Development of a non-amphibious amphibian - an interview with a coquí

Elinson, Richard P.

doi:10.1387/ijdb.190386re

Cited by 3 publications

(2 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…143 E coqui has allowed researchers to learn more about developmental conservation and novelties and has also led to hypotheses as to how the amniotic egg evolved. 144 The limb buds of E coqui form just after the neural folds close and neurulation ends, similar to the timing of limb bud formation in amniotes. 143 Once the limb bud has formed, the patterning of the limb bud is largely conserved when compared with other model systems, with a few variations.…”

Section: Direct Developersmentioning

confidence: 67%

“…One species which has served as a quasi‐model system for direct developing frogs is Eleutherodactylus coqui , a species native to Puerto Rico that has spread to California and Hawaii 143 . E coqui has allowed researchers to learn more about developmental conservation and novelties and has also led to hypotheses as to how the amniotic egg evolved 144 …”

Section: Amphibiansmentioning

confidence: 99%

See 1 more Smart Citation

Limb positioning and initiation: An evolutionary context of pattern and formation

Royle

Tabin

Young

2021

Developmental Dynamics

View full text Add to dashboard Cite

Before limbs, or fins, can be patterned and grow they must be initiated. Initiation of the limb first involves designating a portion of lateral plate mesoderm along the flank as the site of the future limb. Following specification, a myriad of cellular and molecular events interact to generate a bud that will grow and form the limb. The past three decades has provided a wealth of understanding on how those events generate the limb bud and how variations in them result in different limb forms.Comparatively, much less attention has been given to the earliest steps of limb formation and what impacts altering the position and initiation of the limb have had on evolution. Here, we first review the processes and pathways involved in these two phases of limb initiation, as determined from amniote model systems. We then broaden our scope to examine how variation in the limb initiation module has contributed to biological diversity in amniotes. Finally, we review what is known about limb initiation in fish and amphibians, and consider what mechanisms are conserved across vertebrates. Developmental DynamicsWhile spatially distinct, the underlying tissues of the limb forming region and the flank have similar properties prior to induction. In experiments conducted almost 100 years ago, Balinsky observed that implanting the otic vesicle, nasal placode, or pituitary gland in the flank of a developing newt embryo could induce ectopic limb formation. 8 The important interpretation of this experiment is that the whole flank is competent to form a limb and that there must be an inductive factor which drives limb formation. This result raises two questions: what are the factors which induce limb formation, and what are the mechanisms which restrict the limbs to their correct position, despite the limb forming potential in the flank.Many different fibroblast growth factors (Fgfs) can induce an ectopic limb in the flank of a chick embryo. 9-12 However, only two Fgfs are expressed in the right place at the right time to be involved in endogenous limb initiation. These are Fgf8, which is detected in the ectoderm of the limb field prior to limb budding, 12,13 and Fgf10, which is restricted to the prospective limb mesoderm. 11 Importantly, Fgf10 is expressed prior to the time Fgf8 is detectable. Moreover, while Fgf10 directly triggers downstream events of limb initiation (within 17 hours), Fgf8 only does so (in 28 hours) after it first induces Fgf10 expression. 11 Although mice that carry mutations in Fgf8 still initiate formation, mice which are deficient for Fgf10 fail to form limbs or even express Fgf8 in the pre-limb ectoderm. 14,15 The ability of the downstream gene Fgf8 to induce Fgf10 when ectopically applied is explained by a feedback loop that is normally establish in the subsequent step of limb patterning. Once expressed, Fgf10 in the mesoderm also induces Fgf8 in the overlying ectoderm, leading to apical ectodermal ridge (AER) formation. 11 In turn, this ectopically-derived Fgf8 reciprocally induces Fgf10 in the mesoderm, set...

show abstract

Section: Direct Developersmentioning

confidence: 67%

Section: Amphibiansmentioning

confidence: 99%

Limb positioning and initiation: An evolutionary context of pattern and formation

Royle

Tabin

Young

2021

Developmental Dynamics

View full text Add to dashboard Cite

show abstract

Pregastrular Development of Amphibians: Ontogenetic Diversity and Eco-Devo

Desnitskiy

2023

Russ J Dev Biol

View full text Add to dashboard Cite

Pregastrular Development of Amphibians: Ontogenetic Diversity and Eco-Devo

Desnitskiy

2023

Ontogenez

View full text Add to dashboard Cite

Comparative and ecological aspects of the reorganizations of early development in the class Amphibia are analyzed. We used data on the developmental diversity in a number of families belonging to the orders Anura and Caudata, in which many species had lost their connection with the aquatic environment. Model representatives of the class Amphibia (Ambystoma mexicanum, Rana temporaria, and Xenopus laevis) have small eggs (no more than 2.5 mm in diameter). In these species, the slowdown in the rate of cell divisions and the loss of synchrony occur at the midblastula stage. However, phylogenetically basal amphibian species (Ascaphus truei, Cryptobranchus alleganiensis) are characterized by the large (4–6 mm in diameter) yolky eggs and a short series of synchronous blastomere divisions (the synchrony is already lost at the 8-cell stage of cleavage). They do not have a “midblastula transition”, which is characteristic of the above model species. On the other hand, many evolutionarily advanced non-model species of caudate and anuran amphibians (for example, Desmognathus fuscus, Gastrotheca riobambae, Philoria sphagnicolus), as well as the basal species, are characterized by the large, yolk-rich eggs and the early loss of cell division synchrony. Phylogenetic analysis suggests that the cleavage pattern of the most extensively studied amphibians, the Mexican axolotl (Caudata) and the African clawed frog (Anura), represents a homoplasy. The midblastula transition, which is characteristic of these two species, might have evolved convergently in these two orders of amphibians as an embryonic adaptation to development in lentic water.

show abstract

Development of a non-amphibious amphibian - an interview with a coquí

Cited by 3 publications

References 25 publications

Limb positioning and initiation: An evolutionary context of pattern and formation

Limb positioning and initiation: An evolutionary context of pattern and formation

Pregastrular Development of Amphibians: Ontogenetic Diversity and Eco-Devo

Pregastrular Development of Amphibians: Ontogenetic Diversity and Eco-Devo

Contact Info

Product

Resources

About