lowland rainforest canopy of Yasuni National Park, Amazonian Ecuador

A new species of Eleutherodactylus from the lowland rainforest canopy in northeastern Amazonian Ecuador is described. It is placed in the Eleutherodactylus lacrimosus assemblage of the greater unistrigatus group. It is most similar to the sympatric species Eleutherodactylus lacrimosus, but differs by the lack of a papilla at the tip of the snout, tubercles on upper eyelids, tubercles on dorsum, dorsal markings, and larger body size, and the presence of lateral fringes on the fingers and a tarsal fold. The new species inhabits tank bromeliads in the upper strata of the rainforest canopy at heights of 23.5-38.0 m. The effects of implementation of canopy surveys on biological diversity are briefly discussed.

A new species of tree frog, genus Dendropsophus (Anura: Hylidae), from the Amazon of northern Bolivia

We describe a new species of small Dendropsophus from lowland Amazonia of the Departamento Pando, northern Bolivia. The new species is mainly characterized by smooth dorsal skin, indistinct tympanic annulus, lack of tarsal folds, yellowish-tan to reddish-brown dorsum with obscure dark brown markings, colouration of loreal-tympanic region and flanks sharply outlined and contrasting against dorsum and yellowish-green to bluish-green vocal sac in life. The advertisement call consists of a series of very short pulsed notes, with note repetion rate being the highest known within the species group. Regarding the morphological similarities of adults, the new species is tentatively grouped with species placed in the Dendropsophus microcephalus group.

Another New Species of Small Hyla (Anura, Hylidae) from Amazonian Sub-Andean Forest of Western Bolivia

We describe a new species of small Hyla from sub-Andean forest of the Departamento La Paz, Bolivia. The new species is mainly characterized by smooth dorsal skin with few minute scattered tubercles, presence of a tympanic annulus, lack of tarsal folds, a brown dorsum with irregular longitudinal dark brown stripes, a broad dark brown lateral stripe extending to loreal region, and advertisement call. The phylogenetic relationships of the new species remain unknown, but given the morphological similarities of adults, we tentatively place it in the Hyla microcephala group.

Experiences with transconjunctival upper blepharoplasty.

Upper blepharoplasty remains a valuable procedure in rejuvenating the upper eyelid. An innovative technique was recently reported whereby medial fat is removed through a transconjunctival approach. This is a preliminary report of our experience with 60 patients treated over the past 10 months using this technique. The technique will be described in detail and cases will be reported. There were no perioperative or postoperative complications. All of the patients are satisfied with the results of their surgical procedure. The technique has the advantage of avoiding an incision of the medial upper eyelid and the inherent risks of excessive scarring in this area. We have found the technique especially useful in secondary blepharoplasty with an isolated prominence of residual medial fat. Other advantages include the following: primary cases in which the surgeon is able to avoid medial extension of the cutaneous incision, patients who possess deep tarsal folds with prominent medial fat, or as an adjunct to eyebrow lifting techniques where in both cases cutaneous excision is unnecessary. No disadvantages have been noted.